Causes of damage of single use ureteroscope: a single center 2-year experience

Causes of damage of single use ureteroscope: a single center 2-year experience | 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 Causes of damage of single use ureteroscope: a single center 2-year experience Mohamed El-Shazly, Ammar Alorabi, Hossam Kandeel, Mohammed Aziz This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5850232/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 14 Oct, 2025 Read the published version in African Journal of Urology → Version 1 posted 11 You are reading this latest preprint version Abstract Background Since the evolution of flexible ureteroscopy from being reusable to disposable then reused disposable scopes aimed basically to reduce the cost, this study was conducted to evaluate the causes of reused disposable flexible ureteroscope damage in order to extend its longevity and increase the number of procedures per scope. Patients and Methods: This retrospective study was conducted in a single center between September 2022 and September 2024. Sixty-two reused disposable flexible ureteroscopes after resterilization were used for 202 patients over 235.7 hours. Potential causes of scope damage were observed, recorded and analyzed. Results The observed causes of reused disposable flexible ureteroscope damage were as follows: 32.3% of scopes were damaged by laser fiber related damage (either by sudden withdrawal of fiber during firing or transmitted energy), 27.4% by sustained excessive deflection, 19.4% by scope backloading technique, 9.6% by traumatic ureteral access sheath usage (such as scope withdrawal while deflected over the access sheath and stone fragment lodgment between the sheath and scope) and 11.3% by instrumental working channel damage. On comparing different related causes of damage, fine deflection proved to be superior to excessive deflection (p < 0.001) and access sheath usage proved to be significantly superior to backloading (p = 0.005) while there were no significant difference on comparing laser settings. Conclusion Longevity of su-FURS can be extended through the avoidance of possible causes of damage. The best cost effective practice can be achieved by performing flexible ureteroscopy with avoidance of scope backloading in tight ureter and using of ureteral access sheath, avoidance of excessive deflection by lower calyceal stone relocation and avoidance of in-situ disintegration and insertion of laser fiber in a straight scope before deflection with careful holding of the fiber to avoid its sudden withdrawal while firing inside the scope. reused disposable flexible ureteroscope flexible ureteroscopy scope damage durability longevity Introduction Since the first use of flexible ureteroscope (FURS), FURS has been advancing (1, 2) . Therefore, the use of FURS has increased rapidly and widely utilized for both diagnostic and therapeutic purposes for many upper urinary tract pathologies (3) . Less invasive procedures, shorter operative time, higher stone free rate, and shorter length of hospital stay resulted from this technology advancement (4) . The reusable flexible ureteroscope (re-FURS) has proved to have enhanced manoeuvrability because of its small scope diameter. However, the costs of purchasing, maintenance and repair are high (5, 6) . The Scopes will require frequent repair after only 12–15 procedures (7) . Additionally, many studies suggest that scope failure will occur at an average of 9–50 cases (8, 9) . The development of single use flexible ureteroscope (su-FURS) has eliminated the need for scope maintenance and repair along with their high costs (5, 10) . Furthermore, in countries with limited resources, su-FURS is believed to be resterilized and reused as a cost-conscious approach with a low infectious complication rate (11) . Nevertheless, su-FURS can be damaged by several causes such as excessive stress on the deflection mechanism, fault insertion of the laser fiber or basket and the traumatic usage of ureteric access sheath (UAS) (12) . The aim of this study is to evaluate and analyse the causes of reused disposable flexible ureteroscope (rd-FURS) damage. Patients and methods This retrospective study was conducted in a single center between September 2022 and September 2024. The study included 62 reused disposable flexible ureteroscopes which were used for 202 procedures over a duration of 235.7 hours. The study received ethics approval from our local university ethics committee under the number 12-2024UROL13. We performed all procedures using su-FURS. The used su-FURS included a 7.4Fr tip diameter and 8.6Fr outer diameter with full 275-degree scope active deflection in both directions (WiScope® Single-Use Digital Flexible Ureteroscope), a 7.7Fr tip diameter and 9.5Fr outer diameter with full 270-degree scope active deflection in both directions (LithoVue™ Single-Use Digital Flexible Ureteroscope, Boston scientific), a 8.4Fr uniform outer diameter with full 285-degree scope active deflection in both directions (Scivita Medical single-use Videoscope). In pre-stented or non-tight ureters, a 10/12Fr Elephant II Flexible & Navigable Suction Access Sheath (FANS), (YiGaoMed, China) were used. Endoscopic lithotripsy was conducted by Holmium:YAG laser lithotripsy (Sphinx 30 Litho ®, katlenburg-Lindeau, Germany) and using Laser fiber (SureFib reusable 272 µm laser fiber). Renal stones were extracted using nitinol baskets (The Dakota™ nitinol basket 1.9F, Boston Scientific, Natick, MA, USA). All scopes were sterilized prior to reusing using low-temperature hydrogen peroxide gas. The process occurred at a temperature 18–35°C with average total time of 40 minutes. sterilization procedures were conducted by specialized sterilization personnel. Patients who had renal stone(s) diagnosed by abdominopelvic CT with negative preoperative urine culture were included while patients who were unfit for surgery or with active urinary tract infection were excluded. Based on the European Association of Urology guidelines 2024 recommendations, all patients received a single dose of prophylactic antibiotic (Fluoroquinolones) preoperatively. Under general anaesthesia, procedures were undergone by experienced staff in supine lithotomy position. Flexible ureteroscopies were preceded by 2–4-week double J stenting in the majority of cases. Following flexible ureteroscopies, all cases had a double J stent inserted for 2–4 weeks then removed. Data on the total duration and number of usage times for each scope were recorded. Possible causes of FURS damage were observed and recorded. Statistical analysis of the data Data were fed to the computer and analysed using IBM SPSS software package version 20.0. (Armonk, NY: IBM Corp, released in 2011). Categorical data were represented as numbers and percentages. Chi-square test was applied to compare between two groups. Alternatively, Fisher Exact correction test was applied when more than 20% of the cells have expected count less than 5. For continuous data, they were tested for normality by the Kolmogorov-Smirnov test. Quantitative data were expressed as range (minimum and maximum), mean, standard deviation and median Student t-test was used to compare two groups for normally distributed quantitative variables while. On the other hand, Mann Whitney test was used to compare two groups for not normally distributed quantitative variables while Kruskal Wallis test was used to compare different groups for not normally distributed quantitative variables. Significance of the obtained results was judged at the 5% level. Results Regarding stone characters, 25 stones were in lower calyx (40.3%), 18 (29.0%) of which were disintegrated in place while 7 (11.3%) were disintegrated after relocation to another site in the pelvicalyceal system, 14 stones were in middle calyx (22.6%), 11 stones were in renal pelvis (17.7%), 8 stones were in pelvi-ureteric junction (12.9%) and 4 stones were in upper calyx (6.5%). The median stone volume was 1775 mm 3 and the median Hounsfield unit was 900 HU. The majority of stones were radio-opaque (88.7%) while only 4.8% and 6.5% were radio-faint and lucent respectively. 