Effects of first year COVID-19 pandemic on urology practice in three major Arab Countries: Sub-Analysis of a survey by Arab association of urology research group.

BACKGROUND AND OBJECTIVES: The World Health Organization (WHO) declared the coronavirus disease-19 (COVID-19) pandemic on March 11, 2020. The health care system faced tremendous challenges in providing ethical and high-quality care. The impact of COVID-19 on urological practices varied widely worldwide, including in Arab countries. This study aimed to compare the influence of the COVID-19 pandemic on urology practice in Egypt, the KSA, and the UAE during the first year of the pandemic. METHODS: This sub-analysis assessed the demographics and COVID-19's effects on urological practice in terms of adjustments to hospital policy, including outpatient consultations, the management of elective and urgent surgical cases, and the continuation of education across the three countries. The availability of personal protective equipment (PPE) and urologists' emotional, physical, and verbal intimidation during COVID-19 were also compared. RESULTS: Regarding the impact on hospital policy, consultations replaced by telemedicine were significantly higher in the KSA (36.15%), followed by the UAE (33.3%), then Egypt (10.4%) (P = 0.008). Elective cases requiring ICU admission were 65.1% in Egypt, 45.2% in the KSA, and 58.2% in the UAE and were performed only in high-risk patients. PPE was freely available in 20.8% of the Egyptian hospitals compared to 83.3% in the KSA and 81.8% in the UAE. Online courses were significantly higher in Egypt (70.8%), followed by the UAE (53%) and the KSA (41.7%) (P = 0.02). Emotional intimidation was higher than verbal intimidation, representing 80%, 75.9%, and 76% in the UAE, KSA, and Egypt, respectively. CONCLUSION: This sub-analysis outlined significant hospital policy changes across the three Arab countries. Exposure to emotional, verbal, and physical intimidation was observed. The development of teleconsultations and online platforms for educational purposes was observed.

PCNL vs RIRS in management of stones in calyceal diverticulum: outcomes from a global multicentre match paired study that reflects real world practice.

INTRODUCTION: Calyceal diverticulum (CD) is the outpouching of a calyx into the renal parenchyma, connected by an infundibulum. Often associated with recurrent stones, common surgical options include percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS). We aim to present the real-world practises and outcomes comparing both approaches and the technical choices made. MATERIALS AND METHODS: Retrospective data including 313 patients from 11 countries were evaluated. One hundred and twenty-seven underwent mini-PCNL and one hundred and eighty-six underwent RIRS. Patient demographics, perioperative parameters, and outcomes were analysed using either T test or Mann-Whitney U test. Categorical data between groups were analysed using the Chi-squared test. Propensity score matching (PSM) was performed matching for baseline characteristics. Subgroup analyses for anomalous/malrotated kidneys and difficult diverticulum access were performed. RESULTS: After PSM, 123 patients in each arm were included, with similar outcomes for stone-free rate (SFR) and complications (p < 0.001). Hospitalisation was significantly longer in PCNL. Re-intervention rate for residual fragments (any fragment > 4 mm) was similar. RIRS was the preferred re-intervention for both groups. Intraoperative bleeding was significantly higher in PCNL (p < 0.032) but none required transfusion. Two patients with malrotated anatomy in RIRS group required transfusion. Lower pole presented most difficult access for both groups, and SFR was significantly higher in difficult CD accessed by RIRS (p < 0.031). Laser infundibulotomy was preferred for improving diverticular access in both. Fulguration post-intervention was not practised. CONCLUSION: The crux lies in identification of the opening and safe access. Urologists may consider a step-up personalised approach with a view of endoscopic combined approach where required.

Does gender influence retrograde intrarenal surgery (RIRS) outcomes? Data from the Flexible Ureteroscopy Outcomes Registry (FLEXOR).

