Atsushi Fujio

Collagenase H is Crucial for Isolation of Rat Pancreatic Islets

The role(s) of collagenase G (ColG) and collagenase H (ColH) during pancreatic islet isolation remains controversial, possibly due to the enzyme blends used in the previous studies. We herein examined the role of ColG and ColH using highly pure enzyme blends of recombinant collagenase of each subtype. Rat pancreases were digested using thermolysin, together with ColG, ColH, or ColG/ColH (n = 9, respectively). No tryptic-like activity was detected in any components of the enzyme blends. The efficiency of the collagenase subtypes was evaluated by islet yield and function. Immunohistochemical analysis, in vitro collagen digestion assay, and mass spectrometry were also performed to examine the target matrix components of the crucial collagenase subtype. The islet yield was highest in the ColG/ColH group (4,101 ± 460 islet equivalents). A substantial number of functional islets (2,811 ± 581 islet equivalents) was obtained in the ColH group, whereas no islets were retrieved in the ColG group. Mass spectrometry demonstrated that ColH reacts with collagen I and III. In the immunohistochemical analysis, both collagen I and III were located in exocrine tissues, although collagen III expression was more pronounced. The collagen digestion assay showed that collagen III was more effectively digested by ColH than by ColG. The present study reveals that ColH is crucial, while ColG plays only a supporting role, in rat islet isolation. In addition, collagen III appears to be one of the key targets of ColH.

Risk Factors for Hepatic Artery Thrombosis After Microsurgical Vascular Reconstruction in Liver Transplantation

OBJECTIVE In liver transplantation, microsurgical reconstruction of a hepatic artery is essential but requires challenging techniques. Especially in living-donor liver transplantation, the recipient artery is short and located deep in the abdominal cavity. Furthermore, hepatic artery thrombosis (HAT) can be a lethal complication. This study sought to uncover the risk factors for HAT after microsurgical vascular reconstruction. METHODS From 1991 to 2011, we performed 151 microsurgical vascular reconstructions, including 3 deceased-donor liver transplantations. We retrospectively investigated the cases, performing univariate and multivariate analyses to identify independent risk factors for HAT. The patients had undergone ultrasonographic examinations for HAT over the first 14 days after transplantation. RESULTS Upon univariate analysis, the risk factors identified to be associated with P < .20 were young age (P = .0484), low body weight (P = .0466), short height (P = .0128), high graft-to-recipient weight ratio (P = .0031), small liver graft volume (P = .0416), small amounts of gabexate mesilate infusion (P = .0516), and the conventional technique (without a back-wall support suture; P = .1326). A multiple logistic regression analysis identified low body weight to be the only independent risk factor for HAT. CONCLUSION On the univariate analysis, we found that using the back-wall support suture technique contributed to the reduction of HAT, whereas on multivariate analysis, the only independent risk factor for HAT was low body weight.

Edaravone, a Free Radical Scavenger, Improves the Graft Viability on Liver Transplantation From Non–heart-beating Donors in Pigs

BACKGROUND Although liver transplantation from non-heart-beating donors (NHBDs) is an effective way to overcome shortage of donors, primary graft nonfunction is often noted in these grafts. We have previously reported that edaravone, a free radical scavenger, has a cytoprotective effect on warm ischemia-reperfusion injury and improves the function of liver grafts from NHBDs in a rat model of ischemia-reperfusion. The purpose of this study was to investigate the effects of edaravone on liver transplantations from NHBDs. METHODS Pigs were divided into three groups: (1) a heart-beating (HB) group (n = 5), in which liver grafts were retrieved from HB donors; (2) a non-heart-beating (NHB) group (n = 4), in which liver grafts were retrieved under apnea-induced NHB conditions; and (3) an edaravone-treated (ED) group (n = 5), in which liver grafts were retrieved in the same manner as the NHB group and treated with edaravone at the time of perfusion (3 mg/L in University of Wisconsin [UW] solution), cold preservation (1 mg/L in UW solution), and after surgery (1 mg/kg/d). The grafts from all groups were transplanted after 4 hours of cold preservation. RESULTS In the ED group, the 7-day survival rate was significantly higher than that in the NHB group (80% versus 0%, P = .0042, Kaplan-Meier log-rank test). Furthermore, on histologic examination, the structure of sinusoids in the ED group was well preserved and similar to that in the HB group. CONCLUSIONS Edaravone may improve the viability of liver grafts from NHBDs.

Long-Term Survival with Growth Hormone Replacement after Liver Transplantation of Pediatric Nonalcoholic Steatohepatitis Complicating Acquired Hypopituitarism

Nonalcoholic steatohepatitis (NASH) is the most severe form of nonalcoholic fatty liver disease (NAFLD). In adult patients, liver transplantation (LT) is the treatment of choice for end-stage liver disease secondary to NASH. However, little information is available regarding outcomes of LT in pediatric patients with NASH. We describe here a pediatric patient with NASH associated with hypopituitarism who underwent living donor liver transplantation (LDLT). An 11-year-old boy was diagnosed with a pituitary tumor, which was removed by trans-interhemispheric approach following bifrontal craniotomy. Histopathological examination revealed a mature teratoma. Eighteen months later, magnetic resonance imaging showed recurrence of the pituitary tumor, which was found to be a germinoma. He underwent 3 months of chemoradiotherapy, with a complete response. He gradually became obese, with elevated transaminase levels. At age 15 years, he developed fatigue and dyspnea and was found to have liver cirrhosis secondary to NASH with severe hepatopulmonary syndrome. He underwent LDLT using a right liver graft from his mother. Twelve months later, abdominal computed tomography showed recurrence of NAFLD. Five years after the LDLT, transaminases were slightly elevated. Growth hormone replacement therapy was started, reducing transaminase levels to their normal ranges. Ten years after LDLT, fatty liver remains stable, although his body mass index has not been reduced. Growth hormone replacement therapy may be effective in graft maintenance. This is the first case report of a patient with maintained stable liver function 10 years after LDLT for pediatric NASH.