64.5% of procedures were preoperatively stented with double J (Table 1 ). Regarding postoperative complications, fever was reported after 40 procedures out of 202 procedures (19.8%) and hematuria was reported after 13 procedures out of 202 procedures (6.4%). The postoperative fever was not associated with serious sepsis in any of our cases. Moreover, fever following the first su-FURS use was observed in 9 out of 62 cases (14.5%) versus 31 out 140 cases (22.1%) following resterilized rd-FURS with no significant difference between both (p = 0.209) (Table 1 ). Data on the longevity and device burden per scope was demonstrated in (Table 1 ). Median scope lifespan was 3 hours and median number of procedures undergone by each scope was 3 procedures with a median procedure duration of 1.17 hours. Dormia was used in 40.3% of procedures. Table 1 treatment characteristics, device longevity and burden Treatment characteristics Stone site, n (%) Upper calyx 4 (6.5%) Middle calyx 14 (22.6%) Lower calyx 25 (40.3%) Lower calyx stone (disintegrated in-situ) 18 (29.0%) Lower calyx stone (disintegrated after relocation) 7 (11.3%) Pelvi-ureteric junction 8 (12.9%) Renal pelvis 11 (17.7%) Median stone Volume, mm³ (IQR) 1775.0 (1500.0–3000.0) Stone radio-opacity, n (%) Opaque 55 (88.7%) Faint 3 (4.8%) Lucent 4 (6.5%) Median Hounsfield unit, HU (IQR) 900.0 (800.0–1000.0) Procedures with preoperative double J stenting, n (%) 40 (64.5%) Postoperative reported complications, n (%) 53/202 (26.2%) Hematuria 13/202 (6.4%) Fever 40/202 (19.8%) Fever following the first su-FURS use 9/62 (14.5%) P value = 0.209 Fever following the resterilized rd-FURS use 31/140 (22.1%) Longevity and device burden per scope Median scope lifespan, h (IQR) 3.00 (2.00–5.25) Median number of procedures, n (IQR) 3 (2–5) Median procedure duration, h (IQR) 1.17 (1.00–1.33) Procedures with access sheath usage, n (%) 43 (69.4%) Procedures with dormia basket usage, n (%) 25 (40.3%) HU, Hounsfield unit; IQR, interquartile range; SD, standard deviation; su-FURS, single use flexible ureteroscope; rd-FURS, reused disposable flexible ureteroscope. Causes of scope damage were analysed. The most prevalent cause for scope damage was laser fiber related damage in 20 scopes (32.3%) followed by sustained excessive deflection in 17 scopes (27.4%). Scope backloading technique caused damage to 12 scopes (19.4%) while traumatic UAS usage was associated with damage of 6 scopes (9.6%). Instrumental working channel damage caused damage to 7 (11.3%) scopes (Table 2 ). Table 2 Causes of damaged scopes. Cause of damage Number (%) Scope backloading, n (%) 12 (19.4%) Laser fiber related damage, n (%) 20 (32.3%) Sustained excessive deflection, n (%) 17 (27.4%) Traumatic access sheath usage, n (%) 6 (9.6%) Instrumental working channel damage, n (%) 7 (11.3%) Different related causes of damage were compared to each other. Comparison between laser settings, high and low energy settings, showed no significant difference between both arms of comparison either for the overall number of damaged scopes (p = 0.098) or the specific causes of damage either sudden withdrawal of laser fiber during firing or transmitted energy (p = 0.568) (Table 3 ). Regarding scopes damaged by loss of deflection system, there were 15 damaged scopes out of 18 scopes that experienced excessive deflection (83.3%) versus 2 damaged scopes out of 44 scopes that experienced fine deflection (4.5%) which represented a statistically significant difference (p < 0.001) (Table 3 ). Another comparison between scope backloading and UAS usage showed a significant difference between both groups regarding the overall number of damaged scopes (p = 0.005) while there was no difference regarding the specific causes of damage including guide wire malfunction, stone fragment lodgement, ureteric resistance and scope withdrawal while deflected over the UAS (p = 0.332) (Table 3 ). Table 3 Comparisons between different related causes of scope damage. High energy laser setting (2J/10Hz) (n = 34) Low energy laser setting (1J/15Hz) (n = 28) P-value Damaged scopes, n (%) 14/34 (41.2%) 6/28 (21.4%) 0.098 Cause of damage Sudden fiber withdrawal, n (%) 10 (71.4%) 5 (83.3%) 0.573 Transmitted energy, n (%) 4 (28.6%) 1 (16.7%) Excessive deflection (n = 18) Fine deflection (n = 44) P-value Damaged scopes by loss of deflection system, n (%) 15/18 (83.3%) 2/44 (4.5%) < 0.001 Scope backloading (n = 19) Access sheath usage (n = 43) P-value Damaged scopes, n (%) 12/19(63.1%) 6/43(13.9%) 0.005 Cause of damage Guide wire malfunction, n (%) 5 (41.7%) 1 (16.6%) 0.332 Stone fragment lodgment, n (%) 5 (41.7%) 4 (66.8%) Ureteric resistance, n (%) 2 (16.6%) 0 (0.0%) scope withdrawal while deflected over the access sheath, n (%) 0 (0.0%) 1 (16.6%) Discussion Over the last decade, su-FURS has proven to be a comparable alternative to re-FURS (13) . There is a lack of clinical evidence supporting su-FURS standard use or its specific indications despite the fact that su-FURS have advantages over reusable ones (14) . The evolution of reusing su-FURS approach aimed to decrease the cost of su-FURS usage without affecting postoperative outcomes (11) . In order to prolong the durability of disposable scopes and increase the number of procedures per scope, our study aimed to highlight the common causes of rd-FURS damage. To the best of our knowledge, no previous studies investigated the causes of rd-FURS. However, Sugino et al, (2022) evaluated factors associated with microdamage to su-FURS following a single procedure (15) . Multiple studies discussed causes that contributed to re-FURS damage either through data collected from the manufacturer or by direct scope evaluation (1, 16, 17) . This study included 62 rd-FURS used for 202 procedures, with median procedures per scope of 3 procedures, over duration of 235.7 hours with median scope lifespan of 3 hours. The most frequent cause of damage was mediated by laser fiber which we observed in 32.3% of the damaged scopes. Since stone ureteroscopy was the only indication for flexible ureteroscopy in our procedures, laser was used in all procedures either in high energy laser setting (2J/10Hz) or low energy laser setting (1J/15Hz). Consequently, we compared the overall number of damaged scopes in both setting groups to each other with no significant difference between both groups. Additionally, we compared the specific mode of damage in both setting groups including transmitted energy and sudden laser fiber withdrawal during firing with no significant difference between both groups. On the contrary, Sugino et al, (2022) founded that laser energy was not associated with the risk of scope damage (15) . This may be attributed to the fact that laser energy effect is believed to be accumulated over multiple procedures. As a confirmation to this, Juliebø-Jones et al, (2023) showed that direct laser energy caused damage to 23 (15.6%) of the damaged re-FURS versus 0% of the damaged su-FURS (17) . Moreover, Sung et al,(2005) showed that laser energy damage was the primary cause of re-FURS damage by causing burns and punctures to working channel, optic fibers, shaft and even to the deflection components (6) . Loss of deflection system was the second most frequent mode of damage that was observed in 27.4% of the damaged scopes. Loss of deflection system is believed to result from excessive, sustained and prolonged deflection which occur mostly in lower calyceal stones management. We compared the deflection for lower calyx stone disintegration in-situ versus the deflection for relocated lower calyx stones to another site in pelvicalyceal system, upper and middle calyceal, pelvic and pelvicalyceal stones. Lower calyceal stone disintegration in-situ required excessive deflection while the other stones required only fine or no deflection. This comparison revealed that stones that required excessive deflection caused deflection system failure more than stones that required