Impact of Diabetes Mellitus on Stone Access and Surgical Outcomes in Patients Undergoing Ureteroscopic Lithotripsy: A Retrospective Cohort Study

Impact of Diabetes Mellitus on Stone Access and Surgical Outcomes in Patients Undergoing Ureteroscopic Lithotripsy: A Retrospective Cohort Study | 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 correspondence Impact of Diabetes Mellitus on Stone Access and Surgical Outcomes in Patients Undergoing Ureteroscopic Lithotripsy: A Retrospective Cohort Study Emrah Küçük, Haydar Güler, Reha Ordulu, Mustafa Aydın, Uğur Öztürk, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7590092/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objectives: This study aimed to assess the independent effect of diabetes mellitus (DM) on ureteral stone access and surgical outcomes in patients undergoing ureteroscopic lithotripsy (URS). Materials and Methods: Between February 2024 and August 2024, a total of 149 patients, including 50 patients with DM (Group 1) and 99 patients without DM (Group 2), were included in the study. Patients aged 18 to 80 years who were scheduled for surgery for ureteral calculi in our hospital were included in the study. Patients with any systemic disease other than diabetes mellitus, patients with previous surgery for kidney stones or ureteral calculi, patients undergoing diagnostic URS, pregnant women, patients with oncologic diseases and patients with one kidney were excluded. Results: There were statistically significant differences between the groups in terms of age, height, BMI and stone volume (p<0.001, p<0.001, p=0.004, p=0.004). The stone access rate was significantly different between the groups (p<0.001), with a higher success rate in group 2 (85.9%) compared to group 1 (58.0%). The stone-free rate was also significantly higher in group 2 (p=0.033). Patients with diabetes mellitus had a significantly lower likelihood of successful stone access, indicating a strong and statistically significant contribution of this variable to the model (p<0.001) Conclusion: Patients with diabetes mellitus have significantly lower stone access rates during URS. In DM patients scheduled for surgery for urolithiasis, considering the possibility of difficult ureters, structuring preoperative evaluation and surgical planning processes accordingly and implementing different preventive strategies if necessary may increase clinical success. Diabetes mellitus Stone access rate Ureteroscopic lithotripsy Introduction Urinary tract stone disease is an increasing and widespread health problem worldwide. Although its prevalence varies depending on environmental, dietary and genetic factors, its lifetime prevalence varies between 1–20%. It is most common between 20 and 50 years of age ( 1 ). Ureteral stones are seen as primary due to anatomical anomalies or more commonly as secondary after progression of renal stones to the ureter. Localization, size and hardness of the stone are among the effective factors in determining the treatment method for ureteral stones. Treatment modalities such as extracorporeal shock wave lithotripsy (SWL), ureteroscopy (URS) and open/laparoscopic ureterolithotomy are used ( 2 ). Today, minimally invasive methods are preferred as a result of developing technology and instrumental advances. Ureteroscopy is the most commonly used method in the treatment of ureteral calculi. In the European urology guideline, URS or SWL is recommended for ureteral stones of 10 mm and smaller and URS is recommended as the first treatment method for stones larger than 10 mm ( 3 ). Complications such as infection, ureteral trauma, perforation, bleeding, ureteral stricture and stone migration may occur during and after ureteroscopy. Conditions such as tuberculosis, ureteral cancer, and endometriosis that may lead to ureteral stricture and decrease the rate of access to ureteral calculi should also be kept in mind. Routine stent placement before ureteroscopy is not recommended ( 4 ). The relationship between diabetes mellitus and stone disease is attracting more and more attention. Especially type 2 DM is an endocrine disorder that increases with obesity and metabolic syndrome and is of great importance in terms of public health. Recent studies have shown that the incidence of urolithiasis is significantly higher in diabetic patients. The reasons for this increase include decreased urine pH, predisposition to uric acid stones, altered renal tubular function and impaired urine composition. Especially in the formation of uric acid stones, insulin resistance affects urinary ammonium production and bicarbonate secretion, leading to acidification of urine. Therefore, uric acid stones are frequently observed in patients with type 2 DM ( 5 ). Diabetes mellitus causes neurogenic, myogenic and urothelial dysfunctions in the lower urinary system and may also manifest itself with smooth muscle hyperproliferation in the ureter. This may decrease the peristalsis of the ureter and make stone excretion difficult ( 6 ). In this study, we aimed to evaluate the effect of DM on operative outcomes by examining stone access rates in patients with DM undergoing ureteroscopic lithotripsy. Materials and Methods This study was approved by the Samsun University Non-Interventional Clinical Research Ethics Committee with protocol code GOKAEK 2024/2/10 and was conducted in accordance with the ethical principles defined in the Declaration of Helsinki. The study was planned as a retrospective cohort study. Given the retrospective design, the need for informed consent was waived by the ethics committee. Between February 2024 and August 2024, a total of 149 patients, including 50 patients with DM (Group 1) and 99 patients without DM (Group 2) who underwent URS operation for ureteral calculi, were included in the study. The sample size was determined based on a power analysis. Patients aged 18 to 80 years who were scheduled for surgery for ureteral calculi in our hospital were included in the study. Patients with any systemic disease other than diabetes mellitus, patients who had previously undergone surgery for kidney stones or ureteral calculi, patients who had previously undergone diagnostic URS, pregnant women, patients with oncologic diseases and patients with one kidney were excluded. Detailed history, physical examination, routine preoperative laboratory tests, urinalysis and urine culture, direct urinary tract radiography and non-contrast computed tomography using a stone protocol were retrospectively analyzed in all patients in whom URS was planned for treatment of ureteral calculi. Preoperative hydronephrosis grading was classified according to the Society of Fetal Urology (SFU). After preoperative preparation, URS was performed under general anesthesia in the operating room. Intravenous 3rd generation cephalosporin was given prophylactically 30 minutes before surgery. All patients had negative urine cultures before the procedure. In the dorsal lithotomy position, the surgical field was disinfected twice with 10% povidone iodine solution and covered sterile. The bladder was emptied with a 16 Fr bidirectional foley catheter. Isotonic saline was used for irrigation. An 8 Fr Rigid URS (4 Fr − 8 Fr Single Channel Ureteroscope, Karl Storz, Germany) was inserted into the bladder via urethral route. Routine cystoscopy was performed to evaluate the bladder mucosa and bilateral orifices. A hydrophilic guidewire (ZIPwire Hydrophilic Guidewire, 0.038 inch, Boston Scientific, USA) was passed through the rigid URS through the ureteral orifice on the side of the procedure into the renal collecting system. All URS procedures were performed with a