Muneaki Matsumoto

An experimental evaluation of the order of revascularization after interrupting hepatic afferent blood flow

The purpose of this study was to investigate the influence of the order of revascularization on hepatic metabolic function after interruption of hepatic afferent blood flow to reconstruct the portal vein and the hepatic artery. Hepatic ischemia was induced in male rabbits by clamping the afferent hepatic blood supply. In the cases in which portal blood flow was released after 15 min of hepatic ischemia and hepatic arterial blood flow was released 15 min later, hepatic metabolic function, which was assessed by arterial ketone body ratio, plasma lactate, and hepatic energy charge levels, recovered immediately. When hepatic arterial blood flow was released in the reverse order, the recovery of hepatic function was delayed. In the cases in which portal and hepatic arterial blood flow were released simultaneously after 30 min of hepatic ischemia, hepatic function did not recover even 180 min after reperfusion. In contrast, the venous bypass was established during portal clamping, restoration of hepatic function was accelerated, and there was no significant difference in restoration between the methods of releasing portal blood flow first or releasing hepatic arterial blood flow first. In the method of simultaneous releasing, however, it was most delayed, probably due to the prolonged ischemic time. These results suggest that releasing first the portal or hepatic arterial blood flow with the establishment of venous bypass during the portal clamping would be the best order of revascularization for hepatic function when reconstructing the portal vein and the hepatic artery.

Effect of a platelet activating factor antagonist (CV6209) on shock caused by temporary hepatic inflow occlusion.

Platelet activating factor (PAF) is a newly discovered inflammatory chemical mediator, which was reported to play a pivotal role in various types of shock. There is also a great possibility that PAF plays an important role in the shock caused by hepatic inflow occlusion. In the present study, the effect of CV6209, a PAF antagonist, on the shock caused by the occlusion was investigated. Intravenous 3 micrograms/kg of PAF caused hypotension in Wistar rats (n=6), and pretreatment with intravenous 3 mg/kg of CV6209 significantly (p less than 0.01) prevented the hypotension (n=6). Forty-five minutes of hepatic inflow occlusion caused hypotension in rats during the occlusion period, and the hypotension continued even after restoration of blood flow in control group (pretreated with saline i.v. only, n=5). In contrast, this hypotension was significantly (p less than 0.01) reversed in PAF antagonist group (pretreated with 3 mg/kg of CV6209 i.v., n=5). In sham-operated rats (n=6), arterial pressure remained unchanged and not hypotensive during the monitoring period. The survival rate of rats 90 minutes after declamp was 30% in control group (n=20), and that was significantly (p less than 0.05) improved to be 65% in PAF antagonist group (n=20). In conclusion, PAF plays an important role in the shock and death caused by temporary hepatic inflow occlusion, and a PAF antagonist could be a therapeutic drug against temporary hepatic inflow occlusion.

Initial hepatic metabolic function in canine liver and pancreas cluster transplantation.

In this study, initial hepatic metabolic function was evaluated by determining the arterial ketone body ratio (AKBR) and plasma amino acid concentrations in an experimental orthotopic combined hepatopancreatic transplantation (OHPT), and comparing the same values in orthotopic liver transplantation (OLT). In OHPT, AKBR decreased in the anhepatic phase and recovered to the preoperative value just 1 h after reperfusion. On the other hand, in OLT, the recovery of AKBR took 3 h after reperfusion with a significant difference compared to OHPT (P<0.05). Plasma amino acid levels, especially alanine and total free plasma amino acids increased in the anhepatic phase and recovered within 1 h of reperfusion in OHPT. However, they did not recover until 3 h after reperfusion in OLT. This rapid recovery of hepatic metabolic function in OHPT should be attributed to the order of reperfusion in which the reconstruction of arterial blood flow precedes that of portal blood flow. This model is useful for assessing the best way by which the grafted liver can control the timing, order, rate, and volume of blood that should be released.

