Description of the Dunning-Kruger effect in general surgery residents during laparoscopic cholecystectomy: a blinded prospective study.

PURPOSE: The purpose of this study is to assess whether the Dunning-Kruger effect occurs in surgical residents when performing laparoscopic cholecystectomy in a porcine model. METHODS: Prospective blinded study, which counted with forty PGY-1 general surgery residents who agreed to participate in the study were blindly recruited to perform a laparoscopic cholecystectomy in a porcine model. At the end of the procedure, the participants assigned a score of 0-10 for their own performance and the video of the operation was independently assessed by 2 experienced laparoscopic surgeons using a validated tool. RESULTS: Participants were divided into groups of 10 individuals according to objective performance and compared. The group with the worst objective result was inferior to the group with the best objective result (3.77 ± 0.44 vs. 8.1 ± 0.44, p < 0.001), but they were similar in self-perception of performance (5.11 ± 1.69 vs. 6.1 ± 1.79, p = 0.999). CONCLUSIONS: In the studied sample, it was possible to demonstrate the presence of the Dunning-Kruger effect.

Antibiotics prophylaxis at the time of catheter removal after radical prostatectomy: a systematic review of the literature and meta-analysis.

PURPOSE: To conduct a systematic literature review with meta-analysis to identify whether antibiotic prophylaxis after removal of the indwelling urinary catheter reduces posterior infections. METHODS: A systematic literature review was conducted in the databases PubMed, Embase, Cochrane, Google Scholar, and Latin American and Caribbean Health Sciences Literature, using the keywords "antibiotics" AND "prostatectomy" AND "urinary catheter." RESULTS: Three articles were identified having the scope of our review, with 1,040 patients, which were subjected to our meta-analysis revealing a marginally significant decrease in the risk of urinary infection after indwelling urinary catheter removal (odds ratio-OR = 0.51; 95% confidence interval-95%CI 0.27-0.98; p = 0.04; I2 = 0%). No difference was found regarding the presence of bacteriuria (OR = 0.39; 95%CI 0.12-1.24; p = 0.11; I2 = 73%). CONCLUSIONS: In our meta-analysis, there was a significant decrease in urinary tract infection with antibiotic prophylaxis after indwelling urinary catheter removal following radical prostatectomy.

Can the learning of laparoscopic skills be quantified by the measurements of skill parameters performed in a virtual reality simulator?

PURPOSE: To ensure patient safety and surgical efficiency, much emphasis has been placed on the training of laparoscopic skills using virtual reality simulators. The purpose of this study was to determine whether laparoscopic skills can be objectively quantified by measuring specific skill parameters during training in a virtual reality surgical simulator (VRSS). MATERIALS AND METHODS: Ten medical students (with no laparoscopic experience) and ten urology residents (PGY3-5 with limited laparoscopic experience) were recruited to participate in a ten-week training course in basic laparoscopic skills (camera, cutting, peg transfer and clipping skills) on a VRSS. Data were collected from the training sessions. The time that individuals took to complete each task and the errors that they made were analyzed independently. RESULTS: The mean time that individuals took to complete tasks was significantly different between the groups (p < 0.05), with the residents being faster than the medical students. The residents' group also completed the tasks with fewer errors. The majority of the subjects in both groups exhibited a significant improvement in their task completion time and error rate. CONCLUSION: The findings in this study demonstrate that laparoscopic skills can be objectively measured in a VRSS based on quantified skill parameters, including the time spent to complete skill tasks and the associated error rate. We conclude that a VRSS is a feasible tool for training and assessing basic laparoscopic skills.

Vasopressin in vasoplegic shock in surgical patients: systematic review and meta-analysis.