safety guidewire. With the help of the guidewire, the rigid URS was entered through the ureteral orifice. The rigid URS was advanced with the help of a guidewire to the segment where the ureteral stone was located. The stone access rate was considered successful when the stone was seen directly endoscopically with rigid URS. If the stone could not be visualized directly by rigid URS due to stenosis distal to the stone, the stone access rate was deemed unsuccessful, and the ureter classified as difficult. In patients with unsuccessful stone access, passive dilatation was planned by placing only a JJ stent. In patients with successful stone access, the stone was intervened and then a 4.8 Fr or 6 Fr JJ stent was placed. A 270 µm holmium YAG laser fiber (Singleflex holmium laser fiber, Dornier MedTech, Germany) and Holmium:YAG laser (Dornier Medilas H Solvo, Dornier MedTech, Germany) were used for stone fragmentation. Patients were evaluated for stone-free by imaging methods on postoperative days 1 and 30. Statistical Analysis IBM Statistical Package for The Social Sciences (SPSS) version 25 package program was used for statistical analysis of the study. Categorical variables are presented as frequency (%). Continuous variables are presented as mean ± standard deviation. The conformity of the variables to normal distribution was evaluated using the Shapiro-Wilk test. Differences between independent groups were evaluated using Student-t test and Mann-Whitney U test. The relationship between categorical variables was evaluated using Chi-square tests. A multiple logistic regression model was used to determine the risk factors predicting stone access rate in patients. In all statistical analyses, p-values less than 0.05 were considered statistically significant. Results A total of 149 patients who underwent URS for ureteral calculi were divided into two groups as DM (Group 1, n = 50) and non–DM (Group 2, n:99) (Table 1 ). A statistically significant difference was observed between the groups in terms of age, height, BMI and stone volume (p < 0.001, p < 0.001, p = 0.004, p = 0.004). Stone access rate was significantly different between the groups (p < 0.001), with a higher success rate in group 2 (85.9%) compared to group 1 (58.0%). Stone-free rate was also significantly higher in group 2 (p = 0.033). There were no significant differences between group 1 and group 2 in terms of gender, weight, operative time, hydronephrosis, side of stone, localization of stone, complications and Clavien-Dindo classification (Table 1 ). Logistic regression analysis was performed to evaluate the effects of body mass index, stone volume (mm³), smoking status, hydronephrosis and diabetes mellitus on stone access rate (Table 2 ). The overall model was statistically significant (χ²=18.302, p = 0.006), indicating that the set of predictors reliably discriminated between those with and without stone access. The model explained about 17.3% of the variance (Nagelkerke R² = 0.173) and the overall classification accuracy reached 78.7%. Sensitivity was 95.7% and specificity 22.9%. Multivariate logistic regression analysis also revealed that only diabetes mellitus significantly predicted stone access (OR: 2.59, 95% CI: 1.11–6.03, p = 0.027). Patients with diabetes mellitus were significantly less likely to successfully access the stone, indicating a strong and statistically significant contribution of this variable to the model (Wald = 13.833, p < 0.001; OR = 0.188, 95% CI [0.078, 0.453]). Other predictors (stone volume, BMI, smoking and hydronephrosis) were not statistically significant as shown by Wald values and p values. Table 1 Comparison of demographic and clinical characteristics of the groups Characteristic DM (n = 50) Non-DM (n = 99) p-value Age 62.10 ± 11.56 43.05 ± 13.15 < 0.001 Gender 0.991 Woman 29 (58.0) 59 (59.6) Male 21 (42.0) 40 (40.4) Height (cm) 167.30 ± 7.16 172.29 ± 8.43 < 0.001 Weight (kg) 77.86 ± 10.42 77.86 ± 10.67 0.999 BMI (kg/m2) 27.88 ± 3.63 26.06 ± 3.19 0.004 Stone volume (mm³) 269.76 ± 421.05 367.27 ± 475.19 0.020 Duration of surgery 40.26 ± 23.60 33.77 ± 16.73 0.178 Access to stone rate < 0.001 Access failure 21 (42.0) 14 (14.1) Access success 29 (58.0) 85 (85.9) Hydronephrosis 0.487 No 10 (20.0) 14 (14.1) Grade 1–2 29 (58.0) 67 (67.7) Grade 3–4 11 (22.0) 18 (18.2) Side 0.353 Left 27 (54.0) 44 (44.4) Right 23 (46.0) 55 (55.6) Localization of the stone 0.834 Proximal ureter 20 (40.0) 36 (36.4) Middle ureter 11 (22.0) 26 (26.3) Distal ureter 19 (38.0) 37 (37.4) Stone-free 0.033 23 (46.0%) 65 (65.7%) Type of complication 0.982 PULS 0 46 (92.0) 89 (89.9) PULS 1 1 (2.0) 4 (4.0) PULS 2 1 (2.0) 1 (1.0) PULS 3 0 (0.0) 0 (0.0) PULS 4 0 (0.0) 0 (0.0) PULS 5 0 (0.0) 0 (0.0) Clavien-Dindo 0.926 No complications 46 (92.0) 89 (89.9) Grade 1 3 (6.0) 8 (8.1) Grade 2 0 (0.0) 1 (1.0) Grade 3a 1 (2.0) 1 (1.0) Values are presented as mean ± SD or frequency (%) Table 2 Characteristics of the study groups and results of the multivariate logistic regression analysis 95% CI 95% CI Predictor Variable OR Lower limit Upper limit p-value BMI 1.107 0.964 1.272 0.149 Stone volume (mm³) 1.000 0.999 1.002 0.620 Smoking (yes) 0.609 0.265 1.400 0.243 Hydronephrosis (Grade 1–2) 1.360 0.464 3.991 0.575 Hydronephrosis (Grade 3–4) 1.364 0.316 5.897 0.677 Diabetes Mellitus (yes) 0.188 0.078 0.453 < 0.001 OR, odds ratio; CI, confidence interval; Note For a result to be considered statistically significant, the 95% confidence interval (CI) of the odds ratio (OR) should not include 1. Variables that are not statistically significant have CIs that include 1. Discussion Urinary tract stone disease is an important health problem that has been known since ancient times and causes serious cost and morbidity. Although it varies according to various factors, its prevalence is known to be between 1% and 20%. In the last 20 years, both prevalence and recurrence rates have increased with industrialization, changes in dietary habits and lifestyle ( 7 ). The high prevalence and high recurrence rates of stone disease worldwide have led to the need for higher stone-free rates and lower complications in treatment ( 7 ). If left untreated for a long time, ureteral calculi may lead to serious complications including acute pyelonephritis and irreversible deterioration in renal function. Complications that may occur due to ureteral calculi can be prevented by URS performed at the appropriate time (8). Urologists may encounter narrow and difficult ureters during ureteroscopy. Preoperative stenting and medical treatments have positive effects such as shortening the duration of URS, increasing the stone-free rate and decreasing the risk of ureteral injury. The presence of ureteral stricture not only prevents spontaneous stone drop but also hinders retrograde passage of the endoscope. Standard access to the ureter in endoscopic treatment of ureteral calculi may be difficult due to narrow ureteral lumen, anatomical abnormalities, tortuous ureteral tract or previous surgery. In the literature, this condition is defined as ‘difficult ureter’ or ‘tight ureter’ ( 9 ). Choi et al. showed that DM causes hyperproliferation in ureteral smooth muscle cells and this is mediated by p-ERK/p-JNK/VEGF/PKC pathways. These changes decrease the peristaltic movements of the ureter, making stone excretion difficult and may reduce the success of endoscopic interventions. The concept of "difficult ureter" reported by Imano et al. similarly supports that structural changes in the ureteral wall and luminal stenosis are among the main factors affecting surgical success ( 10 ). In our study, it was shown that stone access rates with URS were