Prediction for spontaneous passage of ureteral stones with renal insufficiency

Prediction for spontaneous passage of ureteral stones with renal insufficiency | 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 Prediction for spontaneous passage of ureteral stones with renal insufficiency MingBin Xu, Jiawen Zhao, Shuming He, Chengyang Li This is a preprint; it has not been peer reviewed by a journal.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-7231132/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract We sought to identify the predictors of spontaneous stone passage (SSP) in patients with ureteral stones, specifically those complicated by renal insufficiency and thus at greater risk for requiring intervention. Retrospective cohort study was performed for patients with ureteric stones and renal insufficiency who received conservative treatment at The Second Affiliated Hospital of Hainan Medical University from May 2015 to May 2025. Data regarding clinical, radiological and inflammatory findings were obtained from medical records. The primary outcome was SSP, defined as spontaneous confirmed or imaged clearance within 4 weeks; failure was intervention or residual stones at 4-weeks. Statistical analyses: logistic regression (univariate/multivariate), receiver operating characteristic(ROC) curve analysis. In 152 of the patients (32.8%), SSP was achieved while it failed in 311patients(67.2%) Patients in both groups had significant differences with respect to serum creatinine, GFR and stone related parameters including stone location, hydronephrosis grade, largest transverse diameter of calculus density (p < 0.05), maximum ureter wall thickness(UWT), dialysis-dependent and daily urine volume alone using the results of univariate analysis that demonstrate a significantly different relationship between patient subgroups as outlined above. Multivariate logistic regression showed that higher GFR (OR = 1.039, 95% CI: 1.013–1.066, p = 0.003), distal ureteral stone location (OR = 1.692, 95% CI: 1.006–2.844, p = 0.047), smaller diameter of the stones' transverse diameter(OR = 0.726, 95% CI: 0.629–0.837, p < 0.001), absence of dialysis therapy before SSP(OR = 0.161, 95% CI: 0.041–0.629, p = 0.009], and higher average daily urine output (OR = 1.002, 95% CI: 1.001–1.002, p < 0.001). The Area under the cure(AUC) of the ROC curve for our predictive model was all good equal to 0.879 (95% CI: 0.846–0.911). This is the first attempt to approach SSP predictors in renal insufficiency patients with a striking systematic analysis. The identified factors and predictive model might facilitate other physicians to decide the optimum approach in terms of conservative management, with early intervention as required, hence avoiding complications and preserving renal function through timely interventions in this high-risk group. spontaneous stone passage(SSP) ureteral stones renal insufficiency Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Ureteral stones are one of the most common urological emergencies worldwide, with an increasing global prevalence that presents considerable clinical and economic implications[ 1 ]. Successful SSP is a clinical metric that has direct implications in reducing downstream invasive interventions such as ureteroscopy and extracorporeal shock wave lithotripsy, which reduces complications of procedural intervention, along with improved healthcare delivery costs[ 2 ]. Nonetheless, SSP prediction remains difficult especially in high-risk subgroups like patients with renal insufficiency. Impaired glomerular filtration and alteration in renal physiology are two of the many issues associated with ureteral stones which is further complicated by other unresolved matters like renal insufficiency. With the potential implications of stone-induced obstruction, urosepsis and enhancing renal failure in this patient configuration accurate prediction of SSP is crucial to establishing a balance between conservative management alone or on-time intervention. However, Previous research on SSP predictors, such as stone size and location, UWT, inflammatory markers [Neutrophil to Lymphocyte ratio(NLR) & C reactive protein(CRP)] mostly excluded patients with renal insufficiency[ 3 , 4 ]. Traditional predictors for SSP have focused on anatomical and radiological features. Size of the stone has been a well-recognized variable; it was found that smaller stones were more likely to pass than larger ones[ 5 ]. Furthermore, nature of stone placement is also important as it has been demonstrated that distal ureteric stones are more prone to spontaneous expulsion than proximal ones[ 6 ]. Radiological markers like UWT that reflect inflammation and obstruction have become strong predictors with thinner UWT being associated higher SSP rate[ 7 ]. In addition, a systemic representation of the response to obstruction via NLR and PLR is provided by inflammatory indices[ 4 ]. Renal insufficiency patients have specific pathophysiological characteristics that could alter the performance of SSP. Reduced renal perfusion and ureteral motility, as well as the presence of comorbidities (diabetes mellitus or hypertension) could delay passage of stones or increase risk for impaction[ 8 ]. On the other hand, markers such as NLR can be otherwise accurate in normotensive and non-azotemic individuals but chronic inflammation associated with renal insufficiency may undermine its utility. However, given these complexities regarding subgroup definition, few studies have specifically examined SSP predictors in this group resulting to uncertainty with respect to clinical decision-making. In the context of this, we sought to address what is an area that has not been performed in detail previously and conduct a study investigating predictors for SSP but uniquely restricted to patients with renal insufficiency. By combining radiological, inflammatory and clinical characteristics that are inspired from the former models aforementioned we endeavor to formulating an individualized risk-stratification model for predicting SSP this high-risk cohort. Such a framework may increase the appropriate use of conservative management, facilitate de-emphasizing inappropriate interventions and reduce renal function attrition in high-risk patients. Materials and methods The study is carried out in The Second Affiliated Hospital of Hainan Medical University for this retrospective cohort research from May 2015 to May 2025. Ethical approval was obtained from the Institutional Ethics Committee of our hospital, and followed by Declaration of Helsinki. Informed consent was waived by ethics committee as the study is retrospective. Ureteral stones and renal insufficiency patients who received conservative treatment were enrolled consecutively. Eligibility criteria:Age ≧ 18 years; Solitary, unilateral ureteral stones confirmed by non-contrast computed tomography (NCCT); Stone size ≦ 10 mm in all directions(most axial or longitudinal diameter measured on imaging). The estimated glomerular filtration rate(GFR) is less than < 60mL/min/1.73mm 2 . Conservative management for this cohort referred to observation with or without medical expulsive therapy, using α-blockers and a follow-up duration of at least 4 weeks. Exclusion criteria are multiple or bilateral ureteral stones, untreated congenital urinary tract anomalies (e.g., ureteral stricture) and solitary kidney/neurogenic bladder with active infection in the urinary system. Clinical, laboratory, and imaging data were extracted from electronic medical records and imaging archives. Inflammatory markers: NLR, measured within 24 hours of admission. Imaging data were reviewed by two experiened radiologists blinded to clinical outcomes. Discrepancies were resolved by consensus. Stone location was categorized as upper (caudal to renal pelvis, cranial to iliac crest), mid (between iliac crest and sacroiliac joint), or lower (caudal to sacroiliac joint) based on anatomical landmarks on imaging. UWT(Fig. 1 ): maximum thickness of the ureteral wall at the stone site (including periureteral edema)[ 9 ]; Kidney parenchymal thickness was defined as the average thickness of the renal parenchyma measured at the upper, middle, and lower poles of the kidney on axial NCCT images[ 7 ](Fig. 2 ). The presence and grading of hydronephrosis in the collecting system, which is secondary to ureteral stones, were assessed using a commonly employed CT grading classification system[ 10 ](Fig. 3 ). The primary outcome was SSP, defined as: Confirmed by patient-reported stone excretion with subsequent negative imaging (US/NCCT) at 4 weeks; or