The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Shinji Uemoto - One of the best experts on this subject based on the ideXlab platform.
-
Portocaval Shunt for hepatocyte package challenging application of small intestinal graft in animal models
Organogenesis, 2013Co-Authors: Junji Iwasaki, Shuji Hishikawa, Yasuhiro Fujimoto, Shinji Uemoto, Toshiyuki Hata, Hiroyuki Kanazawa, Takumi Teratani, Eiji KobayashiAbstract:In developing therapeutic alternatives to liver transplantation, we have used the strategy of applying a small intestinal segment as a scaffold for hepatocyte transplantation and also as a Portocaval Shunt (PCS) system to address both liver dysfunction and portal hypertension. The aim of this study was to investigate the feasibility of such an intestinal segment in animal models. Hepatocytes isolated from luciferase-transgenic Lewis rats were transplanted into jejunal segments of wild-type Lewis rats with mucosa removal without PCS application. Luciferase-derived luminescence from transplanted hepatocytes was stably detected for 30 days. Then, we performed autologous hepatocyte transplantation into the submucosal layer of an isolated and vascularized small intestinal segment in pigs. Transplanted hepatocytes were isolated from the resected left-lateral lobe of the liver. On day 7, hepatocyte clusters and bile duct-like structures were observed histologically. To create an intestinal PCS system in pigs, an auto-graft of the segmental ileum and interposing vessel graft were anastomosed to the portal vein trunk and inferior vena cava. However, thrombi were observed in vessels of the intestinal PCSs. We measured the correlation between infusion pressure and flow volume in whole intestines ex vivo in both species and found that the high pressure corresponding to portal hypertension was still insufficient to maintain the patency of the intestinal grafts. In conclusion, we demonstrated the feasibility of the small intestine as a scaffold for hepatocyte transplantation in rat and pig models, but PCS using an intestinal graft failed to maintain patency in a pig model.
-
development of a Portocaval Shunt using a small intestinal segment in rats
Microsurgery, 2010Co-Authors: M Toshiyuki D Hata, M Junji D Iwasaki, Shuji Hishikawa, Yasuhiro Fujimoto, Shinji Uemoto, Eiji KobayashiAbstract:The transjugular portosystemic Shunt, widely used to treat portal hypertension today, may increase the risk of encephalopathy and reduce effective hepatic flow. To address these issues, a strategy to produce a Portocaval Shunt (PCS) with hepatic function using intestinal grafts was conceived, and rat models were developed. We transplanted ileal grafts from wild-type and luciferase transgenic Lewis rats to wild-type Lewis rats, anastomosing the graft mesenteric artery (SMA) and portal vein (PV) to the recipient PV trunk and inferior vena cava, respectively. Recipient survival was significantly longer in the partial PCS model, in which the graft SMA was anastomosed to the recipient PV trunk in an end-to-side fashion, than in the total PCS model, with the end-to-end anastomosis. In the partial PCS model, histological and luminescence analyses showed graft survival for 1 month. These results suggest that intestinal grafts can be maintained in the particular conditions required for our strategy. © 2010 Wiley-Liss, Inc. Microsurgery, 2010.
-
selective hemi Portocaval Shunt based on portal vein pressure for small for size graft in adult living donor liver transplantation
American Journal of Transplantation, 2008Co-Authors: T Yamada, K Tanaka, Kenji Uryuhara, K Ito, Yasutsugu Takada, Shinji UemotoAbstract:We developed an algorithm of graft selection in which left lobe donation is considered primarily if the graft-to-recipient weight ratio (GRWR) is estimated to be greater than 0.6% in preoperative volumetry with utilization of a hemi-Portocaval Shunt (HPCS) based on portal vein pressure (PVP) more than 20 mmHg at the time of laparotomy. A total of 11 consecutive adult living donor liver transplantations with small-for-size graft according to our graft selection algorithm were performed between December 2005 and August 2007. Ten patients required HPCS using a vein graft all survived without small-for-size syndrome (SFSS) and Shunt complications with a median follow-up of 296 days. One patient without HPCS died of chronic vascular rejection. In all cases, PVP were regulated successfully under 20 mmHg by HPCS. Graft volume reached in mean 84.3% of standard liver volume in right lobe grafts and mean 95.4% in left lobe grafts at 3 months after liver transplantation. Actuarial rate of Shunt patency at 1, 3, 6 months and 1 year were 80%, 55%, 26% and 20%, respectively. Selective HPCS based on PVP is an effective procedure and results in excellent patient and graft survival with avoidance of SFSS in grafts greater than 0.6% of GRWR.