PURPOSE: Vasoplegia, or vasoplegic shock, is a syndrome whose main characteristic is reducing blood pressure in the presence of a standard or high cardiac output. For the treatment, vasopressors are recommended, and the most used is norepinephrine. However, new drugs have been evaluated, and conflicting results exist in the literature. METHODS: This is a systematic review of the literature with meta-analysis, written according to the recommendations of the PRISMA report. The SCOPUS, PubMed, and ScienceDirect databases were used to select the scientific articles included in the study. Searches were conducted in December 2022 using the terms "vasopressin," "norepinephrine," "vasoplegic shock," "postoperative," and "surgery." Meta-analysis was performed using Review Manager (RevMan) 5.4. The endpoint associated with the study was efficiency in treating vasoplegic shock and reduced risk of death. RESULTS: In total, 2,090 articles were retrieved; after applying the inclusion and exclusion criteria, ten studies were selected to compose the present review. We found no significant difference when assessing the outcome mortality comparing vasopressin versus norepinephrine (odds ratio = 1.60; confidence interval 0.47-5.50), nor when comparing studies on vasopressin versus placebo. When we analyzed the length of hospital stay compared to the use of vasopressin and norepinephrine, we identified a shorter length of hospital stay in cases that used vasopressin; however, the meta-analysis did not demonstrate statistical significance. CONCLUSIONS: Considering the outcomes included in our study, it is worth noting that most studies showed that using vasopressin was safe and can be considered in managing postoperative vasoplegic shock.

The learning curve of bilateral laparoscopic varicocelectomy: a prospective study.

Varicocele occurs in 15% of general male population and in 35% of infertile men. Since 1992, surgical correction with laparoscopic varicocelectomy is the gold standard for treatment of symptomatic patients or patients with abnormal seminal analysis. The learning curve for this frequently performed procedure has not yet been described. In the present study, we investigated the learning curve of a single urologist in training performing his first 21 laparoscopic varicocelectomies using qualitative and quantitative tools to evaluate his performance during the process. Our results show that 14 bilateral laparoscopic varicocelectomies are enough to achieve the plateau of the learning curve.

Use of artificial intelligence for sepsis risk prediction after flexible ureteroscopy: a systematic review.

INTRODUCTION: flexible ureteroscopy is a minimally invasive surgical technique used for the treatment of renal lithiasis. Postoperative urosepsis is a rare but potentially fatal complication. Traditional models used to predict the risk of this condition have limited accuracy, while models based on artificial intelligence are more promising. The objective of this study is to carry out a systematic review regarding the use of artificial intelligence to detect the risk of sepsis in patients with renal lithiasis undergoing flexible ureteroscopy. METHODS: the literature review is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The keyword search was performed in MEDLINE, Embase, Web of Science and Scopus and resulted in a total of 2,496 articles, of which 2 met the inclusion criteria. RESULTS: both studies used artificial intelligence models to predict the risk of sepsis after flexible uteroscopy. The first had a sample of 114 patients and was based on clinical and laboratory parameters. The second had an initial sample of 132 patients and was based on preoperative computed tomography images. Both obtained good measurements of Area Under the Curve (AUC), sensitivity and specificity, demonstrating good performance. CONCLUSION: artificial intelligence provides multiple effective strategies for sepsis risk stratification in patients undergoing urological procedures for renal lithiasis, although further studies are needed.

Does displacement of lower pole stones during retrograde intrarenal surgery improves stone-free status? A systematic review and meta-analysis.

PURPOSE: Kidney stones are one of the most common urological diseases worldwide. The size and location of the stone are the most important factors in determining the most suitable treatment options. The aim of this review was to evaluate the displacement of lower pole stones. METHODS: Three studies assessing the efficacy of translocating kidney stones from the lower pole of the kidney to other locations during retrograde intrarenal surgery published in the last 20 years were included. A systematic search was conducted in the PubMed, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), and Web of Science databases using the following search terms: "Lower pole," "Lithotripsy." Meta-analysis was performed using Review Manager version 5.4. RESULTS: Stone-free rates were improved through displacement (odds ratio - OR = -0.15; 95% confidence interval-95%CI -0.24--0.05; p = 0.002; I2 = 21%), but at the cost of increased surgical duration (mean difference = -12.50; 95%CI -24.06--0.95; p = 0.03; I2 = 94%). Although this represents a potentially negative outcome, the improvement in clearance rates justifies the additional investment of time and effort. CONCLUSIONS: Displacement of lower pole kidney stones for subsequent lithotripsy brings significant benefits in terms of stone-free rate, with no difference in laser energy usage. However, it results in increased surgical time. Despite these factors, the benefits to patients undergoing the procedure are substantial.

Diameter of ureteral access sheath and ureteral stenosis development: a systematic review.