Negative findings on follow-up imaging (US/NCCT) at 4 weeks without intervention. Failure of SSP was defined as: Need for intervention (extracorporeal shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy) within 4 weeks; or Persistent stone on imaging at 4 weeks. Statistical analysis We performed all statistical analyses using IBM SPSS Statistics version 29.0 (IBM Corp, Armonk, NY). Continuous variables were expressed as means ± standard deviations for the normal distribution and medians (interquartile ranges) for non-normally distributed data. The normality of data distribution was tested through Kolmogorov-Smirnov test. Between-group comparisons for normally distributed continuous data were performed using two-tailed unpaired Student's t-tests. Categorical variables uses percentages (and will be tested by chi-square test) for association between categorical non-ordinal with the outcome. The purpose of this study is to use univariate and multivariable binary logistic regression analysis in order to determine the associations with SSP between these variables. We quantified the discriminative performance of the predictors for SSP using ROC curve analysis. Statistical analyses were performed using R version 4.1.0 (R Foundation for Statistical Computing, Vienna, Austria). The 'mice' package was used for multiple imputation, and the 'rms' package was applied for model development, as well as internal and temporal validation, calibration, nomogram construction. A p value < 0.05 was considered statistically significant. Results A total of 463 patients with ureteral stones and renal insufficiency were included in the study, with 152 cases in the SSP group and 311 cases in the failed passage group. There were no significant differences in age, gender, BMI, presence of stone history, diabetes mellitus, hypertension, coronary artery disease, NLR, kidney parenchymal thickness, alpha-blocker usage, laterality, or stone shape between the two groups (all p > 0.05). However, several parameters showed statistically significant differences. In terms of renal function indices, the SSP group had a lower serum creatinine level (357 ± 192 umol/l vs. 531 ± 207 umol/l, p < 0.001) and a higher GFR (40 ± 24 ml/min/1.73m2 vs. 23 ± 17 ml/min/1.73m2, p < 0.001) compared to the failed group. Regarding stone location, a higher proportion of stones in the SSP group were located in the lower ureter, while the failed group had more stones in the upper/middle ureter, with a significant difference (p = 0.003). For hydronephrosis, the SSP group had a higher proportion of Grade 3/4, and the failed group had more Grade 1/2 cases, with p < 0.001. In terms of stone characteristics, the SSP group had a smaller transverse diameter of the stone (4.6 ± 2.1 mm vs. 6.4 ± 2.3 mm, p < 0.001) and lower stone density (539 ± 298 HU vs. 587 ± 205 HU, p < 0.001), while there was no significant difference in the longitudinal diameter of the stone (6.2 ± 2.7 mm vs. 6.6 ± 2.6 mm, p = 0.114). The maximal ureteral wall thickness in the SSP group was thinner than that in the failed group (3.1 ± 1.0 vs. 3.4 ± 1.3, p < 0.001). Additionally, the SSP group had a lower dialysis rate (p < 0.001) and a higher daily urine volume (p < 0.001)(Table 1 ). Multivariate analysis showed that GFR (OR = 1.039, 95% CI: 1.013–1.066, p = 0.003), stone location (OR = 1.692, 95% CI: 1.006–2.844, p = 0.047), transverse diameter of the stone (OR = 0.726, 95% CI: 0.629–0.837, p < 0.001), dialysis (OR = 0.161, 95% CI: 0.041–0.629, p = 0.009), and urine volume (OR = 1.002, 95% CI: 1.001–1.002, p 0.05)(Table 2 ). The ROC curve for predicting spontaneous ureteral stone passage in patients with renal insufficiency had an AUC of 0.879 (95% CI: 0.846–0.911), indicating good predictive performance(Fig. 4 ). Table 1 Patients' characteristics according to spontaneous ureteral stone passage status Parameters SSP Group(n = 152) Failed Group(n = 311) p-value Age (years) 61.1 ± 11.0 61.6 ± 11.6 0.654 Gender 0.307 Male 96(63.2%) 181(58.2%) Female 56(36.8%) 130(41.8%) BMI (kg/m 2 ) 24.2 ± 5.7 24.0 ± 5.9 0.628 Serum creatinine(umol/l) 357 ± 192 531 ± 207 < 0.001 GFR(ml/min/1.73m 2 ) 40 ± 24 23 ± 17 < 0.001 Stone location 0.003 Upper/middle 73(23.5%) 195(62.7%) Lower 79(25.4%) 116(37.3%) Laterality 0.587 Right 72(47.4%) 139(44.7%) Left 80(52.6%) 172(55.3%) Hydronephrosis < 0.001 Grade 1/2 69(45.4%) 204(65.6%) Grade 3/4 83(54.6%) 107(34.4%) Longitudinal diameter of stone (mm) 6.2 ± 2.7 6.6 ± 2.6 0.114 Transverse diameter of stone (mm) 4.6 ± 2.1 6.4 ± 2.3 < 0.001 Stone density (HU) 539 ± 298 587 ± 205 < 0.001 Maximal ureteral Wall thickness 3.1 ± 1.0 3.4 ± 1.3 < 0.001 Presence of stone history 51(33.6%) 112(36.0%) 0.603 Diabetes mellitus 61(40.1%) 136(43.7%) 0.462 Hypertension 87(57.2%) 168(54.0%) 0.513 Coronary artery disease 38(25.0%) 73(23.5%) 0.718 Neutrophil/lymphocyte ratio (NLR) 2.20 ± 0.81 2.21 ± 0.75 0.850 kidney parenchymal thickness(mm) 17 ± 7 18 ± 7 0.184 Alpha-blocker usage 130(85.5%) 254(81.7%) 0.301 Shape 0.315 Oval 97(63.8%) 213(68.5%) irregular 55(36.2%) 98(31.5%) dialysis 3(2.0%) 116(37.3%) < 0.001 urine volume(ml/d) 1210 ± 582 579 ± 463 < 0.001 Table 2 Multivariate analysis of risk factors for spontaneous ureteral stone passage Parameters Multivariate OR (95% CI) p Serum creatinine(umol/l) 1.001(0.998–1.004) 0.343 GFR(ml/min/1.73m 2 ) 1.039(1.013–1.066) 0.003 Stone location 1.692(1.006–2.844) 0.047 Hydronephrosis 1.500(0.897–2.510) 0.122 Transverse diameter of stone (mm) 0.726(0.629–0.837) < 0.001 Stone density (HU) 0.999(0.998−1.000) 0.305 Maximal ureteral Wall thickness 0.924(0.748–1.141) 0.462 dialysis 0.161(0.041–0.629) 0.009 urine volume(ml/d) 1.002(1.001–1.002) < 0.001 A nomogram was developed based upon the model's independent predictors (GFR, transverse stone diameter, location of the stone, dialysis status, and daily urinary volume) to visually predict the probability of SSP (Fig. 5 ). Each predictor contributed points based upon its regression coefficient, and the total number of points corresponded to the predicted probability of SSP. The external validation calibration curve (Fig. 6 ) indicated good agreement between the probabilities predicted by the nomogram and the rates of SSP. This demonstrates the predictions from the model are reliable since the bias-corrected curve had a good fit with the ideal line. Discussion This study sought to determine the predictors of SSP among patients with renal insufficiency, a population where the interplay between impaired renal function and stone dynamics remains underexplored. We can predict SSP by higher GFR, smaller transverse stone diameter, distal ureter location and absence of dialysis or a higher daily urine volume according to our results, with a predictive model demonstrating good discriminatory power (AUC = 0.879). This work builds upon existing knowledge by emphasizing additional nuances in patients with renal insufficiency and further characterizes SSP among this high-risk population. As far as we know, this study is the first worldwide to predict a spontaneous passage of ureteral stones specifically focusing in renal insufficiency patients and undergoes such literature integrate with results. As expected from similar prior studies in whole population groups stone size and location were major determinants of SSP[ 6 ]. It has been known for some time that smaller stones and those located in the distal ureter are more profoundly associated with a greater likelihood of SSP due to decreased mechanical obstruction and shorter transit distance[ 11 ]. Our data supports this with a 1 mm decrease in transverse stone diameter was associated with a 27.4% higher odds of SSP (OR = 0.726), reinforcing the role of stone morphology in determining passage likelihood. Our study extends these observations to patients with renal insufficiency by highlighting the importance of renal function in and for itself. Higher GFR (OR = 1.039) was a strong significant independent predictor, probably due to underlying maintained residual kidney function that provides sufficient urine output and ureteral peristalsis, important forces for stone passage Conversely, dialysis dependence (OR = 0.161) was associated with lower SSP rates potentially due to the fact of fluid restriction, decreased urine output and urodynamic alterations secondary to chronic renal replacement therapy. This reinforces the caveat that estimates of SSP should be adjusted downwards in patients receiving dialysis, due to likely poorer outcomes with conservative management. Daily urine volume was found to be another critical factor (OR = 1.002), confirming the importance