significantly lower in patients with DM compared to patients without DM. According to the results of statistical analysis, DM was found to be the only variable that significantly negatively affected stone access success. This finding suggests that DM may increase surgical difficulty by causing morphologic and functional changes at the ureteral level. Imano et al. examined the relationship between DM, hypertension, smoking, history of cardiovascular disease and difficult ureter due to atherosclerosis of peripheral vessels in the ureteral wall and found no increase in the risk of encountering difficult ureter in the presence of DM in contrast to our study. Imano et al. argued that the reason for this was passive dilatation of the ureteral wall due to increased urinary flow and neuropathy caused by polyuria in DM ( 12 ). In our study, other clinical parameters including stone volume, BMI, smoking and hydronephrosis were included in the logistic regression analysis and no significant effect of these variables was found on the stone access rate. This finding suggests that the specific effect of DM on ureteral structure is independent of and more dominant than other factors. Although no significant difference in complication rates was found between groups, the DM-diagnosed group may still be more prone to complications. It may be more prone to complications in the DM-diagnosed group because of the damage caused by DM to the ureteral wall. Tailly et al. emphasized that infection rates after endoscopic stone surgery were significantly higher in patients with DM ( 13 ). Similarly, El-Nahas et al. reported an increased incidence of febrile urinary infection after stone surgery in diabetic patients ( 14 ). Diabetes is known to lead to micro- and macrovascular complications and impaired immune response ( 15 ). This may increase the risk of mucosal trauma resulting in infection during ureterorenoscopy. In addition, decreased elasticity of glycosylated tissues in DM patients may predispose to delayed healing of the ureteral wall and thus more frequent complications such as perforation or stricture ( 16 ). A recent systematic review confirmed that diabetes is significantly associated with postoperative infectious complications and adverse surgical outcomes following endourological procedures ( 17 ). In difficult ureteral cases encountered during ureteroscopy, active or passive dilatation methods may be preferred and the operation may be postponed with preoperative stenting when necessary ( 11 , 18 ). Therefore, being prepared for such possibilities, especially in patients with DM, is important in terms of surgical success and informing patients about possible complications. Careful evaluation of these patients before URS may provide a significant advantage to urologists in preoperative planning. The retrospective single-center design and relatively limited sample size are important limitations of our study. In addition, the absence of glycemic control parameters such as HbA1c and detailed stone composition data limited our ability to stratify patients according to metabolic status. Future multicenter, prospective studies incorporating these variables are warranted to confirm and expand upon our findings. Conclusion Patients with diabetes mellitus have significantly lower stone access rates during URS. This may be due to the effects of DM on ureteral smooth muscle tissue and peristaltic function. DM emerges as an independent and powerful risk factor in predicting URS success. In DM patients scheduled for surgery for urolithiasis, structuring the preoperative evaluation and surgical planning processes accordingly, taking into account the possibility of a difficult ureter, and implementing different preventive strategies if necessary, may improve clinical success. Declarations Author Contribution E.K. and M.A. wrote the main manuscript text, H.G. and R.O. collected the data, U.Ö. and M.K.K. performed data analysis and interpretation, M.K.A. critically revised the manuscript, and I.Ü. prepared Tables 1-2. All authors reviewed the manuscript. Acknowledgement The authors gratefully acknowledge Dr. Mahmut Ulubay, Chief Physician of Samsun University Samsun Training and Research Hospital, for his valuable assistance in providing critical clinical data that significantly contributed to this study. References Stamatelou KK, Francis ME, Jones CA, Nyberg LM, Curhan GC. Time trends in reported prevalence of kidney stones in the United States: 1976-1994. Kidney Int. 2003;63(5):1817-23. Smith RD, Shah M, Patel A. Recent advances in management of ureteral calculi. F1000 Med Rep 2009;1:53. European Association of Urology Guidelines on Urolithiasis 2025, https://uroweb.org/guidelines/urolithiasis. American Urological Association Guidelines on Kidney Stones: Surgical Management Guideline 2016, https://www.auanet.org/guidelines/guidelines/kidney-stones-surgical-management-guideline Liu LH, Kang R, He J, Zhao SK, Li FT, Zhao ZG. Diabetes mellitus and the risk of urolithiasis: a meta-analysis of observational studies. Urolithiasis. 2015 Aug;43(4):293-301. doi: 10.1007/s00240-015-0773-5. Epub 2015 Apr 17. PMID: 25894627. Wu, J., Zhou, X., Lu, H., & Li, H. (2021). Effects of diabetes mellitus on ureteral structure and function in rats: Evidence for smooth muscle proliferation and impaired peristalsis. Molecular Medicine Reports , 24(1), 548. Romero, V., Akpinar, H., & Assimos, D. G. (2010). Kidney stones: A global picture of prevalence, incidence, and associated risk factors. Reviews in Urology , 12(2–3), e86–e96. Türk, C., Petřík, A., Sarica, K., Seitz, C., Skolarikos, A., Straub, M., & Knoll, T. (2024). EAU Guidelines on Urolithiasis 2024. European Association of Urology. https://uroweb.org/guidelines/urolithiasis Söylemez H, Yıldırım K, Utangac MM, Aydoğan TB, Ezer M, Atar M. A New Alternative for Difficult Ureter in Adult Patients: No Need to Dilate Ureter via a Balloon or a Stent with the Aid of 4.5F Semirigid Ureteroscope. J Endourol. 2016;30(6):650-4. Choi T, Lee JW, Kim SK, Yoo KH. Diabetes Mellitus Promotes Smooth Muscle Cell Proliferation in Mouse Ureteral Tissue through the P-ERK/P-JNK/VEGF/PKC Signaling Pathway. Medicina (Kaunas). 2021 Jun 1;57(6):560. doi: 10.3390/medicina57060560. PMID: 34206139; PMCID: PMC8230221. Kawahara T, Ito H, Terao H, et al. Preoperative stenting for ureteroscopic lithotripsy for a large renal stone. Int J Urol. 2012;19(9):881–885. Imano M, Tabei T, Ito H, Ota J, Kobayashi K. Clinical Factors to Predict Difficult Ureter during Ureteroscopic Lithotripsy. Minim Invasive Surg. 2023 Feb 2;2023:2584499. doi: 10.1155/2023/2584499. PMID: 36777400; PMCID: PMC9911238. Tailly, T. O., Denstedt, J. D., & Razvi, H. A. (2015). Complications of ureteroscopy. In Smith’s Textbook of Endourology. El-Nahas, A. R., Ibrahim, H. M., Youssef, R. F., Sheir, K. Z. (2017). Risk factors of fever after ureterorenoscopy. Urology, 79(3), 547-552. Nitzan, O., Elias, M., Chazan, B., Saliba, W. (2015). Urinary tract infections in patients with type 2 diabetes mellitus: review of prevalence, diagnosis, and management. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy, 8, 129-136. Ghani, K. R., & Wolf, J. S. (2015). What is the stone-free rate following flexible ureteroscopy for kidney stones? Nature Reviews Urology, 12(5), 281-288. Zeng G, Traxer O, Zhong W, Osther PJ, Pearle M, Preminger G, et al. International Alliance of Urolithiasis guideline on retrograde intrarenal surgery. BJU Int. 2023;131(2):153-164. doi:10.1111/bju.15836. R. J. Cetti, S. Biers, and S. R. Keoghane,“The difficult ureter: what is the incidence of pre-stenting?” Annals of the Royal College of Surgeons of England , vol. 93, no. 1, pp. 31–33, 2011. