Miniaturized Holmium Laser Enucleation of the Prostate (MiLEP): A retrospective Analysis of Technical Efficacy and Safety Using Slim and Ultra Slim Instruments

Miniaturized Holmium Laser Enucleation of the Prostate (MiLEP): A retrospective Analysis of Technical Efficacy and Safety Using Slim and Ultra Slim Instruments | 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 Miniaturized Holmium Laser Enucleation of the Prostate (MiLEP): A retrospective Analysis of Technical Efficacy and Safety Using Slim and Ultra Slim Instruments Patrick Rein, Christina Meisl, Orlando Burkardt, Dominik Abt This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6274610/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 09 Jul, 2025 Read the published version in World Journal of Urology → Version 1 posted 15 You are reading this latest preprint version Abstract Purpose Minimally invasive laser enucleation of the prostate has emerged as a promising treatment for benign prostatic hyperplasia. This study investigates the efficacy and safety of miniaturized holmium laser enucleation of the prostate (MiLEP) using Slim- (22 Fr) and Ultra Slim-HoLEP (18.5 Fr). Methods We retrospectively analyzed 84 patients who underwent MiLEP between February 2022 and October 2023, performed by a single experienced surgeon. Thirteen patients were treated with Ultra Slim HoLEP, and 71 with Slim HoLEP. Perioperative parameters, functional outcomes, and complications were assessed intraoperatively and at 2, 6, and 12 weeks postoperatively. Results Median patient age was 62 [53–80] and 72 [54–86] years in the Ultra Slim and Slim groups, respectively. The median prostate volume was 45 ml [25–75] and 65 ml [20–150], with similar enucleation weights (36 g vs. 35 g). No urethral strictures were observed at three months. Continence rates at 12 weeks reached 100% in the Ultra Slim group and 95.6% in the Slim group. Perioperative efficiency, including total operation time and laser energy use, was comparable between the groups despite differences in prostate volume. Conclusion MiLEP using Slim and Ultra Slim instruments provides a safe and effective alternative to standard HoLEP (≥ 26 Fr), demonstrating favorable postoperative continence and a low complication profile. The findings suggest potential benefits of miniaturized instruments in reducing urethral trauma while maintaining enucleation efficiency. Further prospective studies are warranted to validate these results and explore long-term outcomes. Benign Prostatic Hyperplasia (BPH) Miniaturized HoLEP MiLEP Slim HoLEP Ultra Slim HoLEP Minimally Invasive Prostate Surgery Figures Figure 1 Figure 2 Figure 3 Introduction Holmium laser enucleation of the prostate (HoLEP) has emerged as a gold-standard surgical treatment for BPH, offering durable and effective outcomes comparable to transurethral resection of the prostate (TUR-P) and simple open prostatectomy, with the added benefit of minimal invasiveness( 1 ). Recent advancements in HoLEP techniques have focused on refining surgical outcomes and patient experience, particularly through the introduction of miniaturized instruments( 2 ). Miniaturized Holmium Laser Enucleation of the Prostate (MiLEP) might represent a significant step forward in the evolution of HoLEP. By utilizing smaller-caliber endoscopes, such as the slim (22 Fr) and ultra-slim (18.5 Fr) instruments, MiLEP aims to optimize procedural efficiency while potentially reducing urethral trauma and improving postoperative recovery( 3 ). These innovations are particularly relevant for patients with challenging urethral anatomy, as smaller instruments may contribute to lower rates of urethral strictures and improved continence outcomes ( 3 ). While the effectiveness of Slim HoLEP instruments has been demonstrated in a limited number of studies, no data on Ultra Slim HoLEP has been investigated to date( 2 ). This retrospective study seeks to evaluate efficacy and saftey of MiLEP and compare the clinical outcomes using slim (22 Fr) and ultra-slim (18.5 Fr) HoLEP instruments in the treatment of BPH. Key parameters analyzed include laser time, energy utilization, enucleated tissue weight, pre- and postoperative prostate volume, and patient outcomes such as continence rates and the incidence of urethral strictures at two, six, and twelve weeks postoperatively. By providing a comprehensive assessment of these parameters, this study aims to offer new insights into the efficacy and safety profiles of slim and ultra-slim HoLEP techniques, thereby contributing to the optimization of surgical management for BPH. Methods and Materials Study Design This was a retrospective, single-center study conducted at Cantonal Hospital Grabs to evaluate the outcomes of MiLEP performed by a single surgeon (PR) who had completed the learning curve, defined as 25 consecutive cases under supervision( 4 ). Data were collected and analyzed for procedures conducted between February 2023 and September 2024. The study was approved by the Institutional Review Board (IRB) of Ethikkommission Ostschweiz (EKOS 24/229, Project ID 2024–02405), and patient confidentiality was maintained according to ethical guidelines and the Declaration of Helsinki. Participants All men treated by MiLEP due to LUTS/BPO after completion of the surgeons initial learning curve were included to the study. Intervention The procedure was performed under spinal or general anesthesia, based on patient preference, in lithotomy position. Trimetoprim / Sulfometaxol 160/800mg was administered intraoperatively according to local guidelines or based on preoperative antibiogram. Slim HoLEP (22 Fr) and Ultra Slim HoLEP (18.5 Fr) instruments were obtained from RZ Medizintechnik (Tuttlingen, Germany). A holmium-YAG laser (Cyber-Ho 100, Quanta Laser Systems, Milan, Italy) equipped with a 550-µm end-firing fiber was used, operating at 50 Hz and 1.5 J in Virtual Basket Mode for enucleation, and at 42 Hz and 1.2 J for coagulation. The Ultra Slim HoLEP instrument was employed for prostate volumes below 50 ml, if available. Following enucleation, coagulation was performed using either the laser or bipolar coagulation, utilizing the Slim HoLEP (22 Fr) instrument and the Autocon III generator (Karl Storz, Tuttlingen, Germany). Morcellation was carried out with the Morcescope (22 Fr) from RZ Medizintechnik and the Drill Cut II Morcellator (Karl Storz, Tuttlingen, Germany). Enucleation followed the single-lobe technique with early apical release as described by Saitta et al. ( 5 ). In case of meatal stenosis, Otis meatotomy was performed. Coagulation was conducted both prior to and, if necessary, after morcellation. A 20 Fr irrigation catheter was inserted and typically removed on postoperative day two. All procedures adhered to standardized equipment and protocols to ensure consistency and safety. Data Collection