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Biomedical subjects

M Knoop

Publications and source records attributed to M Knoop.

At least 73 records · Page 4Linked to original sources
PubMed1994

Does concommitant splenectomy raise the mortality of liver transplant recipients?

Within a 17-month period, 130 orthotopic liver transplantations were performed in our hospital. Nine of these were retransplantations and were not included in our analysis. In the remaining 121 patients, splenectomy was performed in 34 patients, either synchronously with the transplant procedure (27 patients) or in the postoperative period (7 patients). Indications for splenectomy were lienalis-steal syndrome in 15 patients and hypersplenism in 15 cases. The number of rejection episodes was fairly equal in both groups (splenectomized vs. non-splenectomized, 61.7% vs. 63.9%, respectively). There was a marked difference in the frequency of infectious episodes (61.7% vs. 25.3%) that resulted in a decreased survival rate (77.5% vs. 95.4%) for splenectomized patients. Therefore, we recommend splenectomy only for very selected patients and investigate the banding of the splenic artery as an alternative.

Female↗
PubMed1994

[Therapy of unilobar Caroli syndrome by liver resection].

Caroli's disease is characterized by uni- or bilobar cystic enlargement of the intrahepatic biliary tract. Clinical symptoms include recurrent cholangitis, right upper quadrant abdominal pain and jaundice. The diagnosis is usually established preoperatively based on abdominal ultrasound, computertomography and ERCP. Eight patients suffering from unilobar Caroli's disease underwent liver resection during a period of six years. The postoperative course was uneventful, and after a median follow-up of 39.6 months in one case only a temporary jaundice occurred. Liver resection is the method of choice for Caroli's syndrome when feasible. Apart from the curative intention liver resection represents also a prophylactic method since the risk of malignant transformation to cholangiocellular carcinoma in the cystic walls after draining procedures is considerably high. For diffuse spread of Caroli's disease in the liver orthotopic liver transplantation has emerged as therapeutic option.

Adult↗
PubMed1994

Treatment of the Budd-Chiari syndrome with orthotopic liver transplantation and long-term anticoagulation.

The Budd-Chiari syndrome (BCS) with hepatic vein occlusion is a rare disorder that can effectively be treated with orthotopic liver transplantation. In this retrospective analysis we report on 7 patients who received 9 liver grafts for terminal BCS. One patient died after 4 months due to cytomegalovirus-pneumonia. The actuarial survival rate is 85.7% compared to more than 90% in all other 376 patients transplanted between September 1988 and April 1993 at our institution. Anticoagulation management consisted of early postoperative intravenous heparin and continuation with dicoumarin. One patient with thrombocytosis received hydroxyurea. Under this regimen one postoperative hemorrhage requiring laparotomy was observed. Discontinuation of oral anticoagulation due to gastrointestinal bleeding caused hepatic artery and portal vein thrombosis in 1 patient who had to be retransplanted. One recurrence requiring retransplantation as well was due to an insufficient dicoumarin intake. In conclusion, terminal BCS represents a good indication for orthotopic liver transplantation with a closely-monitored anticoagulation to avoid such adverse side effects as thrombosis and hemorrhage.

Adolescent↗
PubMed1993

[Liver transplantation as a routine procedure? Indications and results in 270 patients].

AIM: To represent the current state of the art of orthotopic liver transplantation (OLT). The constantly expanding spectrum of indications are discussed in detail, and the specific risks of the individual indications considered. Major points discussed: On the basis of the authors' own results obtained at the Rudolf Virchow Hospital, University of Berlin, the current survival rates following orthotopic liver transplantation are shown. In addition to established indications for liver transplantation (primary biliary cirrhosis, primary sclerosing cholangitis, acute hepatic failure, various metabolic diseases, small hepatocellular carcinomas and a number of posthepatic cirrhoses) the indication and results of liver transplantation in HbsAg-positive and alcoholic cirrhosis are presented in detail. In contrast to reports in the Anglo-American literature, the incidence and severity of graft re-infections with the hepatitis virus was appreciably reduced through the use of anti-HBs hyperimmunoglobulin preparations in HBsAg-positive cirrhotics. The results obtained were comparable with those achieved for other indications.

Follow-Up Studies↗
PubMed1993

[Experiences with simultaneous exploration of the bile ducts in surgical therapy of gallstone ileus].

During the last 16 years, 14 patients with a gallstone ileus were treated at our institution. In 11 cases we performed in addition to the enterolithotomy, a cholecystectomy and a resection of the fistula as one-stage repair. Despite the high average age (74.3 years) and the presence of various other serious morbidity in our patient population, we only observed a hospital mortality of 7.1%. Serious postoperative complications, such as sepsis and/or shock were not observed. Utilizing today's advanced anesthesia and proper intensive-care therapy, as well as early operative intervention and safe surgical technique, we believe that enterolithotomy with cholecystectomy and fistula resection as one-stage operation, should primarily be considered before performing enterolithotomy alone.

Aged↗
PubMed1992

Multivisceral cluster transplantation in the rat.

