Extended left hepatic lobectomy for hepatic hilar bile duct cancer: a novel surgical procedure in which the right hepatic duct is transected before the hepatoduodenal ligament is skeletonized.

As a general principle, the procedure of isolating a cancer region from surrounding tissues (skeletonization) is not taken until the last stage of a cancer operation. This principle is often disregarded in surgery for cancers of the hepatic hilar duct, however, as it may be mandatory to skeletonize the region before resecting the liver. Our group invented 'extended left hepatic lobectomy', a new surgical procedure for hepatic hilar bile duct cancer, in which we isolate the liver and transect the right hepatic duct before skeletonizing the cancer region in the hepatoduodenal ligament.

Regeneration of extrahepatic bile duct--possibility to clinical application by recognition of the regenerative process.

The biliary epithelium is continuously exposed to highly cytotoxic bile acids and pathogens and thus is at persistent risk for injury. The monolayer mucosal epithelium protects the body from these dangers and once injured. The bile duct repair process essentially involves reconstruction of the bile duct with migrating cells, but there are many questions about the process. It is reported that implantation of a bioabsorbable polymer tube as a bypass graft into the extrahepatic bile duct resulted in bile duct regeneration in the graft site after the artificial duct had been degraded and absorbed. We briefly describe our findings on extrahepatic biliary tissue regeneration with the possibility for clinical applications in mind. The creation of this artificial bile duct may be able to promote the development of the treatment for biliary diseases.

Tissue-engineered patch for the reconstruction of inferior vena cava during living-donor liver transplantation.

In living-donor liver transplantation, only a portion of the donor's liver is grafted into the recipient; therefore, if the hepatic vein and inferior vena cava (IVC) in the recipient fail to be transformed or dilated properly, it could cause inadequate blood flow from the liver graft to the IVC. We have developed an easy-to-use tissue engineered patch that can be used for the reconstruction of the hepatic vein and IVC. Five hybrid pigs (weighing 15-30 kg) served as the recipients of the patch. A bioabsorbable polymer sheet was used to produce the patch, with no cells seeded. The pigs were laparotomized, followed by the removal of a 3 x 2-cm portion of the infrahepatic IVC, which was then patched with the polymer sheet. Three months after the operation, the graft site was removed and subjected to gross and histologic examinations. All five pigs survived until they were killed 3 months after the operation. On gross examination, the polymer sheet grafted onto the IVC was completely absorbed, and the graft site was morphologically similar to the native IVC. In all five pigs, the patched IVC was free of stenosis or deformation. Immunohistochemical examination revealed that the patch site was lined with endothelial cells and that smooth muscle was present under the epithelium. Like the native IVC, the patch site tested positive for factor VIII. These findings suggest that this polymer sheet may be useful for the reconstruction of the IVC and hepatic vein during living-donor liver transplantation in humans.

Does a surgery for hepatocellular carcinoma with tumor thrombus highly occupying in the right atrium have significance? A case report and review of the literature.

Hepatocellular carcinoma (HCC) advancing to the right atrium (RA) through the hepatic vein has generally been regarded as a terminal lesion of carcinoma. However, because tumor thrombus (TT) in the RA may cause sudden death by heart failure or pulmonary embolism, it is a pathologic condition that needs emergency extraction. Our case was a 55-year-old male. The HCC had a main lesion in the anterior region of the hepatic right lobe, accompanying TT highly occupying the region from the middle hepatic vein and inferior vena cava to the RA. For this tumor, we conducted an extended right anterior segmentectomy and extraction of the TT in the RA under an extracorporeal circulation. He was discharged on the 28th day after surgery, and at present, when 12 months have passed since the surgery, survives without any sign of its recurrence. There have been eight HCC cases including our case, reported regarding the simultaneous resections of a main tumor and TT under cardiopulmonary bypass. Because two patients among this group of eight survived for more than two years, resection is recommended even for advanced HCC highly infiltrating to the RA.

A novel treatment for bile duct injury with a tissue-engineered bioabsorbable polymer patch.

BACKGROUND: With the recent widespread use of laparoscopic cholecystectomy and living-donor liver transplantation, complications involving the biliary system, and stenosis in particular, are encountered frequently. Although various invasive and noninvasive techniques are now available for the treatment of biliary stenosis, recurrence and other problems limit their value and utility. Our group sought to investigate whether a bioabsorbable polymer (BAP) patch could serve as a novel treatment for biliary stenosis. METHODS: In anesthetized hybrid pigs (n = 12), a spindle-shaped portion of the lower common bile duct wall was excised, and a BAP patch was implanted at the excision site. The animals underwent repeat laparotomy at 5 weeks (n = 6) and at 4 months (n = 6) after implantation to recover the graft sites for gross and histologic studies. Blood chemistry was analyzed from samples taken during the patch implantation and recovery. RESULTS: All of the recipient pigs survived until killing. All gained weight and showed no evidence of jaundice. The BAP-patched duct remained patent without obstruction at 5 weeks postimplantation. Blood chemistry did not reveal any increases in hepatobiliary enzyme activities. Histology showed accessory glandular structures in the neo-bile duct. At 4 months, the graft site was indistinguishable from the native duct. Intra-operative cholangiography revealed dilation of the patched site, but no dilatation of the intrahepatic bile ducts. Blood chemistry values were within normal ranges. Histology at the site of the patch confirmed the growth of a cuboidal columnar epithelium similar to that of the native duct. CONCLUSION: The bile duct was dilated only focally at the site of implantation. This newly designed substitute has potential for application as a novel treatment for biliary injury and stenosis.