Intraoperative data were extracted from the institution’s electronic medical records (EMR). Outcome Measures Main outcomes of interest were efficacy and safety of MiLEP. Assessed data are summarized in Table 1 – 3 and included patient baseline characteristics, periprocedural details (e.g., total operation time, enucleation and morcellation time, weight of resected tissue ) and safety outcomes, such as urinary continence at 2, 6 and 12 weeks and urethral strictures at 3 months,. Urinary continence was defined as no urine leakage at all. Adverse events were classified according to Clavien-Dindo classification (Clavien ≥ 3) ( 6 ). Statistical Analysis Descriptive statistics were used to summarize baseline characteristics and study outcomes. Continuous variables were reported as medians with interquartile ranges. Group comparisons were performed using Welch’s two-sample t-test for normally distributed continuous variables and the Wilcoxon rank-sum test for non-normally distributed continuous variables. Categorical variables were presented as absolute counts and percentages and analyzed using the chi-square test or Fisher’s exact test, as appropriate. All results were reported with p-values, and statistical significance was defined as p < 0.05 (two-tailed). Statistical analysis was performed using R (version 4.4.1 R Project for Statistical Computing) within Rstudio Inc. (Boston, MA, USA). Results A total of 84 patients undergoing MiLEP were included in the study, 13 patients underwent Ultra Slim HoLEP, and 71 patients underwent Slim HoLEP (Table 1 ). Patient characteristics are shown in Table 1 . The two groups were similar regarding age, preoperative PSA values and maximum free urinary flow rate, whereas statistically significant differences were found for preoperative prostate volume an indwelling catheter. Table 1 Baseline patient characteristics (values are presented as median [range]) Ultra Slim HoLEP (N = 13) Slim HoLEP (N = 71) p Overall (N = 84) Age 62 [53–80] 72 [54–86] 0.088 70 [53–86] Preop PSA (ng/ml) 1.90 [0.230–11.1] 3.06 [0.320 - 28.0] 0.068 2.84 [0.230–28.0] Prostate volume (ml) 45 [25–75] 65 [20–150] 0.004 63.5 [20–150] Maximum free urinary flow rate (Qmax; ml/s) 8.40 [3.70–14.1] 8.60 [1.60–18.5] 0.657 8.50 [1.60–18.5] Indwelling catheter 1 (7.7%) 21 (29.6%) 0.168 22 (26.2%) Intake of pharmacotherapy for LUTS 13 (100%) 71 (100%) 1 84 (100%) Patients with previous interventions n (%) 2 (15.4%) (PAE) 4 (5.9%) (TURP) 0.231 6 (7.4%) Perioperative findings are summarized in Table 2 . The two groups were similar in terms of the weight of enucleated prostate tissue, total operation time, total laser energy, and morcellation time. The mean total laser time was almost identical between the two groups. Although there was a trend towards longer enucleation time in the 22 Fr group, this difference was not statistically significant. An average enucleation speed of 1.21 g/min was achieved. For each gram of resected prostate tissue, a laser energy of 3.58 KJ was required. Histopathological examination found incidental prostate cancer in 2 patients (15.4%) in the 18.5 Fr group and in 7 patients (9.9%) in the 22 Fr group. All of these patients were suitable for active surveillance or watchful waiting except from one patient that underwent external beam radiation therapy. Table 2 Perioperative outcomes (values are presented as median [range]) Ultra Slim HoLEP (N = 13) Slim HoLEP (N = 71) p Overall (N = 84) Weight of enucleated prostate tissue (g) 36.0 [8.0–63.0] 35.0 [4.0–129] 0.528 35.5 [4.0–129] Total operation time (min) 65 [45–92] 72.5 [20–180] 0.434 71.0 [20–180] Total laser time (min) 30.5 [22.3–34.5] 28.7 [8.32–52.2] 0.960 29.1 [8.32–52.2] Total laser energy (KJ) 132 [87.9–152] 121 [37–232] 0.811 125 [37–232] Enucleation time (min) 36 [26–48] 40 [12–65] 0.154 40 [12–65] Morcellation time (min) Median [range] 8 [6–23] 12 [2–27] 0.458 12 [2–27] OTIS Meatotomy 6 Functional outcomes and complication are shown in Table 3 . Limited data were available for IPSS. Maximum urinary flow rate was higher in the 18.5 Fr group (33.4 ml/s vs. 19.2 ml/s), but the difference was not statistically significant. PSA drop was statistically significant at 3 months in both groups. A larger PSA drop was found in the Slim HoLEP group, most likely due to higher values at baseline. Postoperatively, both groups reached similar PSA levels. Temporary urinary stress incontinence tended to be more frequent in the Ultra Slim group. However, the difference was not statistically significant and in general a fast improvement was found in both groups with only one out of 84 patients losing urine after 12 weeks. None of the patients developed urethral strictures during the follow-up. Regarding other complications, 3 patients (4.2%) in the Slim HoLEP group developed hematuria, and 2 patients (2.8%) exhibited excessive fibrin formation. All five patients required transurethral revision procedures, 3 patients underwent tamponade evacuation and hemostasis, and 2 patients had the fibrinous tissue removed (Clavien-Dindo 3b). The postoperative course was unremarkable after the second intervention Table 3 Outcomes and complications (values are presented as median [range]) Ultra Slim HoLEP (N = 13) Slim HoLEP (N = 71) p Overall (N = 84) Postoperative outcomes Maximum free urinary flow rate (Qmax; ml/s) 33.4 [17.4–43.5] 19.2 [6.3–54.4] 0.067 19.7 [6.3–54.4] Postop PSA (ng/ml) 0.415 [0.02–2.90] 0.46 [0.02 - 4.20] 0.603 0.46 [0.02–4.20] Postop PSA drop from baseline (ng/ml) 1.01 [0.04–10.4] 2.72 [-1.30–27.7] 0.028 2.19 [-1.30–27.7] Complications Urinary incontinence - at 2 weeks 3 (23.1%) 7 (9.9%) 0.181 10 (11.9%) - at 6 weeks 0 (0%) 3 (4.2%) 1 3 (3.6%) - at 12 weeks 0 (0%) 1 (1.4%) 1 1 (1.2%) Urethral strictures 0 (0%) 0 (0%) 1 0 (0%) Discussion This study demonstrates that MiLEP is safe and effective for the treatment of BPH, showing comparable outcomes to standard instruments while potentially offering advantages in postoperative continence and reduced urethral strictures. The use of both Slim (22 Fr) and Ultra Slim (18.5 Fr) instruments resulted in similar enucleation efficiency, functional outcomes, and safety profiles. Notably, no urethral strictures were observed during the follow-up period, and continence rates at 12 weeks were high in both groups, with 100% continence in the Ultra Slim group and 95.6% in the Slim group. Despite the significant difference in preoperative prostate volumes, operative times were comparable between the groups, suggesting that the enucleation efficiency of MiLEP remains consistent across different prostate sizes. Our findings align with previous studies that have demonstrated the efficacy and safety of HoLEP in treating BPH. Similar to the results reported by Huang et al. (2019) ( 1 ), this study confirms that HoLEP provides significant symptom relief with