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R J Porte

Publications and source records attributed to R J Porte.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prognostic factors for long-term actual patient survival after orthotopic liver transplantation in children.

BACKGROUND: Orthotopic liver transplantation has become the treatment of choice for children with end-stage liver disease. Although results have improved the last decades, still a considerable number of children die after transplantation. The aim of this study was to analyze long-term actual survival and to identify prognostic factors for such survival rates. METHODS: A consecutive series of 66 children receiving transplants who had or could have had a follow-up of at least 5 years was retrospectively analyzed. Actual survival and prognostic factors in relation to patient, donor, and operation related variables were assessed after multivariate analysis. RESULTS: Actual 1-, 3-, and 5-year patient survival was 86%, 79%, and 73%, respectively. A high Child-Pugh (C-P) score or C-P class C, high donor age, high blood loss index, and retransplantation were predictive factors for actual patient survival. A high blood loss index was correlated with biliary atresia, low recipient age and weight, and with previous upper abdominal operations. The duration of stay of the donor at the intensive care unit (ICU) was a predictive factor for retransplantation. CONCLUSIONS: Children with diseases eligible for liver transplantation should be seen early in the course of their disease in a transplantation center. All possible measures should be taken during the transplantation procedure to keep the blood loss at a minimum. Children with biliary atresia deserve special attention in this respect. The choice of donors has implications for survival.

Adolescent↗
PubMed2000

Aprotinin and transfusion requirements in orthotopic liver transplantation: a multicentre randomised double-blind study. EMSALT Study Group.

BACKGROUND: Intraoperative hyperfibrinolysis contributes to bleeding during adult orthotopic liver transplantation. We aimed to find out whether aprotinin, a potent antifibrinolytic agent, reduces blood loss and transfusion requirements. METHODS: We did a randomised, double-blind, placebo-controlled trial in which six liver-transplant centres participated. Patients undergoing primary liver transplantation were randomly assigned intraoperative high-dose aprotinin, regular-dose aprotinin, or placebo. Primary endpoints were intraoperative blood loss and transfusion requirements. Secondary endpoints were perioperative fluid requirements, postoperative blood transfusions, complications, and mortality. FINDINGS: 137 patients received high-dose aprotinin (n=46), regular-dose aprotinin (n=43), or placebo (n=48). Intraoperative blood loss was significantly lower in the aprotinin-treated patients, with a reduction of 60% in the high-dose group and 44% in the regular-dose group, compared with the placebo group (p=0.03). Total amount of red blood cell (homologous and autologous) transfusion requirements was 37% lower in the high-dose group and 20% lower in the regular-dose group, than in the placebo group (p=0.02). Thromboembolic events occurred in two patients in the high-dose group, none in the regular-dose group, and in two patients in the placebo group (p=0.39). Mortality at 30 days did not differ between the three groups (6.5%, 4.7%, and 8.3%; p=0.79). INTERPRETATION: Intraoperative use of aprotinin in adult patients undergoing orthotopic liver transplantation significantly reduces blood-transfusion requirements and should be routinely used in patients without contraindications.

Adolescent↗
PubMed2000

Platelets induce sinusoidal endothelial cell apoptosis upon reperfusion of the cold ischemic rat liver.

BACKGROUND & AIMS: Sinusoidal endothelial cell (SEC) apoptosis is a central feature of reperfusion injury in liver transplantation. Platelet sequestration occurs after transplantation with possible deleterious effects. We tested the hypothesis that platelets mediate SEC apoptosis. METHODS: Livers were perfused after 24 hours of cold preservation in University of Wisconsin solution in an isolated perfused rat liver model. The perfusate contained isolated syngeneic red blood cells and purified platelets. Effects of inhibiting platelet adhesion on SEC apoptosis was tested using sialyl Lewis-X oligosaccharide (sLe(x)), a natural ligand of selectin adhesion molecules. Reperfusion injury was assessed by established markers of injury. Apoptosis was determined by TUNEL and electron microscopy. RESULTS: A third of the circulating platelets was rapidly sequestered in the liver after reperfusion. This was associated with increased graft injury. Single platelets were adherent to sinusoidal lining without morphological or dynamic evidence of impairment of microcirculation. TUNEL staining revealed a 6-fold increase in the number of apoptotic SECs at 1 hour of reperfusion. No hepatocyte death or evidence of necrosis was detected up to 3 hours of reperfusion. Addition of sLe(x) inhibited adhesion and significantly reduced SEC apoptosis. CONCLUSIONS: Platelets cause SEC apoptosis upon reperfusion of liver grafts. Prevention of adhesion is protective.