Regeneration of the inferior vena cava with a bioabsorbable polymer implant: a histological study.

BACKGROUND: Cell implantation into ischemic regions has recently been introduced as a novel strategy for therapeutic angiogenesis. Little is known, however, about the process of blood vessel regeneration, particularly that of the inferior vena cava (IVC). The indicators of normal angiogenesis are also unestablished. PURPOSE: To investigate the process of regeneration of the IVC from a histological viewpoint and to speculate on how the new formation and regeneration of the blood vessels proceed. MATERIALS AND METHODS: Our previous studies showed that a bioabsorbable polymer patch implanted into the IVC formed vessels resembling the native IVC (J Gastrointest Surg 2005;9:789). Using this model system, we investigated the histology and time course of IVC regeneration in the graft site. A 3 x 2 portion of infrahepatic IVC was substituted by a bioabsorbable polymer patch of the same size in hybrid pigs. The patched area was excised for histology at 2 weeks and 3, 6, and 12 months after implantation (n = 3, each). RESULTS: By 2 weeks, the patched area had developed vascular endothelial cells of the same type seen in native veins. The polymer implant was still detectable at 2 weeks but histologically absorbed at 3 months. Smooth muscle was barely formed at 2 weeks, but the ratio of smooth muscle to subendothelial connective tissue gradually increased as time advanced to 3, 6, and 12 months. Even at the last observation at 12 months, however, the amount of smooth muscle formed made up no more than one-half of the native IVC. The case with the elastic fibers accounted for about 90% of the total number of native fibers at 12 months. On gross examination, the patched area resembled the native IVC at 3 months after implantation. CONCLUSION: These results demonstrated that the subendothelial tissue regenerated gradually, requiring more than 1 year to resemble native tissue, whereas the vascular endothelium regenerated in the early phase after injury. Our findings make it possible to establish criteria by which to evaluate venous regeneration.

Development of an ion attachment mass spectrometer for direct detection of intermediates in combustion flames.

A system with Li+ ion attachment (IA) ionization has been developed for the direct detection of intermediates formed in burning flames by mass spectrometry. Dimethyl ether (DME) among alternative fuels was selected as a test substance to examine the capability of the system. As a result, intermediates generated in a premixed DME-air flame were directly detectable as Li+ adduct ions. By moving the burner on an X-Y stage, spatial distribution profiles of different species, including unburned DME and formaldehyde, were obtained for three types of flames: diffusion, partially premixed, and premixed.

Hepatocyte dynamics in a three-dimensional rotating bioreactor.

BACKGROUND AND AIMS: The use of an artificial liver system with extracorporeal circulation or a three-dimensional bioreactor perfused with liquid culture medium inevitably exposes hepatocytes to fluid mechanical stress (MS). The expression of liver-specific hepatocyte functions seems to be modulated by the magnitude of MS. Nonetheless, few studies have focused on the direct effects of MS on hepatocytes. We subjected hepatocytes to MS using an MS loading device and investigated the effects on the cytoskeleton and hepatocyte dynamics inside three-dimensional scaffolds by monitoring the changes in actin fiber, one of the components of the cytoskeleton. We also assessed the influence of MS on specific hepatocyte functions. METHODS: We subjected hepatocytes to MS by a rotating radial flow bioreactor (RRFB) and examined the effects by comparing the MS-loaded culture cells with cells cultured under stationary conditions without MS loading. The hepatocytes (1 x 10(6)/cm(3)) were seeded on gauze without collagen coating and examined to determine morphological changes after 60 h incubation. Actin filaments in samples from the MS-loaded hepatocyte culture were stained by fluorescein isothiocyanate-labeled phalloidin. RESULTS: Hepatocyte aggregation was observed in the MS-loaded culture, but not in the unloaded stationary culture. Better albumin products were observed in the MS-loaded group than in the stationary culture group at all measurement points. Actin filaments extended toward the scaffold after the start of MS loading incubation and polymerized around the hepatocytes. The hepatocyte aggregation eventually advanced to the formation of spheroids. CONCLUSION: These results suggest that MS-induced polymerization of actin filaments stimulate hepatocyte aggregation and thereby improve hepatocyte-specific function.