minimal complications. While Alves et al. (2024) ( 2 ) found that MiLEP achieves comparable enucleation efficacy to conventional HoLEP, our data extend these findings by incorporating Ultra Slim HoLEP as a new approach with potential advantages in patient recovery and continence preservation. In contrast to studies using standard (≥ 26 Fr) instruments, where urethral stricture rates as high as 4% have been reported ( 7 ) ( 8 ), our results suggest that miniaturized HoLEP may reduce this complication. The absence of urethral strictures in our cohort aligns with previous research indicating that smaller-caliber instruments may lead to less urethral trauma ( 3 ) Additionally, Ibis et al. (2021) ( 9 ) and Alves et al. (2024) ( 2 ) reported faster postoperative continence recovery in MiLEP patients, findings that are supported by our study, where only one patient remained incontinent at 12 weeks. Despite the significant difference in preoperative prostate volumes between our groups, operative times were not statistically different. This may be attributed to the relatively high efficiency of HoLEP compared to resection-based techniques such as TURP, which are more volume-dependent. However, the lack of statistical significance in the observed time difference (7 minutes) may also be due to the relatively small sample size, leading to limited statistical power. A key strength of this study is the focus on miniaturized HoLEP, particularly the inclusion of Ultra Slim instruments, which has not been extensively analyzed in prior literature. By evaluating both Slim and Ultra Slim instruments within a standardized surgical approach performed by a single experienced surgeon, this study minimizes inter-operator variability. Furthermore, our findings support the potential advantages of smaller-caliber instruments in reducing postoperative complications, particularly regarding stricture formation and early continence recovery. Despite these strengths, several limitations must be acknowledged. The retrospective design inherently introduces selection bias, and the relatively small sample size - particularly for the Ultra Slim group (n = 13) - limits the statistical power of subgroup analyses. Furthermore, the study lacks a direct comparison with conventional (≥ 26 Fr) HoLEP instruments, making it difficult to draw definitive conclusions regarding the relative advantages of MiLEP over standard techniques. Another limitation is the absence of validated patient-reported outcome measures such as the International Prostate Symptom Score (IPSS), which would provide a more comprehensive assessment of postoperative symptom relief. Additionally, the follow-up period of three months may not capture long-term complications such as delayed stricture formation or symptom recurrence. While the standardized surgical approach by a single experienced surgeon minimizes inter-operator variability, it also limits the generalizability of the results, as outcomes may differ in a multi-surgeon setting with varying levels of expertise. Our findings suggest that MiLEP achieves similar efficacy to standard HoLEP in terms of tissue removal and functional outcomes while potentially reducing early postoperative incontinence and urethral stricture rates. The use of miniaturized instruments may be particularly beneficial for patients with narrow urethral anatomy or those at higher risk for postoperative strictures. While these results are promising, further studies are needed to confirm these benefits and establish clear patient selection criteria for Slim vs. Ultra Slim HoLEP. Future prospective randomized studies are warranted to confirm these findings and further evaluate long-term outcomes associated with miniaturized HoLEP instruments. Key areas for future research include a randomized comparison with standard-sized HoLEP instruments, long-term continence outcomes, patient satisfaction metrics, and the cost-effectiveness of miniaturized HoLEP in routine clinical practice. Abbreviations PSA Prostate specific antigen HoLEP Holmium Laserenucleation of the Prostate BPH Benign Prostate Hyperplasia PAE Prostate Arteric Embolisation TUR P Transurethrale Prostate Resection MiLEP Minimal Invasive Holmium Laserenucleation of the Prostate EMR Electronic Medical Record Ultra Slim HoLEP Ultra Slim Holmium Laserenucleation of the Prostate Slim HoLEP Slim Holmium Laserenucleation of the Prostate Declarations All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Patrick Rein and Christina Meisl. The first draft of the manuscript was written by Patrick Rein and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Conflicts of interests Dominik Abt works as a procter and consultant for Cook – Quanta Laser Systems, consultant for Janssen References Huang SW, Tsai CY, Tseng CS et al. Comparative efficacy and safety of new surgical treatments for benign prostatic hyperplasia: systematic review and network meta-analysis. BMJ. 2019;367:l5919. Alves BB, Gabrich P, Favorito LA. Prospective results of the minimally invasive laser enucleation of the prostate (MiLEP). Prostate. 2024 de Figueiredo FCA, Teloken PE. Minimally invasive laser enucleation of the prostate (MiLEP): slim (22Ch) and ultra slim (18.5 Ch) HoLEP. Urology Video Journal. 2022;14:100146. Chavali JSS, Rivera ME, Lingeman JE. HoLEP Learning Curve-Resident Perspective: Survey of Senior Residents from High-Volume Tertiary Center. J Endourol. 2024;38:977-981. Saitta G, Becerra JEA, Del Álamo JF et al. ‘En Bloc’ HoLEP with early apical release in men with benign prostatic hyperplasia. World J Urol. 2019;37:2451-2458. Clavien PA, Barkun J, de Oliveira ML et al. The Clavien-Dindo Classification of Surgical Complications. Ann Surg. 2009;250:187-196. Elsaqa M, Risinger J, El Tayeb MM. Urethral Complications Post-Holmium Laser Enucleation of the Prostate: A Seven-Year Experience. J Endourol. 2022;36:1575-1579. Licari LC, Bologna E, Manfredi C et al. Incidence and management of BPH surgery-related urethral stricture: results from a large U.S. database. Prostate Cancer Prostatic Dis. 2024;27:537-543. Ibis MA, Tokatlı Z. Does the use of a small-size resectoscope during enucleation prevent transient urinary leakage and urethral stricture following holmium laser enucleation of the prostate? Low Urin Tract Symptoms. 2021 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 09 Jul, 2025 Read the published version in World Journal of Urology → Version 1 posted Editorial decision: Revision requested 25 Apr, 2025 Reviews received at journal 25 Apr, 2025 Reviews received at journal 12 Apr, 2025 Reviews received at journal 05 Apr, 2025 Reviews received at journal 01 Apr, 2025 Reviewers agreed at journal 31 Mar, 2025 Reviewers agreed at journal 31 Mar, 2025 Reviews received at journal 29 Mar, 2025 Reviewers agreed at journal 27 Mar, 2025 Reviewers agreed at journal 26 Mar, 2025 Reviewers agreed at journal 26 Mar, 2025 Reviewers invited by journal 26 Mar, 2025 Editor assigned by journal 21 Mar, 2025 Submission checks completed at journal 21 Mar, 2025 First submitted to journal 21 Mar, 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. 