Predictors of postoperative renal function recovery in patients with ureteral stones: asymptomatic Vs symptomatic ureteral stones

Predictors of postoperative renal function recovery in patients with ureteral stones: asymptomatic Vs symptomatic ureteral stones | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Predictors of postoperative renal function recovery in patients with ureteral stones: asymptomatic Vs symptomatic ureteral stones Mingbin Xu, Guoliang Wu, Daoyuan Li, Shuming He, ChengYang Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7732690/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Oct, 2025 Read the published version in International Urology and Nephrology → Version 1 posted You are reading this latest preprint version Abstract Purpose This study aimed to comprehensively compare the clinical, radiological, and functional characteristics of asymptomatic and symptomatic ureteral stones, and identify independent predictors of postoperative renal function recovery in patients with ureteral stones. Methods A two-center retrospective cohort study was conducted at tertiary hospitals from March 2018 to March 2023. Consecutive patients who underwent ureteroscopic lithotripsy (URSL) for ureteral stones were included, while those with incomplete follow-up data or other exclusion criteria were excluded. Patients were divided into asymptomatic and symptomatic groups. Baseline characteristics, stone parameters, surgical data, and postoperative renal function were collected. Renal function recovery was defined as postoperative glomerular filtration rate(GFR) of the affected kidney exceeding 90% of the contralateral normal kidney’s GFR at 1 year. Statistical analyses included t-tests, chi-square tests, Cox regression, and nomogram development with internal validation. Results A total of 635 patients with ureteral stones who underwent ureteroscopic lithotripsy (URSL) were enrolled in this study, and divided into two groups based on the presence of stone-related symptoms: the asymptomatic group (n = 38, 5.98%) and the symptomatic group (n = 597, 94.02%). Regarding baseline characteristics, the asymptomatic group showed significantly higher rates of diabetes mellitus (DM, 40.8% vs. 8.0%), larger stone size (17 ± 4 mm vs. 13 ± 4 mm), higher proportion of upper ureteral stones (63.8% vs. 17.0%), and higher incidence of Grade IV hydronephrosis (52.0% vs. 21.3%) compared with the symptomatic group (all p < 0.001). Preoperatively, the glomerular filtration rate (GFR) of the asymptomatic group (21 ± 13 mL/min/1.73m²) was significantly lower than that of the symptomatic group (36 ± 8 mL/min/1.73m²) (p < 0.001). Postoperatively, the symptomatic group exhibited a significant increase in GFR, while the asymptomatic group showed no significant change in GFR and maintained a persistently lower level. Multivariate Cox regression analysis identified six independent predictors of postoperative renal function recovery (all p < 0.05): older age, DM, Grade IV hydronephrosis, and complete intraoperative obstruction were negative predictors, while a higher preoperative GFR ratio (ipsilateral/contralateral normal kidney) and symptomatic status were positive predictors. A nomogram constructed based on these predictors showed good discriminative ability (area under the receiver operating characteristic curve, AUC = 0.841) and calibration performance (mean absolute error, MAE = 0.02). Conclusion Asymptomatic ureteral stones exhibit distinct features (larger size, upper ureteral location, severe hydronephrosis) and poorer postoperative renal function recovery than symptomatic stones, mainly due to chronic obstruction-induced irreversible injury. Age, DM, Grade IV hydronephrosis, complete obstruction, and low preoperative split renal function are key predictors of poor recovery. The validated nomogram facilitates accurate recovery risk prediction, supporting personalized treatment and monitoring to preserve renal function. Predict renal function asymptomatic ureteral stones surgery Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Urolithiasis is among the most common urological problems in the world, and the incidence is rising as a result of dietary lifestyle changes and an increasingly sedentary population, coupled with rising incidences of metabolic comorbidities such as obesity and diabetes mellitus [ 1 , 2 ]. Ureteral stones, as one major subtype of urolithiasis, typically cause acute symptoms (eg, renal colic, gross hematuria, or urinary tract infection) which serves as a motivator to diagnose and treat urgently [ 3 ]. For some ureteral stones, the opposite scenario occurs; these stones are clinically termed asymptomatic or "silent stones". They lack of timely symptoms, leading them to be undiagnosed until incidental detection on an imaging study or screening for other diseases [ 4 , 5 ]. Though asymptomatic ureteral stones comprise only 1.1%–5.3% of the prevalence of all ureteral stones [ 6 , 5 , 4 ], many factors raise their clinical importance, these stones are associated with a higher incidence of severe hydronephrosis, with a larger size, and located in the upper ureter compared to symptomatic ureteral stones [ 7 , 6 ], especially if timely diagnosis and treatment are avoided, the risk for irreversible renal function impairment is concerning. The clinical implications differ between asymptomatic and symptomatic ureteral stones in addition to their presenting conditions, which also impacts post-treatment renal function recovery. Prior studies have pointed out relevant differences: Noh et al. [ 7 ] noted that asymptomatic stones were larger than symptomatic stones, with 32.8% of asymptomatic cases having high-grade hydronephrosis as opposed to 12.3% in symptomatic cases. More troubling, asymptomatic stones were associated with irreversible renal dysfunction after removal, while symptomatic stones had significant recovery in eGFR at 12-month follow-up and there was no recovery in eGFR after asymptomatic stones were removed [ 7 ]. Marchini et al.[ 6 ] went on to confirm that, even after successful removal of the stone, that asymptomatic ureteral stones did not restore function in the renal unit, while hydronephrosis improved on CT imaging, there was no corresponding improvement in renal function. These findings are challenging the assumption that if a stone is asymptomatic it poses 'low risk,' and that ultimately, the strategy that one chooses may improve outcomes for patients and their kidneys. Even as awareness of the clinical burden of asymptomatic ureteral stones grows, two significant knowledge gaps remain. First, while some cross-sectional studies have compared the characteristics of asymptomatic and symptomatic stones [ 4 , 7 , 6 ], there is limited longitudinally-reported data on post-treatment renal function recovery, especially for large cohorts with long-term follow-up. For example, Wimpissinger et al.[ 4 ] provided the demographic and radiological characteristics of 40 asymptomatic cases, but did not report on their long-term renal recovery. Second, few studies have specifically characterized the predictors of renal function recovery in patients with asymptomatic ureteral stones. While some authors have described predictive factors (e.g., stone size, hydronephrosis grade, preoperative renal function), this work has been primarily focused on patients with symptomatic stones [ 8 , 9 ], As a result, clinicians lack evidence-based tools to stratify the risk and offer post-treatment recommendations for patients with asymptomatic ureteral stones. This is potentially problematic given that patients with asymptomatic stones frequently present with delay in attention to treatment for stones resulting in advanced obstruction and impaired renal function at presentation [ 7 , 6 ], making predictions about recovery highly relevant and individualized. The current study attempts to address these limitations by utilizing a large two-center cohort to: (1) respectfully compare the clinical, radiological, and functional characteristics of asymptomatic and symptomatic ureteral stones; and (2) identify independent predictors of postoperative renal function recovery in ureteral stone patients. This study sought to clarify the divergent outcomes between asymptomatic and symptomatic ureteral stones and establish modifiable and non-modifiable predictors of renal recovery, to discuss implications in clinical decision-making, risk stratifying for intervention and follow-up based on risk of renal impairment. The end goal of this study is to reduce permanent renal impairment in ureteral stone patients, a group of patients at risk, but often excluded in clinical guidelines [ 10 ]. Method Study design This two-institution retrospective cohort study was performed at The Second Affiliated Hospital of Hainan Medical University and Hainan Provincial People's Hospital from March 2018 to March 2023. The study protocol was reviewed and approved by the Hainan Medical University and carried out in accordance with the Declaration of Helsinki. Informed consent was not sought because of the retrospective nature of the study. We included consecutive patients undergoing URSL for ureteral stones. Inclusion Criteria: Age ≥ 18 years; No evidence of any lesions in contralateral renal. The surgery was performed by seasoned professional surgeons with extensive clinical experience. Patients were excluded if they satisfied any of the following criteria: (1) medical expulsive therapy, extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, or percutaneous nephrolithotomy; (2) ureteral stenosis, postoperative residual stones, bilateral ureteral stones or contralateral renal atrophy; (3) incomplete postoperative glomerular filtration rate (GFR) during follow-up; (4) renal dynamic imaging data incomplete preoperative and postoperative follow-up (Fig. 1 ); (5) chronic heart failure/liver cirrhosis, as well as long-term use of nephrotoxic drugs (e.g., nonsteroidal anti-inflammatory drugs [NSAIDs]), all of which were considered factors that may directly affect postoperative renal function recovery. Patients were allocated to one of two groups based on recognizable stone-related symptoms: Symptomatic group: patients who had at least one of the following symptoms; acute/chronic flank pain, gross hematuria, urinary tract infection (UTI)-symptoms (dysuria, frequency, fever). These patients tended to undergo surgery due to either ongoing symptoms or low rate of spontaneous stone passage. Asymptomatic group: patients without any symptoms mentioned above. The timeframe for symptom recall is remaining asymptomatic throughout the period before diagnosis. Patients with a history of symptoms that spontaneously resolved preoperatively were excluded. Stones were found incidentally during either: (1) routine health screening (abdominal ultrasound or testing for microscopic hematuria); or (2) a work-up of another (non-urologic) disease. Information on symptoms was obtained from preoperative medical records, and grouping was double-confirmed via two independent urologists (and at all times discrepancies were resolved by consensus). We retrospectively extracted data from electronic medical records and the institutional urolithiasis database, including three categories: patient baseline characteristics, stone characteristics, and surgical/functional outcomes. Demographics: Age, sex, body mass index (BMI). Comorbidities: Diabetes mellitus (DM), hyperlipidemia, hypertension (HTN), and chronic kidney disease (CKD)[ 11 ]. All stone-related parameters were evaluated via non-contrast computed tomography (CT) preoperatively: Hydronephrosis grade: Classified as Grade 0/I (no/mild dilation), Grade II (moderate dilation without parenchymal thinning), Grade III (severe dilation with mild parenchymal thinning), or Grade IV (severe dilation with significant parenchymal thinning)[ 12 ]. Surgical method: Operative time: From endoscopic access to stent placement (minutes). Ureteral stents were all removed in patients of both groups 2–4 weeks postoperatively. Intraoperative obstruction degree: Classified as “partial” (urine flow present around the stone) or “complete” (no urine flow) via intraoperative observation. Preoperative split renal function: Measured via 99mTc-diethylenetriamine pentaacetic acid (99mTc-DTPA) renal dynamic scintigraphy to calculate the ratio of preoperative GFR of the affected kidney to the contralateral normal kidney (GFR ratio)[ 13 ]. Part of patients were followed for 12 months postoperatively, with scheduled visits at 1, 3, 6, 12 months. At each visit, assessments included GFR measurement and urinary system color Doppler ultrasound. Since the difference in GFR between the two kidneys of normal individuals does not exceed 10% and this variation is recognized as a physiological phenomenon[ 14 ], I define the recovery of renal function as follows: Defined as postoperative GFR of the affected kidney exceeding 90% of the contralateral normal kidney’s GFR at 1 year postoperatively(GFR 90) (assessed via 99mTc-DTPA scintigraphy). Statistics All analyses were performed using SPSS 26.0 (IBM Corp., Armonk, NY, USA) and R 4.3.0 (R Foundation for Statistical Computing, Vienna, Austria). Continuous variables: Presented as mean ± standard deviation (SD) if normally distributed (Shapiro–Wilk test, p > 0.05); otherwise, median (interquartile range). Categorical variables: Presented as frequency (percentage). Continuous variables: Independent samples t-test (between asymptomatic and symptomatic groups) or paired t-test (preoperative vs. postoperative GFR within each group). Categorical variables: Chi-square test or Fisher’s exact test (for small expected frequencies). Univariate Cox regression: Used to screen variables associated with 1-year renal function recovery (variables with p < 0.05 were included in multivariate analysis). Multivariate Cox regression: Adjusted for potential confounders to identify independent predictors. Hazard ratios (HR) and 