Ultrasound evaluation of visceral and subcutaneous fat reduction in morbidly obese subjects undergoing laparoscopic gastric banding, sleeve gastrectomy, and Roux-en-Y gastric bypass: a prospective comparison study.

Background: Visceral fat (VF) plays a major role in the development of metabolic syndrome associated with obesity. The aim of our study is to compare VF and subcutaneous fat (SCF) reduction measured by ultrasonography (US) after laparoscopic adjustable gastric banding (LAGB), laparoscopic sleeve gastrectomy (LSG), and laparoscopic Roux-En-Y gastric bypass (LRYGB).

Methods: Thirty-nine morbidly obese patients were prospectively evaluated by US before surgery and 3, 6, and 12 months following surgery to determine VF and SCF thickness.

Results: Three statistically comparable groups of morbidly obese patients underwent LRYGB (n = 13), LSG (n = 15), and LAGB (n = 11). The three groups did not differ in initial age, gender, body mass index (BMI), VF, or SCF. Final excess weight loss (EWL%) was highest after LSG and LRYGB followed by LAGB (81 ± 5.8 vs. 69.5 ± 4.5 vs. 43.4 ± 5.2, p < 0.001). LSG and LRYGB were significantly more efficient in VF reduction (ΔVF) compared with LAGB (7.1 ± 0.5 vs. 5.6 ± 0.6 vs. 3.6 ± 0.8, p = 0.004). SCF reduction (ΔSCF) was also highest after LSG followed by LRYGB and LAGB (3 ± 0.2 vs. 2.2 ± 0.4 vs. 1.9 ± 0.4, p = 0.08). The change in fat distribution, determined as Δ(VF/SCF), showed a preferential VF reduction in the LSG and LRYGB patients compared with patients that underwent LAGB (0.59 ± 0.1 vs. 0.52 ± 0.2 vs. 0.19 ± 0.2, p = 0.42). In a subgroup analysis comparing only LSG to LRYGB, no statistically significant difference was seen in EWL%, ΔVF, ΔSCF, or in fat distribution Δ(VF/SCF).

Conclusion: LSG and LRYGB show better preferential and overall VF reduction than LAGB. US may serve as a simple tool of evaluating postoperative fat distribution.