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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-6274610","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":442168608,"identity":"99b5aebd-8802-4dba-b6cd-06027067e335","order_by":0,"name":"Patrick 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00:17:19","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":403932,"visible":true,"origin":"","legend":"\u003cp\u003eIllustration 2:\u003cem\u003e Slim HoLEP Morcescope\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6274610/v1/2faf9ed1a43e8aedb72df45d.jpeg"},{"id":80584166,"identity":"ca8876ed-9c3e-46e6-a8c7-266d753b878b","added_by":"auto","created_at":"2025-04-15 00:17:19","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":434956,"visible":true,"origin":"","legend":"\u003cp\u003eIllustration 3:\u003cem\u003e Slim HoLEP Enucleoscope\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6274610/v1/0eb01da470622d3d3428edc1.jpeg"},{"id":86699361,"identity":"8bb92d31-fc66-476f-b330-373abca803e1","added_by":"auto","created_at":"2025-07-14 16:08:19","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2663985,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6274610/v1/5b39981c-fefe-4df0-b1b5-4c4f43d2072d.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Miniaturized Holmium Laser Enucleation of the Prostate (MiLEP): A retrospective Analysis of Technical Efficacy and Safety Using Slim and Ultra Slim Instruments","fulltext":[{"header":"Introduction","content":"\u003cp\u003eHolmium laser enucleation of the prostate (HoLEP) has emerged as a gold-standard surgical treatment for BPH, offering durable and effective outcomes comparable to transurethral resection of the prostate (TUR-P) and simple open prostatectomy, with the added benefit of minimal invasiveness(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Recent advancements in HoLEP techniques have focused on refining surgical outcomes and patient experience, particularly through the introduction of miniaturized instruments(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMiniaturized Holmium Laser Enucleation of the Prostate (MiLEP) might represent a significant step forward in the evolution of HoLEP. By utilizing smaller-caliber endoscopes, such as the slim (22 Fr) and ultra-slim (18.5 Fr) instruments, MiLEP aims to optimize procedural efficiency while potentially reducing urethral trauma and improving postoperative recovery(\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). These innovations are particularly relevant for patients with challenging urethral anatomy, as smaller instruments may contribute to lower rates of urethral strictures and improved continence outcomes (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWhile the effectiveness of Slim HoLEP instruments has been demonstrated in a limited number of studies, no data on Ultra Slim HoLEP has been investigated to date(\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThis retrospective study seeks to evaluate efficacy and saftey of MiLEP and compare the clinical outcomes using slim (22 Fr) and ultra-slim (18.5 Fr) HoLEP instruments in the treatment of BPH. Key parameters analyzed include laser time, energy utilization, enucleated tissue weight, pre- and postoperative prostate volume, and patient outcomes such as continence rates and the incidence of urethral strictures at two, six, and twelve weeks postoperatively. By providing a comprehensive assessment of these parameters, this study aims to offer new insights into the efficacy and safety profiles of slim and ultra-slim HoLEP techniques, thereby contributing to the optimization of surgical management for BPH.\u003c/p\u003e"},{"header":"Methods and Materials","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design\u003c/h2\u003e \u003cp\u003eThis was a retrospective, single-center study conducted at Cantonal Hospital Grabs to evaluate the outcomes of MiLEP performed by a single surgeon (PR) who had completed the learning curve, defined as 25 consecutive cases under supervision(\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Data were collected and analyzed for procedures conducted between February 2023 and September 2024. The study was approved by the Institutional Review Board (IRB) of Ethikkommission Ostschweiz (EKOS 24/229, Project ID 2024\u0026ndash;02405), and patient confidentiality was maintained according to ethical guidelines and the Declaration of Helsinki.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eParticipants\u003c/h3\u003e\n\u003cp\u003eAll men treated by MiLEP due to LUTS/BPO after completion of the surgeons initial learning curve were included to the study.\u003c/p\u003e\n\u003ch3\u003eIntervention\u003c/h3\u003e\n\u003cp\u003eThe procedure was performed under spinal or general anesthesia, based on patient preference, in lithotomy position. Trimetoprim / Sulfometaxol 160/800mg was administered intraoperatively according to local guidelines or based on preoperative antibiogram. Slim HoLEP (22 Fr) and Ultra Slim HoLEP (18.5 Fr) instruments were obtained from RZ Medizintechnik (Tuttlingen, Germany).\u003c/p\u003e \u003cp\u003eA holmium-YAG laser (Cyber-Ho 100, Quanta Laser Systems, Milan, Italy) equipped with a 550-\u0026micro;m end-firing fiber was used, operating at 50 Hz and 1.5 J in Virtual Basket Mode for enucleation, and at 42 Hz and 1.2 J for coagulation. The Ultra Slim HoLEP instrument was employed for prostate volumes below 50 ml, if available.\u003c/p\u003e \u003cp\u003eFollowing enucleation, coagulation was performed using either the laser or bipolar coagulation, utilizing the Slim HoLEP (22 Fr) instrument and the Autocon III generator (Karl Storz, Tuttlingen, Germany). Morcellation was carried out with the Morcescope (22 Fr) from RZ Medizintechnik and the Drill Cut II Morcellator (Karl Storz, Tuttlingen, Germany).\u003c/p\u003e \u003cp\u003eEnucleation followed the single-lobe technique with early apical release as described by Saitta et al. (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). In case of meatal stenosis, Otis meatotomy was performed.\u003c/p\u003e \u003cp\u003eCoagulation was conducted both prior to and, if necessary, after morcellation. A 20 Fr irrigation catheter was inserted and typically removed on postoperative day two. All procedures adhered to standardized equipment and protocols to ensure consistency and safety.\u003c/p\u003e\n\u003ch3\u003eData Collection\u003c/h3\u003e\n\u003cp\u003eIntraoperative data were extracted from the institution\u0026rsquo;s electronic medical records (EMR).