Experimental anaesthesiologic protocol for porto-intracaval shunt for liver total vascular exclusion: preliminary study in the rabbit

The aim of this study was to evaluate the effects and interference of different anaesthetic techniques in rabbits undergoing liver total vascular exclusion using a porto-intracaval shunt. Twenty New Zealand rabbits were divided in three groups: group A receiving diazepam as premedication, ketamine + atropine for induction and maintenance of anaesthesia and undergoing a porto-intracaval shunt operation; group B receiving midazolam as premedication, ketamine + fentanyl + atropine for induction and maintenance of anaesthesia and undergoing a porto-intracaval shunt operation; group C receiving the same drugs as group B but undergoing a simple portal and caval clamping. The following parameters were studied: efficacy of premedication, vital parameters before and after clamping and insertion of the shunt, mean time to clamp and insert the shunt, mean survival time after clamping (group C) or activation of the shunt (groups A and B). Midazolam was significantly better for premedication; there was no statistically significant difference between groups A and B for the vital parameters, for the time necessary to clamp and insert the shunt, for the intraoperative course, and for the mean survival time. The absence of a statistically significant difference between groups could be due to the low number of animals used in the study. There is actually evidence that a correct anaesthesiologic protocol, especially referring to analgesia and fluid management, improves the outcome of operated animals. Surely further studies, possibly conducted on a larger number of animals, are required to evaluate better the results observed and to consider applying these data and this experience to humans.