An obese body habitus does not preclude a minimally invasive partial nephrectomy

Introduction: Partial nephrectomy (PN) via open or minimally invasive (MI) techniques is the referent standard for managing renal cell carcinoma (RCC) whenever possible. Outcomes of MIPN in the obese patient population are incompletely defined. We investigate the feasibility of MIPN in obesity class I-III patients via comparison of surgical outcomes to those with a lower body mass index (BMI). Materials and methods: The electronic medical records of 184 consecutive patients undergoing MIPN via laparoscopic (n = 109) or robotic (n = 75) techniques were reviewed. Patients were classified into the following patient cohorts stratified by BMI: 1) BMI < 30; 2) BMI 30-35 - obesity class I; 3) BMI 35-40 - obesity class II; 4) BMI > 40 - obesity class III. The association between obesity class and perioperative and pathologic outcomes was determined. Results: Ninety-five men and 89 women with a median age of 55 years, BMI of 31, tumor size of 2.9 cm, and RENAL nephrometry score of 6 were included. Median operative time was 218 minutes, ischemia duration was 23.5 minutes, estimated blood loss (EBL) was 150 cc, and length of stay was 3.0 days. Of the 184 patients, 71 (39%) were non-obese, 58 (32%) had class I obesity, 33 (18%) patients had class II obesity, and 22 (12%) had class III obesity. Compared to patients with a BMI < 30, neither an obese body habitus nor the degree of obesity was associated with any adverse perioperative or pathologic outcomes. In a multivariate model querying variables associated with complications, only a RENAL nephrometry ≥ 8 (HR 5.1, 95% CI 2.4-7.9, p < 0.001) was significant. Conclusion: An increase in obesity classification was not associated with adverse outcomes following MIPN. Increasing nephrometry score was the sole variable associated with perioperative complications. The presence of an obese body habitus alone should not preclude offering appropriate patients a MIPN.