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M Pouyet

Publications and source records attributed to M Pouyet.

At least 19 recordsLinked to original sources
PubMed2001

[Hemodynamic tolerance and rapid hypertrophy of a hepatic graft corresponding to less than 30% of the ideal mass in pigs].

BACKGROUND AND OBJECTIVE: Evaluation of a new pig liver transplantation technique for survival and hypertrophy of a small-sized graft by providing adapted and controlled venous portal flow. MATERIAL AND METHODS: [corrected] Twenty Large-White pigs underwent heterotopic liver transplantation after a mesocaval shunt and ligation of the superior mesenteric vein downstream from the shunt. The donor-to-recipient weight ratio was below 30%. Furthermore, recipient's biliary duct and portal vein into the hilum were tied. In a control group, no mesocaval shunt was performed and the graft received the entire splanchnic venous flow. RESULTS: The mesocaval shunt provided diversion of 60% of the splanchnic blood flow. The median survival of study pigs was 39 days (range: 8-98). Median serum bilirubin levels at 1 week were 12 micromol/L (range: 4-59). At autopsy, graft weight was increased to 2.7 times the initial weight and histological findings were normal. In the control group, all pigs died quickly from acute splanchnic congestion. CONCLUSION: In a model of heterotopic liver transplantation using small-sized grafts, complete diversion of mesenteric blood flow through a mesocaval shunt resulted in hemodynamic tolerance and hypertrophy of a graft corresponding to less than 30% of the ideal mass.

Anastomosis, Surgical↗
PubMed1997

Pilot study of the combination of interferon alfa and ribavirin as therapy of recurrent hepatitis C after liver transplantation.

Recurrent hepatitis C virus (HCV) in liver transplant patients is a major cause of graft loss, liver failure, and need for retransplantation. The results available to date with the use of interferon alfa (IFN-alpha) in the treatment of recurrent HCV in liver transplant patients have been disappointing. The aim of this study was to evaluate the efficacy and clinical utility of post-transplant combination therapy with IFNalpha2b (3 million units 3 times weekly) and oral ribavirin (1,200 mg/d) for a duration of 6 months, followed by maintenance with ribavirin alone for an additional 6 months. Twenty-one liver transplant recipients with recurrent hepatitis C infection (HCV-RNA-positive; active hepatitis without rejection on biopsy) were enrolled in this study. Pretreatment serum alanine transaminase (ALT) levels were at least two times the upper limit of normal. Before treatment, all patients were HCV-RNA-positive and mean HCV-RNA titers were 125 million genome-equivalents/mL. Mean pretreatment histological score was 6.3 +/- 2. After 6 months of combination therapy, all 21 patients had normal ALTs. Ten patients (48%) cleared HCV-RNA from their serum, as assessed by polymerase chain reaction (PCR), and HCV-RNA levels decreased significantly in the others (P = .0001). Improvement in histological score was seen in all patients after combination therapy (P = .0013). During maintenance ribavirin monotherapy, ALT remained normal in all but 1 of the 18 patients who tolerated therapy. HCV-RNA reappeared in 5 patients, but HCV-RNA levels did not return to pretreatment levels (P = .0004). Comparison of pretreatment and postribavirin monotherapy liver biopsies revealed improvement in all but 1 of the 18 patients who tolerated ribavirin (P = .0002). Side effects were restricted to anemia, which necessitated cessation of ribavirin therapy in 3 patients. No patient experienced graft rejection during the study period. These results are significantly better than those reported with IFN-alpha monotherapy. Most importantly, there was a complete absence of graft rejection. These results suggest that the combination of IFN-alpha and ribavirin is effective in reducing HCV-RNA levels and ameliorating hepatocellular injury in recurrent HCV after liver transplantation, and that maintenance therapy with ribavirin monotherapy can maintain the biochemical and histological response.

Adult↗
PubMed1997

The isolated perfused porcine liver: assessment of viability during and after six hours of perfusion.

Isolated liver perfusion was developed for the study of liver physiology and preservation. The recent development of new perfusion devices and appropriate liver preservation solutions prompted us to reconsider liver perfusion for the specific purpose of evaluating viability in terms of biochemical changes, paying special attention to modifications in the histological ultrastructure. Twenty-two isolated pig livers were perfused with autologous blood. Arterio-portal perfusions were carried out using an extracorporeal perfusion circuit with a hollow fibre membrane oxygenator. Four groups of pig livers were studied using three different liver flushing solutions [Ringer's lactate, ELOHES, and University of Wisconsin (UW)] and two different oxygenation modalities. Liver function tests and histological studies were done. Our results revealed that a high partial oxygen pressure (PO2) level was deleterious to the ultrastructural elements of hepatocytes, in particular to the mitochondria. It was also associated with deficient metabolic performance, i.e., poor bile production and lack of aerobic metabolism. Normal blood gas values could be obtained with the use of air for liver oxygenation. Flushing of the liver with Ringer's lactate or a macromolecular solution such as ELOHES was associated with severe liver cell injuries, as reflected by a marked rise in liver enzymes and histological lesions. Satisfactory results were obtained when UW solution was used for liver harvesting. We conclude that an appropriate liver preservation solution, normal blood gas values, and normal physiological arterio-portal pressure and blood flow are essential for appropriate liver function with preservation of liver architecture and of hepatocyte ultrastructures. Total bilirubin in bile and Factor V are sensitive indicators of good liver function.