PURPOSE: Ureteral access sheaths (UAS) are widely used in ureteroscopy. UAS are believed to pose a significant risk for ureteral stenosis due to ureteral mucosal compression, but little evidence supports this claim. Our systematic review aimed to investigate the relationship between different UAS diameters and stenosis risk. METHODS: A systematic search was conducted in PubMed, Embase, Web of Science, Scopus, and Cochrane, from its inception to May 2023. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane guidelines were followed. χ2 test was performed to compare the prevalence within the groups. RESULTS: Six nonrandomized trials and one randomized, with a total of 962 patients, were included. The overall incidence of ureteral stenosis of 0.9%. UAS sizes were: 9.5/11.5Fr, 10/12Fr, 11/13Fr, 12/14Fr, and 14/16Fr. Within each subgroup, the incidence of ureteral stenosis was: 0.4, 8, 0, 1, and 1% (p = 0.099). No trend for stenosis was observed among larger UAS. CONCLUSIONS: In this systematic review, no relationship between UAS diameter and incidence of ureteral stenosis was observed. Nonetheless, additional randomized controlled trials are required to support this finding.

Comparing financing models for supplementary healthcare in appendectomy: activity-based costing (fee-for-service) vs. diagnosis related group remuneration (bundled payment) - a systematic review and meta-analysis.

PURPOSE: In Brazil, healthcare services traditionally follow a fee-for-service (FFS) payment system, in which each medical procedure incurs a separate charge. An alternative reimbursement with the aim of reducing costs is diagnosis related group (DRG) remuneration, in which all patient care is covered by a fixed amount. This work aimed to perform a systematic review followed by meta-analysis to assess the effectiveness of the Budled Payment for Care Improvement (BPCI) versus FFS. METHODS: Our work was performed following the items of the PRISMA report. We included only observational trials, and the primary outcome assessed was the effectiveness of FFS and DRG in appendectomy considering complications. We also assessed the costs and length of hospital stay. Meta-analysis was performed with Rev Man version 5.4. RESULTS: Out of 735 initially identified articles, six met the eligibility criteria. We demonstrated a shorter hospital stay associated with the DRG model (mean difference = 0.39; 95% confidence interval - 95%CI - 0.38-0.40; p < 0.00001; I2 = 0%), however the hospital readmission rate was higher in this model (odds ratio = 1.57; 95%CI 1.02-2.44, p = 0.04; I2 = 90%). CONCLUSIONS: This study reveals a potential decrease in the length of stay for appendectomy patients using the DRG approach. However, no significant differences were observed in other outcomes analysis between the two approaches.

Underexpression of MMP-2 and its regulators, TIMP2, MT1-MMP and IL-8, is associated with prostate cancer.

OBJECTIVE: Extracellular matrix homeostasis is strictly maintained by a coordinated balance between the expression of metalloproteinases (MMPs) and their regulators. The purpose of this study was to investigate whether MMP-2 and its specifi c regulators, TIMP-2, MT1-MMP and IL-8, are expressed in a reproducible, specific pattern and if the profiles are related to prognosis and clinical outcome of prostate cancer (PCa). MATERIALS AND METHODS: MMP-2, TIMP-2, MT1-MMP and IL-8 expression levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in freshly frozen malignant and benign tissue specimens collected from 79 patients with clinically localized PCa who underwent radical prostatectomies. The control group consisted of 11 patients with benign prostate hyperplasia (BPH). The expression profile of the MMP-2 and its regulators were compared using Gleason scores, pathological stage, pre-operative PSA levels and the fi nal outcome of the PCa. RESULTS: The analysis of 79 specimens of PCa revealed that MMP-2, TIMP-2, MT1-MMP and IL-8 were underexpressed at 60.0%, 72.2%, 62.0% and 65.8%, respectively, in malignant prostatic tissue in relation to BPH samples. Considering the prognostic parameters, we demonstrated that high Gleason score tumors (≥ 7) overexpressed MMP-2 (p = 0.048) and TIMP-2 (p = 0.021), compared to low Gleason score tumors (< 7). CONCLUSION: We have demonstrated that MMP-2 and its regulators are underexpressed in PCa. Alternatively, overexpression of MMP-2 and TIMP-2 was related to higher Gleason score tumors. We postulate that alterations in metalloproteinase expression may be important in the control of tissue homeostasis related to prostate carcinogenesis and tumor behavior.

