Category: Clinical Stones: PCNL
Introduction & Objective :
Percutaneous nephrolithotomy (PCNL) is the “gold standard” in the treatment of large and/or complex kidney lithiasis. The higher incidence of urolithiasis and the greater risk of complications in obese patients pose some challenges in their minimally invasive stone treatment. The objective of this retrospective study is to compare the efficacy and safety of PCNL with respect to body mass index (BMI) in a contemporary series of patients.
The medical records of 771 patients with 811 renal units, who underwent PCNL between May 2011 and May 2017 were retrospectively reviewed. Patients were divided into 2 groups based on their BMI: group 1 - < 30 kg/m2 (normal and overweight) – 89.5%, and group 2 - > 30 kg/m2 (obese and morbidly obese) – 10.5%. Patients’ preoperative data and treatment outcomes were compared.
Obese patients were significantly older (p=0.000), had a higher ASA score (p=0.000) and significantly higher incidence of comorbidities (p=0.000) and anticoagulation therapy (p=0.006). Mean stone size was significantly greater in the obese group (44.3±17.9 mm vs 39.3±16.9 mm; p=0.011). Stone-free rates after single procedure and at 3rd month of follow-up were lower in the obese group, but not statistically significant (81.2% vs 82.9%, p=0.687 and 87.1% vs 90.5%, p=0.514, respectively). Operative time was longer for the obese group (55.1±13.6 vs 51.9±13.9 min, p=0.035). Intra- and postoperative complication rates were comparable between the two groups (p=0.587 and p=0.992, respectively). Obese patients had a greater decrease of hemoglobin level and higher transfusion rate, but not statistically significant (16.4±11.1 vs 14.2±10.2 g/l, p=0.072 and 2.4% vs 1.4%, p=0.363, respectively).
Obesity had no adverse impact on PCNL outcomes in this retrospective study. The outcomes of PCNL in obese patients were comparable to that achieved in nonobese patients, with similar stone-free and complication rates.
Department of Urology and Nephrology, Military Medical Academy - Sofia
Sofia, Sofiya, Bulgaria