\u003c/p\u003e\n\u003ch3\u003eOutcome Measures\u003c/h3\u003e\n\u003cp\u003eMain outcomes of interest were efficacy and safety of MiLEP. Assessed data are summarized in Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and included patient baseline characteristics, periprocedural details (e.g., total operation time, enucleation and morcellation time, weight of resected tissue ) and safety outcomes, such as urinary continence at 2, 6 and 12 weeks and urethral strictures at 3 months,. Urinary continence was defined as no urine leakage at all. Adverse events were classified according to Clavien-Dindo classification (Clavien\u0026thinsp;\u0026ge;\u0026thinsp;3) (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e).\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eDescriptive statistics were used to summarize baseline characteristics and study outcomes. Continuous variables were reported as medians with interquartile ranges. Group comparisons were performed using Welch\u0026rsquo;s two-sample t-test for normally distributed continuous variables and the Wilcoxon rank-sum test for non-normally distributed continuous variables. Categorical variables were presented as absolute counts and percentages and analyzed using the chi-square test or Fisher\u0026rsquo;s exact test, as appropriate. All results were reported with p-values, and statistical significance was defined as p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 (two-tailed). Statistical analysis was performed using R (version 4.4.1 R Project for Statistical Computing) within Rstudio Inc. (Boston, MA, USA).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 84 patients undergoing MiLEP were included in the study, 13 patients underwent Ultra Slim HoLEP, and 71 patients underwent Slim HoLEP (Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Patient characteristics are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The two groups were similar regarding age, preoperative PSA values and maximum free urinary flow rate, whereas statistically significant differences were found for preoperative prostate volume an indwelling catheter.\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\u003eBaseline patient characteristics (values are presented as median [range])\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=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUltra Slim HoLEP (N\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSlim HoLEP\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;71)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eOverall\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;84)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e62 [53\u0026ndash;80]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72 [54\u0026ndash;86]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.088\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e70 [53\u0026ndash;86]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePreop PSA (ng/ml)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.90 [0.230\u0026ndash;11.1]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.06 [0.320 - 28.0]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.068\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.84 [0.230\u0026ndash;28.0]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eProstate volume (ml)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45 [25\u0026ndash;75]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65 [20\u0026ndash;150]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e63.5 [20\u0026ndash;150]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMaximum free urinary flow rate (Qmax; ml/s)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.40 [3.70\u0026ndash;14.1]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.60 [1.60\u0026ndash;18.5]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.657\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.50 [1.60\u0026ndash;18.5]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eIndwelling catheter\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (7.7%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21 (29.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.168\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e22 (26.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eIntake of pharmacotherapy for LUTS\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e71 (100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e84 (100%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePatients with previous interventions n (%)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 (15.4%)\u003c/p\u003e \u003cp\u003e(PAE)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (5.9%)\u003c/p\u003e \u003cp\u003e(TURP)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.231\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6 (7.4%)\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\u003ePerioperative findings are summarized in Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The two groups were similar in terms of the weight of enucleated prostate tissue, total operation time, total laser energy, and morcellation time. The mean total laser time was almost identical between the two groups. Although there was a trend towards longer enucleation time in the 22 Fr group, this difference was not statistically significant. An average enucleation speed of 1.21 g/min was achieved. For each gram of resected prostate tissue, a laser energy of 3.58 KJ was required.\u003c/p\u003e \u003cp\u003eHistopathological examination found incidental prostate cancer in 2 patients (15.4%) in the 18.5 Fr group and in 7 patients (9.9%) in the 22 Fr group. All of these patients were suitable for active surveillance or watchful waiting except from one patient that underwent external beam radiation therapy.