The learning curve for retrograde intrarenal surgery: A prospective analysis.

INTRODUCTION: retrograde intrarenal surgery (CRIR) is an evolving tool. Its learning curve is not well established, despite the common use of flexible ureteroscopes today. Our aim is to estimate the number of procedures needed for one to perform RIRS consistently. MATERIAL AND METHODS: a urology resident had his first 80 RIRS for nephrolithiasis analyzed quantitatively and qualitatively. The procedures were divided into 4 groups containing 20 surgeries each (I to IV), according to their order, for comparison. RESULTS: there was no difference in stone sizes between groups. All qualitative variables varied significantly between groups (p<0.001), except between III and IV. In the quantitative analysis, there was a difference between groups I and IV in time for double-J catheter placement (p=0.012). There was an increasing difference in sheath placement time (p<0.001) and in total operative time (p=0.004). The time fot stone treatment (p=0.011) was significant only between groups I, II and III. There was difference in total sheath time only between groups I and III (p=0.023). Stone free status did not change between groups. DISCUSSION: the differences between the qualitative and quantitative variables show the relation between number of surgeries performed and proficiency in the procedure. Intergroup comparisons show sequential optimization of parameters. CONCLUSIONS: we found that 60 is a reasonable number of surgeries to be performed in order to reach the plateau of RIRSs learning curve.

Bladder exstrophy: reconstructed female patients achieving normal pregnancy and delivering normal babies.

PURPOSE: Bladder exstrophy (BE) is an anterior midline defect that causes a series of genitourinary and muscular malformations, which demands surgical intervention for correction. Women with BE are fertile and able to have children without this disease. The purpose of this study is to assess the sexual function and quality of life of women treated for BE. MATERIALS AND METHODS: All patients in our institution treated for BE from 1987 to 2007 were recruited to answer a questionnaire about their quality of life and pregnancies. RESULTS: Fourteen women were submitted to surgical treatment for BE and had 22 pregnancies during the studied period. From those, 17 pregnancies (77.2%) resulted in healthy babies, while four patients (18.1%) had a spontaneous abortion due to genital prolapse, and there was one case (4.7%) of death due to a pneumopathy one week after delivery. There was also one case (5.8%) of premature birth without greater repercussions. During pregnancy, three patients (21.4%) had urinary tract infections and one patient (7.14%) presented urinary retention. After delivery, three patients (21.4%) presented temporary urinary incontinence; one patient (7.14%) had a vesicocutaneous fistula and seven patients (50%) had genital prolapsed. All patients confirmed to have achieved urinary continence, a regular sexual life and normal pregnancies. All patients got married and pregnant older than the general population. CONCLUSIONS: BE is a severe condition that demands medical and family assistance. Nevertheless, it is possible for the bearers of this condition to have a satisfactory and productive lifestyle.

Antibiotics prophylaxis at the time of catheter removal after radical prostatectomy: a systematic review of the literature and meta-analysis

Purpose: To conduct a systematic literature review with meta-analysis to identify whether antibiotic prophylaxis after removal of the indwelling urinary catheter reduces posterior infections. Methods: A systematic literature review was conducted in the databases PubMed, Embase, Cochrane, Google Scholar, and Latin American and Caribbean Health Sciences Literature, using the keywords "antibiotics" AND "prostatectomy" AND "urinary catheter." Results: Three articles were identified having the scope of our review, with 1,040 patients, which were subjected to our meta-analysis revealing a marginally significant decrease in the risk of urinary infection after indwelling urinary catheter removal (odds ratio-OR = 0.51; 95% confidence interval-95%CI 0.27-0.98; p = 0.04; I2 = 0%). No difference was found regarding the presence of bacteriuria (OR = 0.39; 95%CI 0.12-1.24; p = 0.11; I2 = 73%). Conclusions: In our meta-analysis, there was a significant decrease in urinary tract infection with antibiotic prophylaxis after indwelling urinary catheter removal following radical prostatectomy.