Animals↗
PubMed2000

Early vascular complications after pediatric liver transplantation.

Vascular complications have a detrimental effect on the outcome after liver transplantation. Most studies focus exclusively on hepatic artery thrombosis (HAT). The current study analyzed the incidence, consequences, and risk factors for HAT, portal vein thrombosis (PVT), and venous outflow tract obstruction (VOTO) in a consecutive series of 157 pediatric liver transplantations. The overall incidence of vascular complications was 21%. The incidences of HAT, PVT, and VOTO were 10%, 4%, and 6%, respectively. Patient survival after PVT and VOTO and graft survival after HAT and PVT were less compared with survival of grafts without vascular complications. To identify risk factors for vascular complications, factors related to recipient, donor, and surgical techniques were analyzed. A low donor-recipient (D/R) age ratio, long surgical time, and use of the proper hepatic artery of the recipient for arterial reconstruction were risk factors for HAT. Young age, low weight, segmental grafts, and piggyback technique were risk factors for PVT. Fulminant hepatic failure, high D/R age and weight ratios, and use of segmental grafts were related to VOTO. Vascular complications, which occurred in 21% of the pediatric liver transplantations, had a significant impact on patient and graft survival. Size disparity between donor and recipient was an important risk factor for vascular complications, especially in the case of transplantation of segmental grafts. Patient and graft survival might improve by avoiding the identified risk factors.

Adolescent↗
PubMed2000

Blood loss in orthotopic liver transplantation: a retrospective analysis of transfusion requirements and the effects of autotransfusion of cell saver blood in 164 consecutive patients.

Liver transplantation is associated with excessive blood loss. In order to identify factors influencing blood loss and to provide a basis for a pilot study to evaluate recombinant activated factor VII as a haemostatic agent, a retrospective study was performed in 164 consecutive patients with cholestatic or noncholestatic liver disease, who underwent orthotopic liver transplantation at a single centre between 1989 and 1996. Transfusion of allogeneic and autologous (cell saver) blood was used as a measurement of blood loss. Transfusion requirements were associated with age, gender, primary disease, Child-Pugh classification, serum levels of activated partial thromboplastin time, antithrombin III, urea and creatinine, platelet number, year of transplantation, length of cold ischaemia time and autologous blood transfusion. Of these variables, Child-Pugh classification (P = 0.001), urea (P = 0.0007), year of transplantation (P = 0.002), cold ischaemia time (P = 0.01) and autologous blood transfusion (P < 0.0001) were independent predictors of transfusion requirements by multivariate analysis. Thus, blood loss and transfusion requirements depend primarily on the severity of liver disease, quality of the donor liver, experience of the transplantation team and use of autologous (cell saver) blood transfusion. These findings emphasize the need for appropriate drug therapy and a critical reappraisal of current transfusion policy.

Adult↗
PubMed2000

Blunted rise in platelet count in critically ill patients is associated with worse outcome.

OBJECTIVE: To test the hypothesis that a low rate of change of platelet counts (PCs) after admission to the intensive care unit (ICU) is associated with mortality. Low PCs are known to be associated with disease severity in critically ill patients, but the relevance of time-dependent changes of PCs has not been investigated. DESIGN: Retrospective study. SETTING: A 12-bed surgical ICU of a university hospital. PATIENTS: All adult patients admitted to the ICU for at least 4 days during a 7-yr period. INTERVENTIONS: At admission, Acute Physiology and Chronic Health Evaluation scores were calculated. PCs and leukocyte counts were analyzed from admission to day 10. The daily rise of the PCs (deltaPC/deltat from day 2 to day 10 was calculated. Rates for 30-day mortality as well as hospital mortality were determined. MEASUREMENTS AND MAIN RESULTS: A total of 1,415 admissions were studied. Median PCs (interquartile range) initially decreased and subsequently increased, with a higher PC in 1,203 survivors than in 212 nonsurvivors from day 2 onward (302 [range,181-438] x 10(3)/mm3/day vs. 129 [range, 62-228] x 10(3)/mm3 at day 10; p < 0.001). After stratification of patients per type of surgery, within each group PC was also higher in survivors. Mean deltaPC/deltat was more than five times higher in survivors compared with nonsurvivors: 30 +/- 46 x 10(3)/mm3/day vs. 6 +/- 28 x 10(3)/mm3/day (p < 0.001). The area under the receiving operating characteristic curve of deltaPC/deltat for 30-day survival was 0.743 compared with 0.728 for the Acute Physiology and Chronic Health Evaluation. Leukocyte counts showed marginal differences between nonsurvivors and survivors. CONCLUSION: A blunted or absent rise in PCs in critically ill patients is associated with increased mortality. deltaPC/deltat is a readily available and simple parameter to improve assessment of critically ill patients.