95% confidence intervals (CI) were reported. A nomogram was developed based on independent predictors from multivariate Cox regression to predict the probability of 1-year renal function recovery. Internal validation: Performed via 1000 bootstrap resamples to assess. Discrimination: Area under the receiver operating characteristic (ROC) curve (AUC). Calibration plots (comparing predicted vs. observed recovery probabilities) and mean absolute error (MAE). A p-value < 0.05 was considered statistically significant. Results A retrospective cohort study was conducted on patients who underwent URSL for ureteral stones. A total of 635 eligible patients were included in the analysis. According to the presence of stone-related symptoms, patients were divided into two groups: the asymptomatic stone group (n = 38, 5.98%) and the symptomatic stone group (n = 597, 94.02%) (Fig. 1 ). Table 1 summarizes the incidental diagnosis methods for asymptomatic ureteral stones. Ultrasonography was the most common detection approach, accounting for 55.3% (21/38) of cases. The second most frequent method was microscopic hematuria screening, which identified 23.7% (9/38) of asymptomatic stones. Additionally, 21.0% (8/38) of asymptomatic stones were incidentally discovered during diagnostic work-up for other diseases. Table 1 Incidental diagnosis of silent stones. Detection Asymptomatic stones (n = 38 ) Ultrasonography (%) 21(55.3%) Microscopic hematuria (%) 9(23.7%) Other disease work-up (%) 8(21.0%) Baseline characteristics of the two groups are presented in Table 2 . No statistically significant differences were observed between the asymptomatic and symptomatic groups in terms of age, sex distribution, body mass index (BMI), comorbidities (hyperlipidemia, hypertension, chronic kidney disease), previous stone history, stone lateralization, urine pH, or stone density (all p > 0.05); In contrast, four variables showed significant differences between the two groups (all p < 0.05). The prevalence was significantly higher in the asymptomatic group (39.5%, 15/38) than in the symptomatic group (8.7%, 52/597) (p < 0.001); Grade IV hydronephrosis was more common in the asymptomatic group (36.8%, 14/38) compared to the symptomatic group (14.1%, 84/597), with an overall significant difference in hydronephrosis grades between groups (p < 0.001); Upper ureteral stones accounted for 71.1% (27/38) of cases in the asymptomatic group, which was significantly higher than the 31.5% (188/597) in the symptomatic group. Conversely, mid-ureteral (18.4% vs. 37.4%) and lower ureteral stones (10.5% vs. 31.2%) were more frequent in the symptomatic group (p < 0.001); The asymptomatic group had larger stones (13.4 ± 4.2 mm) than the symptomatic group (11.3 ± 4.5 mm) (p = 0.005). Table 2 Patient characteristics. Characteristic(n = 635) Asymptomatic stones(n = 38) Symptomatic stones(n = 597) p-value Number of patients (%) 38(5.98%) 597(94.02%) Age (year), mean ± SD 54.3 ± 12.1 52.5 ± 12.6 0.407 Sex(n, %) 0.220 Male 13(34.2%) 265(44.4%) Female 25(65.8%) 332(55.6%) Body mass index (kg/m 2 ), mean ± SD 23.9 ± 4.9 24.1 ± 4.7 0.823 Underlying disease (%) Diabetes mellitus (n, %) 15(39.5%) 52(8.7%) < 0.001 Hyperlipidemia(n, %) 6(15.8%) 80(13.4%) 0.676 Hypertension(n, %) 7(18.4%) 181(30.3%) 0.119 chronic kidney disease(n, %) 7(18.4%) 98(16.4%) 0.747 Previous history of stone(n, %) 12(31.6%) 191(32.0%) 0.958 Hydronephrosis grade (n, %) < 0.001 None or I 3(7.9%) 184(30.8%) II 11(28.9%) 187(31.3%) III 10(26.3%) 142(23.8%) IV 14(36.8%) 84(14.1%) Location (n, %) < 0.001 Upper ureter 27(71.1%) 188(31.5%) Mid ureter 7(18.4%) 223(37.4%) Lower ureter 4(10.5%) 186(31.2%) Lateralization(n, %) 0.357 Left 17(44.7%) 313(52.4%) Right 21(55.3%) 284(47.6%) Stone size (mm), mean ± SD 13.4 ± 4.2 11.3 ± 4.5 0.005 Urine analysis (pH) 6.1 ± 1.7 6.2 ± 1.7 0693 Density (HU) 634 ± 203 684 ± 224 0.178 Changes in ipsilateral GFR (mL/min/1.73m²) before and after surgery in both groups are shown in Table 3 and Fig. 2 . Table 3 Impact of Asymptomatic vs. Symptomatic Stones on Postoperative Ipsilateral Renal Function (Assessed by GFR) (n = 635). GFR value (mL/min/1.73m 2 ) Asymptomatic stones (n = 38, 5.98%) p-value * Symptomatic stones (n = 597, 94.02%) p-value * p-value ** PRE OP 22.0 ± 10.8 38.5 ± 9.0 < 0.001 POD 1M 23.9 ± 11.3 0.005 42.8 ± 8.3 < 0.001 < 0.001 POD 3M 25.0 ± 11.5 < 0.001 45.3 ± 8.0 < 0.001 < 0.001 POD 6M 25.3 ± 11.9 0.057 47.5 ± 7.9 < 0.001 < 0.001 POD 12M 24.7 ± 12.1 0.006 48.7 ± 7.9 < 0.001 < 0.001 Abbreviations: GFR = glomerular filtration rate; PREOP = preoperative; POD = postoperative day; D = day; M = month.) *A paired t-test was used to compare two adjacent GFR values(Such as PRE OP vs.POD 1M; POD 1M vs. POD 3M). **An independent t-test was used to compare the mean GFR between patients with symptomatic stones and those with asymptomatic stones. Preoperatively (PRE OP), the mean GFR of the asymptomatic group (22.0 ± 10.8) was significantly lower than that of the symptomatic group (38.5 ± 9.0) (p < 0.001). This difference persisted at all postoperative time points, with the asymptomatic group consistently showing lower GFR values than the symptomatic group (all p < 0.001). Asymptomatic group: GFR increased significantly from the preoperative level to 23.9 ± 11.3 at 1 month postoperatively (POD 1M, p = 0.005), further rose to 25.0 ± 11.5 at 3 months postoperatively (POD 3M, p < 0.001), and slightly increased to 25.3 ± 11.9 at 6 months postoperatively (POD 6M, p = 0.057). No further improvement was observed at 12 months postoperatively (POD 12M, 24.7 ± 12.1), though the value remained significantly higher than the preoperative level. Symptomatic group: GFR exhibited a continuous and significant upward trend over the 12-month follow-up: 42.8 ± 8.3 at POD 1M (p < 0.001 vs. PRE OP), 45.3 ± 8.0 at POD 3M (p < 0.001 vs. POD 1M), 47.5 ± 7.9 at POD 6M (p < 0.001 vs. POD 3M), and 48.7 ± 7.9 at POD 12M (p < 0.001 vs. POD 6M). As shown in Fig. 2 , several factors influenced postoperative GFR recovery: Stone size: Stones ≥ 10 mm were associated with poorer GFR recovery compared to stones < 10 mm, with a persistent GFR gap between the two subgroups postoperatively; Stone location: Upper ureteral stones showed inferior GFR recovery compared to mid- and lower ureteral stones; Hydronephrosis grade: Patients with Grade III–IV hydronephrosis had minimal GFR improvement, while those with Grade None/I–II hydronephrosis exhibited steady and better recovery; Diabetes mellitus: Patients with diabetes mellitus had marginal GFR improvement, and their GFR values were lower than those of non-diabetic patients at all time points; Obstruction degree: Complete obstruction was associated with worse GFR recovery compared to partial obstruction. Univariate and multivariate Cox proportional hazards analyses were performed to identify predictors of renal function recovery at 1 year postoperatively (Table 4 ). Renal function recovery was defined based on postoperative GFR outcomes. Table 4 Univariate and multivariate Cox analyses of patients' renal recovery status at 1 year after surgery, with renal function evaluated by GFR. N = 635 Univariate Analysis Multivariate Analysis Variable HR 95% CI P value HR 95% CI P value Age 0.966 0.952–0.980 P < 0.001 0.966 0.950–0.983 P < 0.001 Diabetes mellitus 0.351 0.209–0.588 P < 0.001 0.421 0.220–0.806 0.009 Hydronephrosis grade P < 0.001 P < 0.001 None or I Reference - - Reference - - II 0.465 0.276–0.785 0.004 0.538 0.303–0.953 0.034 III 0.396 0.230–0.682 P < 0.001 0.429 0.235–0.781 0.006 IV 0.161 0.091–0.286 P < 0.001 0.221 0.115–0.426 P < 0.001 Hypertension 1.285 0.865–1.908 0.215 Degree of obstruction** (complete obstruction) 0.361 0.251–0.518 P < 0.001 0.414 0.274–0.627 P < 0.001 The ration of operative GFR* 55.956 15.758−198.697 P < 0.001 26.459 4.962−141.094 P < 0.001 Stone size 0.976 0.939–1.014 0.211 Operation time 0.999 0.992–1.007 0.820 Symptomatic stones 28.812 10.047–82.627 P < 0.001 8.809 2.719–28.538 P < 0.001 *The ratio of preoperative GFR of the diseased kidney to that of the normal kidney in the same patient.**The degree of obstruction is categorized into partial obstruction and complete obstruction, with this classification determined by intraoperative observations. Variables significantly associated with renal function recovery included age, diabetes mellitus, hydronephrosis grade, intraoperative obstruction degree, preoperative GFR ratio (ipsilateral/contralateral normal kidney), and symptomatic status (all p 0.05). After adjusting for potential confounders, six independent predictors of renal function recovery were identified: Age: Older age was a negative predictor (HR = 0.966, 95% CI: 0.950–0.983, p < 0.001), indicating that each 1-year increase in age was associated with a 3.4% reduction in the hazard of renal function recovery; Diabetes mellitus: Patients with diabetes mellitus had a significantly lower probability of recovery (HR = 0.421, 95% CI: 0.220–0.806, p = 0.009); Hydronephrosis grade: Compared with Grade None/I hydronephrosis (reference), Grade II (HR = 0.538, 95% CI: 0.303–0.953, p = 0.034), Grade III (HR = 0.429, 95% CI: 0.235–0.781, p = 0.006), and Grade IV (HR = 0.221, 95% CI: 0.115–0.426, p < 0.001) were all negative predictors, with Grade IV showing the strongest adverse effect; Complete obstruction: Patients with complete intraoperative obstruction had a lower recovery probability (HR = 0.414, 95% CI: 0.274–0.627, p < 0.001); Preoperative GFR ratio: A higher preoperative GFR ratio (ipsilateral/contralateral) was a positive predictor (HR = 26.459, 95% CI: 4.962–141.094, p < 0.001), indicating better recovery potential in patients with higher baseline ipsilateral renal function; Symptomatic status: Symptomatic patients had a significantly higher recovery probability than asymptomatic patients (HR = 8.809, 95% CI: 2.719–28.538, p < 0.001). A nomogram was constructed to predict the probability of renal function recovery at 1 year postoperatively, based on the six independent predictors identified by multivariate Cox analysis (Fig. 4 ). Internal validation was performed using 1000 bootstrap resamples. Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the nomogram was 0.787 (Fig. 3 ), indicating good discriminative performance in distinguishing between patients with and without renal function recovery; The calibration plot (Fig. 5 ) demonstrated high consistency between the predicted probability of renal function recovery by the nomogram and the observed probability. The mean absolute error (MAE) was 0.02, confirming excellent calibration of the nomogram. Discussion According to the literature, this marks the first time that GFR has been used to evaluate the changes in renal function after ureteral calculi surgery and predict the recovery of renal function post-surgery by nomogram. Furthermore, this study is also the first to propose the ratio of 90% GFR (GFR 90) as an indicator for evaluating post-surgical renal recovery. Our study systematically compared the postoperative renal function recovery and clinical characteristics of patients with symptomatic ureteral stones and asymptomatic ureteral stones, and identified significant predictors of renal function recovery. The findings in conjunction with the referenced literature offers important insights for the management of ureteral stones, particularly the often overlooked risks of asymptomatic stones and the individualized postoperative care needed. Supportive and compatible with previous studies [ 7 , 4 ], asymptomatic ureteral stones in our study cohort were possibly different in distinctive ways: the stones were larger, more often located in the upper ureter, and had developed very significant hydronephrosis. Each one of these characteristics could be indicative of chronic obstruction that was asymptomatic: upper ureteral stones may migrate at a slower rate and, subclinical features that occur with an absence of existing symptoms result in detaining diagnosis, allowing the stones to grow and produce progressively increasing hydronephrosis [ 6 , 5 ]. Interestingly, the overall incidence of diabetes mellitus was significantly higher in the asymptomatic group, supporting Noh, et al. finding that asymptomatic patients have a greater incidence of DM. DM may create augmented opportunities for renal injury as it is associated with impairments to microcirculation and fibrosis in renal function, further limiting recovery potential in individuals with long-standing obstruction [ 9 ]. A key finding however was the difference in renal function recovery across groups. In the symptomatic group, renal function was quickly and significantly improved as early as 6 months post operatively and continued to improve throughout the 12-month period, although the difference in renal function between the 6th and 12th months post-surgery was quantitatively minimal. In contrast, The asymptomatic group’s renal function demonstrated continuous improvement within the first 6 months post-surgery; however, no significant improvement was observed from 6 to 12 months after the operation. Regarding the final renal function recovery (at the 12th month post-surgery), the magnitude of recovery in the asymptomatic group was notably lower than that in the symptomatic group (2 mL/min/1.73m 2 vs. 10 mL/min/1.73m 2 ). The discrepancy is based on the time frame and nature of obstruction: symptomatic stones create acute obstruction (the stone will pass), and often with minimal irreversible renal parenchymal damage [ 15 ]. Asymptomatic stones induce chronic obstruction, studies [ 6 ] have reported a mean time of 8.1 months for each asymptomatic patient having confirmed stone diagnosis until scheduled treatment, resulting in renal fibrosis and nephron loss [ 6 , 5 ]. It was also noted, it seems that stones were associated to already impaired kidney function, and no change in function was seen after stone removal, confirming irreversible damage [ 5 ]. However, our study found that asymptomatic