of appropriate hydration in favoring stone expulsion. Although oliguria is common due to fluid limitations in renal insufficiency, our data indicates that even modest daily volume increments are associated with an increased likelihood of being discharged on the SSP. It shows that the increase in urine flow may facilitate deploying of stone by ureteral flushing and decreases adhesion of stones to mucosa. Of interest, many of the factors that had previously been associated with SSP in populations without renal insufficiency including UWT, stone density and hydronephrosis grade did not independently predict SSP using our multivariate model. The marker of ureteral inflammation and impaction, UWT may show diminished utility in renal insufficiency due to baseline uremic inflammation, which could mask the relationship between UWT each other or with SSP. Furthermore, the degree of hydronephrosis which is often used as a surrogate for obstruction severity may be less specific in this population due to chronic kidney disease itself causing structural changes that can mimic obstruction. Stone density also did not predict SSP, the opposite of studies reporting larger stone densities are less likely to pass[ 7 ]. So that may account for the discrepancy because renal insufficiency frequently disrupts urine chemistry, thus stone composition and fragility beyond its affect on density. Further research on stone composition among chronic kidney disease patients is warranted to elucidate this relationship. The different pathophysiology of renal insufficiency is presumably a key factor in the modified dynamics observed for SSP. GFR impairment leads to diminished filtration and thereby also lower urine production, reducing the mechanical force necessary for stones to pass. Furthermore, systemic inflammation associated with chronic kidney disease may increase ureteral edema and worsen passage[ 12 ]. However, our data indicate that even modest preservation of GFR is protective against these manifestations and highlights the critical role of residual renal function in ureteral physiology. This is in line with the anatomical advantage of 69.2% higher odds for SSP seen distally as was the case regarding ureteral stones[ 7 ]. The prognostic significance of distal location is increasingly important in renal insufficiency, where proximal ureteral motility may be further impaired by concurrent uremic myopathy. This predictive model may provide a convenient guide to clinicians handling renal insufficiency patients with ureteral stones. By incorporating GFR, stone size and location; dialysis status; and urinary volume, clinicians can categorize patients into low, or high-risk groups for SSP. Low risk patients can still be managed conservatively with follow up. Early intervention to prevent the development of obstructive uropathy and progressive renal insufficiency should be considered in patients who would otherwise have been labeled as high-risk. Notably, the model’s high AUC (0.879) supports its clinical utility, outperforming simpler metrics and enabling personalized decision-making. This study has several limitations. Selection bias, especially including patients that had complete follow-up data, as well as the retrospective design are limitations of our study. The single-center nature of the report restricts generalizability and requires multicenter validation. Finally, stone composition, a possible modifier of SSP was not analyzed because the data on this point were largely missing. Further validation of our data and additional potential predictors to increase SSP predictive accuracy in renal insufficiency, including urinary markers or ureteral jet frequency[ 13 ], among others will likely require prospective studies. Prospective long-term studies are also warranted to explore whether successful SSP maintains renal function – a crucial end-point for this cohort. Conclusion In conclusion, our study identifies key predictors of SSP in patients with renal insufficiency, highlighting the interplay between renal function, stone characteristics, and lifestyle factors. The proposed model facilitates risk stratification, supporting personalized management to balance conservative observation and timely intervention, ultimately improving outcomes in this vulnerable population. Abbreviations SSP spontaneous stone passage ROC receiver operating characteristic AUC Area under the cure UWT maximum ureter wall thickness NLR Neutrophil to Lymphocyte ratio CRP C reactive protein NCCT non-contrast computed tomography GFR glomerular filtration rate Declarations Acknowledgements The authors have nothing to report. Author contributions Mingbin Xu conceived and designed the study. Jiawen Zhao, Shuming He and Chengyang Li performed the data collection and analyzed the data. All authors reviewed and revised the article. Funding N/A. Data availability No datasets were generated or analysed during the current study. Competing interests The authors declare no competing interests. References Hyams ES, Matlaga BR (2014) Economic impact of urinary stones [J]. Transl Androl Urol 3(3):278–283 Falagario UG, Calò B, Auciello M et al (2021) Advanced ureteroscopic techniques for the management of kidney stones [J]. Curr Opin Urol 31(1):58–65 Mohammadinejad P, Ferrero A, Bartlett DJ et al (2021) Automated radiomic analysis of CT images to predict likelihood of spontaneous passage of symptomatic renal stones [J]. Emerg Radiol 28(4):781–788 Aghaways I, Ibrahim R, Bapir R et al (2022) The role of inflammatory serum markers and ureteral wall thickness on spontaneous passage of ureteral stone < 10 mm: A prospective cohort study [J]. Ann Med Surg (Lond) 80:104198 Bulbul E, Ilki FY, Sezer A et al (2025) Evaluation of the patient and stone related parameters on the likelihood of spontaneous ureteral stone passage: A critical evaluation focusing on the urinary tract infection without pyuria due to luminal obstruction [J]. Urol Int: 1–12 Khan RU, Nazim SM, Anwar S (2024) CT-Based Predictors of Spontaneous Ureteral Stone Passage [J]. J Coll Physicians Surg Pak 34(8):879–884 Coşkun A, Can U (2022) Is it possible to predict spontaneous passage of a ureteral stone? An up-to-date comment on the current problem with new concepts concerning the patient and the stone [J]. Cent Eur J Urol 75(3):305–310 Selvi I, Baydilli N, Tokmak TT et al (2021) CT-related parameters and Framingham score as predictors of spontaneous passage of ureteral stones ≤ 10 mm: results from a prospective, observational, multicenter study [J]. Urolithiasis 49(3):227–237 Yoshida T, Inoue T, Taguchi M et al (2019) Ureteral wall thickness as a significant factor in predicting spontaneous passage of ureteral stones of ≤ 10 mm: a preliminary report [J]. World J Urol 37(5):913–919 Kadırhan Ö, Aydın S, Keskin E et al (2025) Role of ureteral wall thickness and computed tomography imaging in predicting spontaneous passage of ureteral stones [J]. Diagn Interv Radiol Heiniger Y, Foerster B, Bodmer NS et al (2025) Prediction for spontaneous passage of ureteral stones with indwelling ureteral stent: PASS score [J]. World J Urol 43(1):259 Hasan A, Kumar V, Kant Kumar S et al (2024) Radiological and Hematological Parameters Predicting Success of Medical Expulsive Therapy in Patients With Ureteral Calculus [J]. Cureus 16(8):e67356 Wang C, Di M, Qin J et al (2024) Applying urinary ultrasound to predict the risk of spontaneous ureteral stone passage: a retrospective cohort study [J]. BMC Urol 24(1):171 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 14 Aug, 2025 Reviews received at journal 14 Aug, 2025 Reviews received at journal 01 Aug, 2025 Reviewers agreed at journal 01 Aug, 2025 Reviewers agreed at journal 31 Jul, 2025 Reviewers invited by journal 29 Jul, 2025 Editor assigned by journal 28 Jul, 2025 Submission checks completed at journal 28 Jul, 2025 First submitted to journal 28 Jul, 2025 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. 