APACHE↗
PubMed1998

Long-term graft survival after liver transplantation in the UW era: late effects of cold ischemia and primary dysfunction. European Multicentre Study Group.

The use of University of Wisconsin (UW) solution in liver transplantation (LTX) has significantly prolonged preservation times and facilitated semielective transplant procedures. Despite this advantage potential risk factors related to the donor, recipient, or cold storage method will persist in the UW era and detrimental effects will be reflected by primary dysfunction (PDF) after LTX. Concern has been voiced about the maximum period of UW preservation in LTX and various cold ischemia times (CIT) are mentioned. To evaluate the effect of UW solution in LTX, a prospective European multicenter study was initiated in 1988 and short-term results have been reported previously. This report focuses on the long-term effects and survival of prolonged preservation with UW solution and primary function after LTX. Three hundred and fifteen LTXs were performed in 288 patients in participating European centers. Complete follow up of at least 6 years was available for 296 grafts in 277 patients. Effects of donor, preservation, and recipient risk factors on PDF including primary non-function (PNF) and initial poor function (IPF) were evaluated. Next, the effect of risk factors on graft survival (GS) was analyzed including the long-term impact of PNF and IPF using multivariate analyses and the Kaplan-Meyer method. PDF occurred in 15.2% (45/296) with PNF in 7.8% and IPF in 7.4%. Patients with IPF had a 34% lower GS at 3 months those with immediate function (IF; 58% vs 91%; P < 0.001). This difference persisted up to 6 years for patients with IPF with a 39% GS vs 72% after IF (P < 0.001). Median CIT was significantly longer in grafts with PNF compared to IPF or IF (P = 0.03). Long-term GS, however, was significantly influenced at a lower CIT threshold with a 6-year GS for CIT < or = 16 h of 67%, compared to a CIT > 16 h of 51% (P = 0.02). Other independent risk factors for the 6-year survival rate were re-LTX, ABO incompatibility, and recipient diagnosis of acute hepatic failure. In conclusion, liver patients with PNF, but not with IPF, have a significantly lower CIT. IPF is associated with a significantly lower 3 month GS compared to IF, but this difference of 34% does not further increase during a 6-year follow up. Although a short term follow up (3 months) shows that with UW solution CIT up to 18 h has no adverse effect on GS, the 6-year data clearyl suggest that CIT should be kept to less than < 16 h to avoid tetrimental effects on lang-term GS after LTX.

Adenosine↗
PubMed1996

False aneurysm of a hepatic artery branch and a recurrent subphrenic abscess: two unusual complications after laparoscopic cholecystectomy.

Although laparoscopic cholecystectomy has become a safe and effective alternative for open cholecystectomy as treatment of symptomatic cholelithiasis, it may be followed by different complications. Two cases are presented with unusual complications after laparoscopic cholecystectomy. One patient was readmitted 11 days after laparoscopic cholecystectomy with severe upper abdominal pain and a false aneurysm of a branch of the right hepatic artery. The other patient developed a recurrent subphrenic abscess 10 months after the initial operation, which eventually was shown to be caused by a lost gallstone. Although these are rare complications of laparoscopic cholecystectomy, they should be recognized as potential causes of recurrent abdominal pain, even months after the procedure.

Aged↗
PubMed1996

Laparoscopic versus open cholecystectomy: a prospective matched-cohort study.

To compare the results of laparoscopic cholecystectomy (LC) and open cholecystectomy (OC) for symptomatic cholelithiasis in elective surgery we performed a prospective matched-cohort study. Hundred consecutive patients who underwent LC in the period Sept. 1990-June 1992, and 100 patients who were age and sex matched and underwent an elective OC in the foregoing two years (1989-1990) were studied. The median operation time for LC (75, 40-180 min) was significantly longer than for OC (55, 20-155 min; p <0.001). Postoperative hospitalization was significantly shorter after LC (3, 1-16 days), compared with OC (7, 4-22 days; p <0.001). Conversion of LC to OC occurred in 12 (12%) patients initially scheduled to undergo LC. Complications occurred in 5 patients (5%) after LC and in 5 patients (5%) after OC. The calculated expenses (operation and postoperative hospitalization, 3rd class) were approximately fl. 3740,- for LC (excl. investments for pieces of apparatus) and fl. 6725,- for OC. This study demonstrates that LC can be performed safely with the number of complications comparable to those for OC. Bile duct injury is a serious potential threat. The main advantages of LC are the minimal trauma, with more rapid recovery. Insurers seem to benefit from reduced postoperative disability and earlier discharge.