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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. 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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-7590092","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"correspondence","associatedPublications":[],"authors":[{"id":513554250,"identity":"147534ec-8cf9-4486-9ade-e66c2349b385","order_by":0,"name":"Emrah Küçük","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2klEQVRIiWNgGAWjYDCCAxCSmZ+9AUgbWBCvhV2yB8QykCBeC7/BjQQQgwgtfLcPH91cUXNHmuHm86sbfhRIMPC3dyfg1SJ5Li3t5pljz4wZZ+eU3ewBOkzizNkNeLUYnOExu9nAdjiZWTon7QYPUIuBRC4hLfzfbjb8O1zfJnkm7eYf4rTwsN1sbDvMzCPBfuw2UbZInmEzu9nYd5hZgieH7baMgQQPQb/wnWF+drPh22Fm++PHn91888dGjr+9F78WJMBjACaJVQ4C7A9IUT0KRsEoGAUjCAAAKXZOAGQIUtcAAAAASUVORK5CYII=","orcid":"","institution":"University of Samsun, Samsun Training and Research Hospital","correspondingAuthor":true,"prefix":"","firstName":"Emrah","middleName":"","lastName":"Küçük","suffix":""},{"id":513554251,"identity":"d97aec5e-3566-417c-a863-015341ce52e1","order_by":1,"name":"Haydar Güler","email":"","orcid":"","institution":"Kanuni Sultan Suleiman Training and Research Hospital","correspondingAuthor":false,"prefix":"","firstName":"Haydar","middleName":"","lastName":"Güler","suffix":""},{"id":513554252,"identity":"e15f06ae-a204-45d2-b447-b18dc9293e0c","order_by":2,"name":"Reha Ordulu","email":"","orcid":"","institution":"University of Samsun, Samsun Training and Research Hospital","correspondingAuthor":false,"prefix":"","firstName":"Reha","middleName":"","lastName":"Ordulu","suffix":""},{"id":513554253,"identity":"ca0e315d-63e9-4738-8323-af2ffb3e0f1e","order_by":3,"name":"Mustafa Aydın","email":"","orcid":"","institution":"University of Samsun, Samsun Training and Research Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mustafa","middleName":"","lastName":"Aydın","suffix":""},{"id":513554254,"identity":"f4fb16d6-2cb7-4219-b83d-6a6fe4e49387","order_by":4,"name":"Uğur Öztürk","email":"","orcid":"","institution":"University of Samsun, Samsun Training and Research Hospital","correspondingAuthor":false,"prefix":"","firstName":"Uğur","middleName":"","lastName":"Öztürk","suffix":""},{"id":513554255,"identity":"263421db-6f54-41ae-b794-9a76c4b019a3","order_by":5,"name":"Mustafa Koray Kırdağ","email":"","orcid":"","institution":"University of Samsun, Samsun Training and Research Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mustafa","middleName":"Koray","lastName":"Kırdağ","suffix":""},{"id":513554256,"identity":"66e95c5e-ee0f-4e25-8b6d-f82d293b0807","order_by":6,"name":"Işıl Ünaldı","email":"","orcid":"","institution":"Ondokuz Mayıs University","correspondingAuthor":false,"prefix":"","firstName":"Işıl","middleName":"","lastName":"Ünaldı","suffix":""},{"id":513554257,"identity":"7f361926-396a-46bc-a0fd-fb6ea4f6a45a","order_by":7,"name":"Mustafa Kemal Atilla","email":"","orcid":"","institution":"University of Samsun, Samsun Training and Research Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mustafa","middleName":"Kemal","lastName":"Atilla","suffix":""}],"badges":[],"createdAt":"2025-09-11 09:23:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7590092/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7590092/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91200178,"identity":"8e4a5374-9f20-4707-baca-954230352235","added_by":"auto","created_at":"2025-09-12 15:23:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":558308,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7590092/v1/b127057b-3779-4504-b67e-4d489b0486e9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Impact of Diabetes Mellitus on Stone Access and Surgical Outcomes in Patients Undergoing Ureteroscopic Lithotripsy: A Retrospective Cohort Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eUrinary tract stone disease is an increasing and widespread health problem worldwide. Although its prevalence varies depending on environmental, dietary and genetic factors, its lifetime prevalence varies between 1\u0026ndash;20%. It is most common between 20 and 50 years of age (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Ureteral stones are seen as primary due to anatomical anomalies or more commonly as secondary after progression of renal stones to the ureter. Localization, size and hardness of the stone are among the effective factors in determining the treatment method for ureteral stones. Treatment modalities such as extracorporeal shock wave lithotripsy (SWL), ureteroscopy (URS) and open/laparoscopic ureterolithotomy are used (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eToday, minimally invasive methods are preferred as a result of developing technology and instrumental advances. Ureteroscopy is the most commonly used method in the treatment of ureteral calculi. In the European urology guideline, URS or SWL is recommended for ureteral stones of 10 mm and smaller and URS is recommended as the first treatment method for stones larger than 10 mm (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Complications such as infection, ureteral trauma, perforation, bleeding, ureteral stricture and stone migration may occur during and after ureteroscopy. Conditions such as tuberculosis, ureteral cancer, and endometriosis that may lead to ureteral stricture and decrease the rate of access to ureteral calculi should also be kept in mind. Routine stent placement before ureteroscopy is not recommended (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe relationship between diabetes mellitus and stone disease is attracting more and more attention. Especially type 2 DM is an endocrine disorder that increases with obesity and metabolic syndrome and is of great importance in terms of public health. Recent studies have shown that the incidence of urolithiasis is significantly higher in diabetic patients. The reasons for this increase include decreased urine pH, predisposition to uric acid stones, altered renal tubular function and impaired urine composition. Especially in the formation of uric acid stones, insulin resistance affects urinary ammonium production and bicarbonate secretion, leading to acidification of urine. Therefore, uric acid stones are frequently observed in patients with type 2 DM (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eDiabetes mellitus causes neurogenic, myogenic and urothelial dysfunctions in the lower urinary system and may also manifest itself with smooth muscle hyperproliferation in the ureter. This may decrease the peristalsis of the ureter and make stone excretion difficult (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). In this study, we aimed to evaluate the effect of DM on operative outcomes by examining stone access rates in patients with DM undergoing ureteroscopic lithotripsy.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e This study was approved by the Samsun University Non-Interventional Clinical Research Ethics Committee with protocol code GOKAEK 2024/2/10 and was conducted in accordance with the ethical principles defined in the Declaration of Helsinki. The study was planned as a retrospective cohort study. Given the retrospective design, the need for informed consent was waived by the ethics committee.\u003c/p\u003e\u003cp\u003eBetween February 2024 and August 2024, a total of 149 patients, including 50 patients with DM (Group 1) and 99 patients without DM (Group 2) who underwent URS operation for ureteral calculi, were included in the study. The sample size was determined based on a power analysis. Patients aged 18 to 80 years who were scheduled for surgery for ureteral calculi in our hospital were included in the study. Patients with any systemic disease other than diabetes mellitus, patients who had previously undergone surgery for kidney stones or ureteral calculi, patients who had previously undergone diagnostic URS, pregnant women, patients with oncologic diseases and patients with one kidney were excluded.