\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\u003ePerioperative outcomes (values are presented as median [range])\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=\"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 \u003cdiv align=\"left\" 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 \u003cp\u003eUltra Slim HoLEP\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSlim HoLEP\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;71)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eOverall\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;84)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWeight of enucleated prostate tissue (g)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36.0 [8.0\u0026ndash;63.0]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.0 [4.0\u0026ndash;129]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.528\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e35.5 [4.0\u0026ndash;129]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal operation time (min)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65 [45\u0026ndash;92]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72.5 [20\u0026ndash;180]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.434\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e71.0 [20\u0026ndash;180]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal laser time (min)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.5 [22.3\u0026ndash;34.5]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.7 [8.32\u0026ndash;52.2]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.960\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e29.1 [8.32\u0026ndash;52.2]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal laser energy (KJ)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e132 [87.9\u0026ndash;152]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e121 [37\u0026ndash;232]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.811\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e125 [37\u0026ndash;232]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEnucleation time (min)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36 [26\u0026ndash;48]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40 [12\u0026ndash;65]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.154\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e40 [12\u0026ndash;65]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMorcellation time (min)\u003c/b\u003e\u003c/p\u003e \u003cp\u003eMedian [range]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 [6\u0026ndash;23]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12 [2\u0026ndash;27]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.458\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12 [2\u0026ndash;27]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOTIS Meatotomy\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6\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\u003eFunctional outcomes and complication are shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Limited data were available for IPSS. Maximum urinary flow rate was higher in the 18.5 Fr group (33.4 ml/s vs. 19.2 ml/s), but the difference was not statistically significant.\u003c/p\u003e \u003cp\u003ePSA drop was statistically significant at 3 months in both groups. A larger PSA drop was found in the Slim HoLEP group, most likely due to higher values at baseline. Postoperatively, both groups reached similar PSA levels.\u003c/p\u003e \u003cp\u003eTemporary urinary stress incontinence tended to be more frequent in the Ultra Slim group. However, the difference was not statistically significant and in general a fast improvement was found in both groups with only one out of 84 patients losing urine after 12 weeks.\u003c/p\u003e \u003cp\u003eNone of the patients developed urethral strictures during the follow-up.\u003c/p\u003e \u003cp\u003eRegarding other complications, 3 patients (4.2%) in the Slim HoLEP group developed hematuria, and 2 patients (2.8%) exhibited excessive fibrin formation. All five patients required transurethral revision procedures, 3 patients underwent tamponade evacuation and hemostasis, and 2 patients had the fibrinous tissue removed (Clavien-Dindo 3b). The postoperative course was unremarkable after the second intervention\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\u003eOutcomes and complications (values are presented as median [range])\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=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUltra Slim HoLEP (N\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSlim HoLEP\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;71)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eOverall\u003c/p\u003e \u003cp\u003e(N\u0026thinsp;=\u0026thinsp;84)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePostoperative outcomes\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMaximum free urinary flow rate (Qmax; ml/s)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e33.4 [17.4\u0026ndash;43.5]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.2 [6.3\u0026ndash;54.4]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.067\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e19.7 [6.3\u0026ndash;54.4]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePostop PSA (ng/ml)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.415 [0.02\u0026ndash;2.90]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.46 [0.02 - 4.20]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.603\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.46 [0.02\u0026ndash;4.20]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003ePostop PSA drop from baseline (ng/ml)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.01 [0.04\u0026ndash;10.4]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.72 [-1.30\u0026ndash;27.7]\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.19 [-1.30\u0026ndash;27.7]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eComplications\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003eUrinary incontinence\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e- \u003cb\u003eat 2 weeks\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (23.1%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7 (9.9%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.181\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10 (11.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e- \u003cb\u003eat 6 weeks\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (4.2%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3 (3.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e- \u003cb\u003eat 12 weeks\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (1.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1 (1.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eUrethral strictures\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0 (0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study demonstrates that MiLEP is safe and effective for the treatment of BPH, showing comparable outcomes to standard instruments while potentially offering advantages in postoperative continence and reduced urethral strictures. The use of both Slim (22 Fr) and Ultra Slim (18.5 Fr) instruments resulted in similar enucleation efficiency, functional outcomes, and safety profiles. Notably, no urethral strictures were observed during the follow-up period, and continence rates at 12 weeks were high in both groups, with 100% continence in the Ultra Slim group and 95.6% in the Slim group. Despite the significant difference in preoperative prostate volumes, operative times were comparable between the groups, suggesting that the enucleation efficiency of MiLEP remains consistent across different prostate sizes.