patients still achieved mild recovery of their postoperative renal function within six months after surgery(22.0 ± 10.8 vs. 25.3 ± 11.9), the relative improvement rate (10.5%). Besides, a recovery of more than 10% in the patient's renal function following surgery is widely deemed to be clinically significant [ 16 ]. Although according to KDIGO[ 11 ], a change in glomerular filtration rate (GFR) of 10 mL/min per ≧ 1.73 m 2 is deemed a significant change. Additionally, the renal function recovery rate in this group of asymptomatic patients was slower than that of the symptomatic ureteral calculi group. Overall, these results demonstrate that renal function for patients with asymptomatic ureteral calculi can still be improved to some degree after surgery, contrary to previous studies[ 5 , 4 , 6 ]. Previous studies have typically relied on serum creatinine to assess renal function. However, when a patient’s contralateral kidney functions normally, serum creatinine levels may not adequately reflect the function of the affected kidney, leading to potential inaccuracies in assessment. By contrast, the present study employed renal dynamic imaging(by 99mTc-DMSA) to evaluate bilateral renal function, thereby yielding more accurate results. Our study indicates that renal function may still exhibit slight improvement in patients with asymptomatic ureteral calculi following treatment. A failure to recover reduced functioning kidneys with asymptomatic stones can be explained by two interrelated processes: 1). Obstruction related renal fibrosis. Prolonged obstruction of the renal system increases intrarenal pressure which induces pathways where epithelial-mesenchymal transition begins and collagen deposition occurs [ 6 ]. In the prospective study [ 6 ] in 26 asymptomatic patients and demonstrated 77% had a preoperative split renal function < 45% and function did not improve post-operatively indicating chronic insult had produced a depletion of recoverable nephron mass. Our observation of high-grade hydronephrosis in asymptomatic patients further supports this: high-grade hydronephrosis has a positive correlation with renal parenchymal thinning and irreversible renal fibrosis [ 8 ]. 2). Delayed identification and treatment. Clinical guidelines suggest that asymptomatic stones are often discovered incidentally when assessing for a routine health screen or while conducting an investigations on other disease processes causing obstruction and prolonging obstruction [ 4 ].It can be noted that 32.5% of patients were diagnosed with asymptomatic stones while non-urologic imaging was being utilized to screen for other medical conditions [ 4 ], as well as 22.5% during follow up for prior nephrolithiasis delay, in both scenarios the stones would have now produced progressive damage to the renal unit. In comparison, symptomatic stones induce individuals to seek immediate medical advice, with the majority of patients going to surgery within weeks from the onset of symptoms such patients minimize injury from chronic or prolonged obstruction [ 7 ]. Our study demonstrates that stones > 10mm and upper ureteral location correlate with poorer GFR recovery, compared to smaller stones (< 10mm) and mid-lower ureteral location. This is supported by: Noh et al. [ 7 ] found asymptomatic stones were larger and more often in the upper ureter than symptomatic stones. Larger upper ureteral stones migrate slower[ 4 ], prolonging obstruction and worsening renal injury, explaining their lower GFR recovery. Our observation that upper ureteral stones (vs. mid-lower) have inferior GFR recovery, as their location delays detection and treatment. We found Grade III-IV hydronephrosis leads to minimal GFR improvement, while Grade I-II hydronephrosis has steady recovery. This is validated by studies[ 6 ] noted that severe hydronephrosis (Grade III-IV) in asymptomatic patients correlates with renal parenchymal thinning and irreversible fibrosis, 81% of their asymptomatic patients had impacted stones, and 25.6% had Grade IV hydronephrosis, with no GFR recovery postoperatively. Khalaf et al. [ 8 ] identified a critical threshold: kidneys with preoperative GFR < 10 mL/min/1.73m² (often associated with Grade IV hydronephrosis) are irreversibly damaged. In Fig. 2 , asymptomatic patients with Grade IV hydronephrosis had preoperatively low GFR, leading to poor postoperative recovery. Our study reveals that DM patients have marginal GFR improvement compared to non-DM patients. This aligns with: Noh et al. [ 7 ] reported a higher DM prevalence in asymptomatic patients. DM exacerbates renal microvascular dysfunction and fibrosis [ 9 ], further limiting recovery in obstructed kidneys, explaining why DM patients have lower GFR than non-DM patients at all time points. Reeves et al. [ 9 ] studied CKD patients undergoing URSL and found DM increases complication risk and slows renal recovery, as high glucose levels impair tissue repair and promote oxidative stress, worsening the impact of obstruction on GFR. Multivariate analysis identified six significant predictors of renal function recovery with distinct implications for clinical practice. First, older age and DM were strong negative predictors. Older patients have diminished renal reserve and diminished tissue repair capability and DM aggravates renal microvascular dysfunction [ 9 ]. In a study of patients with CKD undergoing URSL the authors demonstrated that older age and DM were significant factors in delayed eGFR( Estimated GFR) recovery after URSL [ 9 ], This study suggests that further monitoring in older patients and those with DM is important in the postoperative setting. The presence of grade IV hydronephrosis and complete intraoperative obstruction were the most significant structural predictors. The study showed that kidneys that presented with severe hydronephrosis prior to surgery and a preoperative GFR less than 10 mL/min/1.73 m² suffered irreversible damage [ 8 ], This is likely due to sustained ischemia with cellular and vascular injury that diminishes the number of functional nephrons. Complete intraoperative obstruction further exacerbates ischemia and decreases the likelihood of recovery after treatment [ 15 ]. Higher GFR ratio (affected kidney/contralateral normal kidney) was the strongest positive predictor of renal function recovery. The cutoff value for the GFR ratio is 0.505, with a specificity of 0.265 and a sensitivity of 0.974. Notably, a GFR ratio exceeding 0.505 indicates a significantly high probability of postoperative recovery of the affected kidney. This aligns with the conclusion of Khalaf et al. who found that preoperative split renal function was a reliable indicator of recovery potential [ 8 ], kidneys that had maintained some baseline function contained more non-damaged nephrons and therefore had a greater chance of recovery after deobstruction assistance. Symptomatic patients had an 26-fold higher recovery risk, reinforcing that acute symptomatic obstruction is associated with reversible injury[ 7 , 15 ]. Prior prospective study of endoscopic stone treatment found that symptomatic patients had greater long-term eGFR improvement than asymptomatic patients[ 15 ], as symptoms prompt early intervention. The nomogram constructed from these predictors exhibited excellent discriminative ability (AUC = 0.787) and calibration (MAE = 0.02), mirroring the high performance of nomograms for postoperative renal function prediction. This tool offers tangible clinical value: Preoperative counseling: It helps clinicians quantify recovery probability for patients, guiding shared decision-making. Postoperative monitoring: High-risk patients can undergo more frequent eGFR testing and renal dynamic imaging to detect early dysfunction. Treatment optimization: For patients with low recovery potential, proactive measures (e.g., stricter glycemic control, early ureteral stent removal to reduce inflammation) may be prioritized. Delayed intervention for asymptomatic stones is linked to irreversible renal damage due to prolonged obstruction. For asymptomatic stones with high-risk features (size > 10 mm, upper ureteral location, Grade III–IV hydronephrosis, or DM), intervention should be initiated within 1–2 months of diagnosis to avoid progressive fibrosis[ 17 ]. For low-risk asymptomatic stones ( 5%, intervene within 2 weeks. First-line flexible URSL (holmium laser lithotripsy), as it achieves high SFR (91.6–93.7%) and minimal renal trauma [ 9 ]. LUL for proximal/upper ureteral stones (to avoid incomplete fragmentation), or URSL with ureteral access sheath for distal stones[ 5 ]. High-risk patients (DM, Grade III–IV hydronephrosis, CKD) need more frequent monitoring to detect early dysfunction: GFR + renal ultrasound: 1M, 3M, 6M, 12M postoperatively; then every 6 months for 2 years. − 99mTc-DMSA at 3M and 12M to assess split renal function[ 6 ]. Low-risk patients (no comorbidities, Grade I–II hydronephrosis, stones < 10 mm): eGFR + ultrasound: 3M and 12M postoperatively; annual follow-up thereafter. Limitations There are a variety of limitations in this study that we would like to highlight. Selection bias may be present (i.e. patients with incomplete follow-up were excluded) and unmeasured confounders (e.g. asymptomatic obstruction duration) could have influenced findings. First, 635 patients had undergone 99mTc-DTPA scintigraphy, an even larger sample would help optimize the validity and result of the nomogram. It provided no evidence for differences in stone metabolite composition among the asymptomatic and symptomatic group [ 7 ], furthermore it is not feasible for us to routinely conduct stone composition analysis for every patient subsequent to surgery, therefore, we did not use it in the study. However, certain specimen compositions (such as uric acid pathophysiology) could certainly affect those factors of recurrence and indirect renal injury [ 18 ]. Second, the classification of intraoperative obstruction degree (divided into "complete" [no urine flow] and "partial" [urine flow around the stone]) relied solely on the surgeon’s subjective observation, without verification by objective indicators (e.g., Radilogical Urography). Different surgeons may have inconsistent judgment thresholds for urine flow intensity (e.g., whether weak urine flow is classified as "partial obstruction"), which may introduce classification bias and affect the reliability of "complete intraoperative obstruction" as an independent predictor of postoperative renal function recovery. Besides, key factors that may influence renal function recovery were not included in the analysis. For instance, the duration of asymptomatic obstruction (a critical factor for chronic renal injury) was not recorded; and other unmeasured baseline factors (e.g., medication use, lifestyle habits) were not considered. These unaccounted variables may introduce residual confounding and affect the accuracy of the identified predictors. Otherwise, Renal function was evaluated using renal dynamic imaging (e.g., 99mTc-DTPA), but the study did not address the consistency of this detection method across different operators or equipment. Variations in imaging protocols or interpretation standards may lead to measurement bias, potentially affecting the reliability of GFR values and the subsequent analysis of renal function recovery trends. Finally, No long-term follow-up study exceeding one year was performed in the present study, as the GFR of enrolled patients remained essentially stable subsequent to surgery for one year. Nevertheless, we plan to carry out a more prolonged follow-up (e.g., a five-year longitudinal follow-up) in the future to observe the trajectory of patients' renal function recovery. The findings underscore three critical clinical recommendations. Active management of asymptomatic stones: Given their association with chronic obstruction and irreversible renal damage, asymptomatic stones, especially those diabetes mellitus, in the upper ureter, or high-grade hydronephrosis, should not be observed passively. Personalized postoperative care: Patients with low recovery potential require close monitoring and targeted interventions. Validation of the nomogram: Multicenter prospective studies are needed to refine the nomogram, particularly in diverse populations and with longer follow-up (≥ 5 years) to assess long-term renal outcomes. Conclusion Asymptomatic ureteral stones are associated with distinct clinical features (larger size, upper ureteral location, severe hydronephrosis) and significantly worse postoperative renal function recovery compared to symptomatic stones, driven by chronic obstruction-induced irreversible injury. Age, DM, Grade IV hydronephrosis, complete obstruction, and low preoperative split renal function are key predictors of poor recovery. The validated nomogram enables accurate prediction of recovery risk, supporting personalized treatment and monitoring strategies. Clinicians should prioritize active intervention for asymptomatic stones and tailor postoperative care to high-risk subgroups to preserve renal function. Declarations Acknowledgments The authors thank all the study participants and team members for their contributions. Author contributions Mingbin Xu: Conceptualization, Methodology, Software, Writing Original draft preparation; Guoliang Wu: Data curation; Daoyuan Li: Visualization, Investigation. Shuming He: Supervision; Chengyang Li: Writing- Reviewing and Editing. Funding None. Availability of data and materials The data presented in this study are available in the article or the Supplementary material. Deidentified data are available upon reasonable request from the first author. Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Consent to publication Not applicable. Ethical approval and consent to participate This study was approved by the Ethics Committee of The Second Affiliated Hospital of Hainan Medical University, following the Declaration of Helsinki. References Scales CD, Jr., Smith AC, Hanley JM, Saigal CS (2012) Prevalence of kidney stones in the United States. Eur Urol 62 (1):160-165. Taylor EN, Stampfer MJ, Curhan GC (2005) Obesity, weight gain, and the risk of kidney stones. Jama 293 (4):455-462. Teichman JM (2004) Clinical practice. Acute renal colic from ureteral calculus. N Engl J Med 350 (7):684-693. Wimpissinger F, Türk C, Kheyfets O, Stackl W (2007) The silence of the stones: asymptomatic ureteral calculi. J Urol 178 (4 Pt 1):1341-1344; discussion 1344. Marchini GS, Vicentini FC, Mazzucchi E, Brito A, Ebaid G, Srougi M (2012) Silent ureteral stones: impact on kidney function--can treatment of silent ureteral stones preserve kidney function? Urology 79 (2):304-308. Marchini GS, Vicentini FC, Monga M, Torricelli FC, Danilovic A, Brito AH et al (2016) Irreversible Renal Function Impairment Due to Silent Ureteral Stones. Urology 93:33-39. Noh TI, Pyun JH, Shim JS, Kang SH, Cheon J, Kang SG (2023) A comparison between asymptomatic and symptomatic ureteral stones. Sci Rep 13 (1):2757. Khalaf IM, Shokeir AA, El-Gyoushi FI, Amr HS, Amin MM (2004) Recoverability of renal function after treatment of adult patients with unilateral obstructive uropathy and normal contralateral kidney: a prospective study. Urology 64 (4):664-668. Reeves T, Pietropaolo A, Somani BK (2020) Ureteroscopy and Laser Stone Fragmentation Is Safe and Tends to Improve Renal Function in Patients with Chronic Kidney Disease: Prospective Outcomes with a Minimum Follow-Up of 6 Months. J Endourol 34 (4):423-428. Preminger GM, Tiselius HG, Assimos DG, Alken P, Buck C, Gallucci M et al (2007) 2007 guideline for the management of ureteral calculi. J Urol 178 (6):2418-2434. National Kidney F, Kidney D (2013) KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kadırhan Ö, Aydın S, Keskin E, Kantarcı M (2025) Role of ureteral wall thickness and computed tomography imaging in predicting spontaneous passage of ureteral stones. Diagn Interv Radiol. Taylor AT (2014) Radionuclides in nephrourology, part 1: Radiopharmaceuticals, quality control, and quantitative indices. J Nucl Med 55 (4):608-615. Tanriover B, Fernandez S, Campenot ES, Newhouse JH, Oyfe I, Mohan P et al (2015) Live Donor Renal Anatomic Asymmetry and Posttransplant Renal Function. Transplantation 99 (8):e66-74. Selmi V, Sarı S, Caniklioğlu M, Öztekin Ü, Taspinar MS, Işıkay L (2021) Effect of Endoscopic Ureteral Stone Treatment on Kidney Function. Cureus 13 (1):e12883. Siregar S, Mustafa A, Steven S (2024) Can We Predict Renal Function Recovery After Pyeloplasty in Pediatrics with Ureteropelvic Junction Obstruction? A Systematic Review. Urol Res Pract 50 (2):85-93. Han DS, Cher BAY, Lee D, Rajendran S, Riblet NBV, Pais VM, Jr. (2019) The Durability of Active Surveillance in Patients with Asymptomatic Kidney Stones: A Systematic Review. J Endourol 33 (7):598-605. Sorensen MD, Harper JD, Borofsky MS, Hameed TA, Smoot KJ, Burke BH et al (2022) Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse. N Engl J Med 387 (6):506-513. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 29 Oct, 2025 Read the published version in International Urology and Nephrology → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7732690","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":527011116,"identity":"2711c1ef-207a-4766-8f42-508111d31246","order_by":0,"name":"Mingbin Xu","email":"","orcid":"","institution":"The Second Affiliated Hospital of Hainan Medical University","correspondingAuthor":false,"prefix":"","firstName":"Mingbin","middleName":"","lastName":"Xu","suffix":""},{"id":527011118,"identity":"f221dfeb-d9bd-4958-b372-9a5347222e71","order_by":1,"name":"Guoliang Wu","email":"","orcid":"","institution":"The Second Affiliated Hospital of Hainan 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1","display":"","copyAsset":false,"role":"figure","size":116308,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart for study design. CT, computed tomography; GFR, glomerular fltration rate; M, month.\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7732690/v1/917ce8f77235f4649f6c0a43.jpg"},{"id":93557349,"identity":"7e702806-9807-49d0-9cc6-249cefe61b94","added_by":"auto","created_at":"2025-10-15 06:49:31","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":110333,"visible":true,"origin":"","legend":"\u003cp\u003eComparing the impact on GFR between asymptomatic and symptomatic ureteral stones, ureteral stones ≧10mm and \u0026lt;10mm, upper, mid and lower ureteral stones, hydronephrosis grade I, II, III and IV, diabetes mellitus and not, and obstruction condition.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7732690/v1/0e77ee929e6e1f07a2574121.jpg"},{"id":93556149,"identity":"272a8843-5390-4d0b-aac2-9ca36da48f69","added_by":"auto","created_at":"2025-10-15 06:41:30","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":31932,"visible":true,"origin":"","legend":"\u003cp\u003eROC curve analysis for evaluating the probability of the recovery of renal function at 1 year after surgery(AUC=0.787).\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7732690/v1/e5670d7e0f5494c2f9c25a77.jpg"},{"id":93556152,"identity":"04034d24-5c6a-4c16-afe4-5ef475a1c45f","added_by":"auto","created_at":"2025-10-15 06:41:31","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":63902,"visible":true,"origin":"","legend":"\u003cp\u003eA nomogram to predict the probability of recovery of renal function at 1 year after surgery.(*The degree of obstruction is categorized into partial obstruction and complete obstruction, with this classification determined by intraoperative observations.**The ratio of preoperative GFR of the diseased kidney to that of the normal kidney in the same patient.***Define renal function recovery as a state in which the postoperative GFR of the affected renal side in a patient exceeds 90% of the GFR of the contralateral normal renal side at 1-year after surgery.)\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7732690/v1/6b783a84c607fe1afce843ab.jpg"},{"id":93556154,"identity":"ce9483a3-01a4-498c-b701-d2f1b5b5611b","added_by":"auto","created_at":"2025-10-15 06:41:31","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":45187,"visible":true,"origin":"","legend":"\u003cp\u003eThe calibration plots of the nomogram for predicting the probability of recovery of renal function.\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7732690/v1/d247a0e09cf38d17380bd5d0.jpg"},{"id":95039782,"identity":"85351f38-5330-4204-ae43-b11fef4d27a3","added_by":"auto","created_at":"2025-11-03 16:02:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1403567,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7732690/v1/4e04c66b-21f1-4ff5-8cc7-76db509cba16.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Predictors of postoperative renal function recovery in patients with ureteral stones: asymptomatic Vs symptomatic ureteral stones","fulltext":[{"header":"Introduction","content":"\u003cp\u003eUrolithiasis is among the most common urological problems in the world, and the incidence is rising as a result of dietary lifestyle changes and an increasingly sedentary population, coupled with rising incidences of metabolic comorbidities such as obesity and diabetes mellitus [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Ureteral stones, as one major subtype of urolithiasis, typically cause acute symptoms (eg, renal colic, gross hematuria, or urinary tract infection) which serves as a motivator to diagnose and treat urgently [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. For some ureteral stones, the opposite scenario occurs; these stones are clinically termed asymptomatic or \"silent stones\". They lack of timely symptoms, leading them to be undiagnosed until incidental detection on an imaging study or screening for other diseases [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Though asymptomatic ureteral stones comprise only 1.1%\u0026ndash;5.3% of the prevalence of all ureteral stones [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], many factors raise their clinical importance, these stones are associated with a higher incidence of severe hydronephrosis, with a larger size, and located in the upper ureter compared to symptomatic ureteral stones [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], especially if timely diagnosis and treatment are avoided, the risk for irreversible renal function impairment is concerning. The clinical implications differ between asymptomatic and symptomatic ureteral stones in addition to their presenting conditions, which also impacts post-treatment renal function recovery.\u003c/p\u003e\u003cp\u003ePrior studies have pointed out relevant differences: Noh et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] noted that asymptomatic stones were larger than symptomatic stones, with 32.8% of asymptomatic cases having high-grade hydronephrosis as opposed to 12.3% in symptomatic cases. More troubling, asymptomatic stones were associated with irreversible renal dysfunction after removal, while symptomatic stones had significant recovery in eGFR at 12-month follow-up and there was no recovery in eGFR after asymptomatic stones were removed [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Marchini et al.[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] went on to confirm that, even after successful removal of the stone, that asymptomatic ureteral stones did not restore function in the renal unit, while hydronephrosis improved on CT imaging, there was no corresponding improvement in renal function. These findings are challenging the assumption that if a stone is asymptomatic it poses 'low risk,' and that ultimately, the strategy that one chooses may improve outcomes for patients and their kidneys.\u003c/p\u003e\u003cp\u003eEven as awareness of the clinical burden of asymptomatic ureteral stones grows, two significant knowledge gaps remain. First, while some cross-sectional studies have compared the characteristics of asymptomatic and symptomatic stones [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], there is limited longitudinally-reported data on post-treatment renal function recovery, especially for large cohorts with long-term follow-up. For example, Wimpissinger et al.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] provided the demographic and radiological characteristics of 40 asymptomatic cases, but did not report on their long-term renal recovery. Second, few studies have specifically characterized the predictors of renal function recovery in patients with asymptomatic ureteral stones. While some authors have described predictive factors (e.g., stone size, hydronephrosis grade, preoperative renal function), this work has been primarily focused on patients with symptomatic stones [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], As a result, clinicians lack evidence-based tools to stratify the risk and offer post-treatment recommendations for patients with asymptomatic ureteral stones. This is potentially problematic given that patients with asymptomatic stones frequently present with delay in attention to treatment for stones resulting in advanced obstruction and impaired renal function at presentation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], making predictions about recovery highly relevant and individualized.\u003c/p\u003e\u003cp\u003eThe current study attempts to address these limitations by utilizing a large two-center cohort to: (1) respectfully compare the clinical, radiological, and functional characteristics of asymptomatic and symptomatic ureteral stones; and (2) identify independent predictors of postoperative renal function recovery in ureteral stone patients. This study sought to clarify the divergent outcomes between asymptomatic and symptomatic ureteral stones and establish modifiable and non-modifiable predictors of renal recovery, to discuss implications in clinical decision-making, risk stratifying for intervention and follow-up based on risk of renal impairment. The end goal of this study is to reduce permanent renal impairment in ureteral stone patients, a group of patients at risk, but often excluded in clinical guidelines [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e"},{"header":"Method","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStudy design\u003c/h2\u003e\u003cp\u003eThis two-institution retrospective cohort study was performed at The Second Affiliated Hospital of Hainan Medical University and Hainan Provincial People's Hospital from March 2018 to March 2023. The study protocol was reviewed and approved by the Hainan Medical University and carried out in accordance with the Declaration of Helsinki. Informed consent was not sought because of the retrospective nature of the study.\u003c/p\u003e\u003cp\u003eWe included consecutive patients undergoing URSL for ureteral stones. Inclusion Criteria: Age\u0026thinsp;\u0026ge;\u0026thinsp;18 years; No evidence of any lesions in contralateral renal. The surgery was performed by seasoned professional surgeons with extensive clinical experience. Patients were excluded if they satisfied any of the following criteria: (1) medical expulsive therapy, extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, or percutaneous nephrolithotomy; (2) ureteral stenosis, postoperative residual stones, bilateral ureteral stones or contralateral renal atrophy; (3) incomplete postoperative glomerular filtration rate (GFR) during follow-up; (4) renal dynamic imaging data incomplete preoperative and postoperative follow-up (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e); (5) chronic heart failure/liver cirrhosis, as well as long-term use of nephrotoxic drugs (e.g., nonsteroidal anti-inflammatory drugs [NSAIDs]), all of which were considered factors that may directly affect postoperative renal function recovery.