-
improvement of morphological changes after 70 hepatectomy with Portocaval Shunt preclinical study in porcine model
Journal of Surgical Research, 2007Co-Authors: Taku Iida, Shintaro Yagi, Kentaro Taniguchi, Tomohide Hori, Shinji UemotoAbstract:Background After extensive hepatectomy, excessive portal venous flow (PVF) and elevated portal venous pressure (PVP) may lead to postoperative liver damage. We have evaluated the use of Portocaval Shunt (PCS) to control PVF and PVP following partial hepatectomy (PH) to reduce the postoperative liver damage. Method Twenty-four pigs were divided into two Groups: Group C ( n = 10) underwent 70% PH alone and Group S ( n = 14) underwent 70% PH with PCS. The changes in PVF, PVP, serum liver function tests, and histology were evaluated. Results PVP and PVF per unit of remnant liver weight and serum total bilirubin levels in Group S were significantly lower than those in Group C postoperatively ( P P P Conclusion After 70% PH, extensive centrolobular necrosis and neutrophil aggregation were present and may have caused liver damage, manifested as hyperbilirubinemia and coagulopathy. The delayed liver regeneration with PCS may reduce the postoperative liver damages rather than the rapid liver hypertrophy. The diversion of PVF with PCS to maintain adequate PVP is a very effective procedure for avoiding the postoperative liver failure after extensive hepatectomy.
-
the use of transjugular intrahepatic portosystemic Shunt and surgical Portocaval h Shunt for the treatment of colorectal variceal bleeding
Hepato-gastroenterology, 1995Co-Authors: Shinji Uemoto, A J Martin, W Fleming, Nagy A HabibAbstract:Surgical Portocaval H-Shunt was performed after the thrombosis of a transjugular intrahepatic portosystemic Shunt inserted for colorectal variceal bleeding. The surgical procedure successfully controlled the variceal bleeding. However, the patient developed postoperative liver failure and hepatic encephalopathy due to complete portal vein thrombosis and the absence of prograde portal flow. This case illustrates the potential risks of the serial use of transjugular intrahepatic portosystemic Shunt and surgical Portocaval Shunt leading to complete portal vein thrombosis, hepatic encephalopathy and acute liver failure.
Eiji Kobayashi - One of the best experts on this subject based on the ideXlab platform.
-
Portocaval Shunt for hepatocyte package challenging application of small intestinal graft in animal models
Organogenesis, 2013Co-Authors: Junji Iwasaki, Shuji Hishikawa, Yasuhiro Fujimoto, Shinji Uemoto, Toshiyuki Hata, Hiroyuki Kanazawa, Takumi Teratani, Eiji KobayashiAbstract:In developing therapeutic alternatives to liver transplantation, we have used the strategy of applying a small intestinal segment as a scaffold for hepatocyte transplantation and also as a Portocaval Shunt (PCS) system to address both liver dysfunction and portal hypertension. The aim of this study was to investigate the feasibility of such an intestinal segment in animal models. Hepatocytes isolated from luciferase-transgenic Lewis rats were transplanted into jejunal segments of wild-type Lewis rats with mucosa removal without PCS application. Luciferase-derived luminescence from transplanted hepatocytes was stably detected for 30 days. Then, we performed autologous hepatocyte transplantation into the submucosal layer of an isolated and vascularized small intestinal segment in pigs. Transplanted hepatocytes were isolated from the resected left-lateral lobe of the liver. On day 7, hepatocyte clusters and bile duct-like structures were observed histologically. To create an intestinal PCS system in pigs, an auto-graft of the segmental ileum and interposing vessel graft were anastomosed to the portal vein trunk and inferior vena cava. However, thrombi were observed in vessels of the intestinal PCSs. We measured the correlation between infusion pressure and flow volume in whole intestines ex vivo in both species and found that the high pressure corresponding to portal hypertension was still insufficient to maintain the patency of the intestinal grafts. In conclusion, we demonstrated the feasibility of the small intestine as a scaffold for hepatocyte transplantation in rat and pig models, but PCS using an intestinal graft failed to maintain patency in a pig model.
