Hemoglobin Solutions as Blood Substitutes

The technique of a liver autograft in the pig has three advantages: (1) It provides an excellent training model of liver transplantation, (2) it provides an experimental model for cancer research, and (3) it is more economical than liver allotransplant. We describe a facilitated technique of liver autograft, which can be employed to develop experimental models without the use of a biopump. Mean blood arterial pressure, heart rate, pH, and lactates were tested during the liver grafting and at the end of the procedure in pigs that underwent autografting of the liver and compared with pigs that underwent an orthotopic liver allotransplantation. The cell damage was assessed in the same two groups of animals by monitoring aspartate aminotransferase (AST) and alanine aminotransferase (ALT) blood levels and with the MEGX test, 15 min after the beginning of reperfusion. The surgical procedure may be divided into three parts: hepatectomy, side-to-side portocaval shunt with passive caval-jugular shunt, and reimplantation. This procedure could have a clinical indication for otherwise unresectable liver tumors.     

Clinical Implications of Blood Substitutes

Red cell substitutes are developing rapidly and progressing in their clinical testing. The original concept of a shelf storable oxygen carrying solution for use in trauma and other emergency situations still remains valid. Of interest is the potential for red cell substitutes to be used in other areas of surgery, traditionally the realm of autologous transfusion. This article describes some of the logic behind defining which areas of application are potentially useful in the surgical arena.     

Artificial Liver: Present and Future

Early in 1956, the first model of a biological artificial liver, using a live dog's liver incorporated in a cross-hemodialyzer, was placed in an experimental animal with portocaval encephalopathy. This "biological artificial liver," a hybrid artificial liver in the present terminology, was the first in the world. In October 1958, the first human patient, a young male patient in hepatic coma due to liver cirrhosis, was placed on the laboratory-made biological artificial liver composed of four parabiotic cross-hemodialyzers connected with four live dogs' livers to which the "hepatic reactors" for ammonium adsorption and acid-base balance were additionally equipped. This first case was very successful, resulting in the patient's recovery from coma. This article introduces the past history of the artificial liver, research of which has mainly been conducted in Japan since the early 1950s by the author, M. Mito, and Y. Nosé. Until recently, little progress has been made in this field through the application of blood purification principles such as hemoadsorption, plasmapheresis, and other modifications and combinations. Accumulation of clinical experiences with such conventional methods has stimulated the third generation of the artificial liver to a return to a hybrid organ applying modern science and technology. A concept of hybrid organs in comparison with organ transplants is introduced. The Japanese national project of developing a new artificial liver system, as conducted by the author as the chairman and his associates, is introduced.     

Hepatic Assist: Present and Future

Fulminant hepatic failure due to acute massive liver cell necrosis is a complex pathophysiological entity, and treatment is still unsatisfactory. Artificial liver supports such as hemodialysis, hemoperfusion, and plasmapheresis have recently been used clinically to treat fulminant hepatic failure. However, survival rate has not improved as expected, although the consciousness of the patient has improved frequently. In this article the present status of clinical artificial liver support and basic research of hybrid artificial liver will be discussed. Moreover, the future aspects of total artificial liver support and hepatocyte transplantation for chronic liver failure will be introduced.     

Kidney Preservation: Review of Present and Future Perspective

One of the main problems in transplant surgery is the preservation of the organ during the cold ischemic time. The interrupted blood supply triggers a cascade of biological modifications resulting in cell death, which predisposes to discharge of a large quantity of toxic metabolites at the moment of organ reperfusion. Many approaches have been studied to prevent the toxic processes. Immediately after procurement, kidneys are flushed with these solutions. Two main: techniques of organ preservation are cold static storage and hypothermic machine perfusion (HMP). Based on age and comorbidities, individuals can be generally divided into 2 groups: ideal and marginal donors. Characteristics of organs from marginal donors are associated with an increased rate of delayed graft function and primary graft nonfunction (PNF), which reduce transplant survival and increase the acute rejection risk. In the last 20 years, the United Network of Organ Sharing has reported a 170% increase in deceased donors older than 50 years of age. Techniques of perfusion have been demonstrated to play a pivotal role in graft function after transplantation. Some studies suggest that HMP may improve outcomes after transplantation.