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003ePatients were allocated to one of two groups based on recognizable stone-related symptoms: Symptomatic group: patients who had at least one of the following symptoms; acute/chronic flank pain, gross hematuria, urinary tract infection (UTI)-symptoms (dysuria, frequency, fever). These patients tended to undergo surgery due to either ongoing symptoms or low rate of spontaneous stone passage. Asymptomatic group: patients without any symptoms mentioned above. The timeframe for symptom recall is remaining asymptomatic throughout the period before diagnosis. Patients with a history of symptoms that spontaneously resolved preoperatively were excluded. Stones were found incidentally during either: (1) routine health screening (abdominal ultrasound or testing for microscopic hematuria); or (2) a work-up of another (non-urologic) disease. Information on symptoms was obtained from preoperative medical records, and grouping was double-confirmed via two independent urologists (and at all times discrepancies were resolved by consensus).\u003c/p\u003e\u003cp\u003eWe retrospectively extracted data from electronic medical records and the institutional urolithiasis database, including three categories: patient baseline characteristics, stone characteristics, and surgical/functional outcomes.\u003c/p\u003e\u003cp\u003eDemographics: Age, sex, body mass index (BMI). Comorbidities: Diabetes mellitus (DM), hyperlipidemia, hypertension (HTN), and chronic kidney disease (CKD)[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. All stone-related parameters were evaluated via non-contrast computed tomography (CT) preoperatively: Hydronephrosis grade: Classified as Grade 0/I (no/mild dilation), Grade II (moderate dilation without parenchymal thinning), Grade III (severe dilation with mild parenchymal thinning), or Grade IV (severe dilation with significant parenchymal thinning)[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSurgical method: Operative time: From endoscopic access to stent placement (minutes). Ureteral stents were all removed in patients of both groups 2\u0026ndash;4 weeks postoperatively. Intraoperative obstruction degree: Classified as \u0026ldquo;partial\u0026rdquo; (urine flow present around the stone) or \u0026ldquo;complete\u0026rdquo; (no urine flow) via intraoperative observation. Preoperative split renal function: Measured via 99mTc-diethylenetriamine pentaacetic acid (99mTc-DTPA) renal dynamic scintigraphy to calculate the ratio of preoperative GFR of the affected kidney to the contralateral normal kidney (GFR ratio)[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Part of patients were followed for 12 months postoperatively, with scheduled visits at 1, 3, 6, 12 months. At each visit, assessments included GFR measurement and urinary system color Doppler ultrasound. Since the difference in GFR between the two kidneys of normal individuals does not exceed 10% and this variation is recognized as a physiological phenomenon[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], I define the recovery of renal function as follows: Defined as postoperative GFR of the affected kidney exceeding 90% of the contralateral normal kidney\u0026rsquo;s GFR at 1 year postoperatively(GFR 90) (assessed via 99mTc-DTPA scintigraphy).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eStatistics\u003c/h3\u003e\n\u003cp\u003eAll analyses were performed using SPSS 26.0 (IBM Corp., Armonk, NY, USA) and R 4.3.0 (R Foundation for Statistical Computing, Vienna, Austria). Continuous variables: Presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) if normally distributed (Shapiro\u0026ndash;Wilk test, p\u0026thinsp;\u0026gt;\u0026thinsp;0.05); otherwise, median (interquartile range). Categorical variables: Presented as frequency (percentage). Continuous variables: Independent samples t-test (between asymptomatic and symptomatic groups) or paired t-test (preoperative vs. postoperative GFR within each group). Categorical variables: Chi-square test or Fisher\u0026rsquo;s exact test (for small expected frequencies). Univariate Cox regression: Used to screen variables associated with 1-year renal function recovery (variables with p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were included in multivariate analysis). Multivariate Cox regression: Adjusted for potential confounders to identify independent predictors. Hazard ratios (HR) and 95% confidence intervals (CI) were reported.\u003c/p\u003e\u003cp\u003eA nomogram was developed based on independent predictors from multivariate Cox regression to predict the probability of 1-year renal function recovery. Internal validation: Performed via 1000 bootstrap resamples to assess. Discrimination: Area under the receiver operating characteristic (ROC) curve (AUC). Calibration plots (comparing predicted vs. observed recovery probabilities) and mean absolute error (MAE). A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eA retrospective cohort study was conducted on patients who underwent URSL for ureteral stones. A total of 635 eligible patients were included in the analysis. According to the presence of stone-related symptoms, patients were divided into two groups: the asymptomatic stone group (n\u0026thinsp;=\u0026thinsp;38, 5.98%) and the symptomatic stone group (n\u0026thinsp;=\u0026thinsp;597, 94.02%) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e summarizes the incidental diagnosis methods for asymptomatic ureteral stones. Ultrasonography was the most common detection approach, accounting for 55.3% (21/38) of cases. The second most frequent method was microscopic hematuria screening, which identified 23.7% (9/38) of asymptomatic stones. Additionally, 21.0% (8/38) of asymptomatic stones were incidentally discovered during diagnostic work-up for other diseases.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e Incidental diagnosis of silent stones.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDetection\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAsymptomatic stones (n\u0026thinsp;=\u0026thinsp;38 )\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUltrasonography (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e21(55.3%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMicroscopic hematuria (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e9(23.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOther disease work-up (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8(21.0%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eBaseline characteristics of the two groups are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. No statistically significant differences were observed between the asymptomatic and symptomatic groups in terms of age, sex distribution, body mass index (BMI), comorbidities (hyperlipidemia, hypertension, chronic kidney disease), previous stone history, stone lateralization, urine pH, or stone density (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05); In contrast, four variables showed significant differences between the two groups (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The prevalence was significantly higher in the asymptomatic group (39.5%, 15/38) than in the symptomatic group (8.7%, 52/597) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001); Grade IV hydronephrosis was more common in the asymptomatic group (36.8%, 14/38) compared to the symptomatic group (14.1%, 84/597), with an overall significant difference in hydronephrosis grades between groups (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001); Upper ureteral stones accounted for 71.1% (27/38) of cases in the asymptomatic group, which was significantly higher than the 31.5% (188/597) in the symptomatic group. Conversely, mid-ureteral (18.4% vs. 37.4%) and lower ureteral stones (10.5% vs. 31.2%) were more frequent in the symptomatic group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001); The asymptomatic group had larger stones (13.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2 mm) than the symptomatic group (11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5 mm) (p\u0026thinsp;=\u0026thinsp;0.005).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003e Patient characteristics.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristic(n\u0026thinsp;=\u0026thinsp;635)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAsymptomatic stones(n\u0026thinsp;=\u0026thinsp;38)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSymptomatic stones(n\u0026thinsp;=\u0026thinsp;597)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of patients (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e38(5.98%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e597(94.02%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (year), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e54.3\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e52.5\u0026thinsp;\u0026plusmn;\u0026thinsp;12.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.407\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.220\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13(34.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e265(44.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e25(65.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e332(55.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index (kg/m\u003csup\u003e2\u003c/sup\u003e), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.823\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUnderlying disease (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eDiabetes mellitus\u003c/b\u003e(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15(39.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e52(8.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHyperlipidemia(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6(15.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e80(13.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.676\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(18.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e181(30.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003echronic kidney disease(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(18.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98(16.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.747\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePrevious history of stone(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12(31.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e191(32.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.958\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eHydronephrosis grade\u003c/b\u003e(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNone or I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3(7.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e184(30.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11(28.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e187(31.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10(26.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e142(23.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14(36.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e84(14.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLocation\u003c/b\u003e(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUpper ureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e27(71.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e188(31.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMid ureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7(18.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e223(37.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLower ureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4(10.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e186(31.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLateralization(n, %)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.357\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17(44.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e313(52.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21(55.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e284(47.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eStone size (mm), mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13.4\u0026thinsp;\u0026plusmn;\u0026thinsp;4.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11.3\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUrine analysis (pH)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0693\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDensity (HU)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e634\u0026thinsp;\u0026plusmn;\u0026thinsp;203\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e684\u0026thinsp;\u0026plusmn;\u0026thinsp;224\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.178\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eChanges in ipsilateral GFR (mL/min/1.73m\u0026sup2;) before and after surgery in both groups are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eImpact of Asymptomatic vs. Symptomatic Stones on Postoperative Ipsilateral Renal Function (Assessed by GFR) (n\u0026thinsp;=\u0026thinsp;635).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGFR value\u003c/p\u003e\u003cp\u003e(mL/min/1.73m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAsymptomatic stones\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;38, 5.98%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ep-value\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSymptomatic stones\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;597, 94.02%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ep-value\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ep-value\u003csup\u003e**\u003c/sup\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePRE OP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e22.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e38.5\u0026thinsp;\u0026plusmn;\u0026thinsp;9.