الفهرس | Only 14 pages are availabe for public view |
Abstract Orthotopic Liver Transplantation (OLT) involves removing the patient’s own diseased (“native”) liver at surgery and replacing it with a liver from another person. The first liver transplant in humans was performed on March , 1963 by Starzl. Liver transplantation is the ultimate therapy for various acute and chronic liver diseases So, the main indication of Liver transplantation is hepatic failure which may be caused by Cholestatic diseases such as (Primary biliary cirrhosis (P.B.C), Primary sclerosing cholangitis (P.S.C), Biliary atresia and Secondary biliary cirrhosis), Viral related cirrhosis such as (Viral C cirrhosis, Viral B cirrhosis, hepatitis D virus (HDV), autoimmune cirrhosis and alcohol related cirrhosis), Budd-Chiari syndrome, Veno-occlusive disease, Metabolic diseases, Malignancy and Fulminant hepatic failure. Liver transplantation is Contraindicated absolutely in active major systemic infection, advanced cardiopulmonary disease, metastatic hepatobiliary malignancy and AIDS and Relatively in Advanced age (> 70 years), Portal vein thrombosis, Cholangio-carcinoma and others. Hepatocyte transplants have been well-tolerated immunologically, requiring small doses of immunosuppressants, taking into account that in liver graft rejection, the immune response is mainly directed toward the bile duct epithelium and endothelium. However, immunosuppression can be avoided by using autologous hepatocytes retrieved from the patient and transplanted back into him or her after phenotypic correction by introducing a therapeutic gene. It has been widely believed that the optimal site for hepatocyte transplantation was the liver. However, there are ectopic sites for transplantation of the hepato¬cytes such as under the kidney capsule, subcutaneous space, spleen and peritoneal cavity. Of all non-hepatic organs, the spleen has prov¬en to be the best site for hepatocyte engraftment. To improve the survival and function of implanted hepatocytes, the latter have been incorporated into biocompatible support materials, effectively constituting an implantable device. Engraftment detection of cells is done by using 99m Tc (technetium) scintigrams, serial technetium – 99mdiisopropyl- iminodiacetic acid (DISIDA) serial perfusion scans, indium-111 oxyquinoline solution, HLA class I tissue typing together with serial ELISA measurement of (soluble) sHLA class I antigen, Real-time PCR techniques, Short tandem repeats (STR) or Magnetic resonance imaging (MRI). Some post transplant problems have been encountered after hepatocyte infusion limiting the success of this technique, including hepatic haematoma, portal vein thrombosis, haemorrhage, puncture of the biliary system, vasovagal reactions, portal hypertension, lung emboli, immunologic rejection and technical difficulties of cryopreserving hepatocytes. To make use of the limited numbers of organs available for hepatocyte isolation, hepatocyte banks could be established in centers most experienced with the technique of LCT . Also, hepatocytes from other animal species could provide an unlimited supply of predictable quality hepatocytes. |