\u003c/p\u003e\u003cp\u003eDetailed history, physical examination, routine preoperative laboratory tests, urinalysis and urine culture, direct urinary tract radiography and non-contrast computed tomography using a stone protocol were retrospectively analyzed in all patients in whom URS was planned for treatment of ureteral calculi. Preoperative hydronephrosis grading was classified according to the Society of Fetal Urology (SFU).\u003c/p\u003e\u003cp\u003eAfter preoperative preparation, URS was performed under general anesthesia in the operating room. Intravenous 3rd generation cephalosporin was given prophylactically 30 minutes before surgery. All patients had negative urine cultures before the procedure. In the dorsal lithotomy position, the surgical field was disinfected twice with 10% povidone iodine solution and covered sterile. The bladder was emptied with a 16 Fr bidirectional foley catheter. Isotonic saline was used for irrigation. An 8 Fr Rigid URS (4 Fr \u0026minus;\u0026thinsp;8 Fr Single Channel Ureteroscope, Karl Storz, Germany) was inserted into the bladder via urethral route. Routine cystoscopy was performed to evaluate the bladder mucosa and bilateral orifices. A hydrophilic guidewire (ZIPwire Hydrophilic Guidewire, 0.038 inch, Boston Scientific, USA) was passed through the rigid URS through the ureteral orifice on the side of the procedure into the renal collecting system. All URS procedures were performed with a safety guidewire. With the help of the guidewire, the rigid URS was entered through the ureteral orifice. The rigid URS was advanced with the help of a guidewire to the segment where the ureteral stone was located. The stone access rate was considered successful when the stone was seen directly endoscopically with rigid URS. If the stone could not be visualized directly by rigid URS due to stenosis distal to the stone, the stone access rate was deemed unsuccessful, and the ureter classified as difficult.\u003c/p\u003e\u003cp\u003eIn patients with unsuccessful stone access, passive dilatation was planned by placing only a JJ stent. In patients with successful stone access, the stone was intervened and then a 4.8 Fr or 6 Fr JJ stent was placed. A 270 \u0026micro;m holmium YAG laser fiber (Singleflex holmium laser fiber, Dornier MedTech, Germany) and Holmium:YAG laser (Dornier Medilas H Solvo, Dornier MedTech, Germany) were used for stone fragmentation. Patients were evaluated for stone-free by imaging methods on postoperative days 1 and 30.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eIBM Statistical Package for The Social Sciences (SPSS) version 25 package program was used for statistical analysis of the study. Categorical variables are presented as frequency (%). Continuous variables are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. The conformity of the variables to normal distribution was evaluated using the Shapiro-Wilk test. Differences between independent groups were evaluated using Student-t test and Mann-Whitney U test. The relationship between categorical variables was evaluated using Chi-square tests. A multiple logistic regression model was used to determine the risk factors predicting stone access rate in patients. In all statistical analyses, p-values less than 0.05 were considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 149 patients who underwent URS for ureteral calculi were divided into two groups as \u003cem\u003eDM\u003c/em\u003e (Group 1, n\u0026thinsp;=\u0026thinsp;50) and \u003cem\u003enon\u0026ndash;DM\u003c/em\u003e (Group 2, n:99) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). A statistically significant difference was observed between the groups in terms of age, height, BMI and stone volume (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001, p\u0026thinsp;=\u0026thinsp;0.004, p\u0026thinsp;=\u0026thinsp;0.004). Stone access rate was significantly different between the groups (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with a higher success rate in group 2 (85.9%) compared to group 1 (58.0%). Stone-free rate was also significantly higher in group 2 (p\u0026thinsp;=\u0026thinsp;0.033).\u003c/p\u003e\u003cp\u003eThere were no significant differences between group 1 and group 2 in terms of gender, weight, operative time, hydronephrosis, side of stone, localization of stone, complications and Clavien-Dindo classification (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eLogistic regression analysis was performed to evaluate the effects of body mass index, stone volume (mm\u0026sup3;), smoking status, hydronephrosis and diabetes mellitus on stone access rate (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe overall model was statistically significant (χ\u0026sup2;=18.302, p\u0026thinsp;=\u0026thinsp;0.006), indicating that the set of predictors reliably discriminated between those with and without stone access. The model explained about 17.3% of the variance (Nagelkerke R\u0026sup2; = 0.173) and the overall classification accuracy reached 78.7%. Sensitivity was 95.7% and specificity 22.9%.\u003c/p\u003e\u003cp\u003eMultivariate logistic regression analysis also revealed that only diabetes mellitus significantly predicted stone access (OR: 2.59, 95% CI: 1.11\u0026ndash;6.03, p\u0026thinsp;=\u0026thinsp;0.027).\u003c/p\u003e\u003cp\u003ePatients with diabetes mellitus were significantly less likely to successfully access the stone, indicating a strong and statistically significant contribution of this variable to the model (Wald\u0026thinsp;=\u0026thinsp;13.833, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001; OR\u0026thinsp;=\u0026thinsp;0.188, 95% CI [0.078, 0.453]). Other predictors (stone volume, BMI, smoking and hydronephrosis) were not statistically significant as shown by Wald values and p values.\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\u003cem\u003eComparison of demographic and clinical characteristics of the groups\u003c/em\u003e\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\u003eCharacteristic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDM (n\u0026thinsp;=\u0026thinsp;50)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNon-DM (n\u0026thinsp;=\u0026thinsp;99)\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\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62.10\u0026thinsp;\u0026plusmn;\u0026thinsp;11.56\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e43.05\u0026thinsp;\u0026plusmn;\u0026thinsp;13.15\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\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\u003e0.991\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWoman\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29 (58.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e59 (59.6)\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\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21 (42.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e40 (40.4)\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\u003eHeight (cm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e167.30\u0026thinsp;\u0026plusmn;\u0026thinsp;7.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e172.29\u0026thinsp;\u0026plusmn;\u0026thinsp;8.43\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\u003eWeight (kg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e77.86\u0026thinsp;\u0026plusmn;\u0026thinsp;10.