肝膵同時切除ラットモデルを用いた切除限界の検討 The limits of Resection in Hepatopancreatectomies in Rats

博士論文

短縮題名: ラット肝膵同時切除

Hepatopancreatectomy (HPx), one of the most stressful surgery, is occasionally an only way to a curative resection for widely spreading biliary cancer. Little has been known about the pathophysiology after HPx. This study was undertaken to investigate the limits of resection, and the morphological and biochemical findings among HPxs in comparison with their extents, with establishing the reasonable models of HPxs in rats. Male Wistar rats received 6 kinds of HPxs in combination with 3 degrees of hepatectomies (70%, 80% and 90%) and 2 degrees of pancreatectomies (60% and 90%), and hepatectomy (Hx) or pancreatectomy (Px) alone as control. 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, six kinds of HPxs were classified into four as follows: safe HPx (70% Hx + 60% Px; its survival rate was 100% and 70% Hx + 90% Px; 88.2%), critical one (80% Hx + 60% Px; 52.9%), fatal one (80% Hx + 90% Px; 31.3% and 90% Hx + 60% Px; 25.0 %), and poor one (90% Hx + 90% Px; 0%). In the rats receiving HPxs, forty-six out of 49 death cases (95.8%) occurred in the first three postoperative days. In survivors receiving the critical and fatal HPxs, morphological and biochemical values were within permissible range compared with those of 70% Hx or 60% Px. In conclusion, 70% Hx + 90% Px was considered as a safe limit of HPx, and 80% HX ＋ 60% Px as a borderline HPx; sufficient recovery after operation would be expected if survivors are obtained even after critical and fatal HPxs; vitally physiological changes would take place in the early postoperative period.