INTRODUCTION AND OBJECTIVES: As well established flexible ureteroscopy (RIRS). There is still no evidence if gender can have any influence on the outcomes and complication when performing. This study aims to evaluate the role that gender has in performing flexible ureteroscopy from a large series of patients. METHODS: This study retrospectively analyzed patients who underwent RIRS for renal stones from January 2018 to August 2021 within the multicentric FLEXOR registry. Demographics, stone characteristics, perioperative findings, results and complications were analyzed and compared between gender groups. RESULTS: A total of 6669 patients were included, 66.1% were male and 33.9% were female. Stone characteristics was comparable between groups. Female patients had significant higher fever and positive urine culture rates (12% vs. 8% and 37% vs. 34%). Also, females had a slight longer hospital stay (3.8 vs. 3.5 days; P < 0.001) and more residual fragments after the procedure (23.03% vs. 20.97 (P = 0.032). Overall complications were slightly significantly higher in women (15.74% vs. 14% (P = 0.042)) mainly at the expense of fever rates (6.9% vs. 5.7%) whereas the risk of sepsis was similar in both groups. A multivariate analysis showed that larger stone size, multiple and lower pole stones seem to have a negative impact in the incidence of residual stones and complications. CONCLUSION: Our real life global study reflects that female gender may have a correlation with a slightly increased residual fragment rate and overall low grade complications. However, women can safely be treated with RIRS with no increased the rate of sepsis with appropriate care.

A Feasibility Study on Clinical Utility, Efficacy and Limitations of 2 Types of Flexible and Navigable Suction Ureteral Access Sheaths in Retrograde Intrarenal Surgery for Renal Stones.

OBJECTIVE: To evaluate stone-free rate, device maneuverability, and complications after retrograde intrarenal surgery (RIRS) using 2 different sizes of flexible and navigable suction ureteral access sheaths (FANS). METHODS: A retrospective analysis was performed for patients who underwent RIRS for renal stones of any size, number, and location between November 2021 and October 2022. Group 1 had FANS of 12 French. Group 2 had FANS of 10 French. Both sheaths have a Y-shaped suction channel. Tip of 10 French FANS has 20% more flexibility. Lithotripsy was achieved using either thulium fiber or high-power holmium lasers. A 5-point Likert scale was used to assess the performance of each sheath. RESULTS: There were 16 patients in Group 1 and 15 patients in Group 2. Baseline demographics and stone parameters were similar. Four patients in Group 2 had the same session bilateral RIRS. Sheath insertion was successful in all renal units but one. Ten French FANS had a higher percentage of excellent scores for ease of use, manipulation, and visibility. Neither of the sheaths had an average or difficult rating for all evaluation scales. A fornix rupture requiring prolonged stenting occurred in group 2. All patients were discharged within 24 hours of surgery. One patient in each group visited the emergency department (analgesic treatment). There were no infectious complications. At 3 months, a computed tomography scan showed that the absence of residual fragments >2 mm was significantly higher in Group 2 (94.7% vs 68.8%, P = 0.01). CONCLUSION: The 10 Fr FANS showed a higher stone-free rate. There was no infectious complication using both sheaths.

Influence of pre-stenting on RIRS outcomes. Inferences from patients of the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR).

BACKGROUND: Retrograde Intrarenal Surgery (RIRS) is recommended as an alternative to percutaneous nephrolithotomy for stones up to 2 cm. Pre-stenting before RIRS remains controversial with various studies differing in outcomes and recommendations. We aim to understand how pre-stenting influences surgical outcomes. METHODS: A number of 6579 patients from the TOWER group registry were divided into pre-stented (group 1) and non-pre-stented groups (group 2). Patients aged ≥18 years old, with normal calyceal anatomy were enrolled. Patients with ureteric stones, anomalous kidneys, bilateral stones, planned for ECIRS were excluded. RESULTS: Patients are homogeneously distributed in both groups (3112 vs. 3467). The predominant indication for pre-stenting was symptom relief. Overall stone size was comparable, whilst group 1 had a significantly more multiple (1419 vs. 1283, P<0.001) and lower-pole (LP) stones (1503 vs. 1411, P<0.001). The mean operative time for group 2 was significantly longer (68.17 vs. 58.92, P<0.001). Stone size, LP stones, age, recurrence and multiple stones are contributing factors for residual fragments at the multivariable analysis. The incidence of postoperative day 1 fever and sepsis was significantly higher in group 2, indicating that pre-stenting is associated with a lower risk of post-RIRS infection and a lower overall complications rate (13.62% vs. 15.89%) (P<0.001). CONCLUSIONS: RIRS without pre-stenting can be considered safe without significant morbidity. Multiple, lower-pole and large stone is a significant contributor towards residual fragments. Patients who were not pre-stented had significantly higher but low-grade complications, especially for lower pole and large volume stones. While we do not advocate routine pre-stenting, a tailored approach for these patients should include proper counselling regarding pre-stenting.

Comparison Between Holmium:YAG Laser with MOSES Technology vs Thulium Fiber Laser Lithotripsy in Retrograde Intrarenal Surgery for Kidney Stones in Adults: A Propensity Score-matched Analysis From the FLEXible Ureteroscopy Outcomes Registry.