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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-7231132","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":493354117,"identity":"b6014fc8-a9b6-4f0a-98dd-92b56e00dff3","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":493354119,"identity":"1f221427-1f65-455f-824b-5a9f7621b72d","order_by":1,"name":"Jiawen Zhao","email":"","orcid":"","institution":"The First Affiliated Hospital of Guangxi Medical University","correspondingAuthor":false,"prefix":"","firstName":"Jiawen","middleName":"","lastName":"Zhao","suffix":""},{"id":493354120,"identity":"57daef4a-2744-4df1-995c-ddbbaf470522","order_by":2,"name":"Shuming He","email":"","orcid":"","institution":"The Second Affiliated Hospital of Hainan Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shuming","middleName":"","lastName":"He","suffix":""},{"id":493354121,"identity":"104bd0de-adba-4546-8cc4-2f1dd28c1ce6","order_by":3,"name":"Chengyang Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsklEQVRIiWNgGAWjYHACNhAhx8befoA0LcZ8PGcSSNOSOE/CwYA49fz9x589+FBxJ71NgiGB4UfFNsJaJG7kmBvOOPMst0268QBjz5nbRFhzg4dNmrftcG6bzIEEZsY2IrTInz/+TPrvv8PpbBIJBsRpMTiQYCbN2HA4gXgthjdyzCR7jj0zbAMG8kGi/CIHdJjEj5o78vLt7Qcf/KggxvsQcACJJEnLKBgFo2AUjAKsAAAOpj6eCUs//gAAAABJRU5ErkJggg==","orcid":"","institution":"The First Affiliated Hospital of Guangxi Medical University","correspondingAuthor":true,"prefix":"","firstName":"Chengyang","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2025-07-28 07:53:24","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7231132/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7231132/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":88097302,"identity":"40949e1d-74a3-434a-954a-7f54001b8869","added_by":"auto","created_at":"2025-08-01 11:03:48","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":261697,"visible":true,"origin":"","legend":"\u003cp\u003eVisual representation of the methodology employed to measure the UWT around the stone's circumference.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/9e1fdb4feefddd93c9fd5daf.jpeg"},{"id":88100020,"identity":"468da58b-631d-431e-9a29-9391ee0a938d","added_by":"auto","created_at":"2025-08-01 11:19:48","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":130964,"visible":true,"origin":"","legend":"\u003cp\u003eSagittal non-contrast CT scan: parenchymal thickness (mm) was measured using the freehand ROI option at the three thickest levels at the upper, middle, and lower poles of the kidney. The mean values of these measurements were calculated.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/297ffac43c4183f43c9a1068.png"},{"id":88097303,"identity":"1ef74089-3615-4252-84e5-d0044fd328f4","added_by":"auto","created_at":"2025-08-01 11:03:48","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":278505,"visible":true,"origin":"","legend":"\u003cp\u003eHydronephrosis grading system.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/3e57e5307dd40356ab82abf0.png"},{"id":88100022,"identity":"6b422a44-0dd3-4618-81c3-c1f2ea874c01","added_by":"auto","created_at":"2025-08-01 11:19:49","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":10930,"visible":true,"origin":"","legend":"\u003cp\u003eROC curves for predicting spontaneous ureteral stone passage in patients with renal insufficiency.(AUC=0.879 95%CI:0.846-0.911)\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/3f7518299f27bb6bade3984a.png"},{"id":88097308,"identity":"7019aeba-957a-484d-ae06-f3966becf16f","added_by":"auto","created_at":"2025-08-01 11:03:49","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":485801,"visible":true,"origin":"","legend":"\u003cp\u003eNomogram of patient's individual probability of spontaneous stone passage.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/a64a3291b3ff265b604609b0.png"},{"id":88097314,"identity":"9123720d-a022-4e36-99b7-856477ce6abe","added_by":"auto","created_at":"2025-08-01 11:03:49","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":501772,"visible":true,"origin":"","legend":"\u003cp\u003eExternal validation calibration plot.\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/ec990f3bf24ed25cf4bb6f9b.png"},{"id":88101222,"identity":"82d47718-b3ff-4bdf-9a5a-3849b07c1e3f","added_by":"auto","created_at":"2025-08-01 11:27:49","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2373482,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7231132/v1/55fc1e54-efb2-49ef-9c1d-25aba41c563a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Prediction for spontaneous passage of ureteral stones with renal insufficiency","fulltext":[{"header":"Introduction","content":"\u003cp\u003eUreteral stones are one of the most common urological emergencies worldwide, with an increasing global prevalence that presents considerable clinical and economic implications[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Successful SSP is a clinical metric that has direct implications in reducing downstream invasive interventions such as ureteroscopy and extracorporeal shock wave lithotripsy, which reduces complications of procedural intervention, along with improved healthcare delivery costs[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Nonetheless, SSP prediction remains difficult especially in high-risk subgroups like patients with renal insufficiency.\u003c/p\u003e\u003cp\u003eImpaired glomerular filtration and alteration in renal physiology are two of the many issues associated with ureteral stones which is further complicated by other unresolved matters like renal insufficiency. With the potential implications of stone-induced obstruction, urosepsis and enhancing renal failure in this patient configuration accurate prediction of SSP is crucial to establishing a balance between conservative management alone or on-time intervention. However, Previous research on SSP predictors, such as stone size and location, UWT, inflammatory markers [Neutrophil to Lymphocyte ratio(NLR) \u0026amp; C reactive protein(CRP)] mostly excluded patients with renal insufficiency[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eTraditional predictors for SSP have focused on anatomical and radiological features. Size of the stone has been a well-recognized variable; it was found that smaller stones were more likely to pass than larger ones[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Furthermore, nature of stone placement is also important as it has been demonstrated that distal ureteric stones are more prone to spontaneous expulsion than proximal ones[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Radiological markers like UWT that reflect inflammation and obstruction have become strong predictors with thinner UWT being associated higher SSP rate[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In addition, a systemic representation of the response to obstruction via NLR and PLR is provided by inflammatory indices[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eRenal insufficiency patients have specific pathophysiological characteristics that could alter the performance of SSP. Reduced renal perfusion and ureteral motility, as well as the presence of comorbidities (diabetes mellitus or hypertension) could delay passage of stones or increase risk for impaction[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. On the other hand, markers such as NLR can be otherwise accurate in normotensive and non-azotemic individuals but chronic inflammation associated with renal insufficiency may undermine its utility. However, given these complexities regarding subgroup definition, few studies have specifically examined SSP predictors in this group resulting to uncertainty with respect to clinical decision-making.\u003c/p\u003e\u003cp\u003eIn the context of this, we sought to address what is an area that has not been performed in detail previously and conduct a study investigating predictors for SSP but uniquely restricted to patients with renal insufficiency. By combining radiological, inflammatory and clinical characteristics that are inspired from the former models aforementioned we endeavor to formulating an individualized risk-stratification model for predicting SSP this high-risk cohort. Such a framework may increase the appropriate use of conservative management, facilitate de-emphasizing inappropriate interventions and reduce renal function attrition in high-risk patients.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003eThe study is carried out in The Second Affiliated Hospital of Hainan Medical University for this retrospective cohort research from May 2015 to May 2025. Ethical approval was obtained from the Institutional Ethics Committee of our hospital, and followed by Declaration of Helsinki. Informed consent was waived by ethics committee as the study is retrospective. Ureteral stones and renal insufficiency patients who received conservative treatment were enrolled consecutively. Eligibility criteria:Age\u0026thinsp;≧\u0026thinsp;18 years; Solitary, unilateral ureteral stones confirmed by non-contrast computed tomography (NCCT); Stone size\u0026thinsp;≦\u0026thinsp;10 mm in all directions(most axial or longitudinal diameter measured on imaging). The estimated glomerular filtration rate(GFR) is less than \u0026lt;\u0026thinsp;60mL/min/1.73mm\u003csup\u003e2\u003c/sup\u003e. Conservative management for this cohort referred to observation with or without medical expulsive therapy, using α-blockers and a follow-up duration of at least 4 weeks. Exclusion criteria are multiple or bilateral ureteral stones, untreated congenital urinary tract anomalies (e.g., ureteral stricture) and solitary kidney/neurogenic bladder with active infection in the urinary system.