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e77.86\u0026thinsp;\u0026plusmn;\u0026thinsp;10.67\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.999\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e27.88\u0026thinsp;\u0026plusmn;\u0026thinsp;3.63\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26.06\u0026thinsp;\u0026plusmn;\u0026thinsp;3.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.004\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStone volume (mm\u0026sup3;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e269.76\u0026thinsp;\u0026plusmn;\u0026thinsp;421.05\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e367.27\u0026thinsp;\u0026plusmn;\u0026thinsp;475.19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.020\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDuration of surgery\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40.26\u0026thinsp;\u0026plusmn;\u0026thinsp;23.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33.77\u0026thinsp;\u0026plusmn;\u0026thinsp;16.73\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.178\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAccess to stone rate\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\u003eAccess failure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21 (42.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14 (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\u003eAccess success\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29 (58.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e85 (85.9)\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\u003eHydronephrosis\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\u003e0.487\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e10 (20.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14 (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\u003eGrade 1\u0026ndash;2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e29 (58.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67 (67.7)\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\u003eGrade 3\u0026ndash;4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11 (22.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18 (18.2)\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\u003eSide\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\u003e0.353\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\u003e27 (54.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e44 (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\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (46.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e55 (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\u003eLocalization of the stone\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\u003e0.834\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProximal ureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e20 (40.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e36 (36.4)\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\u003eMiddle ureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11 (22.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e26 (26.3)\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\u003eDistal ureter\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19 (38.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e37 (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\u003eStone-free\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\u003e0.033\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (46.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e65 (65.7%)\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\u003eType of complication\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\u003e0.982\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePULS 0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e46 (92.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e89 (89.9)\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\u003ePULS 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (2.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (4.0)\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\u003ePULS 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (2.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1.0)\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\u003ePULS 3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\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\u003ePULS 4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\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\u003ePULS 5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\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\u003eClavien-Dindo\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\u003e0.926\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo complications\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e46 (92.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e89 (89.9)\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 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3 (6.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 (8.1)\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\u003eGrade 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1.0)\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 3a\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (2.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eValues are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD or frequency (%)\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\u003cem\u003eCharacteristics of the study groups and results of the multivariate logistic regression analysis\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e95% CI\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003e95% CI\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePredictor Variable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eOR\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eLower limit\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eUpper limit\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\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\u003eBMI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.107\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.964\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.272\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.149\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStone volume (mm\u0026sup3;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.000\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.999\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.002\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.620\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking (yes)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.609\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.265\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.400\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.243\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydronephrosis (Grade 1\u0026ndash;2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.360\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.464\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e3.991\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.575\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHydronephrosis (Grade 3\u0026ndash;4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.364\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.316\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e5.897\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.677\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes Mellitus (yes)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e0.188\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.078\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.453\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\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eOR, odds ratio;\u003c/p\u003e\u003cp\u003eCI, confidence interval;\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eNote\u003c/strong\u003e\u003cp\u003eFor a result to be considered statistically significant, the 95% confidence interval (CI) of the odds ratio (OR) should not include 1. Variables that are not statistically significant have CIs that include 1.