Biomedical subjects

S Iyomasa

Publications and source records attributed to S Iyomasa.

4 recordsLinked to original sources

PubMed1992

Decrease in regeneration capacity of rat liver after external biliary drainage.

In order to discover the effect of external biliary drainage on liver regeneration, we have produced a model system carrying cannula in the common bile duct of rat liver and examined the regeneration capacity of liver after partial hepatectomy under various conditions. Previously we have shown that hepatic cells proliferate by obstructive jaundice alone without partial hepatectomy [Terasaki et al; Jpn J Cancer Res 1991;82:170-175]. In the present study, we showed that DNA polymerase-alpha was induced by partial hepatectomy of rats suffering from obstructive jaundice and the induced level was similar to that of the normal regenerating liver. The level of DNA polymerase-alpha activity corresponded well to the liver regeneration capacity estimated by mitotic index. Contrary to our expectation, external biliary drainage for obstructive jaundice markedly suppressed the regeneration capacity of the remaining liver which was estimated by DNA polymerase-alpha activity, mitotic index and [3H]thymidine incorporation. The suppression may be due to the external biliary drainage itself because the liver regeneration of normal rats without jaundice was also suppressed by the biliary drainage. These results suggest that the external biliary drainage seriously suppresses the regeneration capacity of liver at least at the early stage of obstructive jaundice.

Animals↗

PubMed1992

An unusual growth pattern of a mucin-producing intrahepatic cholangiocellular carcinoma involving the hepatic hilus.

The case of a mucin-producing intrahepatic cholangiocellular carcinoma in a 73 year-old-man is presented. A tumor originating in the right posterior inferior segment of the liver was found to be invading the right posterior and anterior bile ducts, and the hepatic hilus. Extensive superficial spread was observed in the entire posterior segmental bile duct extending to the hepatic hilus. Mucin produced and excreted by the tumor was retained in the common hepatic and common bile duct. The diagnosis in this case was suggested by percutaneous transhepatic aspiration of mucinous bile, and was confirmed by utilizing the techniques of ultrasonography, percutaneous transhepatic cholangiography, computed tomography and angiography. Curative surgery, which included right hepatic lobectomy with total caudate lobectomy and bile duct resection, was performed. Biliary continuity was maintained by left hepaticojejunostomy using a Roux-en-Y jejunal loop. The histological diagnosis was mucin-producing papillary adenocarcinoma originating in the right posterior inferior segment of the liver. Postoperative recovery was very good and the patient has now been enjoying a good active social life for the last 20 months with no signs of tumor recurrence. This case report discusses the unusual growth pattern of a mucin-producing intrahepatic cholangiocellular carcinoma involving the hepatic hilus, and suggests rational surgical treatment.

Adenocarcinoma, Mucinous↗

PubMed1992

Cholangiocellular carcinoma in the caudate lobe with intraluminal growth in the extrahepatic bile duct.

A case of cholangiocellular carcinoma in the caudate lobe with intraluminal growth in the extrahepatic bile duct is reported. The main tumor in the caudate lobe was detected by computed tomography and angiography, and two intraluminal tumors at the hepatic hilus and at the root of the right posterior segmental duct were well demonstrated by cholangiography and percutaneous transhepatic cholangioscopy. Independent total caudate lobectomy with bile duct resection was performed. Cholangiocellular carcinoma of the liver with intraluminal growth in the extrahepatic bile duct is very rare and has not been reported in the literature. Independent caudate lobe resection requires a rather complicated technique. However, this method has the advantage of reducing to a minimum the hepatic volume to be resected, and is useful for poor-risk patients or for cases with localized carcinoma at the hepatic hilus.

Adenocarcinoma↗

PubMed1991

[Management of cholangitis complicated in biliary carcinoma with hilar bile duct stenosis].

We reviewed 60 cases of biliary carcinoma with hilar bile duct stenosis which had received percutaneous transhepatic cholangio-drainage (PTCD). Of the 60 cases, nine were complicated with acute cholangitis (AC) and three with segmental acute obstructive suppurative cholangitis (S-AOSC). The incidence of cholangitis was 20%. Six patients with AC and three with S-AOSC underwent hepatic resection for carcinoma. As to preoperative management for cholangitis in these 9 cases, conservative chemotherapy was effective in only 2 cases, and additional PTCD or segmental introduction of the drainage catheter under PTCS were useful in 5 cases. The remaining 2 cases with S-AOSC needed urgent hepatic resection including suppurative hepatic segments after various interventional treatments. No significant difference was found in resectability, morbidity and mortality between the cholangitis group and non-cholangitis group. In conclusion, it is emphasized that postoperative outcome of biliary carcinoma with cholangitis will be improved by adequate PTCD and/or urgent hepatic resection.

Acute Disease↗