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePOD 1M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e23.9\u0026thinsp;\u0026plusmn;\u0026thinsp;11.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e42.8\u0026thinsp;\u0026plusmn;\u0026thinsp;8.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePOD 3M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e25.0\u0026thinsp;\u0026plusmn;\u0026thinsp;11.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e45.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePOD 6M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e25.3\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.057\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e47.5\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePOD 12M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e24.7\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.006\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e\u003cp\u003e48.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003eAbbreviations: GFR\u0026thinsp;=\u0026thinsp;glomerular filtration rate; PREOP\u0026thinsp;=\u0026thinsp;preoperative; POD\u0026thinsp;=\u0026thinsp;postoperative day; D\u0026thinsp;=\u0026thinsp;day; M\u0026thinsp;=\u0026thinsp;month.) *A paired t-test was used to compare two adjacent GFR values(Such as PRE OP vs.POD 1M; POD 1M vs. POD 3M). **An independent t-test was used to compare the mean GFR between patients with symptomatic stones and those with asymptomatic stones.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003ePreoperatively (PRE OP), the mean GFR of the asymptomatic group (22.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.8) was significantly lower than that of the symptomatic group (38.5\u0026thinsp;\u0026plusmn;\u0026thinsp;9.0) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). This difference persisted at all postoperative time points, with the asymptomatic group consistently showing lower GFR values than the symptomatic group (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003cp\u003eAsymptomatic group: GFR increased significantly from the preoperative level to 23.9\u0026thinsp;\u0026plusmn;\u0026thinsp;11.3 at 1 month postoperatively (POD 1M, p\u0026thinsp;=\u0026thinsp;0.005), further rose to 25.0\u0026thinsp;\u0026plusmn;\u0026thinsp;11.5 at 3 months postoperatively (POD 3M, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and slightly increased to 25.3\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9 at 6 months postoperatively (POD 6M, p\u0026thinsp;=\u0026thinsp;0.057). No further improvement was observed at 12 months postoperatively (POD 12M, 24.7\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1), though the value remained significantly higher than the preoperative level.\u003c/p\u003e\u003cp\u003eSymptomatic group: GFR exhibited a continuous and significant upward trend over the 12-month follow-up: 42.8\u0026thinsp;\u0026plusmn;\u0026thinsp;8.3 at POD 1M (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. PRE OP), 45.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.0 at POD 3M (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. POD 1M), 47.5\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9 at POD 6M (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. POD 3M), and 48.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.9 at POD 12M (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001 vs. POD 6M).\u003c/p\u003e\u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, several factors influenced postoperative GFR recovery: Stone size: Stones\u0026thinsp;\u0026ge;\u0026thinsp;10 mm were associated with poorer GFR recovery compared to stones\u0026thinsp;\u0026lt;\u0026thinsp;10 mm, with a persistent GFR gap between the two subgroups postoperatively; Stone location: Upper ureteral stones showed inferior GFR recovery compared to mid- and lower ureteral stones; Hydronephrosis grade: Patients with Grade III\u0026ndash;IV hydronephrosis had minimal GFR improvement, while those with Grade None/I\u0026ndash;II hydronephrosis exhibited steady and better recovery; Diabetes mellitus: Patients with diabetes mellitus had marginal GFR improvement, and their GFR values were lower than those of non-diabetic patients at all time points; Obstruction degree: Complete obstruction was associated with worse GFR recovery compared to partial obstruction.\u003c/p\u003e\u003cp\u003eUnivariate and multivariate Cox proportional hazards analyses were performed to identify predictors of renal function recovery at 1 year postoperatively (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Renal function recovery was defined based on postoperative GFR outcomes.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eUnivariate and multivariate Cox analyses of patients' renal recovery status at 1 year after surgery, with renal function evaluated by GFR.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eN\u0026thinsp;=\u0026thinsp;635\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUnivariate Analysis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMultivariate Analysis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95% CI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e95% CI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP value\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.966\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.952\u0026ndash;0.980\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.966\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.950\u0026ndash;0.983\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes mellitus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.351\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.209\u0026ndash;0.588\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.421\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.220\u0026ndash;0.806\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.009\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydronephrosis grade\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNone or I\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eReference\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eReference\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.465\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.276\u0026ndash;0.785\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.004\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.538\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.303\u0026ndash;0.953\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.034\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.396\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.230\u0026ndash;0.682\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.429\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.235\u0026ndash;0.781\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.006\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.161\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.091\u0026ndash;0.286\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.221\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.115\u0026ndash;0.426\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypertension\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.285\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.865\u0026ndash;1.908\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.215\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDegree of obstruction** (complete obstruction)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.361\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.251\u0026ndash;0.518\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.414\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.274\u0026ndash;0.627\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThe ration of operative GFR*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55.956\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15.758\u0026minus;198.697\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e26.459\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e4.962\u0026minus;141.094\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStone size\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.976\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.939\u0026ndash;1.014\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.211\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOperation time\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.999\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.992\u0026ndash;1.007\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.820\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSymptomatic stones\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e28.812\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.047\u0026ndash;82.627\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e8.809\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2.719\u0026ndash;28.538\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eP\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e*The ratio of preoperative GFR of the diseased kidney to that of the normal kidney in the same patient.**The degree of obstruction is categorized into partial obstruction and complete obstruction, with this classification determined by intraoperative observations.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eVariables significantly associated with renal function recovery included age, diabetes mellitus, hydronephrosis grade, intraoperative obstruction degree, preoperative GFR ratio (ipsilateral/contralateral normal kidney), and symptomatic status (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In contrast, hypertension, stone size, and operation time were not significantly associated with recovery (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e\u003cp\u003eAfter adjusting for potential confounders, six independent predictors of renal function recovery were identified: Age: Older age was a negative predictor (HR\u0026thinsp;=\u0026thinsp;0.966, 95% CI: 0.950\u0026ndash;0.983, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), indicating that each 1-year increase in age was associated with a 3.4% reduction in the hazard of renal function recovery; Diabetes mellitus: Patients with diabetes mellitus had a significantly lower probability of recovery (HR\u0026thinsp;=\u0026thinsp;0.421, 95% CI: 0.220\u0026ndash;0.806, p\u0026thinsp;=\u0026thinsp;0.009); Hydronephrosis grade: Compared with Grade None/I hydronephrosis (reference), Grade II (HR\u0026thinsp;=\u0026thinsp;0.538, 95% CI: 0.303\u0026ndash;0.953, p\u0026thinsp;=\u0026thinsp;0.034), Grade III (HR\u0026thinsp;=\u0026thinsp;0.429, 95% CI: 0.235\u0026ndash;0.781, p\u0026thinsp;=\u0026thinsp;0.006), and Grade IV (HR\u0026thinsp;=\u0026thinsp;0.221, 95% CI: 0.115\u0026ndash;0.426, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) were all negative predictors, with Grade IV showing the strongest adverse effect; Complete obstruction: Patients with complete intraoperative obstruction had a lower recovery probability (HR\u0026thinsp;=\u0026thinsp;0.414, 95% CI: 0.274\u0026ndash;0.627, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001); Preoperative GFR ratio: A higher preoperative GFR ratio (ipsilateral/contralateral) was a positive predictor (HR\u0026thinsp;=\u0026thinsp;26.459, 95% CI: 4.962\u0026ndash;141.094, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), indicating better recovery potential in patients with higher baseline ipsilateral renal function; Symptomatic status: Symptomatic patients had a significantly higher recovery probability than asymptomatic patients (HR\u0026thinsp;=\u0026thinsp;8.809, 95% CI: 2.719\u0026ndash;28.538, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003cp\u003eA nomogram was constructed to predict the probability of renal function recovery at 1 year postoperatively, based on the six independent predictors identified by multivariate Cox analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Internal validation was performed using 1000 bootstrap resamples. Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the nomogram was 0.787 (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e), indicating good discriminative performance in distinguishing between patients with and without renal function recovery; The calibration plot (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e) demonstrated high consistency between the predicted probability of renal function recovery by the nomogram and the observed probability. The mean absolute error (MAE) was 0.02, confirming excellent calibration of the nomogram.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003e\u003cb\u003eAccording to the literature, this marks the first time that GFR has been used to evaluate the changes in renal function after ureteral calculi surgery and predict the recovery of renal function post-surgery by nomogram. Furthermore, this study is also the first to propose the ratio of 90% GFR (GFR 90) as an indicator for evaluating post-surgical renal recovery.\u003c/b\u003e Our study systematically compared the postoperative renal function recovery and clinical characteristics of patients with symptomatic ureteral stones and asymptomatic ureteral stones, and identified significant predictors of renal function recovery. The findings in conjunction with the referenced literature offers important insights for the management of ureteral stones, particularly the often overlooked risks of asymptomatic stones and the individualized postoperative care needed.