\u003c/p\u003e\u003cp\u003eClinical, laboratory, and imaging data were extracted from electronic medical records and imaging archives. Inflammatory markers: NLR, measured within 24 hours of admission. Imaging data were reviewed by two experiened radiologists blinded to clinical outcomes. Discrepancies were resolved by consensus. Stone location was categorized as upper (caudal to renal pelvis, cranial to iliac crest), mid (between iliac crest and sacroiliac joint), or lower (caudal to sacroiliac joint) based on anatomical landmarks on imaging. UWT(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e): maximum thickness of the ureteral wall at the stone site (including periureteral edema)[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]; Kidney parenchymal thickness was defined as the average thickness of the renal parenchyma measured at the upper, middle, and lower poles of the kidney on axial NCCT images[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e](Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The presence and grading of hydronephrosis in the collecting system, which is secondary to ureteral stones, were assessed using a commonly employed CT grading classification system[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e](Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The primary outcome was SSP, defined as: Confirmed by patient-reported stone excretion with subsequent negative imaging (US/NCCT) at 4 weeks; or\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eNegative findings on follow-up imaging (US/NCCT) at 4 weeks without intervention. Failure of SSP was defined as: Need for intervention (extracorporeal shock wave lithotripsy, ureteroscopy, or percutaneous nephrolithotomy) within 4 weeks; or Persistent stone on imaging at 4 weeks.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eWe performed all statistical analyses using IBM SPSS Statistics version 29.0 (IBM Corp, Armonk, NY). Continuous variables were expressed as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations for the normal distribution and medians (interquartile ranges) for non-normally distributed data. The normality of data distribution was tested through Kolmogorov-Smirnov test. Between-group comparisons for normally distributed continuous data were performed using two-tailed unpaired Student's t-tests. Categorical variables uses percentages (and will be tested by chi-square test) for association between categorical non-ordinal with the outcome. The purpose of this study is to use univariate and multivariable binary logistic regression analysis in order to determine the associations with SSP between these variables. We quantified the discriminative performance of the predictors for SSP using ROC curve analysis. Statistical analyses were performed using R version 4.1.0 (R Foundation for Statistical Computing, Vienna, Austria). The 'mice' package was used for multiple imputation, and the 'rms' package was applied for model development, as well as internal and temporal validation, calibration, nomogram construction. A p value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 463 patients with ureteral stones and renal insufficiency were included in the study, with 152 cases in the SSP group and 311 cases in the failed passage group. There were no significant differences in age, gender, BMI, presence of stone history, diabetes mellitus, hypertension, coronary artery disease, NLR, kidney parenchymal thickness, alpha-blocker usage, laterality, or stone shape between the two groups (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). However, several parameters showed statistically significant differences. In terms of renal function indices, the SSP group had a lower serum creatinine level (357\u0026thinsp;\u0026plusmn;\u0026thinsp;192 umol/l vs. 531\u0026thinsp;\u0026plusmn;\u0026thinsp;207 umol/l, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and a higher GFR (40\u0026thinsp;\u0026plusmn;\u0026thinsp;24 ml/min/1.73m2 vs. 23\u0026thinsp;\u0026plusmn;\u0026thinsp;17 ml/min/1.73m2, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) compared to the failed group. Regarding stone location, a higher proportion of stones in the SSP group were located in the lower ureter, while the failed group had more stones in the upper/middle ureter, with a significant difference (p\u0026thinsp;=\u0026thinsp;0.003). For hydronephrosis, the SSP group had a higher proportion of Grade 3/4, and the failed group had more Grade 1/2 cases, with p\u0026thinsp;\u0026lt;\u0026thinsp;0.001. In terms of stone characteristics, the SSP group had a smaller transverse diameter of the stone (4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1 mm vs. 6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3 mm, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and lower stone density (539\u0026thinsp;\u0026plusmn;\u0026thinsp;298 HU vs. 587\u0026thinsp;\u0026plusmn;\u0026thinsp;205 HU, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), while there was no significant difference in the longitudinal diameter of the stone (6.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7 mm vs. 6.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6 mm, p\u0026thinsp;=\u0026thinsp;0.114). The maximal ureteral wall thickness in the SSP group was thinner than that in the failed group (3.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0 vs. 3.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Additionally, the SSP group had a lower dialysis rate (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and a higher daily urine volume (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001)(Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Multivariate analysis showed that GFR (OR\u0026thinsp;=\u0026thinsp;1.039, 95% CI: 1.013\u0026ndash;1.066, p\u0026thinsp;=\u0026thinsp;0.003), stone location (OR\u0026thinsp;=\u0026thinsp;1.692, 95% CI: 1.006\u0026ndash;2.844, p\u0026thinsp;=\u0026thinsp;0.047), transverse diameter of the stone (OR\u0026thinsp;=\u0026thinsp;0.726, 95% CI: 0.629\u0026ndash;0.837, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), dialysis (OR\u0026thinsp;=\u0026thinsp;0.161, 95% CI: 0.041\u0026ndash;0.629, p\u0026thinsp;=\u0026thinsp;0.009), and urine volume (OR\u0026thinsp;=\u0026thinsp;1.002, 95% CI: 1.001\u0026ndash;1.002, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) were independent factors associated with spontaneous ureteral stone passage, while serum creatinine, hydronephrosis, stone density, and maximal ureteral wall thickness were not (all p\u0026thinsp;\u0026gt;\u0026thinsp;0.05)(Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The ROC curve for predicting spontaneous ureteral stone passage in patients with renal insufficiency had an AUC of 0.879 (95% CI: 0.846\u0026ndash;0.911), indicating good predictive performance(Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\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 Patients' characteristics according to spontaneous ureteral stone passage status\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=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSSP Group(n\u0026thinsp;=\u0026thinsp;152)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eFailed Group(n\u0026thinsp;=\u0026thinsp;311)\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\u003eAge (years)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e61.1\u0026thinsp;\u0026plusmn;\u0026thinsp;11.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e61.6\u0026thinsp;\u0026plusmn;\u0026thinsp;11.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.654\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender\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=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.307\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\u003e96(63.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e181(58.2%)\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\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56(36.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e130(41.8%)\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\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e24.