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Biomedical subjects

S Iwatsuki

Publications and source records attributed to S Iwatsuki.

At least 163 records · Page 9Linked to original sources

Cyclosporine-steroid combination therapy in 84 cadaveric renal transplants.

Sixty-three primary and 21 retransplant cadaver kidney allografts were placed in 77 patients over a one-year period with three- to six-month follow-up. Eight primary grafts (12.7%) and six retransplants (28.6%) were lost to rejection. Patient mortality was 3.9%. There were no grafts lost and no deaths due to opportunistic infections. Renal function at 6 months after transplantation was similar in all primary transplant recipients regardless of risk factors, including advanced age, diabetes, or the need for postoperative dialysis.

Administration, Oral↗

Immunosuppression and other nonsurgical factors in the improved results of liver transplantation.

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.

Age Factors↗

Advantages of venous bypass during orthotopic transplantation of the liver.

Venous bypass restores normal hemodynamic physiology during the critical anhepatic phase of orthotopic transplantation of the liver. Its routine use in adults undergoing transplantation in Pittsburgh has resulted in lower operative blood losses, a lower frequency of postoperative renal failure, and a greater probability of survival for all but the highest risk patients. Because it allows for a longer anhepatic phase, the surgeon has the option of tailoring the native hepatectomy to the needs of the individual case, even to the point, in difficult cases, of obtaining most of the hemostasis after removal of the native liver, but before sewing in the donor organ. Selective use of bypass in children may offer similar advantages.

Evaluation Studies as Topic↗

Liver rejection and its differentiation from other causes of graft dysfunction.

Numerous causes can lead to hepatic dysfunction following orthotopic liver transplantation. The most common cause is rejection, which is usually nonpreventable. The clinical presentation, time of onset, and even treatment are variable. Other causes, such as perioperative ischemic injury, vascular thrombosis, and complications of bile duct reconstruction may be preventable with good surgical technique. Infections can also be minimized by careful adjustment of immunotherapy, avoidance overimmunosuppression, and the judicious use of antibiotics. Hepatic dysfunction following orthotopic liver transplantation requires rapid assessment and proper treatment in order to prevent serious and possibly fatal complications.

Bile Duct Diseases↗

Influence of selected patient variables and operative blood loss on six-month survival following liver transplantation.

A group of 118 adults who underwent primary, orthotopic transplantation of the liver over a 4-year period served as the subjects of a detailed examination of their ability to survive the first 6 months as a function of their preoperative condition. As a result, a scoring system was developed empirically in an attempt to separate very high-risk from relatively low-risk patients. The scoring method is based on the high degree of correlation between survival probability and various patient characteristics. It allows for additional scoring to account for the dramatic effect of operative blood loss on the eventual outcome. The curve that best describes the relationship between patient scores and survival probability is sigmoidal in shape. Many patients will have scores located on the curve between the inflection points. They represent a group whose relative risk is difficult to estimate but for whom operative blood loss or the occurrence of surgical complications may prove particularly telling.

Actuarial Analysis↗

Retransplantation of the liver.

Since the introduction of cyclosporine-prednisone for primary immunosuppression, retransplantation has become a feasible option for patients whose primary grafts are failing, which may result from primary graft nonfunction, intractable rejection, or consequent to technical complications. Although survival of patients requiring second grafts is less good than in those whose initial graft functions well, 2-year survival rates of 49% have been achieved in retransplanted patients, a record that mandates serious consideration of this approach when the primary graft begins to fail. In general, the retransplant procedure is technically easier, with less blood loss, than is the initial operation. When the reoperation is done electively, it should be done before serious clinical deterioration compromises the chances for success.

Actuarial Analysis↗

Role of liver transplantation in cancer therapy.

Fifty-four patients underwent total hepatectomy and liver replacement in the presence of a primary liver malignancy. In 13 recipients in whom the hepatic tumors were incidental to some other endstage liver disease, recurrence was not seen and 12 of the 13 patients are alive after 4 months to 15 1/2 years. In contrast, tumors recurred in 3 of every 4 patients who received liver replacement primarily because of hepatic malignancies that could not be resected by conventional techniques of subtotal hepatectomy and who lived for at least 2 months after transplantation. The most encouraging results were in patients with the fibrolamellar hepatocellular carcinomas that grow slowly and metastasize late, but even with this lesion, the recurrence rate was 57%. In future trials, additional effective anticancer therapy will be needed to improve the results of liver transplantation for primary liver malignancy, but what an improved strategy should be has not yet been defined.

