Hyperbaric oxygenation after portal vein emobilization for regeneration of the predicted remnant liver.

BACKGROUND: Liver failure often develops after extensive liver resection. Preoperative portal vein embolization to induce compensatory hypertrophy in the predicted remnant liver decreases clinical complications after hepatectomy. The aim of this study was to examine whether hyperbaric oxygenation (HBO) after portal vein embolization increases compensatory hypertrophy of the predicted liver remnant. We performed portal vein ligation and HBO in rats to investigate whether HBO after portal vein embolization increases compensatory hypertrophy of the predicted remnant liver. METHODS: Rats were divided into four groups that underwent (1) laparotomy only (control group); (2) right portal vein ligation (RPL group); (3) RPL followed by HBO at 2 atm (HBO-2 atm group; 1 h/day, 5 days/week for 2 weeks); or (4) RPL followed by HBO at 3 atm (HBO-3 atm group). Laparotomy was repeated after 2 weeks in each group; serum levels of albumin and hepatocyte growth factor (HGF) were measured, and the ratio of the weights of nonligated to ligated hepatic segments and the percentage of hepatocytes expressing proliferating cell nuclear antigen (PCNA) in ligated hepatic segments were determined. RESULTS: In rats that had received HBO after RPL, serum levels of HGF, weight ratios of nonligated to ligated hepatic segments, and the percentage of PCNA-positive hepatocytes in nonligated liver were significantly higher than those in the control group. Furthermore, rats that had undergone 3-atm HBO after RPL had significantly higher serum levels of HGF and percentages of PCNA-positive hepatocytes in nonligated hepatic segments. CONCLUSIONS: Preoperative HBO after portal vein embolization may be useful for inducing compensatory hypertrophy of the predicted remnant liver.

Pancreatic granular cell tumor combined with carcinoma in situ.

A 58-year-old man was treated for a granular cell tumor (GCT) of the pancreas; a very rarely occurring tumor. The patient, who had been followed for 6 years due to alcoholic hepatitis, chronic pancreatitis and elevated carcinoembryonic antigen (CEA) levels from smoking, was admitted to our hospital for evaluation of back pain, diarrhea and constipation. The patient was diagnosed as having pancreatic head cancer using clinical imaging studies, and a pylorus-preserving pancreatico-duodenectomy was done. In the resected specimen, a white tumor measuring 13 mm in diameter was observed at the pancreatic head, and there was marked fibrous change surrounding the tumor. The microscopic appearance of the pancreas showed atrophy of acinar cells, fibrosis, and dilatation of the main pancreatic duct (MPD). Within the tumor were oval cells with low-grade atypia and an increased number of diffuse eosinophilic granules. Neither mitosis nor invasive findings were observed. Periodic acid-Schiff staining and immunohistochemical staining for the S-100 protein were positive, thus the tumor was diagnosed as a benign GCT. In addition, carcinoma in situ was found at the dilated MPD. Therefore, this patient was diagnosed as having GCT with carcinoma in situ of the pancreas. To the best of our knowledge, this is only the fourth case of GCT of the pancreas to be reported.

Ultrasonographic assessment of the risk of injury to branches of the middle hepatic vein during laparoscopic cholecystectomy.

BACKGROUND: Although hemorrhage from the gallbladder bed during laparoscopic cholecystectomy is one of main reasons for conversion to open cholecystectomy, the cause of this life-threatening complication is unclear. PATIENTS AND METHODS: Color Doppler ultrasound was used to examine the cause of venous hemorrhage from the gallbladder bed during laparoscopic cholecystectomy in 4 patients postoperatively and to examine the anatomic relationship between the gallbladder bed and branches of the middle hepatic vein in 50 healthy volunteers. RESULTS: Injury to a large branch of the middle hepatic vein adjacent to the gallbladder bed was diagnosed in all 4 patients. One patient required conversion to open cholecystectomy while the bleeding in 2 patients was immediately controlled by direct pressure with the gallbladder. The branch of the middle hepatic vein was completely adherent to the gallbladder bed in 5 of the 50 volunteers, and in 1 the diameter of the branch was as large as 3.5 mm. In 3 volunteers branches 3.0 to 3.8 mm in diameter traversed as close as 1.0 mm from the gallbladder bed. CONCLUSIONS: Patients with large branches of the middle hepatic vein close to the gallbladder bed are at risk of hemorrhage during laparoscopic cholecystectomy and should be identified preoperatively with ultrasound.

High density culture of immortalized liver endothelial cells in the radial-flow bioreactor in the development of an artificial liver.

Liver endothelial cells are important components of the tissue along the hepatic sinusoid. They are responsible for microcirculation in the liver and scavenger functions. It would therefore be important to include these cells in any hybrid type of artificial liver in addition to hepatocytes. However, it is difficult to culture these cells in vitro. The development of a liver endothelial cell line, which maintains the characteristics of the primary culture, would thus be of great benefit in the development of an artificial liver. In the present study we established immortalized liver endothelial cells from the liver of an H-2Kb-tsA58 transgenic mouse, which harbors the SV40 TAg gene. Hepatic sinusoidal cells isolated from H-2Kb-tsA58 mouse proliferated in the presence of gamma-interferon at 33 degrees C. Four clones were established, out of which clone M1 had the highest amounts of PGI2 production, as well as plasminogen activator activity and internalized acetylated low density lipoprotein. On culture dishes the M1 cells grew individually and spread. Sieve plates on the cell surface were not readily visible, but small pores were detected under electron microscopic observation. These results suggest that M1 clone cells originated from liver endothelial cells. Moreover it was possible to culture the immortalized liver endothelial cells in a radial-flow bioreactor for 5 days, with a maximum 6-keto prostaglandin F1alpha production of 25 microg per day. This suggests that immortalized liver endothelial cells and a radial-flow bioreactor can prove useful tools in the development an artificial liver.