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24.0\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.628\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eSerum creatinine(umol/l)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e357\u0026thinsp;\u0026plusmn;\u0026thinsp;192\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e531\u0026thinsp;\u0026plusmn;\u0026thinsp;207\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" 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\u003e\u003cb\u003eGFR(ml/min/1.73m\u003c/b\u003e\u003csup\u003e\u003cb\u003e2\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40\u0026thinsp;\u0026plusmn;\u0026thinsp;24\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23\u0026thinsp;\u0026plusmn;\u0026thinsp;17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" 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\u003e\u003cb\u003eStone location\u003c/b\u003e\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=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUpper/middle\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e73(23.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e195(62.7%)\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\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e79(25.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e116(37.3%)\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\u003eLaterality\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=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.587\u003c/p\u003e\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\u003e72(47.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e139(44.7%)\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\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e80(52.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e172(55.3%)\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\u003e\u003cb\u003eHydronephrosis\u003c/b\u003e\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=\"char\" char=\".\" 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\u003eGrade 1/2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e69(45.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e204(65.6%)\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\u003eGrade 3/4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e83(54.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e107(34.4%)\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\u003eLongitudinal diameter of stone (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6.2\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.114\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTransverse diameter of stone (mm)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" 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\u003e\u003cb\u003eStone density (HU)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e539\u0026thinsp;\u0026plusmn;\u0026thinsp;298\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e587\u0026thinsp;\u0026plusmn;\u0026thinsp;205\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" 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\u003e\u003cb\u003eMaximal ureteral Wall thickness\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" 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\u003ePresence of stone history\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e51(33.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e112(36.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.603\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\u003e61(40.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e136(43.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.462\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\u003e87(57.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e168(54.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.513\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCoronary artery disease\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e38(25.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e73(23.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.718\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNeutrophil/lymphocyte ratio (NLR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.850\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ekidney parenchymal thickness(mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e17\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.184\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAlpha-blocker usage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e130(85.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e254(81.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.301\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eShape\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=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.315\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOval\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e97(63.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e213(68.5%)\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\u003eirregular\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e55(36.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e98(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\u003e\u003cb\u003edialysis\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3(2.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e116(37.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" 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\u003e\u003cb\u003eurine volume(ml/d)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1210\u0026thinsp;\u0026plusmn;\u0026thinsp;582\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e579\u0026thinsp;\u0026plusmn;\u0026thinsp;463\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\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\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\u003eMultivariate analysis of risk factors for spontaneous ureteral stone passage\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eMultivariate\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOR (95% CI)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ep\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSerum creatinine(umol/l)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.001(0.998\u0026ndash;1.004)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.343\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eGFR(ml/min/1.73m\u003c/b\u003e\u003csup\u003e\u003cb\u003e2\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.039(1.013\u0026ndash;1.066)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eStone location\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.692(1.006\u0026ndash;2.844)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.047\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydronephrosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.500(0.897\u0026ndash;2.510)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.122\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTransverse diameter of stone (mm)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.726(0.629\u0026ndash;0.837)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\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\u003eStone density (HU)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.999(0.998\u0026minus;1.000)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.305\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximal ureteral Wall thickness\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.924(0.748\u0026ndash;1.141)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.462\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003edialysis\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.161(0.041\u0026ndash;0.629)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.009\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eurine volume(ml/d)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.002(1.001\u0026ndash;1.002)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\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\u003e\u003c/p\u003e\u003cp\u003eA nomogram was developed based upon the model's independent predictors (GFR, transverse stone diameter, location of the stone, dialysis status, and daily urinary volume) to visually predict the probability of SSP (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Each predictor contributed points based upon its regression coefficient, and the total number of points corresponded to the predicted probability of SSP. The external validation calibration curve (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e) indicated good agreement between the probabilities predicted by the nomogram and the rates of SSP. This demonstrates the predictions from the model are reliable since the bias-corrected curve had a good fit with the ideal line.