Endoscopic pancreatic duct drainage and stenting for acute pancreatitis and pancreatic cyst and abscess.

BACKGROUND/PURPOSE: Endoscopic drainage of pancreatic pseudocysts using transpapillary and transmural approaches has been reported. In this study, endoscopic nasopancreatic drainage (ENPD) and pancreatic stenting were performed in patients with pseudocyst and abscess associated with acute pancreatitis, and the usefulness and problems of the procedures were investigated. METHODS: After endoscopic retrograde pancreatography was done, ENPD and/or pancreatic stenting were performed in 13 patients with pancreatitis and pseudocyst or abscess that communicated with the main pancreatic duct. RESULTS: ENPD was performed in seven patients, and was effective in all five patients with cysts: the cysts disappeared or shrank. However, the condition in the two patients with abscess was unchanged, and percutaneous drainage was performed. Stenting was carried out in six patients, and the cyst disappeared or pancreatitis was improved in all six. The stent was removed from two patients, but no recurrence has been noted so far. CONCLUSIONS: ENPD and stenting are effective therapeutic choices for acute and chronic pancreatitis and pseudocysts, and they are superior to percutaneous drainage to avoid pancreatic fistula, but they may not be effective for pancreatic abscess. Selection of therapeutic methods corresponding to individual cases is important.

Extended right hepatectomy for hilar cholangiocarcinoma with resection of the left hepatic duct prior to hepatic resection.

Extended hepatectomy for hilar cholangiocarcinoma results in high operative or in-hospital mortality rates despite of the recent progress in perioperative management. As a new procedure to prevent postoperative hepatic failure in hilar cholangiocarcinoma infiltrating predominantly the right hepatic duct, we devised a combination of extended right lobectomy plus caudal lobectomy with resection of the left hepatic duct prior to hepatic resection by utilizing intraoperative cholangiography, and applied the procedure to a 70-year-old patient. He had a favorable postoperative course and remains recurrence-free at 4 years after operation. This is a procedure for confining the extent of hepatectomy to the minimum necessary, aiming at curative resection of hilar cholangiocarcinoma.

A new laparoscopic-assisted hepatectomy (LAH) utilizing radiofrequency ablation and high-frequency electrocautery.

Compared to tumors located at the edge of the liver, tumors located directly on the liver surface are often difficult to resect, especially when the organ is cirrhotic. To remove tumors at this location, our group has developed a round high-frequency electrosurgical knife that allows hemispherical resection of the liver tissue. This study describes a new laparoscopic-assisted hepatectomy utilizing radiofrequency ablation of the tissue surrounding the tumor and high-frequency electrocautery. When compared with the laparoscopic hepatectomy, this new procedure seems to offer a safer, more effective, and less time-consuming means of resecting tumors on the liver surface.

Alpha-fetoprotein-producing clear cell carcinoma of the extrahepatic bile ducts.

A 79-year-old woman visiting our hospital with chief complaints of epigastric pain and jaundice was emergently admitted. Her alpha-fetoprotein (AFP) level was as high as 2265 ng/mL at admission. Her abdominal computed tomography scan revealed dilation of the intrahepatic bile duct and a tumorlike lesion protruding into the cystic duct and gallbladder from the junction between the middle portion of the bile duct and the right and left hepatic ducts. Surgery revealed a tumor extending from the extrahepatic bile duct (EHBD) to the cystic duct, with no intrahepatic tumor components. The tumor was histologically diagnosed as an AFP-producing cholangiocarcinoma of the clear cell type, originating from the EHBD. None of the previously reported cholangiocarcinomas of the AFP-producing clear cell type have been confined to the EHBD or have been resectable in a curative manner without hepatectomy.

A tissue-engineered artificial bile duct grown to resemble the native bile duct.

The aim of this study was to fabricate an artificial bile duct for the development of a new treatment for biliary diseases. Eighteen hybrid pigs were implanted with a bile duct organoid unit (BDOU) made of a bioabsorbable polymer. Twelve of the transplanted BDOUs had been seeded with autologous bone marrow cells (BMCs) in advance. Six animals, the controls, were grafted with the scaffold alone with no BMCs seeded. The common bile duct was cut, the hepatic cut end of the native common bile duct was anastomosed to the BDOU and the other end was anastomosed to the duodenum. The controls underwent a similar operation. The neo-bile duct was removed at pre-determined time points and investigated histologically. All 18 recipient pigs survived until their sacrifice at 6 weeks, 10 weeks or 6 months. Histological examination revealed incomplete epithelialization of the neo-bile duct at 6 weeks and 10 weeks after transplantation. At 6 months, the organoid exhibited a morphology almost identical to that of the native common bile duct. No differences were found between the controls and BMC-seeded pigs. These results show that the artificial bile duct thus fabricated can serve as a substitute for the native bile duct.