\u003c/p\u003e \u003cp\u003eOur findings align with previous studies that have demonstrated the efficacy and safety of HoLEP in treating BPH. Similar to the results reported by Huang et al. (2019) (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e), this study confirms that HoLEP provides significant symptom relief with minimal complications. While Alves et al. (2024) (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) found that MiLEP achieves comparable enucleation efficacy to conventional HoLEP, our data extend these findings by incorporating Ultra Slim HoLEP as a new approach with potential advantages in patient recovery and continence preservation.\u003c/p\u003e \u003cp\u003eIn contrast to studies using standard (\u0026ge;\u0026thinsp;26 Fr) instruments, where urethral stricture rates as high as 4% have been reported (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e) (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e), our results suggest that miniaturized HoLEP may reduce this complication. The absence of urethral strictures in our cohort aligns with previous research indicating that smaller-caliber instruments may lead to less urethral trauma (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Additionally, Ibis et al. (2021) (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e) and Alves et al. (2024) (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) reported faster postoperative continence recovery in MiLEP patients, findings that are supported by our study, where only one patient remained incontinent at 12 weeks.\u003c/p\u003e \u003cp\u003eDespite the significant difference in preoperative prostate volumes between our groups, operative times were not statistically different. This may be attributed to the relatively high efficiency of HoLEP compared to resection-based techniques such as TURP, which are more volume-dependent. However, the lack of statistical significance in the observed time difference (7 minutes) may also be due to the relatively small sample size, leading to limited statistical power.\u003c/p\u003e \u003cp\u003eA key strength of this study is the focus on miniaturized HoLEP, particularly the inclusion of Ultra Slim instruments, which has not been extensively analyzed in prior literature. By evaluating both Slim and Ultra Slim instruments within a standardized surgical approach performed by a single experienced surgeon, this study minimizes inter-operator variability.\u003c/p\u003e \u003cp\u003eFurthermore, our findings support the potential advantages of smaller-caliber instruments in reducing postoperative complications, particularly regarding stricture formation and early continence recovery.\u003c/p\u003e \u003cp\u003eDespite these strengths, several limitations must be acknowledged. The retrospective design inherently introduces selection bias, and the relatively small sample size - particularly for the Ultra Slim group (n\u0026thinsp;=\u0026thinsp;13) - limits the statistical power of subgroup analyses.\u003c/p\u003e \u003cp\u003eFurthermore, the study lacks a direct comparison with conventional (\u0026ge;\u0026thinsp;26 Fr) HoLEP instruments, making it difficult to draw definitive conclusions regarding the relative advantages of MiLEP over standard techniques.\u003c/p\u003e \u003cp\u003eAnother limitation is the absence of validated patient-reported outcome measures such as the International Prostate Symptom Score (IPSS), which would provide a more comprehensive assessment of postoperative symptom relief. Additionally, the follow-up period of three months may not capture long-term complications such as delayed stricture formation or symptom recurrence.\u003c/p\u003e \u003cp\u003eWhile the standardized surgical approach by a single experienced surgeon minimizes inter-operator variability, it also limits the generalizability of the results, as outcomes may differ in a multi-surgeon setting with varying levels of expertise.\u003c/p\u003e \u003cp\u003eOur findings suggest that MiLEP achieves similar efficacy to standard HoLEP in terms of tissue removal and functional outcomes while potentially reducing early postoperative incontinence and urethral stricture rates. The use of miniaturized instruments may be particularly beneficial for patients with narrow urethral anatomy or those at higher risk for postoperative strictures. While these results are promising, further studies are needed to confirm these benefits and establish clear patient selection criteria for Slim vs. Ultra Slim HoLEP.\u003c/p\u003e \u003cp\u003eFuture prospective randomized studies are warranted to confirm these findings and further evaluate long-term outcomes associated with miniaturized HoLEP instruments.\u003c/p\u003e \u003cp\u003eKey areas for future research include a randomized comparison with standard-sized HoLEP instruments, long-term continence outcomes, patient satisfaction metrics, and the cost-effectiveness of miniaturized HoLEP in routine clinical practice.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cul\u003e\n \u003cli\u003ePSA \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Prostate specific antigen\u003c/li\u003e\n \u003cli\u003eHoLEP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Holmium Laserenucleation of the Prostate\u003c/li\u003e\n \u003cli\u003eBPH\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Benign Prostate Hyperplasia\u003c/li\u003e\n \u003cli\u003ePAE\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Prostate Arteric Embolisation\u003c/li\u003e\n \u003cli\u003eTUR P\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Transurethrale Prostate Resection\u003c/li\u003e\n \u003cli\u003eMiLEP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Minimal Invasive Holmium Laserenucleation of the Prostate\u003c/li\u003e\n \u003cli\u003eEMR\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Electronic Medical Record\u003c/li\u003e\n \u003cli\u003eUltra Slim HoLEP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Ultra Slim Holmium Laserenucleation of the Prostate\u003c/li\u003e\n \u003cli\u003eSlim HoLEP\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Slim Holmium Laserenucleation of the Prostate\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Patrick Rein and Christina Meisl. The first draft of the manuscript was written by Patrick Rein and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConflicts of interests\u003c/p\u003e\n\u003cp\u003eDominik Abt works as a procter and consultant for Cook \u0026ndash; Quanta Laser Systems, consultant for Janssen\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eHuang SW, Tsai CY, Tseng CS et al. Comparative efficacy and safety of new surgical treatments for benign prostatic hyperplasia: systematic review and network meta-analysis. BMJ. 2019;367:l5919.