Prognosis of Liver Metastases from Colorectal Cancer After Hepatectomy

Seventy-five patients with liver metastases from colorectal cancer received surgery from 1983 to 1992, and 35 were hepatectomized. Hepatectomy improved the prognosis on condition that extrahepatic disease was completely resected. The 5-year survival of 30 hepatectomized without extrahepatic disease was 28.5% and that of 23 unhepatecotmized was 12.4%. On the other hand, there were no 3-year survivors in the 22 with extrahepatic disease indifferently whether hepatectomized or not. Tumor resection with minimal margin was proved to be a sufficient surgery to removed hepatic metastases, and had similar prognostic contribution as major hepatectomy that may cause major postoperative complications.

Focal nodular hyperplasia of the liver

We present herein two successfully treated cases of focal nodular hyperplasia (FNH) of the liver, a relatively rare disease. Case 1 was a 3 year old child in whom typical FNH developed in the left lateral segment of the liver, whereas Case 2 was a 22 year old man in whom characteristic findings were lacking on preoperative diagnostic imaging. Scintigraphy was not performed in either case, however, postoperative histological examination confirmed FNH. Thus, in patients with a hypervascular tumor and normal liver function, FNH should be strongly suspected and a series of scintigraphy proposed. Both cases showed a negative association with oral contraceptive intake but no other obvious etiology was suggested.

The immunosuppressive effect of hepatocytes in rats : assessment by heart allograft survival and delayed-type-hypersensitivity reactions

The immunosuppressive effect of hepatocytes was examined experimentally by heart allograft and delayed-type-hypersensitivity (DTH) reactions. The hepatocyte inoculation (1×107) of BDE (of the major histocompatibility complex haplotype RT1u), LEW (RT11), and DA (RT1a) into the spleens of LEW rats significantly prolonged the survival of BDE heart allografts to 14.3±2.7 (mean±SD), 9.2±0.8, and 10.8±2.3 days respectively, compared with 6.7±0.8 days in controls (p<0.01). Moreover, the BDE hepatocytes had a significantly prolonged survival compared to the LEW (p<0.01) and DA (0.02<p<0.05) groups. BDE hepatocyte (donor specific) inoculation 4 and 7 days before priming with the spleen cells reduced DTH responses in the LEW rats to 44.6±4.8 per cent, and 74.2±8.0 per cent, respectively. DA hepatocyte inoculation (third party) 4 and 7 days prior to priming reduced DTH responses to 72.5±11.5 per cent, and 76.5±11.9 per cent, respectively. All DTH responses were significantly suppressed after hepatocyte inoculation compared to 100 per cent in the controls (p<0.01). Moreover, the inoculation of BDE hepatocytes (donor specific) 4 days prior to the priming significantly reduced DTH responses compared to the group primed 7 days before (p<0.01). From these results we concluded that hepatocytes produced not only non-specific but also donor specific immunosuppressive effects through T cell immune reaction. Moreover, donor specific immunosuppressive effects were induced at least 4 to 7 days after hepatocyte inoculation.

The influence of transcatheter arterial embolization using lipiodol on non cancerous hepatic function. With special reference of hepatic energy status.

リピオドール併用肝動脈塞栓術 (以下Lp-TAE) が非腫瘍部のエネルギー代謝に及ぼす影響を検討するために, Lp-TAEを施行した13症例を対象として, 肝硬変 (以下LC) の有無により2群に分け検討した. 一般肝機能は, LC (-), LC (+) 群ともにLp-TAE後4週以内に前値に回復した. ICGR15, ICGK値は, LC (-), LC (+) 群ともにLp-TAE後有意の変動を示さなかった. Lipid emulsion testからみたphagocytic indexは, LC (-), LC (+) 群ともにLp-TAE後高値を示すが, 2週目には前値に復しその後漸減して4週目でも低値を示す傾向にあった. 動脈血中ケトン体比は, LC (-) 群では, Lp-TAE後一過性の低下を示すが4週目には前値に復しているのに対し, LC (+) 群では4週目でも有意の低値を示し, 肝エネルギー代謝面での影響の残存が示唆された.