Animals↗
PubMed1996

Mechanical characteristics of fresh and frozen human descending thoracic aorta.

In this study, mechanical characteristics of descending thoracic aorta were evaluated after preservation at +4 degrees C in EuroCollins solution or after programmed cryopreservation with 15% dimethylsulfoxide and compared to control segments. Arterial allografts were procured from multiple organ harvesting over a period of 2 years. All the segments were allowed to incubate in EuroCollins enriched antibiotics solution for 18 to 24 hr after harvest and were then tested as a control group or preserved at +4 degrees C in EuroCollins solution for 4, 7, 21, and 31 days or cryopreserved for 2 or 4 months. Each aorta was cut into parallel blades either in the radial or in the circumferential direction and mounted over a traction-compression apparatus for mechanical testing. Stress-strain characteristics indicated that no discernible differences were found between cryopreserved aorta and the control group. For those preserved at +4 degrees C a greater high strain modulus was noted for graft preserved for 21 and 31 days; however, this difference was not statistically significant. The authors concluded that cryopreservation did not alter the mechanical characteristics of arterial allografts procured from multiple organ harvesting.

Aorta, Thoracic↗
PubMed1996

Hepatic outflow study after piggyback liver transplantation.

BACKGROUND: Hepatic vein outflow is discussed in liver transplantation after preservation of recipient retrohepatic vena cava. The aim of this study was to compare two methods of suparahepatic caval anastomosis. METHODS: From January 1993 to January 1995, 81 patients received 88 liver transplants because of liver cirrhosis (n = 70), acute liver failure (n = 7), elective retransplantation after hepatic artery thrombosis (n = 2), giant hemangioma (n = 1), and combined liver-small bowel transplantation (n = 1). Seven patients underwent urgent retransplantation, 12 had preoperative transjugular intrahepatic portocaval stent, and 11 had portal vein thrombosis. Five patients required extracorporeal venous shunt. A total of 82 liver transplantations had preservation of RHVC, and 70 patients received temporary end-to-side portacaval shunt. Suprahepatic caval anastomosis was carried out in 52 patients (group 1) between the graft suprahepatic vena cava and the ostia of recipient left and median hepatic veins. Thirty patients (group 2) had associated 3 cm vertical cavotomy with partial clamping of RHVC. In the fourth postoperative month 20 patients from each group had pressure and gradient measurement made among the hepatic veins, right atria, and the RHVC. RESULTS: Mean pressure gradient between hepatic veins and right atria was 0.75 +/- 0.49 mm Hg in group 1 and 2.06 +/- 0.85 mm Hg in group 2. Between the RHVC and the right atria it was 0.63 +/- 0.5 mm Hg in group 1 and 2.22 +/- 1.29 mm Hg in group 2. A pressure gradient higher than 3 mm Hg was considered hemodynamically significant. This pressure gradient was found between the hepatic veins and right atria in 10% of patients in group 1 and 40% of patients in group 2 (p = 0.03) and between the RHVC and right atria in 15% of patients in group 1 and 30% of patients in group 2 (p = 0.3). CONCLUSIONS: Preservation of the recipient RHVC with recipient caval anastomosis at the ostia of the median and left hepatic veins is a reliable technique without any hepatic venous outflow alteration. Associated cavotomy is not necessary.

Adult↗
PubMed1996

Fulminant hepatic failure in adult onset Still's disease.

Adult onset Still's disease (AOSD) is a well characterized rheumatoid disorder with frequent liver involvement. This is usually asymptomatic but severe hepatic failure has occasionally been reported. We describe a 44-year-old woman who developed acute liver failure 2 months after presenting symptoms of AOSD. Full etiologic evaluation was done and all other causes of liver failure were excluded. She underwent emergency orthotopic liver transplantation but developed disseminated intravascular coagulation with acute renal failure, seizures, and coma, and died after 48 hours.

Acute Kidney Injury↗
PubMed1995

Auxiliary heterotopic liver graft using splenopancreatic venous blood flow in pig.