fine or no deflection with a statistically significant difference. Deflection failure was observed in 5 out of 30 su-FURS in the study by Sugino et al, (2022) representing the most common cause of microdamage to su-FURS (15) . Juliebø-Jones et al, (2023) likewise found that deflection failure occurred in 8 (5.4%) of the damaged re-FURS and 2 (3.4%) of the damaged su-FURS (17) . Loss of deflection was considered the most frequent cause of re-FURS damage in the review article by Hosny et al, (2019) (1) . Ozimek et al, (2018), who focused on the steep infundibulo-pelvic angle as a risk factor for re-FURS damage, showed that lower calyceal stones with steep infundibulo-pelvic angle were present in 60.53% of the damaged FURS regardless of the complexity of the stone (18) . Additionally, Sung et al, (2005) showed that 15% of the damaged re-FURS were attributed to the failure of deflection system (6) . One of the most frequently observed causes of damage was the scope backloading in 17.7% of the damaged scopes. Although the use of UAS was one of the damage causes, we found that UAS usage was superior to scope backloading without UAS usage. On comparing UAS usage to backloading, 6 scopes were damaged out of 43 scopes in which UAS used (13.9%) versus 12 damaged scopes out of 19 scopes used by backloading technique (63.1%) which represents a statistically significant difference. Nevertheless, when we compared both groups regarding the specific causes of damage (such as stone fragment lodgment, ureteric resistance and guidewire malfunctions), there was no significant difference. In alignment to our findings, Multescu et al, (2014) considered that prolonged lifespan of re-FURS was significantly associated with UAS usage by reducing the resistance during insertion in addition to its beneficial ease of stone fragments removal and minimizing the intrarenal pressure (19) . However, many studies have stated theories about damage mediated by UAS usage including bending of deflected FURS against the tip of the UAS, stone fragment lodgement between the FURS and UAS during forcible removal of the scope (1) . Instrument mediated working channel damage was observed in minority of the damaged scopes in this study in 11.3% of the affected scopes. Sugino et al, (2022) showed that instrumental working channel damage such as using basket wire catheter represents a risk factor for su-FURS damage (15) . Similarly, Juliebø-Jones et al, (2023) found that damaged working channel by basket occurred in 9 (6.1%) of the damaged re-FURS while 0 (0%) of the damaged su-FURS (17) . On the other hand, the working channel accounted for the highest percentage of repairs in 52% of the damaged re-FURS as reported by Sung et al, (2005) (6) . Gauhar et al, (2024) observed Postoperative fever in 13.7% of the cases in which rd-FURS was used while we observed fever in 22.1% of the cases in which resterilized rd-FURS was used (11) . We likewise compared postoperative fever following the first su-FURS use to that following resterilized rd-FURS. However, this difference did not reach the significance level. Our study allowed the evaluation of rd-FURS regarding causes of damage which to our knowledge is a novel study. We managed to observe these causes when using different types of su-FURS which may enhance the robustness of our results. However, there were a few limitations that needed to be addressed. One of these limitations was the relatively small number of evaluated scopes. Additionally, procedures were undergone under different surgical situations and surgeons. We believe our study would contribute to prolongation of su-FURS longevity, avoidance of its damage causes and consequently, reduction of flexible ureteroscopy procedure costs. Conclusion Longevity of su-FURS can be extended through the avoidance of possible causes of damage. The best cost effective practice can be achieved by performing flexible ureteroscopy with avoidance of scope backloading in tight ureter and using UAS, avoidance of excessive deflection by lower calyceal stone relocation and avoidance of in-situ disintegration and insertion of laser fiber in a straight scope before deflection with careful holding of the fiber to avoid its withdrawal and firing inside the scope. Abbreviations Flexible ureteroscope FURS single use flexible ureteroscope su-FURS reusable flexible ureteroscope re-FURS reused disposable flexible ureteroscope rd-FURS ureteric access sheath UAS Flexible & Navigable Suction Access Sheath FANS. Declarations Ethics approval and consent to participate statement: The study received ethics approval from our local university ethics committee (institutional review board [IRB]) under the number 12-2024UROL13. We obtained informed consent from all patients prior to participating in the study. Consent for publication statement: Not applicable. Funding statement: No funding was received for conducting this study or to assist with the preparation of this manuscript. Author Contribution M.E. conceived the idea and design of the work. A.A. wrote the main manuscript text. H.K. collected the data. M.A. did the data analysis and interpretation. All authors reviewed the manuscript. Acknowledgement The authors would like to express gratitude towards all the patients who participated in our study. References Hosny K, Clark J, Srirangam SJ. Handling and protecting your flexible ureteroscope: how to maximise scope usage. Translational andrology and urology . 2019;8(Suppl 4):S426. Alenezi H, Denstedt JD. Flexible ureteroscopy: Technological advancements, current indications and outcomes in the treatment of urolithiasis. Asian Journal of Urology . 2015;2(3):133. Ordon M, Urbach D, Mamdani M, Saskin R, Honey RJDA, Pace KT. A population based study of the changing demographics of patients undergoing definitive treatment for kidney stone disease. The Journal of urology . 2015;193(3):869. Mi Y, Ren K, Pan H, Zhu L, Wu S, You X, Shao H, Dai F, Peng T, Qin F. Flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stone< 2 cm: a meta-analysis. Urolithiasis . 2016;44:353. Shah K, Monga M, Knudsen B. Prospective randomized trial comparing 2 flexible digital ureteroscopes: ACMI/Olympus Invisio DUR-D and Olympus URF-V. Urology . 2015;85(6):1267. Sung JC, Springhart WP, Marguet CG, James O, Tan YH, Albala DM, Preminger GM. Location and etiology of flexible and semirigid ureteroscope damage. Urology . 2005;66(5):958. Landman J, Lee DI, Lee C, Monga M. Evaluation of overall costs of currently available small flexible ureteroscopes. Urology . 2003;62(2):218. Traxer O, Dubosq F, Jamali K, Gattegno B, Thibault P. 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Juliebø-Jones P, Somani BK, Tzelves L, Æsøy MS, Gjengstø P, Moen CA, Beisland C, Ulvik Ø. Device failure and adverse events related to single-use and reusable flexible ureteroscopes: findings and new insights from an 11-year analysis of the manufacturer and user facility device experience database. Urology . 2023;177:41. Ozimek T, Cordes J, Wiessmeyer J, Schneider M, Hupe M, Gilbert N, Merseburger A, Kramer M. Steep infundibulopelvic angle (IPA) as a new risk factor for flexible ureteroscope damage and complicated postoperative course. European Urology Supplements . 2018;17(4):e2005. Multescu R, Geavlete B, Georgescu D, Geavlete P. Improved durability of flex-Xc digital flexible ureteroscope: how long can you expect it to last? Urology . 2014;84(1):32. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 14 Oct, 2025 Read the published version in African Journal of Urology → Version 1 posted Editorial decision: Revision requested 22 May, 2025 Reviews received at journal 18 May, 2025 Reviews received at journal 09 May, 2025 Reviewers agreed at journal 02 May, 2025 Reviewers agreed at journal 02 May, 2025 Reviews received at journal 30 Apr, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers invited by journal 10 Mar, 2025 Editor assigned by journal 21 Jan, 2025 Submission checks completed at journal 21 Jan, 2025 First submitted to journal 17 Jan, 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. 