\u003c/p\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eUrinary tract stone disease is an important health problem that has been known since ancient times and causes serious cost and morbidity. Although it varies according to various factors, its prevalence is known to be between 1% and 20%. In the last 20 years, both prevalence and recurrence rates have increased with industrialization, changes in dietary habits and lifestyle (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe high prevalence and high recurrence rates of stone disease worldwide have led to the need for higher stone-free rates and lower complications in treatment (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). If left untreated for a long time, ureteral calculi may lead to serious complications including acute pyelonephritis and irreversible deterioration in renal function. Complications that may occur due to ureteral calculi can be prevented by URS performed at the appropriate time (8).\u003c/p\u003e\u003cp\u003eUrologists may encounter narrow and difficult ureters during ureteroscopy. Preoperative stenting and medical treatments have positive effects such as shortening the duration of URS, increasing the stone-free rate and decreasing the risk of ureteral injury. The presence of ureteral stricture not only prevents spontaneous stone drop but also hinders retrograde passage of the endoscope. Standard access to the ureter in endoscopic treatment of ureteral calculi may be difficult due to narrow ureteral lumen, anatomical abnormalities, tortuous ureteral tract or previous surgery. In the literature, this condition is defined as \u0026lsquo;difficult ureter\u0026rsquo; or \u0026lsquo;tight ureter\u0026rsquo; (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eChoi et al. showed that DM causes hyperproliferation in ureteral smooth muscle cells and this is mediated by p-ERK/p-JNK/VEGF/PKC pathways. These changes decrease the peristaltic movements of the ureter, making stone excretion difficult and may reduce the success of endoscopic interventions. The concept of \"difficult ureter\" reported by Imano et al. similarly supports that structural changes in the ureteral wall and luminal stenosis are among the main factors affecting surgical success (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn our study, it was shown that stone access rates with URS were significantly lower in patients with DM compared to patients without DM. According to the results of statistical analysis, DM was found to be the only variable that significantly negatively affected stone access success. This finding suggests that DM may increase surgical difficulty by causing morphologic and functional changes at the ureteral level.\u003c/p\u003e\u003cp\u003eImano et al. examined the relationship between DM, hypertension, smoking, history of cardiovascular disease and difficult ureter due to atherosclerosis of peripheral vessels in the ureteral wall and found no increase in the risk of encountering difficult ureter in the presence of DM in contrast to our study. Imano et al. argued that the reason for this was passive dilatation of the ureteral wall due to increased urinary flow and neuropathy caused by polyuria in DM (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e12\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn our study, other clinical parameters including stone volume, BMI, smoking and hydronephrosis were included in the logistic regression analysis and no significant effect of these variables was found on the stone access rate. This finding suggests that the specific effect of DM on ureteral structure is independent of and more dominant than other factors.\u003c/p\u003e\u003cp\u003eAlthough no significant difference in complication rates was found between groups, the DM-diagnosed group may still be more prone to complications. It may be more prone to complications in the DM-diagnosed group because of the damage caused by DM to the ureteral wall. Tailly et al. emphasized that infection rates after endoscopic stone surgery were significantly higher in patients with DM (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Similarly, El-Nahas et al. reported an increased incidence of febrile urinary infection after stone surgery in diabetic patients (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Diabetes is known to lead to micro- and macrovascular complications and impaired immune response (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e15\u003c/span\u003e). This may increase the risk of mucosal trauma resulting in infection during ureterorenoscopy. In addition, decreased elasticity of glycosylated tissues in DM patients may predispose to delayed healing of the ureteral wall and thus more frequent complications such as perforation or stricture (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e16\u003c/span\u003e). A recent systematic review confirmed that diabetes is significantly associated with postoperative infectious complications and adverse surgical outcomes following endourological procedures (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e17\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn difficult ureteral cases encountered during ureteroscopy, active or passive dilatation methods may be preferred and the operation may be postponed with preoperative stenting when necessary (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e18\u003c/span\u003e). Therefore, being prepared for such possibilities, especially in patients with DM, is important in terms of surgical success and informing patients about possible complications. Careful evaluation of these patients before URS may provide a significant advantage to urologists in preoperative planning.\u003c/p\u003e\u003cp\u003eThe retrospective single-center design and relatively limited sample size are important limitations of our study. In addition, the absence of glycemic control parameters such as HbA1c and detailed stone composition data limited our ability to stratify patients according to metabolic status. Future multicenter, prospective studies incorporating these variables are warranted to confirm and expand upon our findings.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003ePatients with diabetes mellitus have significantly lower stone access rates during URS. This may be due to the effects of DM on ureteral smooth muscle tissue and peristaltic function. DM emerges as an independent and powerful risk factor in predicting URS success. In DM patients scheduled for surgery for urolithiasis, structuring the preoperative evaluation and surgical planning processes accordingly, taking into account the possibility of a difficult ureter, and implementing different preventive strategies if necessary, may improve clinical success.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.K. and M.A. wrote the main manuscript text, H.G. and R.O. collected the data, U.