Shuji Hishikawa

A case of successful enteroscopic balloon dilation for late anastomotic stricture of choledochojejunostomy after living donor liver transplantation.

Biliary complications remain a major concern after living donor liver transplantation. We describe a pediatric case who underwent a successful endoscopic balloon dilatation of biliary‐enteric stricture following living donor liver transplantation using a newly developed method of enteroscopy. The 7‐year‐old boy with late biliary stricture of choledochojejunostomy was admitted 6 years after transplantation. Since percutaneous transhepatic cholangiography was technically difficult in this case, endoscopic retrograde cholangiography was performed using a double‐balloon enteroscope under general anesthesia. The enteroscope was advanced retrograde through the duodenum, jejunum, and the leg of Roux‐Y by the double‐balloon method, and anastomotic stricture of choledochojejunostomy was clearly confirmed by endoscopic retrograde cholangiography and endoscopic direct vision. Balloon dilatation was performed and the anastomosis was expanded. Restenosis was not noted as of 2 years after the treatment. In conclusion, endoscopic balloon dilation of biliary‐enteric anastomotic stricture using a new enteroscopic method can be regarded as an alternative choice to percutaneous transhepatic management and surgical re‐anatomists. (Liver Transpl 2005;11:1608–1610.)

Arthroscopic, histological and MRI analyses of cartilage repair after a minimally invasive method of transplantation of allogeneic synovial mesenchymal stromal cells into cartilage defects in pigs

Background aims Transplantation of synovial mesenchymal stromal cells (MSCs) may induce repair of cartilage defects. We transplanted synovial MSCs into cartilage defects using a simple method and investigated its usefulness and repair process in a pig model. Methods The chondrogenic potential of the porcine MSCs was compared in vitro. Cartilage defects were created in both knees of seven pigs, and divided into MSCs treated and non-treated control knees. Synovial MSCs were injected into the defect, and the knee was kept immobilized for 10 min before wound closure. To visualize the actual delivery and adhesion of the cells, fluorescence-labeled synovial MSCs from transgenic green fluorescent protein (GFP) pig were injected into the defect in a subgroup of two pigs. In these two animals, the wounds were closed before MSCs were injected and observed for 10 min under arthroscopic control. The defects were analyzed sequentially arthroscopically, histologically and by magnetic resonance imaging (MRI) for 3 months. Results Synovial MSCs had a higher chondrogenic potential in vitro than the other MSCs examined. Arthroscopic observations showed adhesion of synovial MSCs and membrane formation on the cartilage defects before cartilage repair. Quantification analyses for arthroscopy, histology and MRI revealed a better outcome in the MSC-treated knees than in the non-treated control knees. Conclusions Leaving a synovial MSC suspension in cartilage defects for 10 min made it possible for cells to adhere in the defect in a porcine cartilage defect model. The cartilage defect was first covered with membrane, then the cartilage matrix emerged after transplantation of synovial MSCs.

Repetitive allogeneic intraarticular injections of synovial mesenchymal stem cells promote meniscus regeneration in a porcine massive meniscus defect model.

OBJECTIVE A new strategy is required in order to regenerate a meniscus for extensive defects. Synovial mesenchymal stem cells (MSCs) are an attractive cell source for meniscus regeneration due to their high proliferation and chondrogenic potential. We examined the effect of repetitive intraarticular injections of synovial MSCs on meniscus regeneration in a massive meniscal defect of pigs. We followed up the efficacy using MRI evaluation in addition to macroscopic and histological observations. DESIGN Two weeks before the injection of synovial MSCs, the anterior half of the medial menisci was resected in both knees of pigs. Fifty million allogeneic synovial MSCs were injected into the right knee at 0, 2, and 4 weeks and followed up by sequential MRI. The regenerated meniscus, adjacent articular cartilage, and subchondral bone were evaluated by MRI at 2, 4, 8, 12 and 16 weeks. They were also evaluated macroscopically and histologically at 16 weeks (n = 7). RESULTS The resected meniscus regenerated significantly better in the MSC group than in the control group based on histological and MRI analyses. Macroscopically, the meniscal defect already appeared to be filled with synovial tissue at 2 weeks. Articular cartilage and subchondral bone at the medial femoral condyle were also significantly more preserved in the MSC group based on MRI, macroscopic, and histological analyses. CONCLUSIONS Intraarticular injections of allogeneic synovial MSCs appeared to promote meniscus regeneration and provide protection at the medial femoral articular cartilage in a porcine massive meniscal defect model.

