Effect of visceral obesity on minimally invasive partial nephrectomy

Objective To assess the relationship between visceral obesity and perioperative parameters in patients undergoing laparoscopic or robotic-assisted partial nephrectomy. Methods We retrospectively reviewed the medical records of 118 patients who underwent minimally invasive partial nephrectomy. On preoperative imaging, perinephric, visceral, and subcutaneous fat were measured. Higher estimated blood loss, complications, and warm ischemia time were used as surrogates of increased operation difficulty. We examined the association between the 3 groups of patients (ie low, medium, and high fat) with demographic and clinical characteristics. Multivariate analysis was performed to determine whether various measurements of obesity adversely affected surgical outcomes and complexity. Results No statistically significant differences were found between perioperative parameters and either perinephric, visceral, or subcutaneous fat. There was no association between changes in renal function and different fat groups. Multivariate analysis for estimated blood loss, complication rates, and warm ischemia time adjusted for age, race, sex, nephrometry score, Charlson comorbidities score, and other fat types, failed to demonstrate any significant differences. Increasing perinephric fat content was associated with higher visceral (P <.0005), but not subcutaneous fat (P =.55). Hypertension was associated with perinephric (P =.02) and visceral (P =.04), but not subcutaneous obesity (P =.08). Neither Charlson comorbidity nor American Society of Anesthesiologists scores showed any significant association with different fat types. Conclusion Individual patterns of obesity, namely subcutaneous, visceral, and perinephric, do not increase surgical complexity for minimally invasive partial nephrectomy by experienced surgeons. Furthermore, this operation can be performed safely with comparable complications and outcomes in moderately obese patients without compromising renal function.