Transplantation of multivisceral grafts has evolved recently as a new therapeutic modality for hepatopancreatobiliary malignancies. The mutual interactions between the liver, pancreas, small bowel and the recipient organism after cluster grafting are not clearly understood and deserve further experimental evaluation. We present a technique for combined hepatopancreaticoduodenal cluster transplantation in the rat. The cluster grafts consisted of a pancreaticoduodenal graft and an orthotopic arterialized liver graft. A separate arterial anastomosis of the liver and a bile duct anastomosis were not necessary. Bile and exocrine pancreas secretions drained over the duodenal conduit of the graft into the recipients jejunum via an end-to-side anastomosis.

Animals↗
PubMed1992

Quadruple immunosuppression including a new IL-2-receptor antibody and the incidence of infections after liver transplantation.

Immunosuppression is a primary concern after orthotopic liver transplantation (OLT). On the one hand, the graft is at jeopardy through acute or chronic rejection, and on the other, immunosuppression and antirejection therapy increase the risk of infectious complications. Effective immunosuppression therefore should prevent rejections without leading to a high rate of infections, bearing in mind the fact that infections and infection-related complications are the most frequent causes of early death after liver transplantation. With more specific immunosuppression the infectious complications can potentially be minimized. Antithymocyte globulin (ATG) and the first monoclonal antibody OKT3 immunosuppression are non-specific. The replacement of these antibodies in a quadruple immunosuppressive regimen with the new monoclonal IL-2R antibody BT 563 probably reduces the early infection rate. We report on our first experience with BT 563. The incidence of infection was compared with a historical control group with ATG.

Adult↗
PubMed1992

The effect of a new immunosuppressive drug, brequinar sodium, on heart, liver, and kidney allograft rejection in the rat.

Brequinar sodium (BQR) prevents cell proliferation by virtue of its inhibition of de novo pyrimidine biosynthesis. BQR is capable of inhibiting immune responses in vitro and is effective in suppressing the development of contact sensitivity and adjuvant arthritis in rodent models. Based on the antiproliferative and immunosuppressive capacity of BQR, we have evaluated the efficacy of BQR in preventing allograft rejection utilizing experimental models of heterotopic heart and kidney and orthotopic liver transplantation in an MHC and non-MHC mismatched ACI----LEW rat strain combination. The immunosuppressive activity of BQR is illustrated by its ability to inhibit the development of delayed-type hypersensitivity to DNFB in mice. When BQR was administered orally throughout the sensitization and elicitation phases of the DNFB contact sensitivity response, it was found to be a potent immunosuppressant with an ED50 value of 0.5 mg/kg. This immunosuppressive activity is also seen in vitro, where BQR is capable of inhibiting the mixed lymphocyte response between allogeneic ACI and LEW rat strains with an IC50 of 150 ng/ml. The immunosuppressive activity of BQR is highly effective in prolonging heart, liver, and kidney allograft survival in the rat. Cardiac allografts are not rejected during the period of drug treatment at dosage levels of 12 to 24 mg/kg orally three times weekly. The grafts survive until the drug is discontinued (30 days posttransplantation), and the grafts are then rejected approximately 14 days later. Liver and kidney allografts are permanently accepted by approximately 50 to 90% of the recipient rats following 30 days of treatment with BQR at 12 mg/kg. The tolerance that is induced to the liver grafts extends in the majority of animals to greater than 250 days and is specific for the donor ACI strain. Challenge of long-term liver graft survivors with donor cardiac grafts is associated with permanent survival of donor, but not third-party, heart grafts. Combination therapy consisting of suboptimal doses of BQR and CsA demonstrates that the combination of these two immunosuppressive drugs results in an increased efficacy in prolonging graft survival. The results of these allograft experiments demonstrate that this new immunosuppressive agent is highly effective in preventing allograft rejection in the rat. The antiproliferative activity of BQR is effective for inhibiting T-lymphocyte-mediated immune responses, and Brequinar sodium should be an important addition to a polytherapeutic approach in the treatment of organ graft rejection.

Animals↗
PubMed1991

A technique for hepatopancreaticoduodenal cluster transplantation in the rat.

A new technique for combined hepatopancreaticoduodenal transplantation in the rat is described. The composite cluster graft consists of an orthotopic arterialized liver graft in anatomical continuity with the pancreaticoduodenal part that is placed heterotopically into the recipient. A separate arterial anastomosis of the liver and a bile duct anastomosis are not necessary, since these structures are left intact in the hepatoduodenal ligament. Bile and exocrine pancreas secretions drain over the duodenal conduit of the graft into the recipient jejunum via an end-to-side anastomosis. This model adds a new transplantation technique to existing microsurgical models.

Animals↗
PubMed1991

Apoptosis in pancreatic allograft rejection--ultrastructural observations.

Transplantation of pancreaticoduodenal allografts in the PVG.RT1c----PVG.RT1u high responder rat strain combination led to the evolution of haemorrhagic pancreatic necrosis over a rejection course of 8d. A cellular infiltrate consisting mainly of monocytes and macrophages was detectable in the stroma while acinar cells showed degranulation and a progressive decrease in number. From day 4 on apoptotic bodies could be identified ultrastructurally within the exocrine tissue. Apoptosis during pancreas rejection, previously undescribed, contributes to acinar cell loss after transplantation in this model.

Animals↗