Description of the Dunning-Kruger effect in general surgery residents during laparoscopic cholecystectomy: a blinded prospective study

Purpose: The purpose of this study is to assess whether the Dunning-Kruger effect occurs in surgical residents when performing laparoscopic cholecystectomy in a porcine model. Methods: Prospective blinded study, which counted with forty PGY-1 general surgery residents who agreed to participate in the study were blindly recruited to perform a laparoscopic cholecystectomy in a porcine model. At the end of the procedure, the participants assigned a score of 0-10 for their own performance and the video of the operation was independently assessed by 2 experienced laparoscopic surgeons using a validated tool. Results: Participants were divided into groups of 10 individuals according to objective performance and compared. The group with the worst objective result was inferior to the group with the best objective result (3.77 ± 0.44 vs. 8.1 ± 0.44, p < 0.001), but they were similar in self-perception of performance (5.11 ± 1.69 vs. 6.1 ± 1.79, p = 0.999). Conclusions: In the studied sample, it was possible to demonstrate the presence of the Dunning-Kruger effect.

Vasopressin in vasoplegic shock in surgical patients: systematic review and meta-analysis

Purpose: Vasoplegia, or vasoplegic shock, is a syndrome whose main characteristic is reducing blood pressure in the presence of a standard or high cardiac output. For the treatment, vasopressors are recommended, and the most used is norepinephrine. However, new drugs have been evaluated, and conflicting results exist in the literature. Methods: This is a systematic review of the literature with meta-analysis, written according to the recommendations of the PRISMA report. The SCOPUS, PubMed, and ScienceDirect databases were used to select the scientific articles included in the study. Searches were conducted in December 2022 using the terms "vasopressin," "norepinephrine," "vasoplegic shock," "postoperative," and "surgery." Meta-analysis was performed using Review Manager (RevMan) 5.4. The endpoint associated with the study was efficiency in treating vasoplegic shock and reduced risk of death. Results: In total, 2,090 articles were retrieved; after applying the inclusion and exclusion criteria, ten studies were selected to compose the present review. We found no significant difference when assessing the outcome mortality comparing vasopressin versus norepinephrine (odds ratio = 1.60; confidence interval 0.47-5.50), nor when comparing studies on vasopressin versus placebo. When we analyzed the length of hospital stay compared to the use of vasopressin and norepinephrine, we identified a shorter length of hospital stay in cases that used vasopressin; however, the meta-analysis did not demonstrate statistical significance. Conclusions: Considering the outcomes included in our study, it is worth noting that most studies showed that using vasopressin was safe and can be considered in managing postoperative vasoplegic shock.

The learning curve of bilateral laparoscopic varicocelectomy: a prospective study / A curva de aprendizado da varicocelectomia laparoscópica bilateral: um estudo prospectivo

ABSTRACT Varicocele occurs in 15% of general male population and in 35% of infertile men. Since 1992, surgical correction with laparoscopic varicocelectomy is the gold standard for treatment of symptomatic patients or patients with abnormal seminal analysis. The learning curve for this frequently performed procedure has not yet been described. In the present study, we investigated the learning curve of a single urologist in training performing his first 21 laparoscopic varicocelectomies using qualitative and quantitative tools to evaluate his performance during the process. Our results show that 14 bilateral laparoscopic varicocelectomies are enough to achieve the plateau of the learning curve.

RESUMO Varicocele ocorre em 15% dos homens e em 35% dos homens inférteis. Desde 1992, a correção cirúrgica com varicocelectomia laparoscópica é o padrão ouro para o tratamento de pacientes sintomáticos ou com análise seminal anormal. A curva de aprendizado para esse procedimento frequentemente realizado ainda não foi descrita. No presente estudo, investigamos a curva de aprendizado de um único urologista em treinamento realizando suas primeiras 21 varicocelectomias laparoscópicas usando ferramentas qualitativas e quantitativas para avaliar seu desempenho durante o processo. Nossos resultados mostram que 14 varicocelectomias laparoscópicas bilaterais são suficientes para atingir o platô da curva de aprendizado.

Assessment of a new kind of surgical simulator. The physical surgical simulator.

PURPOSE: To evaluate whether the use of the physical surgical simulator may benefit the development of laparoscopic skills. METHODS: Ten medical students were divided into two groups: the first one performed ten weekly training sessions with a physical surgical simulator - ETX A2 LAP and, afterwards, one laparoscopic cholecystectomy in a porcine model, while the second group performed only a laparoscopic cholecystectomy. Both groups were compared regarding bleeding, total surgical time, time to perform each surgical step and qualitative parameters, based on a previously validated tool. RESULTS: There was no difference in any of the evaluated parameters. CONCLUSION: We did not find any evidence of benefit in the use of the physical simulator for surgical performance in medical students.

