Best surgeon position for flexible ureteroscopy in terms of patient outcomes: A retrospective analysis paving way for future practice

Aim: To assess outcomes of retrograde intra-renal surgery (RIRS) for kidney stone disease performed in sitting as compared to standing positions in terms of procedural and patient-related outcomes. Materials and Methods: Experienced endourologists from 20 centres in 15 countries participated in this study. A total of 6669 cases were recorded including 5218 procedures performed standing and 1451 performed sitting. Data including demographics (age, sex, race, stone site and size, anaesthetic and laser used) and outcomes (complications, stone free status (SFR), length of stay and re-intervention required) was collected. Data were retrospectively analysed using SPSS version 25.0 for statistical significance. Results: Flexible ureteroscopy (F-URS) in a sitting position showed overall 18.7% complications versus 11.0% in the standing group which included mild haematuria not needing intervention (9.8% vs 4.3% standing group), temperature spike within 24 hours only (7.8% vs 5.6% sitting group), sepsis not needing intensive care unit (ICU) (1.9% vs 1.1% standing group) and ureteric injuries managed with stent insertion only (1.8% in each). Significantly fewer patients in sitting group had preoperative stents (44.9%) versus standing group (47.2%). The sitting group also had a significantly shorter laser time (22.93 ± 16.73 minutes vs 28.65 ± 17.75 minutes in standing group). The mean length of stay was significantly higher in the sitting group (5.11 ± 3.68 days) versus standing group (3.19 ± 3.28 days). A significantly higher residual fragments (defined as any single fragment ⩾4 mm or multiple fragments of any size) were found in the sitting group (34.2%) versus standing group (18.2%). Conclusion: Our real-world study is the first attempt to objectively compare outcomes of RIRS performed by surgeons in sitting and standing position. While statistically significant findings favour standing in univariate analysis, Multi-variable analysis (MVA) showed that surgeon position is not directly responsible for SFR and complication outcomes. This study does show that sitting position is safe, efficacious and replicates the same principles when done in standing. A dedicated randomized controlled trial (RCT) in a controlled set up with comparable lasing techniques will be needed to make stronger inferences. As sitting position is ergonomically proven better our study encourages surgeons to perform F-URS in this position.