Partial IVC Clamping Improves Intraoperative Hemodynamic Parameters in the Rodent Portacaval Anastomosis Model

Abstract

The mechanisms involved in the development of hepatic encephalopathy still remain uncertain. The rodent portacaval shunt is a model that reproduces many of the pathological features observed in humans (1), but is a technically demanding exercise. While the traditional technique involves complete occlusion of the IVC, a c-clamp was fashioned to partially clamp the IVC thereby sustaining venous return and cardiac output. The aim of this study is to determine if the c-clamp technique provides greater hemodynamic stability and enhances the success rate of the portacaval shunt procedure. To answer this question, two experimental groups, c-clamp (N = 7) and cross-clamp (N = 7), and a sham group (N = 3) were included. Intraoperative hemodynamic parameters were recorded at specific times during the procedure. The c-clamp group showed greater hemodynamic stability when compared to the cross-clamp group. It was manifested by 1) significantly higher mean arterial blood pressure [63 (range, 8) vs 47 (range, 10) mmHg, p < 0.05], 2) faster capillary refill [4 (range, 2) vs 6 (range, 2) seconds, p < 0.05], 3) higher urinary output [0.18 (range, 0.02) vs 0.14 (range, 0.02) ml, p < 0.05], and 4) lower bowel wet-to-dry ratio [4.168 (range, 0.258) vs 4.731 (range, 0.271), p<0.05]. We conclude partial IVC clamping improves hemodynamic stability during the construction of the rat portacaval shunt model.