PURPOSE: We evaluated stone-free rate and complications after flexible ureteroscopy for renal stones, comparing thulium fiber laser and holmium:YAG laser with MOSES technology. MATERIALS AND METHODS: Data from adults who underwent flexible ureteroscopy in 20 centers worldwide were retrospectively reviewed (January 2018-August 2021). Patients with ureteral stones, concomitant bilateral procedures, and combined procedures were excluded. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Stone-free rate was defined as absence of fragments >2 mm on imaging within 3 months after surgery. Multivariable logistic regression analysis was performed to evaluate independent predictors of being stone-free. RESULTS: Of 2,075 included patients, holmium:YAG laser with MOSES technology was used in 508 patients and thulium fiber laser in 1,567 patients. After matching, 284 patients from each group with comparable baseline characteristics were included. Pure dusting was applied in 6.0% of cases in holmium:YAG laser with MOSES technology compared with 26% in thulium fiber laser. There was a higher rate of basket extraction in holmium:YAG laser with MOSES technology (89% vs 43%, P < .001). Total operation time and lasing time were similar. Nine patients had sepsis in thulium fiber laser vs none in holmium:YAG laser with MOSES technology (P = .007). Higher stone-free rate was achieved in thulium fiber laser (85% vs 56%, P < .001). At multivariable analysis, the use of thulium fiber laser and ureteral access sheath ≥8F had significantly higher odds of being stone-free. Lasing time, multiple stones, stone diameter, and use of disposable scopes showed significantly lower odds of being stone-free. CONCLUSIONS: This real-world study favors the use of thulium fiber laser over holmium:YAG laser with MOSES technology in flexible ureteroscopy for renal stones by way of its higher single-stage stone-free rate.

Distal sciatic neuropraxia secondary to lithotomy position: A case report and literature review.

Urolithiasis is one of the commonest urological diseases that can greatly impact the health status of patients with a high socioeconomic burden. Retrograde intrarenal surgery (RIRS) has been considered to be the surgery of choice for small renal stones (Less than 2 cm) due to its feasibility and safety. However, even with potentially low risk, complications can still result with RIRS. In this article we present a unique case of a 12-year-old male who had complete foot drop as a complication following RIRS. No similar case has been reported in the literature.

Is routine re-imaging for high-grade renal injury needed? Retrospective analysis of 1500 abdominal trauma patients from a tertiary care trauma center over 11 years.

INTRODUCTION AND AIM: The AUA and EAU guidelines recommend re-imaging in high-grade renal trauma, regardless of the clinical findings. The aim of this study was to assess the impact of re-imaging on the overall management and outcomes in these patients. METHODS: The trauma registry of our tertiary care Level-1 trauma center was reviewed from January 2007 till October 2018. Out of 1536 patients with abdominal trauma, 174 patients with isolated renal injury were identified. Renal injuries were classified based on the AAST classification. Variables retrieved were demographics, renal injury grade, presence of urinoma, repeated imaging findings, and intervention after initial and repeated imaging. RESULTS: Low-grade injury was found in 78.7% (137/174) compared to 21.3% (37/174) with high-grade injury. The majority (n = 136) of low-grade patients were managed conservatively except one patient with Grade III injury required angioembolization after initial imaging. Of the high-grade patients, 31/37 were treated conservatively except 6/37 patients required surgical intervention after initial imaging. Following re-imaging, only one patient required surgical intervention in the form of insertion of a drainage tube for a hematoma, which was possibly infected. The existence of urinoma (5 patients) or hematoma (47 patients) was not associated with significantly higher rate of intervention (p values: 0.717 and 0.138, respectively). No significant association was noted between hematoma size and rate of intervention (p value = 0.055). CONCLUSION: Re-imaging for high-grade renal injuries could be limited to the presence of urinary extravasation in initial imaging or the presence of clinical deterioration such as pain, fever or decrease in hemoglobin level.

The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP-tool): a Delphi consensus project on standardised evaluation of flexible ureterorenoscopes.

