Does gender influence morbidity or mortality in the surgical treatment of renal masses

Introduction: We determine the relationship between gender and surgical morbidity after radical nephrectomy (RN) and partial nephrectomy (PN) for renal masses on a population level. Methods: We conducted a population-based, retrospective study using the Canadian Institute for Health Information Discharge Abstract Database. This included 20 286 RNs (82.5%) and 4292 PNs (17.5%) from April 1, 1998 to March 31, 2008. Complications were identified by ICD-9 and 10 codes, and comorbidity was assessed with the Charlson Index. The association between gender and in-hospital complication rates and mortality were examined using the Chi-square test, as well as with multivariable logistic regression, adjusting for explanatory variables including type of surgery, age, and comorbidity. Results: Overall, men experienced a higher unadjusted complication rate than women (35.1% vs. 32.7%), as well as a higher unadjusted in-hospital mortality rate (1.46% vs. 0.84%), respectively. Men also demonstrated significantly higher rates of cardiac, wound, nephrectomy-specific, and medical complications. Women experienced fewer complications than men after RN (p = 0.0002), but not after PN (p = 0.33). On multivariable logistic regression analysis, women had a lower overall complication rate (odds ratio [OR] 0.94, 95% confidence interval [CI] 0.88-0.99), and a lower in-hospital mortality rate (OR 0.64, 95% CI 0.49-0.83) after kidney surgery. Conclusions: In our population-based analysis, in-hospital morbidity after renal surgery was significantly lower for women. Further study is needed to determine if the observed effect is related to differences in surgical difficulty, perioperative care, or unmeasured confounders.