Laparoscopic partial nephrectomy in obese patients: how can the body mass index influence the surgical and functional outcomes?

Abstract

Objective: To evaluate the impact of body mass index (BMI) on surgical and functional outcomes of laparoscopic partial nephrectomy (LPN) for T1 renal tumors.

Patients and methods: In this single-center retrospective study, 240 consecutive patients underwent LPN for localized, incidentally discovered renal masses of < 7 cm (cT1). Patients were categorized into four groups according to their BMI, as follows: group 1, normal weight (BMI < 25 kg/m2 ); group 2, overweight (BMI 25–29.9 kg/m2 ); group 3, obese (BMI 30–39.9 kg/m2 ); and group 4, morbidly obese (BMI ≥ 40 kg/m2 ).

Results: Median operative time presented no statistically significant differences between BMI groups, whereas estimated blood loss was higher in morbidly obese patients than in all other groups. Warm ischemia time (WIT) and changes in eGFR were not influenced by the BMI groups but a decrease in the WIT was reported in obese and morbidly obese patients when an early unclamping technique (EUT) was used. An increase in BMI was not significantly associated with the occurrence of postoperative complications. In fact, the median complication rate was 3.3% for normal BMI, 4.5 % for overweight patients, 4.8% for obese patients, and 3.6% for morbidly obese patients.

Conclusion: LPN could be considered a viable treatment option for renal masses amenable to nephron-sparing surgery in patients with higher BMI. An EUT should always be used in obese and morbidly obese individuals, considering the statistically significant decrease in WIT and the higher risk of chronic renal insufficiency in these patients.

Keywords: kidney cancer, partial nephrectomy, laparoscopy, obesity, surgical outcomes