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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-5850232","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":405326889,"identity":"67a8a7a8-2e91-455d-8cfd-42f5387c52c7","order_by":0,"name":"Mohamed El-Shazly","email":"","orcid":"","institution":"Faculty of medicine, Menoufia University","correspondingAuthor":false,"prefix":"","firstName":"Mohamed","middleName":"","lastName":"El-Shazly","suffix":""},{"id":405326890,"identity":"21f864b3-3a35-4004-8112-ca25ba6526e2","order_by":1,"name":"Ammar Alorabi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCUlEQVRIiWNgGAWjYBADGSBmY0io+CcH4h14QIQWHoiWMweMwVoSiNbC2HYgsQHExaeFf9rpxM8VDHY8/NKHnz142HYnfX7Y4YdAW+zkdBuwa5G4nbtZ8gxDMo9kX5q5QcK5Z7kbb6cZALUkG5sdwGHN7dwNkg0MzDwGZxjMJBLKmHM3zk4AaTmQuA2HFnmgLT8bGOqBWti/SSSwMacbzk7/gFeLwe3cbUBbDgO18ABtaTucIC+dg98WQ6AWywaD4zySPTzlBgln0gw3SOcUHEgwwO0XOaDDbjZUVMvx87Bve/ijwkZefnb65g8fKuzkcHof4jxk9gF0EYJAvoEU1aNgFIyCUTASAACD52GMH1gJlgAAAABJRU5ErkJggg==","orcid":"","institution":"Faculty of medicine, Menoufia University","correspondingAuthor":true,"prefix":"","firstName":"Ammar","middleName":"","lastName":"Alorabi","suffix":""},{"id":405326891,"identity":"353b93f6-e096-4b52-84d6-e65790724cd4","order_by":2,"name":"Hossam Kandeel","email":"","orcid":"","institution":"Faculty of medicine, Menoufia University","correspondingAuthor":false,"prefix":"","firstName":"Hossam","middleName":"","lastName":"Kandeel","suffix":""},{"id":405326892,"identity":"64ca4459-50c6-4187-b936-2ef25306f57f","order_by":3,"name":"Mohammed Aziz","email":"","orcid":"","institution":"Faculty of medicine, Menoufia University","correspondingAuthor":false,"prefix":"","firstName":"Mohammed","middleName":"","lastName":"Aziz","suffix":""}],"badges":[],"createdAt":"2025-01-17 15:08:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5850232/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5850232/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12301-025-00532-8","type":"published","date":"2025-10-14T15:57:18+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":93955963,"identity":"19f7bae1-db86-4cbc-90a5-ffd1c97cef8e","added_by":"auto","created_at":"2025-10-20 16:08:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":633595,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5850232/v1/0b3e1761-d87c-448e-a91b-7cca9a577232.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Causes of damage of single use ureteroscope: a single center 2-year experience","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSince the first use of flexible ureteroscope (FURS), FURS has been advancing \u003cb\u003e(1, 2)\u003c/b\u003e. Therefore, the use of FURS has increased rapidly and widely utilized for both diagnostic and therapeutic purposes for many upper urinary tract pathologies \u003cb\u003e(3)\u003c/b\u003e. Less invasive procedures, shorter operative time, higher stone free rate, and shorter length of hospital stay resulted from this technology advancement \u003cb\u003e(4)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eThe reusable flexible ureteroscope (re-FURS) has proved to have enhanced manoeuvrability because of its small scope diameter. However, the costs of purchasing, maintenance and repair are high \u003cb\u003e(5, 6)\u003c/b\u003e. The Scopes will require frequent repair after only 12\u0026ndash;15 procedures \u003cb\u003e(7)\u003c/b\u003e. Additionally, many studies suggest that scope failure will occur at an average of 9\u0026ndash;50 cases \u003cb\u003e(8, 9)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eThe development of single use flexible ureteroscope (su-FURS) has eliminated the need for scope maintenance and repair along with their high costs \u003cb\u003e(5, 10)\u003c/b\u003e. Furthermore, in countries with limited resources, su-FURS is believed to be resterilized and reused as a cost-conscious approach with a low infectious complication rate \u003cb\u003e(11)\u003c/b\u003e. Nevertheless, su-FURS can be damaged by several causes such as excessive stress on the deflection mechanism, fault insertion of the laser fiber or basket and the traumatic usage of ureteric access sheath (UAS) \u003cb\u003e(12)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eThe aim of this study is to evaluate and analyse the causes of reused disposable flexible ureteroscope (rd-FURS) damage.\u003c/p\u003e"},{"header":"Patients and methods","content":"\u003cp\u003eThis retrospective study was conducted in a single center between September 2022 and September 2024. The study included 62 reused disposable flexible ureteroscopes which were used for 202 procedures over a duration of 235.7 hours. The study received ethics approval from our local university ethics committee under the number 12-2024UROL13.\u003c/p\u003e \u003cp\u003eWe performed all procedures using su-FURS. The used su-FURS included a 7.4Fr tip diameter and 8.6Fr outer diameter with full 275-degree scope active deflection in both directions (WiScope\u0026reg; Single-Use Digital Flexible Ureteroscope), a 7.7Fr tip diameter and 9.5Fr outer diameter with full 270-degree scope active deflection in both directions (LithoVue\u0026trade; Single-Use Digital Flexible Ureteroscope, Boston scientific), a 8.4Fr uniform outer diameter with full 285-degree scope active deflection in both directions (Scivita Medical single-use Videoscope). In pre-stented or non-tight ureters, a 10/12Fr Elephant II Flexible \u0026amp; Navigable Suction Access Sheath (FANS), (YiGaoMed, China) were used. Endoscopic lithotripsy was conducted by Holmium:YAG laser lithotripsy (Sphinx 30 Litho \u0026reg;, katlenburg-Lindeau, Germany) and using Laser fiber (SureFib reusable 272 \u0026micro;m laser fiber). Renal stones were extracted using nitinol baskets (The Dakota\u0026trade; nitinol basket 1.9F, Boston Scientific, Natick, MA, USA).\u003c/p\u003e \u003cp\u003eAll scopes were sterilized prior to reusing using low-temperature hydrogen peroxide gas. The process occurred at a temperature 18\u0026ndash;35\u0026deg;C with average total time of 40 minutes. sterilization procedures were conducted by specialized sterilization personnel.\u003c/p\u003e \u003cp\u003ePatients who had renal stone(s) diagnosed by abdominopelvic CT with negative preoperative urine culture were included while patients who were unfit for surgery or with active urinary tract infection were excluded.\u003c/p\u003e \u003cp\u003e Based on the European Association of Urology guidelines 2024 recommendations, all patients received a single dose of prophylactic antibiotic (Fluoroquinolones) preoperatively. Under general anaesthesia, procedures were undergone by experienced staff in supine lithotomy position. Flexible ureteroscopies were preceded by 2\u0026ndash;4-week double J stenting in the majority of cases. Following flexible ureteroscopies, all cases had a double J stent inserted for 2\u0026ndash;4 weeks then removed.\u003c/p\u003e \u003cp\u003eData on the total duration and number of usage times for each scope were recorded. Possible causes of FURS damage were observed and recorded.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis of the data\u003c/h2\u003e \u003cp\u003eData were fed to the computer and analysed using IBM SPSS software package version 20.0. (Armonk, NY: IBM Corp, released in 2011). Categorical data were represented as numbers and percentages. Chi-square test was applied to compare between two groups. Alternatively, Fisher Exact correction test was applied when more than 20% of the cells have expected count less than 5. For continuous data, they were tested for normality by the Kolmogorov-Smirnov test. Quantitative data were expressed as range (minimum and maximum), mean, standard deviation and median Student t-test was used to compare two groups for normally distributed quantitative variables while. On the other hand, Mann Whitney test was used to compare two groups for not normally distributed quantitative variables while Kruskal Wallis test was used to compare different groups for not normally distributed quantitative variables. Significance of the obtained results was judged at the 5% level.