Does displacement of lower pole stones during retrograde intrarenal surgery improves stone-free status?: a systematic review and meta-analysis

Purpose: Kidney stones are one of the most common urological diseases worldwide. The size and location of the stone are the most important factors in determining the most suitable treatment options. The aim of this review was to evaluate the displacement of lower pole stones. Methods: Three studies assessing the efficacy of translocating kidney stones from the lower pole of the kidney to other locations during retrograde intrarenal surgery published in the last 20 years were included. A systematic search was conducted in the PubMed, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), and Web of Science databases using the following search terms: "Lower pole," "Lithotripsy." Meta-analysis was performed using Review Manager version 5.4. Results: Stone-free rates were improved through displacement (odds ratio - OR = -0.15; 95% confidence interval-95%CI -0.24--0.05; p = 0.002; I2 = 21%), but at the cost of increased surgical duration (mean difference = -12.50; 95%CI -24.06--0.95; p = 0.03; I2 = 94%). Although this represents a potentially negative outcome, the improvement in clearance rates justifies the additional investment of time and effort. Conclusions: Displacement of lower pole kidney stones for subsequent lithotripsy brings significant benefits in terms of stone-free rate, with no difference in laser energy usage. However, it results in increased surgical time. Despite these factors, the benefits to patients undergoing the procedure are substantial.

Comparing financing models for supplementary healthcare in appendectomy: activity-based costing (fee-for-service) vs. diagnosis related group remuneration (bundled payment): a systematic review and meta-analysis

Purpose: In Brazil, healthcare services traditionally follow a fee-for-service (FFS) payment system, in which each medical procedure incurs a separate charge. An alternative reimbursement with the aim of reducing costs is diagnosis related group (DRG) remuneration, in which all patient care is covered by a fixed amount. This work aimed to perform a systematic review followed by meta-analysis to assess the effectiveness of the Budled Payment for Care Improvement (BPCI) versus FFS. Methods: Our work was performed following the items of the PRISMA report. We included only observational trials, and the primary outcome assessed was the effectiveness of FFS and DRG in appendectomy considering complications. We also assessed the costs and length of hospital stay. Meta-analysis was performed with Rev Man version 5.4. Results: Out of 735 initially identified articles, six met the eligibility criteria. We demonstrated a shorter hospital stay associated with the DRG model (mean difference = 0.39; 95% confidence interval ­ 95%CI ­ 0.38­0.40; p < 0.00001; I2 = 0%), however the hospital readmission rate was higher in this model (odds ratio = 1.57; 95%CI 1.02­2.44, p = 0.04; I2 = 90%). Conclusions: This study reveals a potential decrease in the length of stay for appendectomy patients using the DRG approach. However, no significant differences were observed in other outcomes analysis between the two approaches.

Diameter of ureteral access sheath and ureteral stenosis development: a systematic review

Purpose: Ureteral access sheaths (UAS) are widely used in ureteroscopy. UAS are believed to pose a significant risk for ureteral stenosis due to ureteral mucosal compression, but little evidence supports this claim. Our systematic review aimed to investigate the relationship between different UAS diameters and stenosis risk. Methods: A systematic search was conducted in PubMed, Embase, Web of Science, Scopus, and Cochrane, from its inception to May 2023. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane guidelines were followed. χ2 test was performed to compare the prevalence within the groups. Results: Six nonrandomized trials and one randomized, with a total of 962 patients, were included. The overall incidence of ureteral stenosis of 0.9%. UAS sizes were: 9.5/11.5Fr, 10/12Fr, 11/13Fr, 12/14Fr, and 14/16Fr. Within each subgroup, the incidence of ureteral stenosis was: 0.4, 8, 0, 1, and 1% (p = 0.099). No trend for stenosis was observed among larger UAS. Conclusions: In this systematic review, no relationship between UAS diameter and incidence of ureteral stenosis was observed. Nonetheless, additional randomized controlled trials are required to support this finding.