Effect of OKT3 on survival and rate of retransplantation.
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Biomedical subjects
Publications and source records attributed to C O Esquivel.
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Liver transplantation is now the preferred treatment for many diseases leading to end-stage liver disease. Transplantation for cancer has been disappointing and there is a significant recurrence rate after transplantation in hepatitis B-virus carriers. Additional strategies will have to be developed if we are to improve the results of transplantation for these patients. The role of immunological factors in liver transplantation continues to reveal significant differences from their role in renal transplantation and will continue to be an interesting area of study for years to come.
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Thirty-nine patients (29 children and ten adults) underwent OLT for liver disease associated with A1AD from March 1980 to March 1986. Thirty of thirty-six patients (83%) with available data were homozygous phenotype PiZZ. The other six were Pi heterozygotes, being either PiMZ or PiSZ. The mean A1A activity in homozygous and heterozygous patients was 38.8 mg/dL and 114.3 mg/dL respectively. Eight patients died during the first 3 months after OLT (20%). The 5-year actuarial survival is 83% and 60% in pediatric and adult recipients respectively. Today 30 (76%) of the recipients are alive, with follow-ups of 8 to 64 months (average 27 months). The quality of life in the surviving patients is excellent.
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Progress in immunosuppression, surgical techniques, and perioperative care has promoted orthotopic liver transplantation from an experimental procedure to an accepted clinical treatment. Orthotopic liver transplantation, in turn, has changed the treatment of terminal liver disease from care that is largely treatment of symptoms and support to cure, but at the price of major surgery and life-long immunosuppression. This article reviews the current status of liver transplantation as practiced at the University of Pittsburgh.
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Patent distal splenorenal shunts (Warren shunt) have been reported to cause decreases in the portal perfusion pressure and the total hepatic blood flow. Such hemodynamic alterations could have adverse effects on the transplanted liver. The experience with hepatic replacement in four patients with patent Warren shunts is reported. Operative findings were phlebosclerotic portal veins of small size and diminished portal blood flows. Hepatofugal collateral channels created by the construction of the Warren shunt were eliminated by division of the shunt and splenectomy in three patients and splenectomy alone in the other. All patients recovered; thus the presence of a patent Warren shunt should not be a contraindication for hepatic transplantation.
Non-heparinized and covalently-heparinized PTFE grafts, sheep aorta, carotid artery and jugular vein were evaluated according to their ability to adsorb and inactivate thrombin. All surfaces, except non-heparinized PTFE caused considerable losses of enzymatically active thrombin from the solution. Covalently-heparinized PTFE and jugular veins adsorbed thrombin, which was inactivated on subsequent contact with antithrombin III. Despite the same loss from the solution as was encountered with veins arteries adsorbed significantly smaller amounts of thrombin. Protamine treatment of covalently-heparinized PTFE almost totally abolished the ability to adsorb thrombin. It is concluded that 1) arteries possess a stronger thrombin inhibitory capacity than veins, possible explanations to this being a different glucosaminoglycan or the presence of antithrombin III in the arterial wall and 2) that heparinizing PTFE results in a pronounced ability to inactivate thrombin.
The results using polytetrafluoroethylene (PTFE) and tanned human umbilical cord vein (HUV) grafts are discussed. These two grafts perform well for reconstructions above the knee and the results are similar to the autogenous saphenous vein (ASV) grafts in several series; however, in more distal reconstructions the PTFE and HUV are far inferior to ASV grafts. The factors responsible for graft failure including the events which take place at the blood interface are reviewed. New material surfaces under investigation such as degradable grafts, heparin-bonded surfaces, and endothelial-seeded fabrics are also addressed.
One hundred seventy orthotopic liver transplants were performed under conventional immunosuppression with azathioprine and steroids with 1- and 5-year survivals of 32.9 per cent and 20.0 per cent, respectively. Since the introduction of cyclosporine-prednisone therapy in March 1980, 313 primary orthotopic liver transplants have been performed. Actuarial survivals at 1 and 5 years have improved to 69.7 per cent and 62.8 per cent, respectively. Biliary atresia is now the most common indication for liver replacement. In adults, primary biliary cirrhosis and sclerosing cholangitis have become more common indications for transplantation, and alcoholic cirrhosis and primary liver malignancy as indications have declined. Early enthusiasm for liver transplantation in patients with hepatic cancer has been tempered by the finding that recurrence is both common and rapid. An increasing number of patients with inborn errors of metabolism originating in the liver are receiving transplants, including patients with Wilson's disease, tyrosinemia, alpha-1-antitrypsin deficiency, glycogen storage disease, familial hypercholesterolemia, and hemochromatosis. Survival in this group of patients has been excellent (74.4 per cent at 1 and 5 years). A hemophiliac who received a transplant for postnecrotic cirrhosis has survived and may have been cured of his hemophilia. About 20 per cent of patients require retransplantation for rejection, technical failure, or primary graft failure. Only four of the patients receiving retransplants under conventional immunosuppression survived beyond 6 months, and all died within 14 months of retransplantation. Sixty-eight patients have received retransplants under cyclosporine-prednisone. Thirty-one patients are surviving, all for at least 1 year. Six of the twelve patients requiring a third transplant are alive 2 to 3 years after the primary operation. An aggressive approach to retransplantation in the patient with a failed graft is justified.