Adult↗

Fungal infections in liver transplant recipients.

Sixty-two adults who underwent orthotopic liver transplantations between February 1981 and June 1983 were followed for a mean of 170 days after the operation. Twenty-six patients developed 30 episodes of significant fungal infection. Candida species and Torulopsis glabrata were responsible for 22 episodes and Aspergillus species for 6. Most fungal infections occurred in the first month after transplantation. In the first 8 weeks after transplantation, death occurred in 69% (18/26) of patients with fungal infection but in only 8% (3/36) of patients without fungal infection (P less than 0.0005). The cause of death, however, was usually multifactorial, and not solely due to the fungal infection. Fungal infections were associated with the following clinical factors: administration of preoperative steroids (P less than 0.05) and antibiotics (P less than 0.05), longer transplant operative time (P less than 0.02), longer posttransplant operative time (P less than 0.01), duration of antibiotic use after transplant surgery (P less than 0.001), and the number of steroid boluses administered to control rejection in the first 2 posttransplant months (P less than 0.01). Patients with primary biliary cirrhosis had fewer fungal infections than patients with other underlying liver diseases (P less than 0.05). A total of 41% (9/22) of Candida infections resolved, but all Aspergillus infections ended in death.

Adult↗

Clinical presentation of hepatic artery thrombosis after liver transplantation in the cyclosporine era.

Hepatic artery thrombosis is a dreadful complication of orthotopic liver transplantation. It should be suspected in cases of fulminant liver failure, delayed bile leak, or intermittent sepsis of unknown cause after liver transplantation. Accurate diagnosis is assisted by ultrasound and computerized tomography scans, but usually requires arteriography. Prompt retransplantation is required in most of the cases.

Adult↗

Angiography of liver transplantation patients.

Over 45 months, 119 angiographic examinations were performed in 95 patients prior to liver transplantation, and 53 examinations in 44 patients after transplantation. Transplantation feasibility was influenced by patency of the portal vein and inferior vena cava. Selective arterial portography, wedged hepatic venography, and transhepatic portography were used to assess the portal vein if sonography or computed tomography was inconclusive. Major indications for angiography after transplantation included early liver failure, sepsis, unexplained elevation of liver enzyme levels, and delayed bile leakage, all of which may be due to hepatic artery thrombosis. Other indications included gastrointestinal tract bleeding, hemobilia, and evaluation of portal vein patency in patients with chronic rejection who were being considered for retransplantation. Normal radiographic features of hepatic artery and portal vein reconstruction are demonstrated. Complications diagnosed using results of angiography included hepatic artery or portal vein stenoses and thromboses and pancreaticoduodenal aneurysms. Intrahepatic arterial narrowing, attenuation, slow flow, and poor filling were seen in five patients with rejection.

Adolescent↗

Cholangiography and interventional biliary radiology in adult liver transplantation.

Radiographic assessment of the biliary tract is often essential in patients who have undergone liver transplantation. T- or straight-tube cholangiography, percutaneous transhepatic cholangiography, and endoscopic retrograde cholangiography all may be used. A total of 264 cholangiograms in 79 adult liver transplant patients (96 transplants) was reviewed. Normal radiographic features of biliary reconstructive procedures, including choledochocholedochostomy and choledochojejunostomy, are demonstrated. Complications diagnosed by cholangiography included obstruction, bile leaks, and tube problems, seen in eight, 24, and 12 transplants respectively. Stretching and incomplete filling of intrahepatic biliary ducts were frequently noted and may be associated with rejection and other conditions. Transhepatic biliary drainage, balloon catheter dilatation of strictures, replacement of dislodged T-tubes, and restoring patency of obstructed T-tubes using interventional radiologic techniques were important in avoiding complications and additional surgery in selected patients.

Adolescent↗