Search PubMed⌕ Search

Biomedical subjects

N D Heaton

Publications and source records attributed to N D Heaton.

At least 37 records · Page 2Linked to original sources
PubMed2001

Use of cadaveric superior mesenteric artery as interpositional vascular graft in orthotopic liver transplantation.

BACKGROUND: Hepatic artery thrombosis remains the most common technical complication that causes graft failure following orthotopic liver transplantation. The development of split liver and living related liver transplantation has led to the use of shorter and smaller arteries for arterial reconstruction to the graft. The present aim was to assess the effectiveness of the superior mesenteric artery as an interpositional graft in arterial reconstruction during liver transplantation. METHODS: Cadaveric superior mesenteric artery was used to reconstruct small and short or multiple hepatic arteries in 35 liver transplants including 29 split, three living related, two whole liver transplants and one emergency revascularization post-transplantation. RESULTS AND CONCLUSION: A low incidence of hepatic artery thrombosis (one of 35 patients) was achieved utilizing cadaveric superior mesenteric artery as an interpositional vascular graft in liver transplantation.

Adolescent↗
PubMed2001

Graft dysfunction mimicking autoimmune hepatitis following liver transplantation in adults.

In children, a type of graft dysfunction associated with autoimmune features has been described. We have identified 7 adult liver-transplant (LT) recipients from a series of over 1,000 consecutive transplant recipients who presented between 0.3 years and 7.2 years following transplantation with characteristic symptoms, autoantibody profiles, and histologic findings of autoimmune disease. The indications for transplantation were Ecstasy overdose, alcohol-related cirrhosis, primary sclerosing cholangitis (PSC) (2), primary biliary cirrhosis (PBC), hepatitis C cirrhosis, and cryptogenic cirrhosis. Two patterns of de novo autoantibody development were noted; anti-liver-kidney-microsome (LKM) antibody development at high titer in association with an aspartate transaminase (AST) > 500 and antinuclear (ANA) and antismooth muscle (AMA) antibody development at titers >1/80 with lower AST levels. All cases had elevated IgG. Liver biopsies showed changes of an autoimmune-type hepatitis with portal and periportal hepatitis in association with a marked infiltrate of plasma cells, lymphocytes, and bridging collapse. Two patients lost their grafts because of the disease. Patients were treated with reintroduction of steroids and azathioprine in cases in which it had been withdrawn. Major histocompatibility class I and II mismatching did not incur risk. Eight of 12 liver allografts were acquired from either DRB*0301- or DRB*0401-positive donors, and 4 recipients were DRB*0301-positive. This series illustrates that both symptoms and histologic findings of graft dysfunction compatible with autoimmune hepatitis (AIH) exist in adult LT recipients. Graft loss may be a consequence. This entity may represent a specific type of rejection that should currently be classified as "graft dysfunction mimicking autoimmune hepatitis."

Adult↗
PubMed2001

Living related liver transplantation in biliary atresia with absent inferior vena cava.

The success of the triangulation technique for hepatic venous anastomosis in left lateral segment liver transplantation has led to standardization of this procedure. We report a case of syndromic biliary atresia with absent inferior vena cava in which we constructed a neo cava to implant a living related left lateral segment graft by using the triangulation technique.

Biliary Atresia↗
PubMed2001

Survival and outcome after hepatic artery thrombosis complicating pediatric liver transplantation.

BACKGROUND/PURPOSE: Hepatic artery thrombosis (HAT) represents a significant cause of graft loss and mortality after pediatric orthotopic liver transplantation (OLT). The incidence and etiology of this complication have been investigated in detail but relatively little is known about outcome. METHODS: A review was conducted of all children with confirmed HAT complicating OLT during a 10-year period (1990 through 1999) in a single center. HAT was established by angiography or at operation in all cases. RESULTS: From a consecutive series of 400 pediatric OLTs, there were 31 (7.8%) instances of HAT in 29 children of median age 3.8 years (range, 8 days to 16 years). Twenty-four (83%) are alive after a median follow-up of 3.6 years. Fourteen cases occurred after transplantation of whole grafts and 17 after reduced or split livers. Of the 18 episodes resulting in retransplantation, there were 5 deaths and 2 second episodes of HAT; surviving children are alive with good graft function. Of the 13 episodes managed without retransplantation, 4 patients underwent attempted early revascularisation of the graft, which was successful in 2, and the remainder initially were treated conservatively. All 13 children are alive after a median follow-up of 4.1 years (range, 0.6 to 5.8), but 5 required radiologic or surgical intervention for biliary or septic complications; biochemical liver function is normal in 8, mildly abnormal in 3, and poor in 2. Retransplantation was less likely in those who had received reduced or split grafts (7 of 17) compared with those who had received whole grafts (11 of 14), but this difference just failed to reach statistical significance (chi(2) = 3.01, 0.1 > P > .05). CONCLUSIONS: Using a selective policy of retransplantation, revascularisation, and conservative treatment, 83% of children survived HAT complicating OLT. Approximately 40% of children with HAT survived without retransplantation. J Pediatr Surg 36:888-891.

