Comparison of postoperative hepatic function after laparoscopic versus open gastric bypass

Background: Pneumoperitoneum has been shown to reduce hepatic portal blood flow and alter postoperative hepatic transaminases. This study evaluated the changes in hepatic function after laparoscopic and open gastric bypass (GBP). Methods: Thirty-six morbidly obese patients were randomly assigned to undergo either laparoscopic (n = 18) or open (n = 18) GBP. Liver function tests - total bilirubin (T Bil), gamma GT (GGT), albumin, alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT) - and creatine kinase levels were obtained preoperatively and at 1, 24, 48, and 72 hours postoperatively. Results: The two groups were similar in age, sex, and body mass index. Albumin and ALP levels decreased while T Bil and GGT levels remained unchanged from baseline in both groups without significant difference between the two groups. After laparoscopic GBP, ALT and AST transiently increased by sixfold and returned to near baseline levels at 72 hours. After open GBP, ALT and AST transiently increased by fivefold to eightfold and returned to near baseline levels by 72 hours. Creatine kinase level was significantly lower after laparoscopic GBP than after open GBP at 48 and 72 hours postoperatively. There was no postoperative liver failure or mortality in either group. Conclusions: Laparoscopic GBP resulted in transient postoperative elevation of hepatic transaminase (ALT, AST) but did not adversely alter hepatic function to any greater extent than open GBP. Creatine kinase levels were lower after laparoscopic GBP reflecting its lesser degree of abdominal wall trauma.