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study sought to determine the predictors of SSP among patients with renal insufficiency, a population where the interplay between impaired renal function and stone dynamics remains underexplored. We can predict SSP by higher GFR, smaller transverse stone diameter, distal ureter location and absence of dialysis or a higher daily urine volume according to our results, with a predictive model demonstrating good discriminatory power (AUC\u0026thinsp;=\u0026thinsp;0.879). This work builds upon existing knowledge by emphasizing additional nuances in patients with renal insufficiency and further characterizes SSP among this high-risk population. \u003cb\u003eAs far as we know, this study is the first worldwide to predict a spontaneous passage of ureteral stones specifically focusing in renal insufficiency patients and undergoes such literature integrate with results.\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAs expected from similar prior studies in whole population groups stone size and location were major determinants of SSP[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. It has been known for some time that smaller stones and those located in the distal ureter are more profoundly associated with a greater likelihood of SSP due to decreased mechanical obstruction and shorter transit distance[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Our data supports this with a 1 mm decrease in transverse stone diameter was associated with a 27.4% higher odds of SSP (OR\u0026thinsp;=\u0026thinsp;0.726), reinforcing the role of stone morphology in determining passage likelihood.\u003c/p\u003e\u003cp\u003eOur study extends these observations to patients with renal insufficiency by highlighting the importance of renal function in and for itself. Higher GFR (OR\u0026thinsp;=\u0026thinsp;1.039) was a strong significant independent predictor, probably due to underlying maintained residual kidney function that provides sufficient urine output and ureteral peristalsis, important forces for stone passage Conversely, dialysis dependence (OR\u0026thinsp;=\u0026thinsp;0.161) was associated with lower SSP rates potentially due to the fact of fluid restriction, decreased urine output and urodynamic alterations secondary to chronic renal replacement therapy. This reinforces the caveat that estimates of SSP should be adjusted downwards in patients receiving dialysis, due to likely poorer outcomes with conservative management.\u003c/p\u003e\u003cp\u003eDaily urine volume was found to be another critical factor (OR\u0026thinsp;=\u0026thinsp;1.002), confirming the importance of appropriate hydration in favoring stone expulsion. Although oliguria is common due to fluid limitations in renal insufficiency, our data indicates that even modest daily volume increments are associated with an increased likelihood of being discharged on the SSP. It shows that the increase in urine flow may facilitate deploying of stone by ureteral flushing and decreases adhesion of stones to mucosa.\u003c/p\u003e\u003cp\u003eOf interest, many of the factors that had previously been associated with SSP in populations without renal insufficiency including UWT, stone density and hydronephrosis grade did not independently predict SSP using our multivariate model. The marker of ureteral inflammation and impaction, UWT may show diminished utility in renal insufficiency due to baseline uremic inflammation, which could mask the relationship between UWT each other or with SSP. Furthermore, the degree of hydronephrosis which is often used as a surrogate for obstruction severity may be less specific in this population due to chronic kidney disease itself causing structural changes that can mimic obstruction. Stone density also did not predict SSP, the opposite of studies reporting larger stone densities are less likely to pass[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. So that may account for the discrepancy because renal insufficiency frequently disrupts urine chemistry, thus stone composition and fragility beyond its affect on density. Further research on stone composition among chronic kidney disease patients is warranted to elucidate this relationship.\u003c/p\u003e\u003cp\u003eThe different pathophysiology of renal insufficiency is presumably a key factor in the modified dynamics observed for SSP. GFR impairment leads to diminished filtration and thereby also lower urine production, reducing the mechanical force necessary for stones to pass. Furthermore, systemic inflammation associated with chronic kidney disease may increase ureteral edema and worsen passage[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However, our data indicate that even modest preservation of GFR is protective against these manifestations and highlights the critical role of residual renal function in ureteral physiology. This is in line with the anatomical advantage of 69.2% higher odds for SSP seen distally as was the case regarding ureteral stones[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. The prognostic significance of distal location is increasingly important in renal insufficiency, where proximal ureteral motility may be further impaired by concurrent uremic myopathy.\u003c/p\u003e\u003cp\u003eThis predictive model may provide a convenient guide to clinicians handling renal insufficiency patients with ureteral stones. By incorporating GFR, stone size and location; dialysis status; and urinary volume, clinicians can categorize patients into low, or high-risk groups for SSP. Low risk patients can still be managed conservatively with follow up. Early intervention to prevent the development of obstructive uropathy and progressive renal insufficiency should be considered in patients who would otherwise have been labeled as high-risk. Notably, the model\u0026rsquo;s high AUC (0.879) supports its clinical utility, outperforming simpler metrics and enabling personalized decision-making.\u003c/p\u003e\u003cp\u003eThis study has several limitations. Selection bias, especially including patients that had complete follow-up data, as well as the retrospective design are limitations of our study. The single-center nature of the report restricts generalizability and requires multicenter validation. Finally, stone composition, a possible modifier of SSP was not analyzed because the data on this point were largely missing.\u003c/p\u003e\u003cp\u003eFurther validation of our data and additional potential predictors to increase SSP predictive accuracy in renal insufficiency, including urinary markers or ureteral jet frequency[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], among others will likely require prospective studies. Prospective long-term studies are also warranted to explore whether successful SSP maintains renal function \u0026ndash; a crucial end-point for this cohort.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, our study identifies key predictors of SSP in patients with renal insufficiency, highlighting the interplay between renal function, stone characteristics, and lifestyle factors. The proposed model facilitates risk stratification, supporting personalized management to balance conservative observation and timely intervention, ultimately improving outcomes in this vulnerable population.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eSSP \u0026nbsp; \u0026nbsp;spontaneous stone passage\u003c/p\u003e\n\u003cp\u003eROC \u0026nbsp; receiver operating characteristic\u003c/p\u003e\n\u003cp\u003eAUC \u0026nbsp; Area under the cure\u003c/p\u003e\n\u003cp\u003eUWT \u0026nbsp; maximum ureter wall thickness\u003c/p\u003e\n\u003cp\u003eNLR \u0026nbsp; \u0026nbsp;Neutrophil to Lymphocyte ratio\u003c/p\u003e\n\u003cp\u003eCRP \u0026nbsp; \u0026nbsp;C reactive protein\u003c/p\u003e\n\u003cp\u003eNCCT \u0026nbsp;non-contrast computed tomography\u003c/p\u003e\n\u003cp\u003eGFR \u0026nbsp; glomerular filtration rate\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e The authors have nothing to report.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u0026nbsp; Mingbin Xu conceived and designed the study. Jiawen Zhao, Shuming He and Chengyang Li performed the data collection and analyzed the data. All authors reviewed and revised the article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e N/A.