An original model of auxiliary heterotopic liver graft perfused by splenopancreatic venous blood flow is studied in pig. Separate portal inflow is performed for each liver and permits efficient function in both graft and native liver. Ten pigs were evaluated 90 days after transplantation, five without portal graft reperfusion (group 1) and five with portal graft reperfusion by splenopancreatic venous blood flow (group 2). Mean biliary output was 4.8 +/- 3.3 ml/hr in group 1, 9.6 +/- 2.3 ml/hr in group 2; biliary conjugated bilirubin level was 0 in group 1, 145 +/- 117 mumol/liter in group 2; intrahepatic glycogen level was 0.9 +/- 1.1 g% in group 1, 4.25 +/- 1.56 g% in group 2. Livers and grafts were weighed to evaluate hepatic mass on the 90th day. A histological examination was performed for each graft and native liver. It was shown that an auxiliary liver graft perfused by splenopancreatic venous blood flow presents satisfying metabolic function for 3 months, without atrophying and without functional impairment of native liver. This original model could be indicated in acute hepatic failure if regeneration of native liver is expected or in metabolic disease when total hepatectomy of the native liver may be unnecessary.

Animals↗
PubMed1994

Bone loss after orthotopic liver transplantation.

PURPOSE: We assessed changes in body composition and bone loss following liver transplantation to determine if bone loss is related to the underlying liver disease or to other factors such as sex, menopause, or graft rejection episodes. PATIENTS AND METHODS: Our cross-sectional study component compared bone mass and body composition in 31 patients at 1 year after liver transplantation versus 33 pregraft patients with chronic liver disease. Bone mass was measured by dual energy X-ray absorptiometry (DXA) using anteroposterior views of the total body to determine bone mineral content (BMC), and of the lumbar spine to assess bone mineral density (BMD). The body fat content was also determined by DXA. Radiographs of the thoracic and lumbar spine were also obtained. In our longitudinal study component, 16 patients from the pregraft group underwent bone mass assessment again 1 year after transplantation. RESULTS: Graft patients and pregraft patients both had reduced lumbar spine BMD compared to age- and sex-matched normal values (P < 0.001). A 4.75% increase in body fat content was observed after liver transplantation (P < 0.05). In the cross sectional study, bone mass of the spine and total body were not different in pre- and posttransplantation patients. However, the longitudinal study revealed significant decreases in spinal BMD and total body BMC, with a mean 3.5% decrease and a rate of loss of 0.55% per month. In addition, a dramatically high prevalence (29%) of vertebral fractures was observed in grafted patients, contrasting with a low prevalence (8.4%) of fractures in pregraft patients. Menopause, primary biliary cirrhosis, and chronic alcohol abuse were the principal contributing factors for osteoporosis. Patients with vertebral fractures had a marked 17.4% decrease of the lumbar spine BMD (P < 0.001) and a 22% decrease in total BMC when compared to patients without fractures (P < 0.01). CONCLUSION: Patients with orthotopic liver transplantation for chronic liver disease evaluated 1 year after transplantation have a high prevalence of vertebral fractures. Cross sectionally, bone mass was not different in patients before and after transplantation, but the longitudinal study showed that liver transplantation induced a marked and rapid bone loss. Bone loss due to transplantation could enhance the risk of new vertebral fractures, as shown by the high prevalence of vertebral fractures. These results emphasize the need to identify patients with low bone mass by bone densitometry before transplantation.

Absorptiometry, Photon↗
PubMed1994

[Heterotopic experimental liver transplantation with portal revascularization of the graft on the distal splenic vein of the recipient].

A model of heterotopic liver transplantation had been studied. The graft was laid under the recipient liver and the portal blood flow was supplied by anastomosis with the distal part of the splenic vein. Both liver can then receive portal blood through two parallel portal circulation. Liver function of transplant was satisfactory at three months after transplantation. Their had been no alteration of the recipient liver during the same period.

Anastomosis, Surgical↗
PubMed1993

Repeated hepatic resections for colorectal metastases.

Repeated hepatic resection (RHR) for recurrent colorectal metastases remains uncommon and controversial. We report our experience in order to assess the feasibility and the potential oncologic benefit of such an aggressive management. From 1981 to 1991, 13 patients underwent a RHR. The first hepatic resection had been an anatomic hepatectomy removing between two and six segments in 10 patients and a wedge resection in three. The RHR was performed after a mean delay of 16 +/- 10 months (5-35) from the first liver procedure. The RHR was an anatomic hepatectomy in eight patients (including a right hepatectomy in three) and a minor resection (tumorectomy or segmentectomy) in five. Three patients underwent a third liver resection for recurrence. There was no post-operative mortality. Eleven patients died from recurrence after a mean survival of 17 +/- 13 months from the second hepatic procedure (range: 6-47). One patient died from unrelated disease after 12 months and one was alive free of recurrence 22, 53 and 84 months after third, second and first hepatectomy respectively. The median survivals from the second and first hepatic resections were 17 and 31 months, respectively. It is concluded that in the well-trained team, RHR is feasible and safe even after major primary hepatectomy. However the oncologic benefit remains questionable.

Adult↗