\u003c/p\u003e\u003cp\u003eSupportive and compatible with previous studies [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], asymptomatic ureteral stones in our study cohort were possibly different in distinctive ways: the stones were larger, more often located in the upper ureter, and had developed very significant hydronephrosis. Each one of these characteristics could be indicative of chronic obstruction that was asymptomatic: upper ureteral stones may migrate at a slower rate and, subclinical features that occur with an absence of existing symptoms result in detaining diagnosis, allowing the stones to grow and produce progressively increasing hydronephrosis [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Interestingly, the overall incidence of diabetes mellitus was significantly higher in the asymptomatic group, supporting Noh, et al. finding that asymptomatic patients have a greater incidence of DM. DM may create augmented opportunities for renal injury as it is associated with impairments to microcirculation and fibrosis in renal function, further limiting recovery potential in individuals with long-standing obstruction [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. A key finding however was the difference in renal function recovery across groups. In the symptomatic group, renal function was quickly and significantly improved as early as 6 months post operatively and continued to improve throughout the 12-month period, although the difference in renal function between the 6th and 12th months post-surgery was quantitatively minimal. In contrast, The asymptomatic group\u0026rsquo;s renal function demonstrated continuous improvement within the first 6 months post-surgery; however, no significant improvement was observed from 6 to 12 months after the operation. Regarding the final renal function recovery (at the 12th month post-surgery), the magnitude of recovery in the asymptomatic group was notably lower than that in the symptomatic group (2 mL/min/1.73m\u003csup\u003e2\u003c/sup\u003e vs. 10 mL/min/1.73m\u003csup\u003e2\u003c/sup\u003e). The discrepancy is based on the time frame and nature of obstruction: symptomatic stones create acute obstruction (the stone will pass), and often with minimal irreversible renal parenchymal damage [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Asymptomatic stones induce chronic obstruction, studies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] have reported a mean time of 8.1 months for each asymptomatic patient having confirmed stone diagnosis until scheduled treatment, resulting in renal fibrosis and nephron loss [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. It was also noted, it seems that stones were associated to already impaired kidney function, and no change in function was seen after stone removal, confirming irreversible damage [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, our study found that asymptomatic patients still achieved mild recovery of their postoperative renal function within six months after surgery(22.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.8 vs. 25.3\u0026thinsp;\u0026plusmn;\u0026thinsp;11.9), the relative improvement rate (10.5%). Besides, a recovery of more than 10% in the patient's renal function following surgery is widely deemed to be clinically significant [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Although according to KDIGO[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], a change in glomerular filtration rate (GFR) of 10 mL/min per ≧\u0026thinsp;1.73 m\u003csup\u003e2\u003c/sup\u003e is deemed a significant change. Additionally, the renal function recovery rate in this group of asymptomatic patients was slower than that of the symptomatic ureteral calculi group. Overall, these results demonstrate that renal function for patients with asymptomatic ureteral calculi can still be improved to some degree after surgery, contrary to previous studies[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Previous studies have typically relied on serum creatinine to assess renal function. However, when a patient\u0026rsquo;s contralateral kidney functions normally, serum creatinine levels may not adequately reflect the function of the affected kidney, leading to potential inaccuracies in assessment. By contrast, the present study employed renal dynamic imaging(by 99mTc-DMSA) to evaluate bilateral renal function, thereby yielding more accurate results. Our study indicates that renal function may still exhibit slight improvement in patients with asymptomatic ureteral calculi following treatment.\u003c/p\u003e\u003cp\u003eA failure to recover reduced functioning kidneys with asymptomatic stones can be explained by two interrelated processes: 1). Obstruction related renal fibrosis. Prolonged obstruction of the renal system increases intrarenal pressure which induces pathways where epithelial-mesenchymal transition begins and collagen deposition occurs [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In the prospective study [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] in 26 asymptomatic patients and demonstrated 77% had a preoperative split renal function\u0026thinsp;\u0026lt;\u0026thinsp;45% and function did not improve post-operatively indicating chronic insult had produced a depletion of recoverable nephron mass. Our observation of high-grade hydronephrosis in asymptomatic patients further supports this: high-grade hydronephrosis has a positive correlation with renal parenchymal thinning and irreversible renal fibrosis [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. 2). Delayed identification and treatment. Clinical guidelines suggest that asymptomatic stones are often discovered incidentally when assessing for a routine health screen or while conducting an investigations on other disease processes causing obstruction and prolonging obstruction [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].It can be noted that 32.5% of patients were diagnosed with asymptomatic stones while non-urologic imaging was being utilized to screen for other medical conditions [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], as well as 22.5% during follow up for prior nephrolithiasis delay, in both scenarios the stones would have now produced progressive damage to the renal unit. In comparison, symptomatic stones induce individuals to seek immediate medical advice, with the majority of patients going to surgery within weeks from the onset of symptoms such patients minimize injury from chronic or prolonged obstruction [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eOur study demonstrates that stones\u0026thinsp;\u0026gt;\u0026thinsp;10mm and upper ureteral location correlate with poorer GFR recovery, compared to smaller stones (\u0026lt;\u0026thinsp;10mm) and mid-lower ureteral location. This is supported by: Noh et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] found asymptomatic stones were larger and more often in the upper ureter than symptomatic stones. Larger upper ureteral stones migrate slower[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], prolonging obstruction and worsening renal injury, explaining their lower GFR recovery. Our observation that upper ureteral stones (vs. mid-lower) have inferior GFR recovery, as their location delays detection and treatment. We found Grade III-IV hydronephrosis leads to minimal GFR improvement, while Grade I-II hydronephrosis has steady recovery. This is validated by studies[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] noted that severe hydronephrosis (Grade III-IV) in asymptomatic patients correlates with renal parenchymal thinning and irreversible fibrosis, 81% of their asymptomatic patients had impacted stones, and 25.6% had Grade IV hydronephrosis, with no GFR recovery postoperatively. Khalaf et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] identified a critical threshold: kidneys with preoperative GFR\u0026thinsp;\u0026lt;\u0026thinsp;10 mL/min/1.73m\u0026sup2; (often associated with Grade IV hydronephrosis) are irreversibly damaged. In Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, asymptomatic patients with Grade IV hydronephrosis had preoperatively low GFR, leading to poor postoperative recovery. Our study reveals that DM patients have marginal GFR improvement compared to non-DM patients. This aligns with: Noh et al. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] reported a higher DM prevalence in asymptomatic patients. DM exacerbates renal microvascular dysfunction and fibrosis [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], further limiting recovery in obstructed kidneys, explaining why DM patients have lower GFR than non-DM patients at all time points. Reeves et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] studied CKD patients undergoing URSL and found DM increases complication risk and slows renal recovery, as high glucose levels impair tissue repair and promote oxidative stress, worsening the impact of obstruction on GFR.\u003c/p\u003e\u003cp\u003eMultivariate analysis identified six significant predictors of renal function recovery with distinct implications for clinical practice. First, older age and DM were strong negative predictors. Older patients have diminished renal reserve and diminished tissue repair capability and DM aggravates renal microvascular dysfunction [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. In a study of patients with CKD undergoing URSL the authors demonstrated that older age and DM were significant factors in delayed eGFR( Estimated GFR) recovery after URSL [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], This study suggests that further monitoring in older patients and those with DM is important in the postoperative setting. The presence of grade IV hydronephrosis and complete intraoperative obstruction were the most significant structural predictors. The study showed that kidneys that presented with severe hydronephrosis prior to surgery and a preoperative GFR less than 10 mL/min/1.73 m\u0026sup2; suffered irreversible damage [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], This is likely due to sustained ischemia with cellular and vascular injury that diminishes the number of functional nephrons. Complete intraoperative obstruction further exacerbates ischemia and decreases the likelihood of recovery after treatment [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Higher GFR ratio (affected kidney/contralateral normal kidney) was the strongest positive predictor of renal function recovery. The cutoff value for the GFR ratio is 0.505, with a specificity of 0.265 and a sensitivity of 0.974. \u003cb\u003eNotably, a GFR ratio exceeding 0.505 indicates a significantly high probability of postoperative recovery of the affected kidney.\u003c/b\u003e This aligns with the conclusion of Khalaf et al. who found that preoperative split renal function was a reliable indicator of recovery potential [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], kidneys that had maintained some baseline function contained more non-damaged nephrons and therefore had a greater chance of recovery after deobstruction assistance.\u003c/p\u003e\u003cp\u003eSymptomatic patients had an 26-fold higher recovery risk, reinforcing that acute symptomatic obstruction is associated with reversible injury[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Prior prospective study of endoscopic stone treatment found that symptomatic patients had greater long-term eGFR improvement than asymptomatic patients[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], as symptoms prompt early intervention.\u003c/p\u003e\u003cp\u003eThe nomogram constructed from these predictors exhibited excellent discriminative ability (AUC\u0026thinsp;=\u0026thinsp;0.787) and calibration (MAE\u0026thinsp;=\u0026thinsp;0.02), mirroring the high performance of nomograms for postoperative renal function prediction. This tool offers tangible clinical value: Preoperative counseling: It helps clinicians quantify recovery probability for patients, guiding shared decision-making. Postoperative monitoring: High-risk patients can undergo more frequent eGFR testing and renal dynamic imaging to detect early dysfunction. Treatment optimization: For patients with low recovery potential, proactive measures (e.g., stricter glycemic control, early ureteral stent removal to reduce inflammation) may be prioritized.\u003c/p\u003e\u003cp\u003eDelayed intervention for asymptomatic stones is linked to irreversible renal damage due to prolonged obstruction. For asymptomatic stones with high-risk features (size\u0026thinsp;\u0026gt;\u0026thinsp;10 mm, upper ureteral location, Grade III\u0026ndash;IV hydronephrosis, or DM), intervention should be initiated within 1\u0026ndash;2 months of diagnosis to avoid progressive fibrosis[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. For low-risk asymptomatic stones (\u0026lt;\u0026thinsp;10 mm, Grade I hydronephrosis, no comorbidities), close monitoring (imaging\u0026thinsp;+\u0026thinsp;eGFR every 4 weeks) is acceptable; if hydronephrosis worsens or GFR drops\u0026thinsp;\u0026gt;\u0026thinsp;5%, intervene within 2 weeks. First-line flexible URSL (holmium laser lithotripsy), as it achieves high SFR (91.6\u0026ndash;93.7%) and minimal renal trauma [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. LUL for proximal/upper ureteral stones (to avoid incomplete fragmentation), or URSL with ureteral access sheath for distal stones[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. High-risk patients (DM, Grade III\u0026ndash;IV hydronephrosis, CKD) need more frequent monitoring to detect early dysfunction: GFR\u0026thinsp;+\u0026thinsp;renal ultrasound: 1M, 3M, 6M, 12M postoperatively; then every 6 months for 2 years. \u0026minus;\u0026thinsp;99mTc-DMSA at 3M and 12M to assess split renal function[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Low-risk patients (no comorbidities, Grade I\u0026ndash;II hydronephrosis, stones\u0026thinsp;\u0026lt;\u0026thinsp;10 mm): eGFR\u0026thinsp;+\u0026thinsp;ultrasound: 3M and 12M postoperatively; annual follow-up thereafter.