title: Elevated liver enzymes following open Roux-en-Y gastric bypass for morbid obesity - does timing of liver retraction affect the rise in the levels of transaminases?
abstract: BACKGROUND
  Liver retraction in open Roux-en-Y gastric bypass (RYGBP) for morbid obesity may cause an elevation in liver transaminase levels postoperatively. This study attempts to ascertain whether timing of placement of the liver retractor would have any effect on the degree of derangement of the liver function tests.
  
  
  METHODS
  12 patients undergoing open RYGBP were prospectively randomized into 2 groups. One group had the liver retractor applied early on in the operation, and had the gastric pouch constructed first, followed by construction of the jejunojejunostomy and Roux-en-Y gastrojejunostomy. The second group had the jejunojejunostomy performed first, followed by placement of the liver retractor to allow construction of the gastric pouch and Roux-en-Y gastro-jejunostomy. Liver function tests were monitored postoperatively in both groups, and these were then statistically analyzed with respect to the duration of liver retraction.
  
  
  RESULTS
  Delayed liver retraction resulted in statistically significantly smaller increases in aspartate transaminase (AST) and alanine transaminase (ALT) compared with early liver retraction. AST levels returned to normal values within 1 week in both groups of patients. ALT levels returned to normal values within 1 week in the delayed liver retraction group, whereas levels took >1 week to return to normal in the early liver retraction group.
  
  
  CONCLUSIONS
  Liver retraction causes abnormal transaminase levels following open RYGBP. Delayed liver retraction results in less rise in the AST and ALT levels compared with early liver retraction. Surgeons should construct the Roux-en-Y limb and jejunoje junostomy first, before proceeding with construction of the gastric pouch and gastrojejunostomy, thereby decreasing the duration of liver retraction and consequent relative liver ischemia.
authors.affiliation: Department of Biostatistics, New York Methodist Hospital, Weill Medical College of Cornell University, Brooklyn, NY 11215, USA. lohlunj@aol.com
authors.forename: John C
authors.initials: JC
authors.lastname: Lohlun
authors.forename: Adel
authors.initials: A
authors.lastname: Guirguis
authors.forename: Leslie
authors.initials: L
authors.lastname: Wise
mesh_terms: D015390:Gastric Bypass / Q000379:methods*; D006801:Humans; D007582:Jejunostomy; D008099:Liver / Q000201:enzymology*; D008111:Liver Function Tests; D009767:Obesity, Morbid / Q000601:surgery; D011184:Postoperative Period; D011446:Prospective Studies; D000637:Transaminases / Q000097:blood*
chemical_list: D000637:Transaminases