OBJECTIVE: To develop a standardised tool to evaluate flexible ureterorenoscopes (fURS). MATERIALS AND METHODS: A three-stage consensus building approach based on the modified Delphi technique was performed under guidance of a steering group. First, scope- and user-related parameters used to evaluate fURS were identified through a systematic scoping review. Then, the main categories and subcategories were defined, and the expert panel was selected. Finally, a two-step modified Delphi consensus project was conducted to firstly obtain consensus on the relevance and exact definition of each (sub)category necessary to evaluate fURS, and secondly on the evaluation method (setting, used tools and unit of outcome) of those (sub)categories. Consensus was reached at a predefined threshold of 80% high agreement. RESULTS: The panel consisted of 30 experts in the field of endourology. The first step of the modified Delphi consensus project consisted of two questionnaires with a response rate of 97% (n = 29) for both. Consensus was reached for the relevance and definition of six main categories and 12 subcategories. The second step consisted of three questionnaires (response rate of 90%, 97% and 100%, respectively). Consensus was reached on the method of measurement for all (sub)categories. CONCLUSION: This modified Delphi consensus project reached consensus on a standardised grading tool for the evaluation of fURS - The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP) tool. This is a first step in creating uniformity in this field of research to facilitate future comparison of outcomes of the functionality and handling of fURS.

Indications, preferences, global practice patterns and outcomes in retrograde intrarenal surgery (RIRS) for renal stones in adults: results from a multicenter database of 6669 patients of the global FLEXible ureteroscopy Outcomes Registry (FLEXOR).

PURPOSE: To collect a multicentric database on behalf of TOWER research group to assess practice patterns and outcomes of retrograde intrarenal surgery (RIRS) for kidney stones. METHODS: Inclusion criteria: age ≥ 18 years, normal renal/calyceal system anatomy, calculi of any size, number, and position. STUDY PERIOD: January 2018 and August 2021. Stone-free status: absence of fragments > 2 mm, assessed post procedure according to the local protocol (KUB X-Ray and/or ultrasound or non-contrast CT scan). RESULTS: Twenty centers from fifteen countries enrolled 6669 patients. There were 4407 (66.2%) men. Mean age was 49.3 ± 15.59 years. Pain was the most frequent symptom indication for intervention (62.6%). 679 (10.2%) patients underwent RIRS for an incidental finding of stones. 2732 (41.0%) patients had multiple stones. Mean stone size was 10.04 ± 6.84 mm. A reusable flexible ureteroscope was used in 4803 (72.0%) procedures. A sheath-less RIRS was performed in 454 (6.8%) cases. Holmium:YAG laser was used in 4878 (73.1%) cases. A combination of dusting and fragmentation was the most common lithotripsy mode performed (64.3%). Mean operation time was 62.40 ± 17.76 min. 119 (1.8%) patients had an intraoperative injury of the ureter due to UAS insertion. Mean postoperative stay was 3.62 ± 3.47 days. At least one postoperative complication occurred in 535 (8.0%) patients. Sepsis requiring intensive care admission occurred in 84 (1.3%) patients. Residual fragments were detected in 1445 (21.7%) patients. Among the latter, 744 (51.5%) patients required a further intervention. CONCLUSION: Our database contributes real-world data to support to a better understanding of modern RIRS practice and outcomes.

Trends of Acute Renal Colic During COVID-19 Lockdown: An Experience From Saudi Arabia.

Introduction The COVID-19 pandemic represents an unprecedented challenge for healthcare systems around the world. Saudi Arabia was one of the first countries to experience a lockdown and postponement of elective surgical procedures. The objective of this study was to assess the trends of acute renal colic presenting to our emergency department. Methods This retrospective study targeted all patients who presented with acute renal colic during the lockdown period (March 23, 2019 to June 20, 2019). Patients' and stone data were collected. The patient's data included age, gender, BMI, and comorbidities. Stones' data included stone size, location, side, evidence of obstruction and UTI, and planned and conducted management. Results A total of 137 patients were identified; 92 (67.2%) patients were males with a mean age of 44 ± 16 years. Positive history of urolithiasis was reported in 47 (34.3%). The most common initial investigation was non-contrast CTs (93.4%). The majority of patients had a stone size of < 10 mm (93%) and ureteric stones (81.2%). A total of 32 patients (32.4%) had evidence of UTI and 63.4% had evidence of obstruction. Most of the patients (73.7%) were offered medical expulsive therapy (MET). Only 2.2% did not receive the planned management. Conclusion The observed pattern shows that the management during the lockdown did not differ from the original recommendations. This could be due to the fact that most patients had stone sizes between 5 and 10 mm and consequently were managed by METs. Larger data need to be conducted to provide concrete evidence. Such data are relevant to provide a clear guide for management and to establish protocols for emergency lockdown situations.