Child↗
PubMed2001

Liver and intestinal lactate metabolism in patients with acute hepatic failure undergoing liver transplantation.

OBJECTIVE: To determine the relative contribution of the gastrointestinal tract and the liver in lactate metabolism in patients with acute liver failure (ALF) and the effect of liver transplantation on this. We hypothesized that the liver and gut are net producers of lactate in ALF and that this is reversed after liver transplantation. SETTING: A university-affiliated specialist liver transplant operating theater. SUBJECTS: Eleven patients with ALF undergoing liver transplantation. MEASUREMENTS AND INTERVENTIONS: After ethical approval, 11 patients with ALF listed for orthotopic hepatic transplantation were studied. Whole blood was analyzed for lactate concentration from radial artery (RA) catheter, portal vein (PV), and hepatic vein (HV) during the dissection phase and was repeated postreperfusion of the liver graft. Gradients across the gut and the liver were calculated to see if there was net production or consumption. RESULTS: HV lactate was significantly higher than arterial (p =.028) in patients with ALF before liver transplantation, suggesting splanchnic production of lactate. Total splanchnic lactate gradient (HV-RA) is positive in ALF. Both the gut (PV-RA) and the liver (HV-PV) were net producers of lactate. After liver transplantation, hepatic venous lactate falls below arterial levels but not significantly. The gradient across the gut (PV-RA) remained positive, but the transhepatic gradient (HV-PV) became significantly negative, showing consumption by the graft (p =.021). The magnitude of lactate consumption after transplantation correlated positively with portal venous lactate concentration (p =.029) and inversely with graft cold ischemic time (p =.007). CONCLUSION: The liver is a net producer of lactate in patients with ALF and an elevated whole blood lactate. After liver transplantation, the graft becomes a consumer of lactate as shown by the negative lactate gradient. The degree of consumption is dependent on portal venous lactate concentration and cold ischemic time.

Female↗
PubMed2000

Recurrence of Langerhans cell histiocytosis in the graft after pediatric liver transplantation.

Two girls were diagnosed with Langerhans cell histiocytosis (LCH) at the age of 16 and 7 months and developed end stage chronic liver disease related to LCH-induced sclerosing cholangitis at 28 and 8 months, respectively. They received liver transplants at 34 and 14 months of age. Five months post-orthotopic liver transplantation (OLT) one of the patients developed posttransplant lymphoproliferative disease, successfully treated with a combination of surgery and reduction of immunosuppression. Fourteen months post-OLT she developed diabetes insipidus, bilateral ear discharge, and new osteolytic lesions. After transplantation both girls had mild skin reactivations of LCH, requiring minimal steroid increments. At 60 and 5 months post-OLT intrahepatic LCH recurrence was diagnosed on the basis of abnormal biliary enzymes and presence of Langerhans cells in the grafts. Initial cholangiography in both patients was unremarkable. LCH activity was controlled by maintenance chemotherapy with vinblastine, etoposide, and prednisolone. Ten months after reappearance of LCH in the liver graft a follow-up cholangiography in one of the girls demonstrated a low grade cholangiopathy. Residual elevation of liver enzymes probably represents an ongoing pathogenic process.

Cholangiography↗
PubMed2000

Isolated liver transplant and sequential small bowel transplantation for intestinal failure and related liver disease in children.

Liver dysfunction is a well-recognized complication of intestinal failure in children. Advances in total parenteral nutrition (TPN) have allowed these children to survive while their intestinal tract gradually adapts. Unfortunately TPN may lead to cholestatic liver disease particularly in the young children. Progression of liver disease is associated with a poor prognosis and is an indication for small bowel transplantation. We report our experience of orthotopic liver transplantation in four children with short gut and sequential liver and small bowel transplantation in one child. All children had TPN-related liver failure. Causes of intestinal failure included necrotising enterocolitis (n=2), gastroschisis (n=1), intestinal atresia (n=1), and megacystic, microcolon syndrome (n=1). At the time of liver transplantation the children's mean age was 10.9 months (2.5-24) and weight 6.7 kg (4.8-10.1). The mean serum bilirubin was 522 micromol/liter (299-823), aspartate transaminase 423 IU/liter (49-1024) and international normalized ratio 2.8 (2-3.9). There were two deaths both from respiratory failure secondary to adenovirus pneumonia including the child who received a sequential small bowel transplant. Three children with isolated liver grafts are alive and off TPN at 20 months (mean) follow up (range 6-35). Isolated orthotopic liver transplantation has a role in selected children with intestinal failure, particularly those with short but normally functioning gut and progressing with satisfactory intestinal adaptation but developing liver disease. Those children with TPN-related liver disease and unadapted gut or irreversible intestinal disease need combined liver and small bowel transplantation. Sequential small bowel transplantation is feasible after orthotopic liver transplantation and may provide an option for the child with terminal liver and small bowel failure.

Adolescent↗
PubMed2000

Liver transplantation for alpha-1-antitrypsin deficiency in children.