The pig as a model for translational research: overview of porcine animal models at Jichi Medical University

To improve the welfare of experimental animals, investigators seek to respect the 3R principle (Replacement, Reduction, and Refinement). Even when large animal studies are essential before moving to clinical trials, it is important to look for ways to reduce the number of experimental animals used. At the Center for the Development of Advanced Medical Technology, we consider ‘medical’ pigs to be ideal preclinical model systems.We have been using both wild-type and genetically modified pigs. We began using this approach about 10 years ago with a ‘total pig system’ to model human health and disease for the purposes of both medical skill education and the development of new devices and therapeutic strategies.At our Center, medical students and residents use pigs to gain experience with surgical skills and train for emergency procedures after appropriate simulation training. Senior clinicians have also used these models to advance the development of innovative tools for endo- and laparoscopic procedures. The Center focuses on translational research for organ transplantation and stem cell therapy. Several pig models have been established for liver, intestine, kidney, pancreas, and lung transplantation. Mesenchymal stromal cells have been established in green fluorescent protein- and red fluorescent protein-transgenic pigs and tested to trans-differentiate organogenesis. A program to establish induced pluripotent stem cells in the pig is ongoing at our Center.Here, we review our 10 years of activity in this field. Based on our experience in surgical education and research, experimental pigs are valuable models in translational research.

Minimizing the inhibitory effect of neutralizing antibody for efficient gene expression in the liver with adeno-associated virus 8 vectors.

Neutralizing antibodies (NAbs) against adeno-associated viruses (AAVs) are known to interfere with AAV vector-mediated gene transfer by intravascular delivery. Evading the inhibitory effects of antibodies against AAV vectors is necessary for efficient transfer of therapeutic genes clinically. For this purpose, we tested the efficacy of saline flushing in order to avoid contact of vectors with NAbs present in blood. Direct injection of the AAV8 vector carrying the factor IX (FIX) gene into the portal vein of macaques using saline flushing achieved transgene-derived FIX expression (4.7 ± 2.10-10.1 ± 5.45% of normal human FIX concentration) in the presence of NAbs. Expression was as efficient as that (5.43 ± 2.59-12.68 ± 4.83%) in macaques lacking NAbs. We next tested the efficacy of saline flushing using less invasive balloon catheter-guided injection. This approach also resulted in efficient expression of transgene-derived FIX (2.5 ± 1.06-9.0 ± 2.37%) in the presence of NAbs (14-56× dilutions). NAbs at this range of titers reduced the efficiency of transduction in the macaque liver by 100-fold when the same vector was injected into mesenteric veins without balloon catheters. Our results suggest that portal vein-directed vector delivery strategies with flushing to remove blood are efficacious for minimizing the inhibitory effect of anti-AAV antibodies.

Elevated blood concentrations of calcineurin inhibitors during diarrheal episode in pediatric liver transplant recipients: Involvement of the suppression of intestinal cytochrome P450 3A and P-glycoprotein

Abstract:  We encountered two cases of pediatric living‐related liver transplant recipients who showed increases in blood concentration of cyclosporine or tacrolimus, a dual substrate for cytochrome P450 (CYP) 3A and P‐glycoprotein (P‐gp), during a diarrheal episode. To investigate the effect of intestinal inflammation on the metabolic and efflux pump activities, we conducted the experiments using the lipopolysaccharide (LPS)‐induced intestinal damage model.

Rendezvous penetration method using double-balloon endoscopy for complete anastomosis obstruction of hepaticojejunostomy after pediatric living donor liver transplantation

A 12-year-old boy underwent a living donor liver transplantation at another facility in March 2006 after undergoing a failed Kasai operation. The left lobe from his mother was used for the graft with a single-orifice bile duct 4 mm in diameter. The biliary reconstruction was performed via a Roux-en-Y hepaticojejunostomy with an interrupted 6-0 absorbable monofilament suture material without a biliary stent. The patient was treated with tacrolimusand methylprednisolone-based immunosuppression. The postoperative course was uneventful, except for an episode of postoperative diabetes requiring a subcutaneous insulin injection. In September 2006, he was referred to our department because of intrahepatic bile duct dilatation. Image findings and laboratory data revealed biliary stricture with liver dysfunction. A percutaneous transhepatic cholangiodrainage (PTCD) was performed, with placement of a 7-French PTCD tube. Complete obstruction of the anastomosis was observed on cholangiography 2 weeks later. The PTCD tube was changed from a 7-French tube to a 9-French tube in order to observe the anastomosis with a 2.8-mm-diameter cholangioscope (CHF-CB30S, Olympus, Tokyo, Japan). This proved ineffective, however, as the guide wire could not be passed through the anastomosis. Because in our experience double-balloon endoscopy (DBE) can reveal the outline of a complete obstruction of hepaticojejunostomy, we were compelled to apply the rendezvous penetration method using DBE. RENDEZVOUS PENETRATION METHOD USING DBE

Double-balloon enteroscopy for bilioenteric anastomotic stricture after pediatric living donor liver transplantation.