Adolescent↗
PubMed1994

Role of the donor liver in the origin of platelet disorders and hyperfibrinolysis in liver transplantation.

We investigated the role of the donor liver in the origin of platelet disorders and hemostatic defects in liver transplantation. Eighteen pigs received an orthotopic or a heterotopic, auxiliary liver graft. Liver biopsies were taken for electron microscopic studies 5-10 min after reperfusion in nine animals. Blood samples were taken from the first hepatic outflow and from the systemic circulation before and 5 min after graft recirculation. Electron microscopy did not show any evidence of microthrombi or platelet aggregation in the graft, either after orthotopic liver transplantation or after heterotopic liver transplantation. Most blood platelets, which were lying free in the sinusoids, showed cell processes and many seemed to have lost their granulae, suggesting a degree of platelet activation. There were also signs of phagocytosis of platelets by the Kupffer cells. In the hepatic outflow, platelet count was significantly lower (p < 0.05) and fibrinolytic activity significantly higher (p < 0.01), than systemic post-reperfusion values. There were no important changes in the coagulation parameters. No significant changes were found between the effects on hemostasis of orthotopic and auxiliary graft reperfusion. In the second part of the study evidence for platelet activation was found after graft reperfusion in human liver transplantation. Plasma levels of platelet factor-4 and beta-thromboglobulin increased significantly after graft reperfusion. These studies suggest that platelet disorders and increased fibrinolytic activity are the major components of the hemostatic defect after graft recirculation in liver transplantation. Sequestration of platelets in the graft is probably due to the accumulation of (activated and degranulated) platelets in the sinusoids and phagocytosis by Kupffer cells.

Animals↗
PubMed1994

The effects of long-term graft preservation on intraoperative hemostatic changes in liver transplantation. A comparison between orthotopic and heterotopic transplantation in the pig.

UNLABELLED: We compared hemostatic changes during OLT and HLT after various periods of graft storage, to investigate whether the host liver in HLT protects the recipient from hemostatic deterioration induced by severe graft storage damage. In particular, the mechanism of fibrinolytic deterioration was investigated. The effect of prostaglandin E1 (PGE1) on these parameters was also studied. MATERIAL AND METHODS: 69 pigs underwent either OLT (N = 32) or HLT (N = 37) with a graft stored for 2 hr (N = 31), 24 hr (N = 16), 48 hr (N = 7), or 72 hr (N = 15). PGE1 was given intravenously to both donor and recipient animals and was added to the preservation and flushing solutions. Fibrinolysis (euglobulin clot lysis time, t-PA activity and alpha 2-antiplasmin) and coagulation parameters (activated partial thromboplasmin time, prothrombin time, fibrinogen and platelet count) were measured at several intervals during transplantation. STATISTICS: Univariate non-parametric tests were used for analysis of coagulation and fibrinolysis parameters. For the three main variables- i.e., the type of transplantation, the use of PGE1, and the preservation time, multiple regression analysis was performed. RESULTS: Fibrinolytic activity increased during the anhepatic period of OLT. Graft reperfusion was followed by a rise in t-PA in both OLT and HLT. In HLT, t-PA quickly returned to normal, whereas a continuous increase was found in OLT. The coagulation parameters, in turn, remained unchanged during the anhepatic period and deteriorated in OLT compared to HLT. The duration of graft storage was directly related to the severity of the hemostatic changes, although this effect was more apparent in OLT than in HLT. CONCLUSIONS: Changes in hemostasis are more pronounced in OLT than in HLT. This suggests that the host liver protects the recipient from the effects of graft storage damage, even after long preservation times. Early postreperfusion fibrinolytic activity was presumably due to t-PA release from the graft both in OLT and HLT. The further rise t-PA in OLT might be caused by the release of cytokines from the graft, that subsequently evoke endothelial t-PA release. In HLT, t-PA and cytokines may be cleared by the native liver. No positive or negative effect of PGE1 on coagulation or fibrinolysis parameters was noticed.