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e No datasets were generated or analysed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e The authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHyams ES, Matlaga BR (2014) Economic impact of urinary stones [J]. Transl Androl Urol 3(3):278\u0026ndash;283\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFalagario UG, Cal\u0026ograve; B, Auciello M et al (2021) Advanced ureteroscopic techniques for the management of kidney stones [J]. Curr Opin Urol 31(1):58\u0026ndash;65\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMohammadinejad P, Ferrero A, Bartlett DJ et al (2021) Automated radiomic analysis of CT images to predict likelihood of spontaneous passage of symptomatic renal stones [J]. Emerg Radiol 28(4):781\u0026ndash;788\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAghaways I, Ibrahim R, Bapir R et al (2022) The role of inflammatory serum markers and ureteral wall thickness on spontaneous passage of ureteral stone\u0026thinsp;\u0026lt;\u0026thinsp;10 mm: A prospective cohort study [J]. Ann Med Surg (Lond) 80:104198\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBulbul E, Ilki FY, Sezer A et al (2025) Evaluation of the patient and stone related parameters on the likelihood of spontaneous ureteral stone passage: A critical evaluation focusing on the urinary tract infection without pyuria due to luminal obstruction [J]. Urol Int: 1\u0026ndash;12\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKhan RU, Nazim SM, Anwar S (2024) CT-Based Predictors of Spontaneous Ureteral Stone Passage [J]. J Coll Physicians Surg Pak 34(8):879\u0026ndash;884\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCoşkun A, Can U (2022) Is it possible to predict spontaneous passage of a ureteral stone? An up-to-date comment on the current problem with new concepts concerning the patient and the stone [J]. Cent Eur J Urol 75(3):305\u0026ndash;310\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSelvi I, Baydilli N, Tokmak TT et al (2021) CT-related parameters and Framingham score as predictors of spontaneous passage of ureteral stones\u0026thinsp;\u0026le;\u0026thinsp;10 mm: results from a prospective, observational, multicenter study [J]. Urolithiasis 49(3):227\u0026ndash;237\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYoshida T, Inoue T, Taguchi M et al (2019) Ureteral wall thickness as a significant factor in predicting spontaneous passage of ureteral stones of \u0026le;\u0026thinsp;10 mm: a preliminary report [J]. World J Urol 37(5):913\u0026ndash;919\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKadırhan \u0026Ouml;, Aydın S, Keskin E et al (2025) Role of ureteral wall thickness and computed tomography imaging in predicting spontaneous passage of ureteral stones [J]. Diagn Interv Radiol\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeiniger Y, Foerster B, Bodmer NS et al (2025) Prediction for spontaneous passage of ureteral stones with indwelling ureteral stent: PASS score [J]. World J Urol 43(1):259\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHasan A, Kumar V, Kant Kumar S et al (2024) Radiological and Hematological Parameters Predicting Success of Medical Expulsive Therapy in Patients With Ureteral Calculus [J]. Cureus 16(8):e67356\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang C, Di M, Qin J et al (2024) Applying urinary ultrasound to predict the risk of spontaneous ureteral stone passage: a retrospective cohort study [J]. BMC Urol 24(1):171\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"urolithiasis","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ures","sideBox":"Learn more about [Urolithiasis](http://link.springer.com/journal/240)","snPcode":"240","submissionUrl":"https://submission.nature.com/new-submission/240/3","title":"Urolithiasis","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"spontaneous stone passage(SSP), ureteral stones, renal insufficiency","lastPublishedDoi":"10.21203/rs.3.rs-7231132/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7231132/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWe sought to identify the predictors of spontaneous stone passage (SSP) in patients with ureteral stones, specifically those complicated by renal insufficiency and thus at greater risk for requiring intervention. Retrospective cohort study was performed for patients with ureteric stones and renal insufficiency who received conservative treatment at The Second Affiliated Hospital of Hainan Medical University from May 2015 to May 2025. Data regarding clinical, radiological and inflammatory findings were obtained from medical records. The primary outcome was SSP, defined as spontaneous confirmed or imaged clearance within 4 weeks; failure was intervention or residual stones at 4-weeks. Statistical analyses: logistic regression (univariate/multivariate), receiver operating characteristic(ROC) curve analysis. In 152 of the patients (32.8%), SSP was achieved while it failed in 311patients(67.2%) Patients in both groups had significant differences with respect to serum creatinine, GFR and stone related parameters including stone location, hydronephrosis grade, largest transverse diameter of calculus density (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05), maximum ureter wall thickness(UWT), dialysis-dependent and daily urine volume alone using the results of univariate analysis that demonstrate a significantly different relationship between patient subgroups as outlined above. Multivariate logistic regression showed that higher GFR (OR\u0026thinsp;=\u0026thinsp;1.039, 95% CI: 1.013\u0026ndash;1.066, p\u0026thinsp;=\u0026thinsp;0.003), distal ureteral stone location (OR\u0026thinsp;=\u0026thinsp;1.692, 95% CI: 1.006\u0026ndash;2.844, p\u0026thinsp;=\u0026thinsp;0.047), smaller diameter of the stones' transverse diameter(OR\u0026thinsp;=\u0026thinsp;0.726, 95% CI: 0.629\u0026ndash;0.837, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), absence of dialysis therapy before SSP(OR\u0026thinsp;=\u0026thinsp;0.161, 95% CI: 0.041\u0026ndash;0.629, p\u0026thinsp;=\u0026thinsp;0.009], and higher average daily urine output (OR\u0026thinsp;=\u0026thinsp;1.002, 95% CI: 1.001\u0026ndash;1.002, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The Area under the cure(AUC) of the ROC curve for our predictive model was all good equal to 0.879 (95% CI: 0.846\u0026ndash;0.911). This is the first attempt to approach SSP predictors in renal insufficiency patients with a striking systematic analysis. The identified factors and predictive model might facilitate other physicians to decide the optimum approach in terms of conservative management, with early intervention as required, hence avoiding complications and preserving renal function through timely interventions in this high-risk group.\u003c/p\u003e","manuscriptTitle":"Prediction for spontaneous passage of ureteral stones with renal insufficiency","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-01 11:03:44","doi":"10.21203/rs.3.rs-7231132/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-14T11:42:51+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-14T09:46:11+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-01T09:12:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"25703609876661690116537900294358398564","date":"2025-08-01T08:31:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"49283259532605272148785226804353987627","date":"2025-07-31T08:42:17+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-29T17:03:45+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-28T08:36:40+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-28T08:35:17+00:00","index":"","fulltext":""},{"type":"submitted","content":"Urolithiasis","date":"2025-07-28T07:40:16+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"urolithiasis","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ures","sideBox":"Learn more about [Urolithiasis](http://link.springer.com/journal/240)","snPcode":"240","submissionUrl":"https://submission.nature.com/new-submission/240/3","title":"Urolithiasis","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6c059ccb-b146-4289-ac1b-81c74baf195b","owner":[],"postedDate":"August 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-12-07T16:08:10+00:00","versionOfRecord":[],"versionCreatedAt":"2025-08-01 11:03:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7231132","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7231132","identity":"rs-7231132","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}