title: Elective laparoscopic cholecystectomy nearly abolishes the postoperative hepatic catabolic stress response.
abstract: OBJECTIVE
  Surgery results in a catabolic state of postoperative stress, where the efficiency of the liver to convert amino acids to urea is increased. This study measured the metabolic consequences of the less traumatic laparoscopic surgery in elective cholecystectomy compared with traditional open surgery technique.
  
  
  BACKGROUND
  The authors previously have shown that open cholecystectomy doubles the urea synthesis measured by the means of the functional hepatic nitrogen clearance. Glucagon and cortisol increased by 50% (p < 0.05) and 75% (p < 0.05), respectively, after open cholecystectomy.
  
  
  METHODS
  Patients undergoing uncomplicated elective laparoscopic cholecystectomies were included. Preoperatively and on the first postoperative day, blood and urine samples were drawn every hour under basal conditions and during amino acid infusion. The urea synthesis rate was calculated from the urea excreted in urine and accumulated in total body water. Functional hepatic nitrogen clearance was quantified as the slope of the linear relation between blood amino-N concentration and the urea synthesis rate. The results were compared with an historic matched group of patients who underwent open cholecystectomies and were studied by the same protocol.
  
  
  RESULTS
  The laparoscopic cholecystectomy increased the functional hepatic nitrogen clearance by only 25% (from 8.7 +/- 0.9 to 11.1 +/- 1.5 mL/sec [mean +/- SEM; p < 0.05]), compared with a doubling after open cholecystectomy (from 9.4 +/- 0.9 to 17.6 +/- 3.3 mL/sec [p < 0.05]). The difference between the groups was significant (p < 0.05). Neither glucagon nor cortisol increased significantly after laparoscopic cholecystectomy.
  
  
  CONCLUSIONS
  The laparoscopic technique results in a much smaller postoperative hepatic catabolic stress response and probably reduced tissue loss of amino-N. This may be important for the more rapid convalescence and reduced postoperative fatigue.
authors.affiliation: Department of Medicine V, University Hospital of Aarhus, Denmark.
authors.forename: H
authors.initials: H
authors.lastname: Glerup
authors.forename: H
authors.initials: H
authors.lastname: Heindorff
authors.forename: A
authors.initials: A
authors.lastname: Flyvbjerg
authors.forename: S L
authors.initials: SL
authors.lastname: Jensen
authors.forename: H
authors.initials: H
authors.lastname: Vilstrup
mesh_terms: D000328:Adult; D002763:Cholecystectomy; D017081:Cholecystectomy, Laparoscopic; D017558:Elective Surgical Procedures; D005934:Glucagon / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D008875:Middle Aged; D009584:Nitrogen / Q000378:metabolism*; D013312:Stress, Physiological / Q000378:metabolism*; D014508:Urea / Q000378:metabolism
chemical_list: D014508:Urea; D005934:Glucagon; D009584:Nitrogen; D006854:Hydrocortisone