[The limits of resection in hepatopancreatectomies in rats]

Hepatopancreatectomy (HPx), one of the most stressful surgeries, is occasionally the only curative resection for widely spreading biliary cancer. Little is known about the pathophysiology after HPx. This study was undertaken to investigate the limits of resection and to compare HPxs with respect to morphological and biochemical findings in order to establish reasonable models of HPxs in rats. Male Wistar rats underwent 6 kinds of HPxs. The HPxs performed were a combination of one of 3 degrees of hepatectomy (70%, 80%, or 90%) and one of 2 degrees of pancreatectomies (60% or 90%). Hepatectomy (Hx) alone and pancreatectomy (Px) alone were used as the controls. The animals were observed with checks on mortality, body weight, and blood sugar level. On day 28, they were sacrificed in order to obtain the liver and pancreas tissue and systemic blood. According to direct survival rate on day 28, the six kinds of HPxs were classified into four as follows: safe HPx (70% Hx + 60% Px, survival rate 100%; and 70% Hx + 90% Px, survival rate 88.2%); critical HPx (80% Hx + 60% Px, survival rate 52.9%); poor HPx (80% Hx + 90% Px, survival rate 31.3%; and 90% Hx + 60% Px, survival rate 25.0%); and fatal HPx (90% Hx + 90% Px, survival rate 0%). In the rats which underwent HPxs, 46 out of 49 deaths (95.8%) occurred in the first three postoperative days. In survivors receiving the critical and poor HPxs, morphological and biochemical values were within permissible ranges, comparable with those of the rats receiving 70% Hx or 60% Px. In conclusion, 70% Hx + 90% Px was considered to be a safe limit for HPx, and 80% HX + 60% Px was considered to be a borderlining limit for HPx; sufficient recovery after operation would be expected since some rats survived even after critical and poor HPxs. Vitally physiological changes would be expected to occur in the early postoperative period.