Unexpected encapsulated hematoma after Rezum therapy: First outcome of an emerging therapy.

Rezum therapy is in emerging minimally invasive treatment for BPH. Complications of Rezum are underreported in the literature. We report a case of a 61-year-old male patient who presented to ED two months after Rezum with hematuria and clot retention. US showed prostate size of 315 g with cystic changes. The patient was managed with TURP and unexpectedly showed big contained hematoma below the bladder neck which was evacuated with adequate hemostasis.

Nail Gun Penetrating Renal Injury: A Case Report.

The kidney is the genitourinary organ most affected by trauma, although the retroperitoneal location provides some protection. Renal injuries are classified according to the mechanism of trauma. Most of the penetrating renal injury cases in the literature are due to knife stabbing or handguns. We present an interesting case of a 22-year-old male with a penetrating renal injury caused by an electric nail gun. There was no report of a similar case in the literature.

Characteristics and Types of Urolithiasis in the Eastern Region of Saudi Arabia: A Single-Center Retrospective Study.

Introduction Urolithiasis is one of the most common conditions encountered in clinical practice with the prevalence increasing globally in the last few decades. Urolithiasis has been found to be more common in areas with a hot climate, such as Saudi Arabia. The aim of this study was to determine the characteristics and the types of urolithiasis most frequently found in the Eastern Region of Saudi Arabia. Methods This was a single-center retrospective cohort study based on data extracted from an electronic hospital information system (BESTCare) of all patients diagnosed with urolithiasis at King Abdulaziz Hospital, a tertiary care center in Saudi Arabia's Eastern Region. From January 2013 to December 2016, all adult patients aged 18 and up who presented with urinary calculi (renal and ureter) were included in the study. Results A total of 235 patients were reviewed, with a mean age of 48.52 years. Renal calculi were more prevalent in males (74.5%). Calcium oxalate was the predominant type (76%), followed by uric acid calculi (18%) and cystine calculi (4.8%). A small proportion (1.2%) was calcium phosphate calculi. The most frequently associated comorbidity was hypertension (17.9%). The majority (78.5%) had a stone removal through a ureteroscopy and 8.2% by percutaneous nephrolithotomy (PCNL). The mean stone size was 12.2 ± 9.91 mm, with a mean stone Hounsfield unit (HU) of 789.9. The mean urinary PH at stone incident was 6.77, and the mean creatinine level was 92.4mmol. Conclusion This study showed that males were more affected by urolithiasis, compared to females in the Eastern Region. Furthermore, calcium oxalate was the predominant type. These findings are consistent with the literature and they highlighted the necessity for further studies in this area, to provide insight into the pathophysiology and incidence of renal calculi for improving patient care.

Ureteral intussusception: a case report and review of literature.

Ureterorenoscopy (URS) is a minimal invasive procedure used for diagnosis and management of the upper urinary tract. Due to the vast advancement in URS technologies, the efficacy and safety greatly improved with lower complication rates. Intussusception is a rare complication of URS. We report a case of iatrogenic ureteral intussusception that was managed with ileal interposition.

Factors Associated with Varicocele Recurrence After Microscopic Sub-Inguinal Varicocelectomy.

PURPOSE: This study has been conducted to identify the rate of varicocele recurrence in patients who underwent microscopic subinguinal varicocelectomy at our center. We also aimed to determine the contributing factors to varicocele recurrence. PATIENTS AND METHODS: A total of 34 married male patients who underwent microscopic sub-inguinal varicocelectomy were retrospectively included in this study. The medical records of recruited patients were reviewed. The diagnosis of varicocele was based on physical examination, while recurrent varicocele was diagnosed based on both physical examination and colored doppler ultrasound. We investigated contributing factors to varicocele recurrence, including demographic characteristics (such as body mass index), clinical (varicocele grade and size of dilated veins), and laboratory data (semen analysis). Patients were followed up at 3 and 6 months after surgery. RESULTS: The mean age of patients was 32.53 years. The majority of patients had left-sided varicocele (70.6%) and underwent surgery due to scrotal pain (82.4%), with a mean operation duration of 92 minutes. Left-sided varicoceles were grade II in 51.7% of patients, while right-sided varicoceles were grade II in 16.1% of patients. Recurrence occurred in 2.9% after 3 and 6 months. Pain recurred in 8.8% and 10.5% of patients at 3 and 6 months, respectively. Pregnancy rates were 44.1% at 3 months and 11.8% at 6 months after surgery. The grade of varicocele (P = 0.24) and the size of the left dilated vein (P = 0.002) was significantly associated with recurrence. CONCLUSION: There was a significant association of advanced grade on the left side and large vein diameter before and after surgery with an increased rate of recurrence; however, due to the small sample size of our study, more and larger studies are still warranted.