\u003c/li\u003e\n\u003cli\u003eAlves BB, Gabrich P, Favorito LA. Prospective results of the minimally invasive laser enucleation of the prostate (MiLEP). Prostate. 2024\u003c/li\u003e\n\u003cli\u003ede Figueiredo FCA, Teloken PE. Minimally invasive laser enucleation of the prostate (MiLEP): slim (22Ch) and ultra slim (18.5 Ch) HoLEP. Urology Video Journal. 2022;14:100146.\u003c/li\u003e\n\u003cli\u003eChavali JSS, Rivera ME, Lingeman JE. HoLEP Learning Curve-Resident Perspective: Survey of Senior Residents from High-Volume Tertiary Center. J Endourol. 2024;38:977-981.\u003c/li\u003e\n\u003cli\u003eSaitta G, Becerra JEA, Del \u0026Aacute;lamo JF et al. \u0026lsquo;En Bloc\u0026rsquo; HoLEP with early apical release in men with benign prostatic hyperplasia. World J Urol. 2019;37:2451-2458.\u003c/li\u003e\n\u003cli\u003eClavien PA, Barkun J, de Oliveira ML et al. The Clavien-Dindo Classification of Surgical Complications. Ann Surg. 2009;250:187-196.\u003c/li\u003e\n\u003cli\u003eElsaqa M, Risinger J, El Tayeb MM. Urethral Complications Post-Holmium Laser Enucleation of the Prostate: A Seven-Year Experience. J Endourol. 2022;36:1575-1579.\u003c/li\u003e\n\u003cli\u003eLicari LC, Bologna E, Manfredi C et al. Incidence and management of BPH surgery-related urethral stricture: results from a large U.S. database. Prostate Cancer Prostatic Dis. 2024;27:537-543.\u003c/li\u003e\n\u003cli\u003eIbis MA, Tokatlı Z. Does the use of a small-size resectoscope during enucleation prevent transient urinary leakage and urethral stricture following holmium laser enucleation of the prostate? Low Urin Tract Symptoms. 2021\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":"world-journal-of-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wjur","sideBox":"Learn more about [World Journal of Urology](https://link.springer.com/journal/345)","snPcode":"345","submissionUrl":"https://submission.nature.com/new-submission/345/3","title":"World Journal of Urology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Benign Prostatic Hyperplasia (BPH), Miniaturized HoLEP, MiLEP, Slim HoLEP, Ultra Slim HoLEP, Minimally Invasive Prostate Surgery","lastPublishedDoi":"10.21203/rs.3.rs-6274610/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6274610/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eMinimally invasive laser enucleation of the prostate has emerged as a promising treatment for benign prostatic hyperplasia. This study investigates the efficacy and safety of miniaturized holmium laser enucleation of the prostate (MiLEP) using Slim- (22 Fr) and Ultra Slim-HoLEP (18.5 Fr).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe retrospectively analyzed 84 patients who underwent MiLEP between February 2022 and October 2023, performed by a single experienced surgeon. Thirteen patients were treated with Ultra Slim HoLEP, and 71 with Slim HoLEP. Perioperative parameters, functional outcomes, and complications were assessed intraoperatively and at 2, 6, and 12 weeks postoperatively.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eMedian patient age was 62 [53\u0026ndash;80] and 72 [54\u0026ndash;86] years in the Ultra Slim and Slim groups, respectively. The median prostate volume was 45 ml [25\u0026ndash;75] and 65 ml [20\u0026ndash;150], with similar enucleation weights (36 g vs. 35 g). No urethral strictures were observed at three months. Continence rates at 12 weeks reached 100% in the Ultra Slim group and 95.6% in the Slim group. Perioperative efficiency, including total operation time and laser energy use, was comparable between the groups despite differences in prostate volume.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eMiLEP using Slim and Ultra Slim instruments provides a safe and effective alternative to standard HoLEP (\u0026ge;\u0026thinsp;26 Fr), demonstrating favorable postoperative continence and a low complication profile. The findings suggest potential benefits of miniaturized instruments in reducing urethral trauma while maintaining enucleation efficiency. Further prospective studies are warranted to validate these results and explore long-term outcomes.\u003c/p\u003e","manuscriptTitle":"Miniaturized Holmium Laser Enucleation of the Prostate (MiLEP): A retrospective Analysis of Technical Efficacy and Safety Using Slim and Ultra Slim Instruments","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-15 00:17:14","doi":"10.21203/rs.3.rs-6274610/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-04-25T11:57:57+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-25T09:14:10+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-13T03:35:41+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-05T10:15:40+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-01T17:20:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"292806939968628345507948702776581991067","date":"2025-03-31T18:39:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"239361335257631713112731852778983912859","date":"2025-03-31T16:09:22+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-03-29T17:39:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"237983122728336908787239009822062726118","date":"2025-03-27T12:07:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"112834200463058555998725118090514394365","date":"2025-03-26T23:39:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"110048742301461077224891545099172795288","date":"2025-03-26T21:56:59+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-03-26T18:35:50+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-03-21T16:58:27+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-03-21T15:14:53+00:00","index":"","fulltext":""},{"type":"submitted","content":"World Journal of Urology","date":"2025-03-21T06:12:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"world-journal-of-urology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wjur","sideBox":"Learn more about [World Journal of Urology](https://link.springer.com/journal/345)","snPcode":"345","submissionUrl":"https://submission.nature.com/new-submission/345/3","title":"World Journal of Urology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"45d4558e-7c54-479a-829c-f00dbc25e4f4","owner":[],"postedDate":"April 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-07-14T16:00:54+00:00","versionOfRecord":{"articleIdentity":"rs-6274610","link":"https://doi.org/10.1007/s00345-025-05785-0","journal":{"identity":"world-journal-of-urology","isVorOnly":false,"title":"World Journal of Urology"},"publishedOn":"2025-07-09 15:57:24","publishedOnDateReadable":"July 9th, 2025"},"versionCreatedAt":"2025-04-15 00:17:14","video":"","vorDoi":"10.1007/s00345-025-05785-0","vorDoiUrl":"https://doi.org/10.1007/s00345-025-05785-0","workflowStages":[]},"version":"v1","identity":"rs-6274610","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6274610","identity":"rs-6274610","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}