Indications and outcomes of an endoscopic approach under laparotomy for the treatment of bilioenteric anastomotic strictures

BAS is a potentially life‐threatening complication of LDLT. The aim of this study was to report on the indications and outcomes of an endoscopic approach under laparotomy being used in our institution to treat BAS after LDLT, using hepaticojejunostomy, for a small case series. Eighty‐three patients underwent an LDLT in our institution between 1991 and 2014. Retrospective chart review indicated that 10 of these patients developed BAS and were included in our analysis. The endoscopic approach under laparotomy was used in three patients who developed BAS 10 yr or more after their LDLT and in whom a percutaneous transhepatic approach and an endoscopic approach had failed. The course of recovery post‐operatively was unremarkable for two of the three patients who underwent the endoscopic approach under laparotomy. One patient required follow‐up laparotomy to treat a perforation of the bowel causing acute peritonitis. At follow‐up one yr post‐operatively, the stent tube was removed in two patients who recovered fully. The other patient had full recovery with the stent remaining in situ. The endoscopic approach under laparotomy could be a safe and promising option in the treatment of BAS to avoid surgical re‐anastomosis.

The Reconstruction of Hepatic Arteries Using Extra-Anatomical Free Autografts in Living Donor Liver Transplantation

Objectives: In living-donor liver transplantation (LDLT), microsurgical reconstruction of a hepatic artery is essential but requires challenging techniques, because graft arteries are short and usable vessel grafts are limited. Furthermore, hepatic artery thrombosis can be a lethal complication. Extra-anatomical jump graft reconstruction using free grafts is reported to have a high reocclusion rate. However, this technique is necessary when there is no other option. We report 4 cases of LDLT that required extra-anatomical reconstruction technique using free autografting from the aorta to the hepatic artery. In this technique, we used the systemic administration of gabexate mesilate that is the strong serine protease inhibitor. Methods: From 1991 to 2015, we performed 164 LDLTs. We retrospectively investigated 4 cases of extraanatomical reconstruction of the hepatic artery using free autografting from the aorta to the hepatic artery. Results: Two cases initially underwent anatomical reconstruction, but the arteries occluded early, because of the dissection of recipient’s artery. There was no arterial graft, so we performed extra-anatomical reconstruction by using free autografting from the aorta to the hepatic artery. In the other two cases, the recipient arteries could not be used. Therefore, we initially performed extra-anatomical reconstruction by using radial artery free autografting as jump grafts from the aorta to the hepatic artery. In all cases, we used the systemic administration of gabexate mesilate, and could rescue all cases. Conclusion: We experienced and were able to salvage 4 cases that required free autografts. When there is no other means of reconstructing arteries, it is necessary to perform this procedure, depending on the condition of the intima of the recipient artery.

The extra‐anatomical jump graft reconstruction of the right hepatic artery after resection of a biliary tract malignancy with a common hepatic artery aneurysm: a case report

Performing resection of a biliary tract malignancy with a hepatic artery aneurysm is very challenging. Resection of the extrahepatic bile duct and extra‐anatomical reconstruction can be successfully performed using free radial artery autografts from the aorta to the right hepatic artery. Hepatic artery thrombosis can be prevented with intimal preservation.

Successful Case of Somatostatin Analog Stopping Gastrointestinal Bleeding, One of the Most Frequent Complications After Simultaneous Pancreas-kidney Transplantation: A Case Report.

OBJECT Pancreas transplantation has the highest surgical complication rate of all routinely performed organ transplantation procedures. The complications are not only caused by the pancreas itself but also occur due to issues with the transplant recipient. We report the case of a patient who experienced massive gastrointestinal bleeding after simultaneous pancreas-kidney transplantation (SPK), which was stopped successfully using somatostatin analog. PATIENTS AND METHODS The patient was a 45-year-old woman with diabetes mellitus type 1 who underwent SPK with enteric drainage. She had melena 5 days after SPK. RESULTS At first, we suspected that the melena was caused by the transplanted duodenum because of rejection and ischemic changes. The patient experienced severe bleeding 9 days after SPK. We quickly performed open surgery and inserted an endoscope from the recipients ileum to investigate the transplanted duodenum. However, no bleeding source was found, including in the transplanted duodenum and the recipients ileum end. We determined that the bleeding source was the recipients ascending colon. We attempted to perform endovascular treatment but could not detect the source of the bleeding; therefore, we used somatostatin analog to let the blood vessels shrink and reduce pancreatic output. Thereafter, the function of the transplanted pancreas and kidney gradually recovered, and the recipient was discharged 154 days after SPK. CONCLUSION Gastrointestinal bleeding is a lethal complication and has several different causes, such as mucosal rejection, ischemic changes, and exocrine output of the pancreas graft. Somatostatin analog is one of the most acceptable treatments for patients who have gastrointestinal bleeding after SPK.