Simultaneous and synchronous bilateral endoscopic treatment of urolithiasis: a multicentric study.

INTRODUCTION: The general prevalence of bilateral urolithiasis has risen to 15% and bilateral non-simultaneous treatment has been reported to have good outcomes. The objective of this study was to evaluate the effectiveness and safety of simultaneous bilateral endoscopic surgery (SBES). MATERIAL AND METHODS: An international multicenter analysis was performed between May 2015 and December 2017. All patients with bilateral stone disease that underwent SBES were included. Patients were treated under general anesthesia in either the supine or lithotomy position. Demographic, clinical, intraoperative and postoperative data were analyzed. RESULTS: A total of 47 patients were included. Mean age was 53.8 years and 70% of the patients were males. The mean American Society of Anesthesiology (ASA) score was 2. The mean diameter of right- and left-sided stones was 29.43 mm (2-83 mm) and 31.15 (4-102 mm), respectively. Staghorn stones were treated in 18 cases (8 right-sided and 10 left-sided), four of them were defined as complete staghorn. The procedures performed were 42 cases of bilateral URS and PCNL and ureteroscopy. Additionally, 5 bilateral flexible ureteroscopy (fURS) cases were described. Intraoperative complications occurred in five patients: four of them were classified as Clavien-Dindo (CD) I and one as CD II. Postoperatively, there were two cases with CD I, 6 with CD II and one CD IIIa.The stone-free status was 70%. Residual stones (30%) were detected only on the side treated for high-volume (complete) staghorn calculi. CONCLUSIONS: SBES is a feasible, effective and safe procedure. It may potentially avoid repeated anesthetic sessions as needed for staged procedures and reduce the length of patients' hospital stay.

Stone fragments migration into subcapsular renal hematoma post flexible ureterorenoscopy (unique presentation).

This is a case report of 45-year-old female patient who presented with right flank pain. Abdominopelvic CT scan showed right renal pelvis stone measuring 20 mm. Right flexible ureterorenoscopy with holmium laser was performed in our institute. Postoperatively, she was febrile and pale. Immediate Abdominopelvic CT scan was obtained which revealed a large right subcapular hematoma. Conservative management was maintained for a week. Two months later, repeated Abdominopelvic CT scan showed regression of right subcapsular renal hematoma with stone fragments migration into the perinephric space as a first presentation in the world.

Effects of flexible ureteroscopy on renal blood flow: a prospective evaluation.

OBJECTIVE: This study aimed to investigate the effects of flexible ureteroscopy (F-URS) on renal blood flow using renal Doppler ultrasound (US). MATERIALS AND METHOD: Patients undergoing F-URS were scheduled for Doppler US preoperatively and postoperatively. Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) were reported. Technical details, operation time, stone characteristics and complications were recorded. Patients were grouped as 9.5/11.5-Flex-X2, 10/12-Flex-X2, 10/12-Flex-XC, 12/14-Flex-X2 and 12/14-Flex-XC, with 28, six, three, seven and two patients in each group, respectively. RESULTS: Forty-six patients with a mean age of 41.24 years and stone volume of 1685 mm³ were enrolled. The PSV, EDV, PI and RI of renal arteries in all groups in preoperative and postoperative periods were similar. Arcuate artery measurements in all groups were also similar in preoperative and postoperative periods, without any significant difference except in two parameters: RI in the 9.5/11.5-Flex-X2 group and PSV in the 12/14-Flex-X2 group. The resistive index in the arcuate artery of the 9.5/11.5-Flex-X2 group was increased from 0.59 to 0.62 cm/sec postoperatively. The PSV in the arcuate artery of the 12/14-Flex-X2 group was decreased from 30.9 to 27.2 cm/sec. Three patients had urinary tract infections postoperatively and two had sepsis. CONCLUSION: This study suggests that compatible ureteroscope-ureteral access sheath combinations with a lumen difference of more than 1.5 Fr can provide safe outcomes in terms of renal blood flow. F-URS can safely be performed in terms of renal perfusion and complication rates with appropriate equipment and instruments.