An experimental study on the relationship of intra-abdominal pressure and renal ischemia

This study was undertaken in order to determine whether or not the increased intra-abdominal pressure during laparoscopic procedures causes renal ischaemia and parenchymal pathology. Fifteen adult New Zealand rabbits were used in the study. Anaesthesia was maintained by 2% isoflurane, 50% O2 in air. Heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), end-tidal carbon dioxide (PETCO2), airway pressure (Paw) and blood gases were monitored. Rabbits in control group (group C, n = 7) and study group (group S, n = 8) had a Veress needle placed supraumbilically. Group S was insufflated with CO2 sequentially at 5, 10 and 15 mmHg of intra-abdominal pressures (IAP); each pressure level was maintained for 20 minutes. At the end of the study, laparotomy was performed and blood was withdrawn from renal vein for measurements of renin and angiotensin I levels, and the other kidney was removed simultaneously for pathological evaluation. Haemodynamic and respiratory measurements were stable in group C and were variable in group S. The renin level was 7.27 +/- 0.34 ng.mL-1 and angiotensin I was 5.01 +/- 0.32 ng.mL-1 in group C. In group S, levels of renin and angiotensin I were 26.2 +/- 5.9 ng.mL-1 and 39.4 +/- 12.1 ng.mL-1 respectively, being significantly higher than group C (p < 0.05). Pathological scores were 0.02 +/- 0.008 in group C and 0.82 +/- 0.124 in group S (p < 0.05). There were significant histological changes in group S compared with group C. During prolonged laparoscopic operations high intra-abdominal pressures may result in intra-abdominal organ ischaemia.