Impact of Preoperative Protein Sparing Modified Fast Diet on Bariatric Surgery

Abstract

Introduction: Bariatric surgery can become technically challenging in the setting of liver steatosis and hepatomegaly. The protein sparing modified fast (PSMF) diet helps in achieving rapid weight loss. The aim of this study is to explore the results of a preoperative PSMF diet on liver volume and steatosis as well as on intraoperative and postoperative complications in patients with hepatomegaly undergoing Roux-en-Y gastric bypass (RYGB).

Methods: Between January 2010 and January 2021, 713 patients undergoing RYGB as a primary bariatric surgery were divided in two groups. Those with a measured liver length above 16 cm and or evidence of liver steatosis on ultrasound (group 1) were offered a preoperative PSMF diet while the remaining (group 2) proceeded directly to surgery. Between January 2010 and April 2012, patients included in group 1 had liver volume measurements on magnetic resonance imaging the day before the diet was started and the day before the surgery. For the length of the study, intraoperative and postoperative data were recorded for both groups.

Results: Five days of preoperative PSMF diet resulted in a significant reduction of total and left liver volume (15.8% and 21% respectively, p < 0.001). There was no difference in intraoperative bleeding and conversion rate or postoperative complication rate between both groups.

Conclusion: The PSMF diet helps in achieving a rapid decrease in liver volume. Patients with hepatomegaly initially thought to be at a higher risk of intraoperative complications reached comparable rates to patients without hepatomegaly after the diet regimen without any impact on the postoperative course.

Keywords: Bariatric surgery; Metabolic surgery; Weight loss diet.