Six hundred seventy-one first, second, and third orthotopic liver allografts in 520 patients were reviewed to determine the effect of donor-recipient mismatches or incompatibilities for the ABO blood groups on graft survival. A significant advantage for ABO donor-recipient identity was found, especially in adults and for first grafts. However, a surprisingly large number of ABO incompatible grafts were successful. We recommend that nonidentical or incompatible grafts be limited to patients such as small children for whom the supply of available donors is severely limited or for patients in urgent need of transplantation or retransplantation.
Six hundred sixty-seven first, second, and third orthotopic liver allografts in 520 patients were reviewed to determine the effect of recipient panel-reactive antibody (PRA) and donor-recipient antibody crossmatch on 2-year patient and liver allograft survival rates. Neither a high panel-reactive antibody nor a positive crossmatch for donor-specific preformed antibody was associated with decreased patient or liver allograft survival for primary grafts or retransplants. Two patients have been given kidney transplants immediately after a liver allograft from a donor with whom each patient had an initial strongly positive donor-specific antibody crossmatch. The liver apparently removed or neutralized circulating anti-donor antibody, since the renal allografts functioned promptly and did not experience hyperacute rejection.
From 1975 to 1985, 60 patients with isolated hepatic metastases from colorectal cancer were treated by 17 right trisegmentectomies, five left trisegmentectomies, 20 right lobectomies, seven left lobectomies, eight left lateral segmentectomies, and three nonanatomic wedge resections. The 1-month operative mortality rate was 0%. One- to 5-year actuarial survival rates of the 60 patients were 95%, 72%, 53%, 45%, and 45%, respectively. The survival rate after liver resection was the same when solitary lesions were compared with multiple lesions. However, none of the seven patients with four or more lesions survived 3 years. The interval after colorectal resection did not influence the survival rate after liver resection, and survival rates did not differ statistically when synchronous metastases were compared with metachronous tumors. A significant survival advantage of patients with Dukes' B primary lesions was noted when compared with Dukes' C and D lesions. The pattern of tumor recurrence after liver resection appeared to be systemic rather than hepatic. The patients who received systemic chemotherapy before clinical evidence of tumor recurrence after liver resection survived longer than those who did not.
The effect of a selective inhibitor of thromboxane synthesis (dazoxiben) was evaluated in different acute models for thrombosis and hemostasis. Dazoxiben significantly reduced the thrombogenicity of the modified human umbilical vein (Dardik Biograft) inserted in the carotid artery position in sheep. The effect was evident concerning patency, thrombus weight and platelet accumulation at the distal anastomosis. This paralleled a decreased production of thromboxane in both anastomoses and the midgraft region. Dazoxiben did not reduce either the frequency of jugular vein thrombosis (induced by a combination of endothelial damage and flow restriction) or arteriolar microembolism after laser injury in rabbits. Neither did it influence initial hemostasis as evaluated by measuring the hemostatic plug formation in the rabbit mesenteric microcirculation. It is concluded that thromboxane synthesis inhibition may be of value when attempting to improve the performance of small diameter vascular prostheses, the data obtained indicating a low risk for hemorrhagic complications.
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During the last 5 years, liver transplantation has become a service as opposed to an experimental operation. The most important factor in making this possible has been the introduction of cyclosporine-steroid therapy. At the same time, liver transplantation has been made more practical by improvements in diagnosing and managing other causes of postoperative hepatic dysfunction. Tissue typing and matching have played no role in improving the results of liver transplantation. With the demonstration that performed antibody states are irrelevant, even avoidance of positive cross-matches caused by cytotoxic antibodies and observance of ABO blood group barriers have become unnecessary if the recipient's needs are great. With the exceptions of malignancy and cirrhosis, the nature of the underlying hepatic disease has not profoundly influenced the results. Retransplantation has played an important role in improving survival, although the costs of retransplantation have been extremely high.