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eRegarding stone characters, 25 stones were in lower calyx (40.3%), 18 (29.0%) of which were disintegrated in place while 7 (11.3%) were disintegrated after relocation to another site in the pelvicalyceal system, 14 stones were in middle calyx (22.6%), 11 stones were in renal pelvis (17.7%), 8 stones were in pelvi-ureteric junction (12.9%) and 4 stones were in upper calyx (6.5%). The median stone volume was 1775 mm\u003csup\u003e3\u003c/sup\u003e and the median Hounsfield unit was 900 HU. The majority of stones were radio-opaque (88.7%) while only 4.8% and 6.5% were radio-faint and lucent respectively. 64.5% of procedures were preoperatively stented with double J (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRegarding postoperative complications, fever was reported after 40 procedures out of 202 procedures (19.8%) and hematuria was reported after 13 procedures out of 202 procedures (6.4%). The postoperative fever was not associated with serious sepsis in any of our cases. Moreover, fever following the first su-FURS use was observed in 9 out of 62 cases (14.5%) versus 31 out 140 cases (22.1%) following resterilized rd-FURS with no significant difference between both (p\u0026thinsp;=\u0026thinsp;0.209) (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eData on the longevity and device burden per scope was demonstrated in (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Median scope lifespan was 3 hours and median number of procedures undergone by each scope was 3 procedures with a median procedure duration of 1.17 hours. Dormia was used in 40.3% of procedures.\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\u003etreatment characteristics, device longevity and burden\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\u003eTreatment characteristics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStone site, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUpper calyx\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e4 (6.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMiddle calyx\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e14 (22.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLower calyx\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e25 (40.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLower calyx stone (disintegrated in-situ)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e18 (29.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLower calyx stone (disintegrated after relocation)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e7 (11.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePelvi-ureteric junction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e8 (12.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRenal pelvis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e11 (17.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian stone Volume, mm\u0026sup3; (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e1775.0 (1500.0\u0026ndash;3000.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStone radio-opacity, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOpaque\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e55 (88.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFaint\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e3 (4.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLucent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e4 (6.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian Hounsfield unit, HU (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e900.0 (800.0\u0026ndash;1000.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedures with preoperative double J stenting, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e40 (64.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePostoperative reported complications, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e53/202 (26.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHematuria\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e13/202 (6.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFever\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e40/202 (19.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFever following the first su-FURS use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9/62 (14.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eP value\u0026thinsp;=\u0026thinsp;0.209\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFever following the resterilized rd-FURS use\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31/140 (22.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLongevity and device burden per scope\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian scope lifespan, h (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e3.00 (2.00\u0026ndash;5.25)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian number of procedures, n (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e3 (2\u0026ndash;5)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian procedure duration, h (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e1.17 (1.00\u0026ndash;1.33)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedures with access sheath usage, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e43 (69.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProcedures with dormia basket usage, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e25 (40.3%)\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\u003eHU, Hounsfield unit; IQR, interquartile range; SD, standard deviation; su-FURS, single use flexible ureteroscope; rd-FURS, reused disposable flexible ureteroscope.\u003c/p\u003e \u003cp\u003eCauses of scope damage were analysed. The most prevalent cause for scope damage was laser fiber related damage in 20 scopes (32.3%) followed by sustained excessive deflection in 17 scopes (27.4%). Scope backloading technique caused damage to 12 scopes (19.4%) while traumatic UAS usage was associated with damage of 6 scopes (9.6%). Instrumental working channel damage caused damage to 7 (11.3%) scopes (Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\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\u003eCauses of damaged scopes.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCause of damage\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eScope backloading, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12 (19.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLaser fiber related damage, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20 (32.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSustained excessive deflection, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17 (27.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTraumatic access sheath usage, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (9.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInstrumental working channel damage, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 (11.3%)\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\u003eDifferent related causes of damage were compared to each other. Comparison between laser settings, high and low energy settings, showed no significant difference between both arms of comparison either for the overall number of damaged scopes (p\u0026thinsp;=\u0026thinsp;0.098) or the specific causes of damage either sudden withdrawal of laser fiber during firing or transmitted energy (p\u0026thinsp;=\u0026thinsp;0.568) (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRegarding scopes damaged by loss of deflection system, there were 15 damaged scopes out of 18 scopes that experienced excessive deflection (83.3%) versus 2 damaged scopes out of 44 scopes that experienced fine deflection (4.5%) which represented a statistically significant difference (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAnother comparison between scope backloading and UAS usage showed a significant difference between both groups regarding the overall number of damaged scopes (p\u0026thinsp;=\u0026thinsp;0.005) while there was no difference regarding the specific causes of damage including guide wire malfunction, stone fragment lodgement, ureteric resistance and scope withdrawal while deflected over the UAS (p\u0026thinsp;=\u0026thinsp;0.332) (Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparisons between different related causes of scope damage.