Eur J Pediatr Surg 2008; 18(6): 380-386
DOI: 10.1055/s-2008-1038920
Original Article

© Georg Thieme Verlag KG Stuttgart · New York

Effect of Elevated Intra-Abdominal Pressure and Hyperoxia on Portal Vein Blood Flow, Hepatocyte Proliferation and Apoptosis in a Rat Model

J. G. Mogilner1 , 4 [*] , H. Bitterman3 , 4 [*] , L. Hayari2 , 4 , V. Brod3 , A. G. Coran5 , R. Shaoul2 , 4 , M. Lurie1 , S. Eldar1 , I. Sukhotnik1 , 4
  • 1Department of Pediatric Surgery, Bnai Zion Medical Center, Haifa, Israel
  • 2Department of Pediatric Surgery, Rambam Medical Center, Haifa, Israel
  • 3Department of Medicine, Ischemia-Shock Research Laboratory, Carmel Medical Center, Haifa, Israel
  • 4Rappaport Faculty of Medicine, Technion – Israel Institute of Technology, Haifa, Israel
  • 5Section of Pediatric Surgery, University of Michigan, Mott Children's Hospital, Ann Arbor, MI, USA
Further Information

Publication History

received June 9, 2008

accepted after revision July 16, 2008

Publication Date:
05 December 2008 (online)

Abstract

Background/Purpose: Indications for a laparoscopic approach for the management of biliary atresia in children are not clearly defined. We have recently shown that persistent intra-abdominal pressure (IAP) significantly decreased portal vein (PV) flow. Ventilation with a high concentration of oxygen after abdomen deflation raises concerns of increased oxidative stress but has also been shown to exert beneficial effects on splanchnic ischemia/reperfusion. The purpose of the present study was to evaluate the effects of IAP and hyperoxia on liver histology, hepatocyte proliferation and apoptosis in a rat model of abdominal compartment syndrome (ACS). Methods: Male Sprague-Dawley rats were anesthetized with intraperitoneal ketamine and xylasine. After a midline laparotomy, the PV was isolated. Ultrasonic blood flow probes were placed on the vessel for continuous measurement of regional blood flow. Mean arterial blood pressure (MABP) was continuously measured. Two large-caliber percutaneous peripheral intravenous catheters were introduced into the peritoneal cavity for inflation of air and measurement of IAP. Rats were divided into three experimental groups: 1) Sham rats were subjected to IAP of 0 mmHg; 2) ACS rats were subjected to IAP of 6 mmHg for 2 hours and were ventilated with air; and 3) ACS‐O2 rats were subjected to IAP of 6 mmHg for 2 hours and were ventilated with 100 % O2 during the operation and ventilation was continued for 6 hours after operation. Liver structural changes, hepatocyte proliferation (using BrdU assay) and apoptosis (using Tunel assay) were determined 24 hours following operation. Results: IAP at 6 mmHg caused a twofold decrease in PV flow compared to sham animals. Hyperoxia resulted in a less significant decrease in PV flow compared to air-ventilated animals. Despite a significant decrease in PV blood flow, 24 hours after abdominal deflation only a few animals demonstrated histological signs of liver damage. The small histological changes were accompanied by increased hepatocyte apoptosis and enhanced hepatocyte proliferation in 25 % of animals, suggesting a liver repair response. Conclusions: Despite a significant decrease in PV blood flow, persistent IAP for 2 hours results in few changes in liver histology, and stimulates hepatocyte proliferation and apoptosis in only a few animals, supporting the presence of a recovering mechanism. Treatment with hyperoxia did not significantly change hepatocyte proliferation and apoptosis.

References

1 The first and second authors contributed equally to the preparation of this manuscript.

M.D. Jorge G. Mogilner

Department of Pediatric Surgery B
Bnai Zion Medical Center

47 Golomb St., P. O. B. 4940

Haifa 31048

Israel

Email: olguer@bezeqint.net