Effect of Obesity on Outcomes of Percutaneous Nephrolithotomy in Renal Stone Management: A Systematic Review and Meta-Analysis.

BACKGROUND Percutaneous nephrolithotomy (PCNL) has been widely used to treat renal stones. The application of PCNL in obese patients results in the emergence of a number of challenges. This study compared the effect of obesity on the outcomes of PCNL in kidney stone treatment. METHODS Eligible studies were searched in PubMed, Web of Science, and Cochrane Library databases. Data were analyzed using RevMan statistical software, weighted mean differences, ORs, and 95% CIs were calculated. RESULTS Seven studies involving 2,720 normal-weight, 1,686 obese, and 286 super-obese individuals were included in this meta-analysis. A pooled analysis of safety revealed that no obvious differences in terms of complication rates after treatment existed between obese and normal-weight individuals (OR 0.97, 95% CI 0.80-1.16, p = 0.73), and between super-obese and normal-weight individuals (OR 0.88, 95% CI 0.61-1.27, p = 0.49). A pooled analysis of effectiveness revealed that no obvious difference in terms of stone-free rate after treatment existed between obese and normal-weight individuals (OR 0.98, 95% CI 0.84-1.15, p = 0.79), and between super-obese and normal-weight individuals (OR 1.20, 95% CI 0.88-1.63, p = 0.25). Moreover, no obvious differences in terms of length of hospital stay after treatment existed between super-obese and normal-weight individuals (95% CI -0.15 to 0.37, p = 0.39). Additionally, no obvious differences in terms of operation time existed between obese and normal-weight individuals (95% CI -3.36 to 1.17, p = 0.34). However, the operation time was longer among super-obese individuals than among normal-weight individuals (95% CI -22.64 to -1.40, p = 0.03), and the length of hospital stay was shorter among obese patients than among normal-weight patients (95% CI 0.04-0.34, p = 0.01). No publication bias was observed in this work. CONCLUSION The PCNL performed in normal-weight, obese, and super-obese individuals for kidney stone treatment showed similar outcomes, except that operation time was longer among super-obese individuals and the hospital stay was shorter in obese individuals than in other groups. Thus, PCNL is a safe and efficacious treatment for renal stones in patients of all sizes.