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHigh energy laser setting (2J/10Hz)\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;34)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLow energy laser setting (1J/15Hz)\u003c/p\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;28)\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\u003eDamaged scopes, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14/34 (41.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6/28 (21.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.098\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCause of damage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSudden fiber withdrawal, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (71.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (83.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.573\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTransmitted energy, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (28.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (16.7%)\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\u003e\u003cb\u003eExcessive deflection\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(n\u0026thinsp;=\u0026thinsp;18)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eFine deflection\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(n\u0026thinsp;=\u0026thinsp;44)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eP-value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDamaged scopes by loss of deflection system, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15/18 (83.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2/44 (4.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eScope backloading\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(n\u0026thinsp;=\u0026thinsp;19)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eAccess sheath usage\u003c/b\u003e\u003c/p\u003e \u003cp\u003e\u003cb\u003e(n\u0026thinsp;=\u0026thinsp;43)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eP-value\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDamaged scopes, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12/19(63.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6/43(13.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCause of damage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGuide wire malfunction, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (41.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (16.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003e0.332\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStone fragment lodgment, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5 (41.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (66.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUreteric resistance, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (16.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003escope withdrawal while deflected over the access sheath, n (%)\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 (16.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOver the last decade, su-FURS has proven to be a comparable alternative to re-FURS \u003cb\u003e(13)\u003c/b\u003e. There is a lack of clinical evidence supporting su-FURS standard use or its specific indications despite the fact that su-FURS have advantages over reusable ones \u003cb\u003e(14)\u003c/b\u003e. The evolution of reusing su-FURS approach aimed to decrease the cost of su-FURS usage without affecting postoperative outcomes \u003cb\u003e(11)\u003c/b\u003e. In order to prolong the durability of disposable scopes and increase the number of procedures per scope, our study aimed to highlight the common causes of rd-FURS damage.\u003c/p\u003e \u003cp\u003eTo the best of our knowledge, no previous studies investigated the causes of rd-FURS. However, Sugino et al, (2022) evaluated factors associated with microdamage to su-FURS following a single procedure \u003cb\u003e(15)\u003c/b\u003e. Multiple studies discussed causes that contributed to re-FURS damage either through data collected from the manufacturer or by direct scope evaluation \u003cb\u003e(1, 16, 17)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eThis study included 62 rd-FURS used for 202 procedures, with median procedures per scope of 3 procedures, over duration of 235.7 hours with median scope lifespan of 3 hours. The most frequent cause of damage was mediated by laser fiber which we observed in 32.3% of the damaged scopes. Since stone ureteroscopy was the only indication for flexible ureteroscopy in our procedures, laser was used in all procedures either in high energy laser setting (2J/10Hz) or low energy laser setting (1J/15Hz). Consequently, we compared the overall number of damaged scopes in both setting groups to each other with no significant difference between both groups. Additionally, we compared the specific mode of damage in both setting groups including transmitted energy and sudden laser fiber withdrawal during firing with no significant difference between both groups.\u003c/p\u003e \u003cp\u003eOn the contrary, Sugino et al, (2022) founded that laser energy was not associated with the risk of scope damage \u003cb\u003e(15)\u003c/b\u003e. This may be attributed to the fact that laser energy effect is believed to be accumulated over multiple procedures. As a confirmation to this, Julieb\u0026oslash;-Jones et al, (2023) showed that direct laser energy caused damage to 23 (15.6%) of the damaged re-FURS versus 0% of the damaged su-FURS \u003cb\u003e(17)\u003c/b\u003e. Moreover, Sung et al,(2005) showed that laser energy damage was the primary cause of re-FURS damage by causing burns and punctures to working channel, optic fibers, shaft and even to the deflection components \u003cb\u003e(6)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eLoss of deflection system was the second most frequent mode of damage that was observed in 27.4% of the damaged scopes. Loss of deflection system is believed to result from excessive, sustained and prolonged deflection which occur mostly in lower calyceal stones management. We compared the deflection for lower calyx stone disintegration in-situ versus the deflection for relocated lower calyx stones to another site in pelvicalyceal system, upper and middle calyceal, pelvic and pelvicalyceal stones. Lower calyceal stone disintegration in-situ required excessive deflection while the other stones required only fine or no deflection. This comparison revealed that stones that required excessive deflection caused deflection system failure more than stones that required fine or no deflection with a statistically significant difference.\u003c/p\u003e \u003cp\u003eDeflection failure was observed in 5 out of 30 su-FURS in the study by Sugino et al, (2022) representing the most common cause of microdamage to su-FURS \u003cb\u003e(15)\u003c/b\u003e. Julieb\u0026oslash;-Jones et al, (2023) likewise found that deflection failure occurred in 8 (5.4%) of the damaged re-FURS and 2 (3.4%) of the damaged su-FURS \u003cb\u003e(17)\u003c/b\u003e. Loss of deflection was considered the most frequent cause of re-FURS damage in the review article by Hosny et al, (2019)\u003cb\u003e(1)\u003c/b\u003e. Ozimek et al, (2018), who focused on the steep infundibulo-pelvic angle as a risk factor for re-FURS damage, showed that lower calyceal stones with steep infundibulo-pelvic angle were present in 60.53% of the damaged FURS regardless of the complexity of the stone \u003cb\u003e(18)\u003c/b\u003e. Additionally, Sung et al, (2005) showed that 15% of the damaged re-FURS were attributed to the failure of deflection system \u003cb\u003e(6)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eOne of the most frequently observed causes of damage was the scope backloading in 17.7% of the damaged scopes. Although the use of UAS was one of the damage causes, we found that UAS usage was superior to scope backloading without UAS usage. On comparing UAS usage to backloading, 6 scopes were damaged out of 43 scopes in which UAS used (13.9%) versus 12 damaged scopes out of 19 scopes used by backloading technique (63.1%) which represents a statistically significant difference. Nevertheless, when we compared both groups regarding the specific causes of damage (such as stone fragment lodgment, ureteric resistance and guidewire malfunctions), there was no significant difference.