This statement appears to be true on many levels and in endourology it applies most notably to the morbidly obese patient cohort undergoing percutaneous stone removal.
Using the CROES (Clinical Research of the Endourological Society) data base of nearly 6000 percutaneous nephrostolithotomy patients, the authors subselected for those individuals with a BMI >40. These 97 patients were then retrospectively matched with 97 normal weight patients on multiple levels. Not surprisingly, the morbidly obese patients had a seven-fold higher incidence of diabetes mellitus (43%) and a three-fold higher incidence of cardiovascular disease (56%) consistent with the “metabolic syndrome” associated with obesity.
From a nephrostolithomy standpoint, despite matching for similar stone characteristics, the morbidly obese patients had longer operative times by 30% and lower stone free rates (66% vs. 77%) despite a higher incidence of secondary procedures (28% vs 12%). The efficiency quotient for the obese group was only 52% meaning that only half of the patients became stone free with only one procedure.
Lastly, while hospital stays and transfusion rates were similar; the obese cohort had a nearly 4-fold higher complication rate (22% vs. 6%).
In short, when dealing with patients with a BMI >40 who are in need of a percutaneous stone removal, the urologist needs to revise the information given to the patient to reflect a lower stone free rate and a higher complication rate than in the nonobese patient population.
Presented by Andrew Fuller at the 29th World Congress of Endourology & SWL (WCE) - November 30 - December 3, 2011 - Kyoto International Conference Center - Kyoto, Japan
Reported for UroToday by Ralph V. Clayman, MD, Chair, Department of Urology, University of California-Irvine Medical Center, Irvine, CA
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