Alprostadil↗
PubMed1993

Intravascular coagulation in liver transplantation--is it present or not? A comparison between orthotopic and heterotopic liver transplantation.

UNLABELLED: It is still not clear whether disseminated intravascular coagulation (DIC) contributes to the hemostatic disturbances in orthotopic liver transplantation (OLT). Theoretically the lack of hepatic clearance of procoagulant factors during the anhepatic period and the release of thromboplastic material from the graft might trigger DIC. During heterotopic liver transplantation (HLT) the host liver is left in situ and procoagulant factors may still be cleared; DIC, if present, may not occur until after reperfusion. The aim of the present study was to gain more insight into the underlying mechanism of the coagulation changes during liver transplantation by comparison of OLT and HLT. Thrombin-antithrombin-III complexes (TAT), and indicator of thrombin generation, fibrin degradation products (FbDP) and routine clotting times were assayed in 12 OLTs, 18 HLTs and in a control group of 10 partial hepatic resections (PHR). TAT increased dramatically after reperfusion to 136 micrograms/l in OLT and to 94 micrograms/l in HLT (p n.s.). In contrast, FbDP levels increased only in OLT, to a maximum of 13.8 micrograms/ml. Routine clotting times changed mildly and similarly in both OLT and HLT. CONCLUSIONS: Graft reperfusion triggers excessive thrombin formation, but there are no other signs of subsequent DIC. Any thrombin formed is probably rapidly inhibited by antithrombin-III. The rise in FbDP during OLT is the result of increased fibrinolysis, which occurred only in OLT and not in HLT.

Antithrombin III↗
PubMed1993

Coagulation and fibrinolysis in orthotopic liver transplantation: current views and insights.

Bleeding in OLT is related to two different mechanisms. There is no doubt that the extensive surgical trauma plays a critical role in the origin of serious bleeding. However, this bleeding can be aggravated by defects in the hemostasis system. Hemostasis defects can be divided into those present before the operation and secondary to the underlying liver disease and those originating during the operation. Intraoperative defects can be classified according to the three main systems of hemostasis: coagulation, fibrinolysis, and platelet function. Serious problems with coagulation are clearly related to the quality of the graft and are less frequent now since better graft preservation techniques have been introduced. Adequate intraoperative monitoring and substitution therapy with plasma products is also important in controlling coagulation defects. However, problems resulting from hyperfibrinolysis seem to be of clinical importance, especially during the anhepatic stage and after graft reperfusion. While lack of hepatic clearance seems to be an important cause of t-PA increase during the anhepatic stage, enhanced release may be important for the rise after graft reperfusion. There is also evidence that decreased platelet numbers and function, especially after graft reperfusion, play a role. The clinical relevance of this finding remains to be elucidated. Finally, it has recently been demonstrated that antifibrinolytic agents may reduce intraoperative blood loss. However, the effect of aprotinin and other antifibrinolytic agents has still to be confirmed by randomized clinical studies. Future scientific research should focus on the mechanisms underlying the hemostasis defects. It can be expected that these efforts may finally result in a further reduction in the usage of blood products during liver transplantation.

Antifibrinolytic Agents↗
PubMed1991

A comparative study on changes in hemostasis in orthotopic and auxiliary liver transplantation in pigs.

We compared blood loss and hemostasis in pigs which had undergone either orthotopic liver transplantation (OLT) (group A, n = 12) or auxiliary heterotopic partial liver transplantation (APLT) (group B, n = 11). Blood samples were taken at regular intervals during and after the operations. In both groups, nine animals survived longer than 24 h and data from these animals were used for analysis. Median (range) intraoperative blood loss was 825 ml (250-1500 ml) in OLT and 425 ml (300-750) in APLT (P less than 0.01). Routine clotting times, as the activated partial thromboplastin time, prothrombin time and thrombin time, showed no major intraoperative changes in either group. Fibrinogen levels decreased in both groups, but no significant difference was found between the two groups. The only significant difference between group A and B was a more sustained increase in fibrinolytic activity after graft recirculation in group A. Postoperatively, restoration of fibrinogen, antithrombin-III and alpha 2-antiplasmin levels was slightly faster in group B, resulting in significantly higher levels during the first day. We conclude that, in this animal model, APLT is associated with significantly lower blood loss and less severe fibrinolytic activity, than OLT. This difference might result from the lack of an anhepatic period and the reduced surgical trauma in auxiliary heterotopic liver transplantation.

Animals↗