\u003c/p\u003e \u003cp\u003eIn alignment to our findings, Multescu et al, (2014) considered that prolonged lifespan of re-FURS was significantly associated with UAS usage by reducing the resistance during insertion in addition to its beneficial ease of stone fragments removal and minimizing the intrarenal pressure \u003cb\u003e(19)\u003c/b\u003e. However, many studies have stated theories about damage mediated by UAS usage including bending of deflected FURS against the tip of the UAS, stone fragment lodgement between the FURS and UAS during forcible removal of the scope \u003cb\u003e(1)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eInstrument mediated working channel damage was observed in minority of the damaged scopes in this study in 11.3% of the affected scopes. Sugino et al, (2022) showed that instrumental working channel damage such as using basket wire catheter represents a risk factor for su-FURS damage \u003cb\u003e(15)\u003c/b\u003e. Similarly, Julieb\u0026oslash;-Jones et al, (2023) found that damaged working channel by basket occurred in 9 (6.1%) of the damaged re-FURS while 0 (0%) of the damaged su-FURS \u003cb\u003e(17)\u003c/b\u003e. On the other hand, the working channel accounted for the highest percentage of repairs in 52% of the damaged re-FURS as reported by Sung et al, (2005) \u003cb\u003e(6)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003eGauhar et al, (2024) observed Postoperative fever in 13.7% of the cases in which rd-FURS was used while we observed fever in 22.1% of the cases in which resterilized rd-FURS was used \u003cb\u003e(11)\u003c/b\u003e. We likewise compared postoperative fever following the first su-FURS use to that following resterilized rd-FURS. However, this difference did not reach the significance level.\u003c/p\u003e \u003cp\u003eOur study allowed the evaluation of rd-FURS regarding causes of damage which to our knowledge is a novel study. We managed to observe these causes when using different types of su-FURS which may enhance the robustness of our results. However, there were a few limitations that needed to be addressed. One of these limitations was the relatively small number of evaluated scopes. Additionally, procedures were undergone under different surgical situations and surgeons.\u003c/p\u003e \u003cp\u003eWe believe our study would contribute to prolongation of su-FURS longevity, avoidance of its damage causes and consequently, reduction of flexible ureteroscopy procedure costs.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eLongevity of su-FURS can be extended through the avoidance of possible causes of damage. The best cost effective practice can be achieved by performing flexible ureteroscopy with avoidance of scope backloading in tight ureter and using UAS, avoidance of excessive deflection by lower calyceal stone relocation and avoidance of in-situ disintegration and insertion of laser fiber in a straight scope before deflection with careful holding of the fiber to avoid its withdrawal and firing inside the scope.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFlexible ureteroscope\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFURS\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003esingle use flexible ureteroscope\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003esu-FURS\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ereusable flexible ureteroscope\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ere-FURS\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ereused disposable flexible ureteroscope\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003erd-FURS\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eureteric access sheath\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eUAS\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eFlexible \u0026amp; Navigable Suction Access Sheath\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eFANS.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate statement:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study received ethics approval from our local university ethics committee (institutional review board [IRB]) under the number 12-2024UROL13. We obtained informed consent from all patients prior to participating in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication statement:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding statement:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for conducting this study or to assist with the preparation of this manuscript.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eM.E. conceived the idea and design of the work. A.A. wrote the main manuscript text. H.K. collected the data. M.A. did the data analysis and interpretation. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors would like to express gratitude towards all the patients who participated in our study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHosny K, Clark J, Srirangam SJ. Handling and protecting your flexible ureteroscope: how to maximise scope usage. \u003cem\u003eTranslational andrology and urology\u003c/em\u003e. 2019;8(Suppl 4):S426.\u003c/li\u003e\n\u003cli\u003eAlenezi H, Denstedt JD. Flexible ureteroscopy: Technological advancements, current indications and outcomes in the treatment of urolithiasis. \u003cem\u003eAsian Journal of Urology\u003c/em\u003e. 2015;2(3):133.\u003c/li\u003e\n\u003cli\u003eOrdon M, Urbach D, Mamdani M, Saskin R, Honey RJDA, Pace KT. A population based study of the changing demographics of patients undergoing definitive treatment for kidney stone disease. \u003cem\u003eThe Journal of urology\u003c/em\u003e. 2015;193(3):869.\u003c/li\u003e\n\u003cli\u003eMi Y, Ren K, Pan H, Zhu L, Wu S, You X, Shao H, Dai F, Peng T, Qin F. Flexible ureterorenoscopy (F-URS) with holmium laser versus extracorporeal shock wave lithotripsy (ESWL) for treatment of renal stone\u0026lt; 2 cm: a meta-analysis. \u003cem\u003eUrolithiasis\u003c/em\u003e. 2016;44:353.\u003c/li\u003e\n\u003cli\u003eShah K, Monga M, Knudsen B. Prospective randomized trial comparing 2 flexible digital ureteroscopes: ACMI/Olympus Invisio DUR-D and Olympus URF-V. \u003cem\u003eUrology\u003c/em\u003e. 2015;85(6):1267.\u003c/li\u003e\n\u003cli\u003eSung JC, Springhart WP, Marguet CG, James O, Tan YH, Albala DM, Preminger GM. Location and etiology of flexible and semirigid ureteroscope damage. \u003cem\u003eUrology\u003c/em\u003e. 2005;66(5):958.\u003c/li\u003e\n\u003cli\u003eLandman J, Lee DI, Lee C, Monga M. Evaluation of overall costs of currently available small flexible ureteroscopes. \u003cem\u003eUrology\u003c/em\u003e. 2003;62(2):218.\u003c/li\u003e\n\u003cli\u003eTraxer O, Dubosq F, Jamali K, Gattegno B, Thibault P. New-generation flexible ureterorenoscopes are more durable than previous ones. \u003cem\u003eUrology\u003c/em\u003e. 2006;68(2):276.\u003c/li\u003e\n\u003cli\u003eZiemba JB, Matlaga BR. Understanding the costs of flexible ureteroscopy. \u003cem\u003eMinerva urologica e nefrologica= The Italian journal of urology and nephrology\u003c/em\u003e. 2016;68(6):586.\u003c/li\u003e\n\u003cli\u003eCarey RI, Martin CJ, Knego JR. Prospective evaluation of refurbished flexible ureteroscope durability seen in a large public tertiary care center with multiple surgeons. \u003cem\u003eUrology\u003c/em\u003e. 2014;84(1):42.