Bilioenteric anastomotic stricture after liver transplantation is still frequent and early detection and treatment is important. We established the management using double‐balloon enteroscopy (DBE) and evaluated the intractability for bilioenteric anastomotic stricture after pediatric living donor liver transplantation (LDLT). We underwent DBE at Jichi Medical University from May 2003 to July 2009 for 25 patients who developed bilioenteric anastomotic stricture after pediatric LDLT. The patients were divided into two types according to the degree of dilatation of the anastomotic sites before and after interventional radiology (IVR) using DBE. Type I is an anastomotic site macroscopically dilated to five times or more, and Type II is an anastomotic site dilated to less than five times. The rate of DBE reaching the bilioenteric anastomotic sites was 68.0% (17/25), and the success rate of IVR was 88.2% (15/17). There were three cases of Type I and 12 cases of Type II. Type II had a significantly longer cold ischemic time and higher recurrence rate than Type I (P = 0.005 and P = 0.006). In conclusion, DBE is a less invasive and safe treatment method that is capable of reaching the bilioenteric anastomotic site after pediatric LDLT and enables IVR to be performed on strictures, and its treatment outcomes are improving. Type II and long cold ischemic time are risk factors for intractable bilioenteric anastomotic stricture.

Living Donor Liver Transplantation for Neonates Using Segment 2 Monosubsegment Graft

The prognosis of liver transplantation for neonates with fulminant hepatic failure (FHF) continues to be extremely poor, especially in patients whose body weight is less than 3 kg. To address this problem, we have developed a safe living donor liver transplantation (LDLT) modality for neonates. We performed LDLTs with segment 2 monosubsegment (S2) grafts for three neonatal FHF. The recipient age and body weight at LDLT were 13–27 days, 2.59–2.84 kg, respectively. S2 or reduced S2 grafts (93–98 g) obtained from their fathers were implanted using temporary portacaval shunt. The recipient portal vein was reconstructed at a more distal site, such as the umbilical portion, to have the graft liver move freely during hepatic artery (HA) reconstruction. The recipient operation time and bleeding were 11 h 58 min–15 h 27 min and 200–395 mL, respectively. The graft‐to‐recipient weight ratio was 3.3–3.8% and primary abdominal wall closure was possible in all cases. Although hepatic artery thrombosis occurred in one case, all cases survived with normal growth. Emergency LDLT with S2 grafts weighing less than 100 g can save neonates with FHF whose body weight is less than 3 kg. This LDLT modality using S2 grafts could become a new option for neonates and very small infants requiring LT.

Living-Donor Liver Transplantation in 126 Patients with Biliary Atresia: Single-Center Experience

OBJECTIVES To describe our experience with 126 consecutive living-donor liver transplantation (LDLT) procedures performed because of biliary atresia and to evaluate the optimal timing of the operation. PATIENTS AND METHODS Between May 2001 and January 2010,126 patients with biliary atresia underwent 130 LDLT procedures. Mean (SD) patient age was 3.3 (4.2) years, and body weight was 13.8 (10.7) kg. Donors included 64 fathers, 63 mothers, and 3 other individuals. The left lateral segment was the most commonly used graft (75%). Patients were divided into 3 groups according to body weight: group 1, less than 8 kg (n = 40); group 2,8 to 20 kg (n = 63); and group 3, more than 20 kg (n = 23). Medical records were reviewed retrospectively. Follow up was 4.5 (2.7) years. RESULTS All group 3 donors underwent left lobectomy, and all group 1 donors underwent left lateral segmentectomy. No donors required a second operation or died. Comparison of the 3 groups demonstrated that recipient Pediatric End-Stage Liver Disease score in group 1 was highest, operative blood loss in group 2 was lowest (78 mL/kg), and operative time in group 3 was longest (1201 minutes). Hepatic artery complications occurred more frequently in group 1 (17.9%), and biliary stenosis (43.5%) and gastrointestinal perforation (8.7%) occurred more frequently in group 3. The overall patient survival rates at 1, 5, and 9 years was 98%, 97%, and 97%, respectively. Five-year patient survival rate in groups 1,2, and 3 were 92.5%, 100%, and 95.7%, respectively. Gastrointestinal perforation (n = 2) was the primary cause of death. CONCLUSIONS Living-donor liver transplantation is an effective treatment of biliary atresia, with good long-term outcome. It seems that the most suitable time to perform LDLT to treat biliary atresia is when the patient weighs 8 to 20 kg.