The impact of body mass index on oncological and surgical outcomes of patients undergoing nephrectomy: a systematic review and meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis to evaluate the impact of body mass index (BMI) on oncological (primary) and surgical (secondary) outcomes of patients who underwent nephrectomy, as obesity or high BMI is a known risk factor for renal cell carcinoma (RCC) and predictor of poorer outcomes. METHODS: Studies were identified from four electronic databases from database inception to 2 June 2021, according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. The review protocol was registered in the International Prospective Register of Systematic Reviews with the identification number: CRD42021275124. RESULTS: A total of 18 studies containing 13 865 patients were identified for the final meta-analysis. Regarding oncological outcomes, higher BMI predicted higher overall survival (BMI >25 vs BMI <25 kg/m2 : hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.58-0.85), cancer-specific survival (BMI >25 vs BMI <25 kg/m2 : HR 0.60, 95% CI 0.50-0.73; BMI 25-30 vs BMI <25 kg/m2 : HR 0.46, 95% CI 0.23-0.95; BMI >30 vs BMI <25 kg/m2 : HR 0.50, 95% CI 0.36-0.69), and recurrence-free survival rates (BMI >25 vs BMI <25 kg/m2 : HR 0.72, 95% CI 0.63-0.82; BMI 25-30 vs BMI <25 kg/m2 : HR 0.59, 95% CI 0.42-0.82). Those with a lower BMI fared better in surgical outcomes, such as operation time and warm ischaemic time, although the absolute difference was minimal and unlikely to be clinically significant. There was no difference between groups for length of hospital stay, intraoperative or postoperative complications, blood transfusion requirements, and conversion to open surgery. CONCLUSION: Our study suggests that a higher BMI is associated with improved long-term oncological survival and similar perioperative outcomes as a lower BMI. More research into the underlying biological and physiological mechanisms will enable better understanding of the effect of BMI, beyond mere association, on post-nephrectomy outcomes.

Role and Importance of Ergonomics in Retrograde Intrarenal Surgery: Outcomes of a Narrative Review.

Background: With recent technological advancement, new and improved endoscopic instruments and laser devices have catapulted flexible ureteroscopy to the forefront, hence making retrograde intrarenal surgery (RIRS) a popular choice for the management of renal stones. However, RIRS has also resulted in an increasing number of work-related musculoskeletal disorders, which can have a detrimental impact on surgeons' physical health and operative lifespan. The aim of our review is to examine the impact and feasibility of ergonomic adjustments and outline future directions and recommendations to improve the awareness of and reduce the prevalence of musculoskeletal injuries among urologists. Methods: This study was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A thorough literature review was conducted of several databases using the following keywords and Medical Subject Headings (MeSH) terms to generate a search strategy: nephrolithiasis, kidney calculus, renal calculus, staghorn calculus, ergonomics, position, fatigue, comfort, tire, physical strain, visual strain, muscle, ureteroscopy, RIRS, laser, and lithotripsy. Studies were chosen for inclusion by reviewers independently, and the data were consolidated for analysis. Results: A total of 1446 articles were identified on initial literature search; 23 were included in the final analysis. The impact of various ergonomic modifications on operative outcomes, surgeons, surgical equipment, and patients, was analyzed. In addition, we summarized all the improvements that resulted in better ergonomics in RIRS. Conclusion: Ergonomics in RIRS is poorly understood and there are currently no formal guidelines for this aspect. While modern endourology armamentarium seems to help with procedural ergonomics, more needs to be done to enhance surgeon comfort, protect surgeon longevity, and prioritize the health and safety of endourologists.