\u0026Ouml;. and M.K.K. performed data analysis and interpretation, M.K.A. critically revised the manuscript, and I.\u0026Uuml;. prepared Tables 1-2. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors gratefully acknowledge Dr. Mahmut Ulubay, Chief Physician of Samsun University Samsun Training and Research Hospital, for his valuable assistance in providing critical clinical data that significantly contributed to this study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eStamatelou KK, Francis ME, Jones CA, Nyberg LM, Curhan GC. Time trends in reported prevalence of kidney stones in the United States: 1976-1994. Kidney Int. 2003;63(5):1817-23.\u003c/li\u003e\n \u003cli\u003eSmith RD, Shah M, Patel A. Recent advances in management of ureteral calculi. F1000 Med Rep 2009;1:53.\u003c/li\u003e\n \u003cli\u003eEuropean Association of Urology Guidelines on Urolithiasis 2025, https://uroweb.org/guidelines/urolithiasis.\u003c/li\u003e\n \u003cli\u003eAmerican Urological Association Guidelines on Kidney Stones: Surgical Management Guideline 2016, https://www.auanet.org/guidelines/guidelines/kidney-stones-surgical-management-guideline\u003c/li\u003e\n \u003cli\u003eLiu LH, Kang R, He J, Zhao SK, Li FT, Zhao ZG. Diabetes mellitus and the risk of urolithiasis: a meta-analysis of observational studies. Urolithiasis. 2015 Aug;43(4):293-301. doi: 10.1007/s00240-015-0773-5. Epub 2015 Apr 17. PMID: 25894627.\u003c/li\u003e\n \u003cli\u003eWu, J., Zhou, X., Lu, H., \u0026amp; Li, H. (2021). Effects of diabetes mellitus on ureteral structure and function in rats: Evidence for smooth muscle proliferation and impaired peristalsis. \u003cem\u003eMolecular Medicine Reports\u003c/em\u003e, 24(1), 548.\u003c/li\u003e\n \u003cli\u003eRomero, V., Akpinar, H., \u0026amp; Assimos, D. G. (2010). Kidney stones: A global picture of prevalence, incidence, and associated risk factors. \u003cem\u003eReviews in Urology\u003c/em\u003e, 12(2\u0026ndash;3), e86\u0026ndash;e96.\u003c/li\u003e\n \u003cli\u003eT\u0026uuml;rk, C., Petř\u0026iacute;k, A., Sarica, K., Seitz, C., Skolarikos, A., Straub, M., \u0026amp; Knoll, T. (2024). EAU Guidelines on Urolithiasis 2024. European Association of Urology.\u003cbr\u003e\u0026nbsp;https://uroweb.org/guidelines/urolithiasis\u003c/li\u003e\n \u003cli\u003eS\u0026ouml;ylemez H, Yıldırım K, Utangac MM, Aydoğan TB, Ezer M, Atar M. A New Alternative for Difficult Ureter in Adult Patients: No Need to Dilate Ureter via a Balloon or a Stent with the Aid of 4.5F Semirigid Ureteroscope. J Endourol. 2016;30(6):650-4.\u003c/li\u003e\n \u003cli\u003eChoi T, Lee JW, Kim SK, Yoo KH. Diabetes Mellitus Promotes Smooth Muscle Cell Proliferation in Mouse Ureteral Tissue through the P-ERK/P-JNK/VEGF/PKC Signaling Pathway. Medicina (Kaunas). 2021 Jun 1;57(6):560. doi: 10.3390/medicina57060560. PMID: 34206139; PMCID: PMC8230221.\u003c/li\u003e\n \u003cli\u003eKawahara T, Ito H, Terao H, et al. Preoperative stenting for ureteroscopic lithotripsy for a large renal stone. Int J Urol. 2012;19(9):881\u0026ndash;885.\u003c/li\u003e\n \u003cli\u003eImano M, Tabei T, Ito H, Ota J, Kobayashi K. Clinical Factors to Predict Difficult Ureter during Ureteroscopic Lithotripsy. Minim Invasive Surg. 2023 Feb 2;2023:2584499. doi: 10.1155/2023/2584499. PMID: 36777400; PMCID: PMC9911238.\u003c/li\u003e\n \u003cli\u003eTailly, T. O., Denstedt, J. D., \u0026amp; Razvi, H. A. (2015). Complications of ureteroscopy. In Smith\u0026rsquo;s Textbook of Endourology.\u003c/li\u003e\n \u003cli\u003eEl-Nahas, A. R., Ibrahim, H. M., Youssef, R. F., Sheir, K. Z. (2017). Risk factors of fever after ureterorenoscopy. Urology, 79(3), 547-552.\u003c/li\u003e\n \u003cli\u003eNitzan, O., Elias, M., Chazan, B., Saliba, W. (2015). Urinary tract infections in patients with type 2 diabetes mellitus: review of prevalence, diagnosis, and management. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy, 8, 129-136.\u003c/li\u003e\n \u003cli\u003eGhani, K. R., \u0026amp; Wolf, J. S. (2015). What is the stone-free rate following flexible ureteroscopy for kidney stones? Nature Reviews Urology, 12(5), 281-288.\u003c/li\u003e\n \u003cli\u003eZeng G, Traxer O, Zhong W, Osther PJ, Pearle M, Preminger G, et al. International Alliance of Urolithiasis guideline on retrograde intrarenal surgery. BJU Int. 2023;131(2):153-164. doi:10.1111/bju.15836.\u003c/li\u003e\n \u003cli\u003eR. J. Cetti, S. Biers, and S. R. Keoghane,\u0026ldquo;The difficult ureter: what is the incidence of pre-stenting?\u0026rdquo; \u003cem\u003eAnnals of the Royal College of Surgeons of England\u003c/em\u003e, vol. 93, no. 1, pp. 31\u0026ndash;33, 2011.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"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":"Diabetes mellitus, Stone access rate, Ureteroscopic lithotripsy","lastPublishedDoi":"10.21203/rs.3.rs-7590092/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7590092/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjectives: \u003c/strong\u003eThis study aimed to assess the independent effect of diabetes mellitus (DM) on ureteral stone access and surgical outcomes in patients undergoing ureteroscopic lithotripsy (URS).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods: \u003c/strong\u003eBetween February 2024 and August 2024, a total of 149 patients, including 50 patients with DM (Group 1) and 99 patients without DM (Group 2), were included in the study. Patients aged 18 to 80 years who were scheduled for surgery for ureteral calculi in our hospital were included in the study. Patients with any systemic disease other than diabetes mellitus, patients with previous surgery for kidney stones or ureteral calculi, patients undergoing diagnostic URS, pregnant women, patients with oncologic diseases and patients with one kidney were excluded.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eThere were statistically significant differences between the groups in terms of age, height, BMI and stone volume (p\u0026lt;0.001, p\u0026lt;0.001, p=0.004, p=0.004). The stone access rate was significantly different between the groups (p\u0026lt;0.001), with a higher success rate in group 2 (85.9%) compared to group 1 (58.0%). The stone-free rate was also significantly higher in group 2 (p=0.033). Patients with diabetes mellitus had a significantly lower likelihood of successful stone access, indicating a strong and statistically significant contribution of this variable to the model (p\u0026lt;0.001)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003ePatients with diabetes mellitus have significantly lower stone access rates during URS. In DM patients scheduled for surgery for urolithiasis, considering the possibility of difficult ureters, structuring preoperative evaluation and surgical planning processes accordingly and implementing different preventive strategies if necessary may increase clinical success.\u003c/p\u003e","manuscriptTitle":"Impact of Diabetes Mellitus on Stone Access and Surgical Outcomes in Patients Undergoing Ureteroscopic Lithotripsy: A Retrospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-12 09:55:17","doi":"10.21203/rs.3.rs-7590092/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":"a6a3545f-7a2f-4cae-9441-efb1eba1a9be","owner":[],"postedDate":"September 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-09-12T15:23:21+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-12 09:55:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7590092","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7590092","identity":"rs-7590092","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}