\u003c/p\u003e\n\u003ch3\u003eLimitations\u003c/h3\u003e\n\u003cp\u003eThere are a variety of limitations in this study that we would like to highlight. Selection bias may be present (i.e. patients with incomplete follow-up were excluded) and unmeasured confounders (e.g. asymptomatic obstruction duration) could have influenced findings. First, 635 patients had undergone 99mTc-DTPA scintigraphy, an even larger sample would help optimize the validity and result of the nomogram. It provided no evidence for differences in stone metabolite composition among the asymptomatic and symptomatic group [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], furthermore it is not feasible for us to routinely conduct stone composition analysis for every patient subsequent to surgery, therefore, we did not use it in the study. However, certain specimen compositions (such as uric acid pathophysiology) could certainly affect those factors of recurrence and indirect renal injury [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Second, the classification of intraoperative obstruction degree (divided into \"complete\" [no urine flow] and \"partial\" [urine flow around the stone]) relied solely on the surgeon\u0026rsquo;s subjective observation, without verification by objective indicators (e.g., Radilogical Urography). Different surgeons may have inconsistent judgment thresholds for urine flow intensity (e.g., whether weak urine flow is classified as \"partial obstruction\"), which may introduce classification bias and affect the reliability of \"complete intraoperative obstruction\" as an independent predictor of postoperative renal function recovery. Besides, key factors that may influence renal function recovery were not included in the analysis. For instance, the duration of asymptomatic obstruction (a critical factor for chronic renal injury) was not recorded; and other unmeasured baseline factors (e.g., medication use, lifestyle habits) were not considered. These unaccounted variables may introduce residual confounding and affect the accuracy of the identified predictors. Otherwise, Renal function was evaluated using renal dynamic imaging (e.g., 99mTc-DTPA), but the study did not address the consistency of this detection method across different operators or equipment. Variations in imaging protocols or interpretation standards may lead to measurement bias, potentially affecting the reliability of GFR values and the subsequent analysis of renal function recovery trends. Finally, No long-term follow-up study exceeding one year was performed in the present study, as the GFR of enrolled patients remained essentially stable subsequent to surgery for one year. Nevertheless, we plan to carry out a more prolonged follow-up (e.g., a five-year longitudinal follow-up) in the future to observe the trajectory of patients' renal function recovery.\u003c/p\u003e\u003cp\u003eThe findings underscore three critical clinical recommendations. Active management of asymptomatic stones: Given their association with chronic obstruction and irreversible renal damage, asymptomatic stones, especially those diabetes mellitus, in the upper ureter, or high-grade hydronephrosis, should not be observed passively. Personalized postoperative care: Patients with low recovery potential require close monitoring and targeted interventions. Validation of the nomogram: Multicenter prospective studies are needed to refine the nomogram, particularly in diverse populations and with longer follow-up (\u0026ge;\u0026thinsp;5 years) to assess long-term renal outcomes.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eAsymptomatic ureteral stones are associated with distinct clinical features (larger size, upper ureteral location, severe hydronephrosis) and significantly worse postoperative renal function recovery compared to symptomatic stones, driven by chronic obstruction-induced irreversible injury. Age, DM, Grade IV hydronephrosis, complete obstruction, and low preoperative split renal function are key predictors of poor recovery. The validated nomogram enables accurate prediction of recovery risk, supporting personalized treatment and monitoring strategies. Clinicians should prioritize active intervention for asymptomatic stones and tailor postoperative care to high-risk subgroups to preserve renal function.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u0026nbsp;\u003c/strong\u003eThe authors thank all the study participants and team members for their contributions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003eMingbin Xu: Conceptualization, Methodology, Software, Writing Original draft preparation; Guoliang Wu: Data curation; Daoyuan Li: Visualization, Investigation. Shuming He: Supervision; Chengyang Li: Writing- Reviewing and Editing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eNone.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003eThe data presented in this study are available in the article or the Supplementary material. Deidentified data are available upon reasonable request from the first author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publication\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval and consent to participate\u0026nbsp;\u003c/strong\u003eThis study was approved by the Ethics Committee of The Second Affiliated Hospital of Hainan Medical University, following the Declaration of Helsinki.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eScales CD, Jr., Smith AC, Hanley JM, Saigal CS (2012) Prevalence of kidney stones in the United States. Eur Urol 62 (1):160-165.\u003c/li\u003e\n\u003cli\u003eTaylor EN, Stampfer MJ, Curhan GC (2005) Obesity, weight gain, and the risk of kidney stones. Jama 293 (4):455-462.\u003c/li\u003e\n\u003cli\u003eTeichman JM (2004) Clinical practice. Acute renal colic from ureteral calculus. N Engl J Med 350 (7):684-693.\u003c/li\u003e\n\u003cli\u003eWimpissinger F, T\u0026uuml;rk C, Kheyfets O, Stackl W (2007) The silence of the stones: asymptomatic ureteral calculi. J Urol 178 (4 Pt 1):1341-1344; discussion 1344.\u003c/li\u003e\n\u003cli\u003eMarchini GS, Vicentini FC, Mazzucchi E, Brito A, Ebaid G, Srougi M (2012) Silent ureteral stones: impact on kidney function--can treatment of silent ureteral stones preserve kidney function? Urology 79 (2):304-308.\u003c/li\u003e\n\u003cli\u003eMarchini GS, Vicentini FC, Monga M, Torricelli FC, Danilovic A, Brito AH et al (2016) Irreversible Renal Function Impairment Due to Silent Ureteral Stones. Urology 93:33-39.\u003c/li\u003e\n\u003cli\u003eNoh TI, Pyun JH, Shim JS, Kang SH, Cheon J, Kang SG (2023) A comparison between asymptomatic and symptomatic ureteral stones. Sci Rep 13 (1):2757.\u003c/li\u003e\n\u003cli\u003eKhalaf IM, Shokeir AA, El-Gyoushi FI, Amr HS, Amin MM (2004) Recoverability of renal function after treatment of adult patients with unilateral obstructive uropathy and normal contralateral kidney: a prospective study. Urology 64 (4):664-668.\u003c/li\u003e\n\u003cli\u003eReeves T, Pietropaolo A, Somani BK (2020) Ureteroscopy and Laser Stone Fragmentation Is Safe and Tends to Improve Renal Function in Patients with Chronic Kidney Disease: Prospective Outcomes with a Minimum Follow-Up of 6 Months. J Endourol 34 (4):423-428.\u003c/li\u003e\n\u003cli\u003ePreminger GM, Tiselius HG, Assimos DG, Alken P, Buck C, Gallucci M et al (2007) 2007 guideline for the management of ureteral calculi. J Urol 178 (6):2418-2434.\u003c/li\u003e\n\u003cli\u003eNational Kidney F, Kidney D (2013) KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.\u003c/li\u003e\n\u003cli\u003eKadırhan \u0026Ouml;, Aydın S, Keskin E, Kantarcı M (2025) Role of ureteral wall thickness and computed tomography imaging in predicting spontaneous passage of ureteral stones. Diagn Interv Radiol.\u003c/li\u003e\n\u003cli\u003eTaylor AT (2014) Radionuclides in nephrourology, part 1: Radiopharmaceuticals, quality control, and quantitative indices. J Nucl Med 55 (4):608-615.\u003c/li\u003e\n\u003cli\u003eTanriover B, Fernandez S, Campenot ES, Newhouse JH, Oyfe I, Mohan P et al (2015) Live Donor Renal Anatomic Asymmetry and Posttransplant Renal Function. Transplantation 99 (8):e66-74.\u003c/li\u003e\n\u003cli\u003eSelmi V, Sarı S, Caniklioğlu M, \u0026Ouml;ztekin \u0026Uuml;, Taspinar MS, Işıkay L (2021) Effect of Endoscopic Ureteral Stone Treatment on Kidney Function. Cureus 13 (1):e12883.\u003c/li\u003e\n\u003cli\u003eSiregar S, Mustafa A, Steven S (2024) Can We Predict Renal Function Recovery After Pyeloplasty in Pediatrics with Ureteropelvic Junction Obstruction? A Systematic Review. Urol Res Pract 50 (2):85-93.\u003c/li\u003e\n\u003cli\u003eHan DS, Cher BAY, Lee D, Rajendran S, Riblet NBV, Pais VM, Jr. (2019) The Durability of Active Surveillance in Patients with Asymptomatic Kidney Stones: A Systematic Review. J Endourol 33 (7):598-605.\u003c/li\u003e\n\u003cli\u003eSorensen MD, Harper JD, Borofsky MS, Hameed TA, Smoot KJ, Burke BH et al (2022) Removal of Small, Asymptomatic Kidney Stones and Incidence of Relapse. N Engl J Med 387 (6):506-513.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Predict, renal function, asymptomatic ureteral stones, surgery","lastPublishedDoi":"10.21203/rs.3.rs-7732690/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7732690/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cb\u003ePurpose\u003c/b\u003e This study aimed to comprehensively compare the clinical, radiological, and functional characteristics of asymptomatic and symptomatic ureteral stones, and identify independent predictors of postoperative renal function recovery in patients with ureteral stones.\u003c/p\u003e\u003cp\u003e\u003cb\u003eMethods\u003c/b\u003e A two-center retrospective cohort study was conducted at tertiary hospitals from March 2018 to March 2023. Consecutive patients who underwent ureteroscopic lithotripsy (URSL) for ureteral stones were included, while those with incomplete follow-up data or other exclusion criteria were excluded. Patients were divided into asymptomatic and symptomatic groups. Baseline characteristics, stone parameters, surgical data, and postoperative renal function were collected. Renal function recovery was defined as postoperative glomerular filtration rate(GFR) of the affected kidney exceeding 90% of the contralateral normal kidney\u0026rsquo;s GFR at 1 year. Statistical analyses included t-tests, chi-square tests, Cox regression, and nomogram development with internal validation.\u003c/p\u003e\u003cp\u003e\u003cb\u003eResults\u003c/b\u003e A total of 635 patients with ureteral stones who underwent ureteroscopic lithotripsy (URSL) were enrolled in this study, and divided into two groups based on the presence of stone-related symptoms: the asymptomatic group (n\u0026thinsp;=\u0026thinsp;38, 5.98%) and the symptomatic group (n\u0026thinsp;=\u0026thinsp;597, 94.02%). Regarding baseline characteristics, the asymptomatic group showed significantly higher rates of diabetes mellitus (DM, 40.8% vs. 8.0%), larger stone size (17\u0026thinsp;\u0026plusmn;\u0026thinsp;4 mm vs. 13\u0026thinsp;\u0026plusmn;\u0026thinsp;4 mm), higher proportion of upper ureteral stones (63.8% vs. 17.0%), and higher incidence of Grade IV hydronephrosis (52.0% vs. 21.3%) compared with the symptomatic group (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Preoperatively, the glomerular filtration rate (GFR) of the asymptomatic group (21\u0026thinsp;\u0026plusmn;\u0026thinsp;13 mL/min/1.73m\u0026sup2;) was significantly lower than that of the symptomatic group (36\u0026thinsp;\u0026plusmn;\u0026thinsp;8 mL/min/1.73m\u0026sup2;) (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Postoperatively, the symptomatic group exhibited a significant increase in GFR, while the asymptomatic group showed no significant change in GFR and maintained a persistently lower level. Multivariate Cox regression analysis identified six independent predictors of postoperative renal function recovery (all p\u0026thinsp;\u0026lt;\u0026thinsp;0.05): older age, DM, Grade IV hydronephrosis, and complete intraoperative obstruction were negative predictors, while a higher preoperative GFR ratio (ipsilateral/contralateral normal kidney) and symptomatic status were positive predictors. A nomogram constructed based on these predictors showed good discriminative ability (area under the receiver operating characteristic curve, AUC\u0026thinsp;=\u0026thinsp;0.841) and calibration performance (mean absolute error, MAE\u0026thinsp;=\u0026thinsp;0.02).\u003c/p\u003e\u003cp\u003e\u003cb\u003eConclusion\u003c/b\u003e Asymptomatic ureteral stones exhibit distinct features (larger size, upper ureteral location, severe hydronephrosis) and poorer postoperative renal function recovery than symptomatic stones, mainly due to chronic obstruction-induced irreversible injury. Age, DM, Grade IV hydronephrosis, complete obstruction, and low preoperative split renal function are key predictors of poor recovery. The validated nomogram facilitates accurate recovery risk prediction, supporting personalized treatment and monitoring to preserve renal function.\u003c/p\u003e","manuscriptTitle":"Predictors of postoperative renal function recovery in patients with ureteral stones: asymptomatic Vs symptomatic ureteral stones","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-15 06:41:26","doi":"10.21203/rs.3.rs-7732690/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6c059ccb-b146-4289-ac1b-81c74baf195b","owner":[],"postedDate":"October 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-11-03T15:59:15+00:00","versionOfRecord":{"articleIdentity":"rs-7732690","link":"https://doi.org/10.1007/s11255-025-04854-y","journal":{"identity":"international-urology-and-nephrology","isVorOnly":false,"title":"International Urology and Nephrology"},"publishedOn":"2025-10-29 15:56:52","publishedOnDateReadable":"October 29th, 2025"},"versionCreatedAt":"2025-10-15 06:41:26","video":"","vorDoi":"10.1007/s11255-025-04854-y","vorDoiUrl":"https://doi.org/10.1007/s11255-025-04854-y","workflowStages":[]},"version":"v1","identity":"rs-7732690","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7732690","identity":"rs-7732690","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}