-
development of a Portocaval Shunt using a small intestinal segment in rats
Microsurgery, 2010Co-Authors: M Toshiyuki D Hata, M Junji D Iwasaki, Shuji Hishikawa, Yasuhiro Fujimoto, Shinji Uemoto, Eiji KobayashiAbstract:The transjugular portosystemic Shunt, widely used to treat portal hypertension today, may increase the risk of encephalopathy and reduce effective hepatic flow. To address these issues, a strategy to produce a Portocaval Shunt (PCS) with hepatic function using intestinal grafts was conceived, and rat models were developed. We transplanted ileal grafts from wild-type and luciferase transgenic Lewis rats to wild-type Lewis rats, anastomosing the graft mesenteric artery (SMA) and portal vein (PV) to the recipient PV trunk and inferior vena cava, respectively. Recipient survival was significantly longer in the partial PCS model, in which the graft SMA was anastomosed to the recipient PV trunk in an end-to-side fashion, than in the total PCS model, with the end-to-end anastomosis. In the partial PCS model, histological and luminescence analyses showed graft survival for 1 month. These results suggest that intestinal grafts can be maintained in the particular conditions required for our strategy. © 2010 Wiley-Liss, Inc. Microsurgery, 2010.
Uday Zachariah - One of the best experts on this subject based on the ideXlab platform.
-
transjugular intrahepatic Portocaval Shunt placed through the strut of an inferior vena cava stent in a patient with budd chiari syndrome a technical modification
British Journal of Radiology, 2010Co-Authors: Narayanam R S Surendrababu, Shyamkumar N Keshava, C E Eapen, Uday ZachariahAbstract:Transjugular intrahepatic Portocaval Shunt (TIPS) is performed in patients with symptomatic Budd–Chiari syndrome (BCS) who do not have repairable hepatic veins. We report the case of a patient who had an inferior vena cava (IVC) stent placed previously as part of the management for BCS, and who subsequently required TIPS. The TIPS tract was created through the strut of the previously placed IVC stent; the TIPS stent was placed after dilatation of the liver parenchyma as well as the strut of the IVC stent. This novel technique of “strutplasty” of a previously placed stent as part of TIPS has not been reported in the literature.
R Pichlmayr - One of the best experts on this subject based on the ideXlab platform.
-
two step procedure in budd chiari syndrome with severe intrahepatic vena cava stenosis vena cava stenting and Portocaval Shunt
The American Journal of Gastroenterology, 1998Co-Authors: Karl J Oldhafer, Markus Frerker, Mathias Prokop, Hauke Lang, Klaus H W Boker, R PichlmayrAbstract:Budd-Chiari syndrome is characterized by hepatic venous outflow obstruction, which often leads to death as a result of portal hypertension and liver failure. Venous decompressive Shunt surgery and liver transplantation represent efficient surgical treatments of Budd-Chiari syndrome. In the case presented here, severe intrahepatic compression of the inferior vena cava (IVC) was caused by the hypertrophic caudate lobe. A mere Portocaval Shunt was not feasible because of a large pressure gradient across the intrahepatic stenosis. A two-step procedure with preoperative radiological dilation and stenting of the intrahepatic IVC followed by a Portocaval Shunt was successfully performed. Consequently, liver transplantation and its subsequent immunosuppression could be avoided.
Didier Lebrec - One of the best experts on this subject based on the ideXlab platform.
-
long term hemodynamic effects of Portocaval Shunt and sugiura procedure in patients with cirrhosis
Hpb Surgery, 1996Co-Authors: Corinne Vons, Antoine Hadengue, Claude Smadja, Dominique Franco, Didier LebrecAbstract:Systemic and splanchnic hemodynamics were studied before and six months after a portal systemic Shunt (n=6) or a Sugiura procedure (n=9) in 15 patients with cirrhosis and a past history of variceal bleeding. Hepatic blood flow was estimated by hepatic extraction and clearance of continuous indocyanine green infusion. Azygos blood flow was measured with a continuous thermodilution catheter. After Portocaval Shunt, the cardiac index increased significantly from 4.0±1.4 to 5.4±0.8 l/min m2 (p<0.05), the hepatic venous pressure gradient and hepatic blood flow were significantly decreased from 21±3 to 13±5 mm Hg (p<0.05) and from 1.20±0.35 to 0.37±0.16 l/min (p<0.05) respectively. The decrease in azygos blood flow was not significant (0.51±0.31 vs 0.25±0.33 l/min; p=0.1). After Sugiura procedure, there was no significant change in cardiac index, hepatic venous pressure gradient, hepatic blood flow or azygos blood flow. This is the first study to show the long-term maintenance of splanchnic and systemic hemodynamics in patients with cirrhosis after Sugiura procedure. The absence of long-term hemodynamic alterations could explain the absence of encephalopathy after this procedure.