WCE 2019: Body Mass Index Impacts Percutaneous Nephrolithotomy and Retrograde Intra - Renal Surgery Results

Abu Dhabi, United Arab Emirates (UroToday.com) Dr. João Torres described how body mass index can impact the outcomes of urologic procedures, percutaneous nephrolithotomy, and retrograde intrarenal surgery. This is an important topic because of the increasing prevalence of overweight and obese patients. Patients who are overweight or obese can present a challenge when determining the ideal procedure to address their stones. 
Their study at the Hospital de Braga in Braga, Portugal included 331 patients with nephrolithiasis. 130 underwent retrograde intra-renal surgery or ureteroscopy, and 201 underwent percutaneous nephrolithotomy. body mass index (BMI) was used to categorize patients into obese (BMI>30), overweight (BMI 25-30), or normal weight (BMI<25). They compared demographic characteristics, stone characteristics such as size, number, and location, surgical outcomes, stone-free rate, and intraoperative complications between the two groups.

Interestingly, they found that having a higher BMI actually may be protective. Overweight and obese patients had fewer postoperative complications when undergoing ureteroscopy, compared to normal-weight patients. In patients undergoing percutaneous nephrolithotomy (PCNL), the obese patients had a lower hemoglobin drop compared to overweight and normal patients. In addition, overweight and obese patients had a lower risk of postoperative hematuria compared to normal-weight patients. However, obese and overweight patients did not have higher stone-free rates, and in these patients, PCNLs had more frequent complications than ureteroscopy.

Based on this study, being obese or overweight may actually have some benefits in urologic procedures. It may be protective in some postoperative outcomes and is especially safer for ureteroscopy.

Presented by: João Torres, MD, Department of Urology, Hospital de Braga, Braga, Portugal

Written by: Rajiv Karani Department of Urology, University of California, Irvine, at the 37th World Congress of Endourology (WCE) – October 29th-November 2nd, Abu Dhabi, United Arab Emirates