\u003c/li\u003e\n\u003cli\u003eGauhar V, Traxer O, Sabnis RB, Fong KY, Gharia P, Grover R, Ragoori D, Lim EJ, Tanidir Y, Mehta A. The reused-disposable scope in flexible ureteroscopy for stones as a cost-conscious approach: Reporting the outcomes of a real-world practice multicenter study of 2183 patients by the team of worldwide endourological researchers group. \u003cem\u003eIndian Journal of Urology\u003c/em\u003e. 2024;40(4):235.\u003c/li\u003e\n\u003cli\u003eSugino T, Taguchi K, Unno R, Hamamoto S, Ando R, Okada A, Yasui T. Microdamage analysis of single-use flexible ureteroscope immediately after lithotripsy use. \u003cem\u003eScientific Reports\u003c/em\u003e. 2022;12(1):18367.\u003c/li\u003e\n\u003cli\u003eJun DY, Cho KS, Jeong JY, Moon YJ, Kang DH, Jung HD, Lee JY. Comparison of surgical outcomes between single-use and reusable flexible ureteroscopes for renal stone management: a systematic review and meta-analysis. \u003cem\u003eMedicina\u003c/em\u003e. 2022;58(10):1388.\u003c/li\u003e\n\u003cli\u003eVentimiglia E, Somani BK, Traxer O. Flexible ureteroscopy: reuse? Or is single use the new direction? \u003cem\u003eCurrent Opinion in Urology\u003c/em\u003e. 2020;30(2):113.\u003c/li\u003e\n\u003cli\u003eSugino T, Taguchi K, Unno R, Hamamoto S, Ando R, Okada A, Yasui T. Factors Associated with Microdamage to Single-Use Flexible Ureteroscope: Prospective Ex Vivo Post-Use Analysis. 2022.\u003c/li\u003e\n\u003cli\u003eLegemate JD, Kamphuis GM, Freund JE, Baard J, Zanetti SP, Catellani M, Oussoren HW, de la Rosette JJ. Durability of flexible ureteroscopes: a prospective evaluation of longevity, the factors that affect it, and damage mechanisms. \u003cem\u003eEuropean urology focus\u003c/em\u003e. 2019;5(6):1105.\u003c/li\u003e\n\u003cli\u003eJulieb\u0026oslash;-Jones P, Somani BK, Tzelves L, \u0026AElig;s\u0026oslash;y MS, Gjengst\u0026oslash; P, Moen CA, Beisland C, Ulvik \u0026Oslash;. Device failure and adverse events related to single-use and reusable flexible ureteroscopes: findings and new insights from an 11-year analysis of the manufacturer and user facility device experience database. \u003cem\u003eUrology\u003c/em\u003e. 2023;177:41.\u003c/li\u003e\n\u003cli\u003eOzimek T, Cordes J, Wiessmeyer J, Schneider M, Hupe M, Gilbert N, Merseburger A, Kramer M. Steep infundibulopelvic angle (IPA) as a new risk factor for flexible ureteroscope damage and complicated postoperative course. \u003cem\u003eEuropean Urology Supplements\u003c/em\u003e. 2018;17(4):e2005.\u003c/li\u003e\n\u003cli\u003eMultescu R, Geavlete B, Georgescu D, Geavlete P. Improved durability of flex-Xc digital flexible ureteroscope: how long can you expect it to last? \u003cem\u003eUrology\u003c/em\u003e. 2014;84(1):32.\u003c/li\u003e\n\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":"african-journal-of-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"afju","sideBox":"Learn more about [African Journal of Urology](http://link.springer.com/journal/12293)","snPcode":"12301","submissionUrl":"https://submission.springernature.com/new-submission/12301/3","title":"African Journal of Urology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"reused disposable flexible ureteroscope, flexible ureteroscopy, scope damage, durability, longevity","lastPublishedDoi":"10.21203/rs.3.rs-5850232/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5850232/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eSince the evolution of flexible ureteroscopy from being reusable to disposable then reused disposable scopes aimed basically to reduce the cost, this study was conducted to evaluate the causes of reused disposable flexible ureteroscope damage in order to extend its longevity and increase the number of procedures per scope.\u003c/p\u003e\u003ch2\u003ePatients and Methods:\u003c/h2\u003e \u003cp\u003eThis retrospective study was conducted in a single center between September 2022 and September 2024. Sixty-two reused disposable flexible ureteroscopes after resterilization were used for 202 patients over 235.7 hours. Potential causes of scope damage were observed, recorded and analyzed.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe observed causes of reused disposable flexible ureteroscope damage were as follows: 32.3% of scopes were damaged by laser fiber related damage (either by sudden withdrawal of fiber during firing or transmitted energy), 27.4% by sustained excessive deflection, 19.4% by scope backloading technique, 9.6% by traumatic ureteral access sheath usage (such as scope withdrawal while deflected over the access sheath and stone fragment lodgment between the sheath and scope) and 11.3% by instrumental working channel damage. On comparing different related causes of damage, fine deflection proved to be superior to excessive deflection (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and access sheath usage proved to be significantly superior to backloading (p\u0026thinsp;=\u0026thinsp;0.005) while there were no significant difference on comparing laser settings.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eLongevity of su-FURS can be extended through the avoidance of possible causes of damage. The best cost effective practice can be achieved by performing flexible ureteroscopy with avoidance of scope backloading in tight ureter and using of ureteral access sheath, avoidance of excessive deflection by lower calyceal stone relocation and avoidance of in-situ disintegration and insertion of laser fiber in a straight scope before deflection with careful holding of the fiber to avoid its sudden withdrawal while firing inside the scope.\u003c/p\u003e","manuscriptTitle":"Causes of damage of single use ureteroscope: a single center 2-year experience","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-24 08:36:19","doi":"10.21203/rs.3.rs-5850232/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-22T14:56:42+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-18T09:09:31+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-09T07:44:22+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"172445934701575012597866572694446489406","date":"2025-05-03T01:10:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"78430565411285897866901114706642225927","date":"2025-05-02T04:20:45+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-01T02:34:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"67014568694012205152809666469666108296","date":"2025-04-30T14:21:55+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-03-10T04:16:35+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-22T00:55:40+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-01-22T00:55:26+00:00","index":"","fulltext":""},{"type":"submitted","content":"African Journal of Urology","date":"2025-01-17T15:04:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"african-journal-of-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"afju","sideBox":"Learn more about [African Journal of Urology](http://link.springer.com/journal/12293)","snPcode":"12301","submissionUrl":"https://submission.springernature.com/new-submission/12301/3","title":"African Journal of Urology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"1695af18-4101-4fb4-a820-081865184cb2","owner":[],"postedDate":"January 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-10-20T16:00:37+00:00","versionOfRecord":{"articleIdentity":"rs-5850232","link":"https://doi.org/10.1186/s12301-025-00532-8","journal":{"identity":"african-journal-of-urology","isVorOnly":false,"title":"African Journal of Urology"},"publishedOn":"2025-10-14 15:57:18","publishedOnDateReadable":"October 14th, 2025"},"versionCreatedAt":"2025-01-24 08:36:19","video":"","vorDoi":"10.1186/s12301-025-00532-8","vorDoiUrl":"https://doi.org/10.1186/s12301-025-00532-8","workflowStages":[]},"version":"v1","identity":"rs-5850232","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5850232","identity":"rs-5850232","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}