Alpha-1-antitrypsin (a1-AT) deficiency is an inborn error of metabolism, which can cause liver disease. The condition is one of the most common genetic disorders in the Caucasian population. Here we review our experience with 21 children suffering from end-stage liver disease due to a1-AT deficiency. All children are PIZZ homozygotes. Nineteen of them initially presented with neonatal jaundice and two with hepatosplenomegaly in childhood. Twenty-five liver transplantations were performed. All children are currently alive at a median followup of 40 months. Liver replacement provides the only definite treatment for children with end-stage liver disease associated with a1-AT deficiency. Excellent results can be achieved by reducing waiting time for transplantation and by early referral to a liver transplant centre.

Adolescent↗
PubMed2000

Prognosis of alpha-1-antitrypsin deficiency-related liver disease in the era of paediatric liver transplantation.

BACKGROUND/AIM: Alpha-1-antitrypsin deficiency (alpha1ATD) is the commonest metabolic disease leading to liver transplantation (LT) in children. Approximately 10-15% of the PiZZ population develops liver disease. Five percent of them will require LT within the first 4 years of life. This study aimed to investigate the prognosis of the liver disease associated with PiZZ alpha1ATD in the era of liver transplantation and to determine predictors of outcome. METHODS: We reviewed retrospectively the clinical notes of 97 consecutive patients referred from January 1989, when LT became routinely available in our Unit, to July 1998. RESULTS: Of 26 (27%) patients who developed end-stage liver disease, 24 have been transplanted and two are waiting for LT. Twenty-one (81%) of these patients presented with neonatal hepatitis at a median age of 2.1 months. Of 71 (73%) children who have not required LT, 61 (86%) presented with neonatal hepatitis at a median age of 1.6 months. Among infants with neonatal hepatitis who required LT, 18 out of 21 (86%) had jaundice for more than 6 weeks compared with 34 of 61 (56%) who survived without LT (p<0.01). Children requiring LT had higher aspartate aminotransferase (AST) at presentation (p<0.0001) and both higher AST and gamma-glutamyl transferase (GGT) at 6 months (p<0.001), 1-year (p<0.0003) and 5-year (p<0.01) follow up when compared to those who are well without LT. Furthermore, children who developed end-stage liver disease more frequently had severe bile duct reduplication (p<0.01), severe fibrosis (p<0.03) with bridging septa (p<0.02) and established cirrhosis (p<0.04) in the initial liver biopsy. Ninety-five of the 97 children (98%) are currently alive; two died after LT. CONCLUSIONS: The advent of liver transplantation has significantly improved the prognosis of liver disease associated with PiZZ alpha1ATD. Duration of jaundice, severity of histological features and biochemical abnormalities predict outcome at an early stage of the disease.

Child↗
PubMed2000

Curative hepatorenal transplantation in systemic amyloidosis caused by the Glu526Val fibrinogen alpha-chain variant in an English family.

A 53-year-old English woman who had been thought to have systemic monoclonal immunoglobulin light chain (AL) amyloidosis was investigated further because of her unusually long 17-year history and a suggestion of renal disease in the family. She was found to have the Glu526Val fibrinogen alpha-chain variant that causes autosomal dominant hereditary systemic amyloidosis. This has not previously been described in a British family. The mutant gene was associated with the same haplotype as in all other reported cases, suggesting a common founder. The patient had already received a renal transplant, but the graft failed within 6 years due to amyloid deposition. Progressive hepatic amyloidosis eventually caused liver failure, although the function of other organs was well preserved. She therefore received hepatic and renal transplants to replace the failed organs and the hepatic source of the amyloidogenic variant fibrinogen. Three years later she is completely well and has no amyloid deposits identifiable by serum amyloid P component scintigraphy. This is the first detailed report of hepatic transplantation for liver failure caused by amyloidosis of any type. The substantial follow-up suggests that fibrinogen alpha-chain amyloidosis is one of the inherited metabolic diseases that can be cured by liver transplantation. The mutation underlying Glu526Val fibrinogen alpha-chain amyloidosis is incompletely penetrant and has a variable phenotype that can clinically mimic AL amyloidosis. Hereditary fibrinogen amyloidosis may be more prevalent than previously suspected and, since AL amyloid is sometimes a diagnosis of exclusion, genotyping for other amyloidogenic proteins is mandatory in all cases in which the amyloid fibrils cannot be positively identified as AL.

Amyloidosis↗
PubMed2000

Bone marrow failure in children with acute liver failure.

BACKGROUND: Aplastic anemia is a rare but well-recognized complication of acute hepatitis and acute liver failure. The cause is unknown, and the condition is fatal without bone marrow recovery. Treatment includes immunosuppression regimens or bone marrow transplantation. The purpose of this study was to investigate the incidence, cause, treatment, and outcomes of this disorder in children. METHODS: Retrospective chart review of 75 patients with acute liver failure in a major pediatric liver center. RESULTS: Eight patients had evidence of bone marrow failure. Of those, six had aplastic anemia, and two had transient bone marrow suppression. There were five boys, median age 57 months (range, 36-132 months). Two had parvovirus B19, six had non-A, non-B, non-C hepatitis. Five underwent liver transplantation: auxiliary in one, orthotopic in four. The interval between initial symptoms and development of aplastic anemia and/or bone marrow suppression was 21 to 99 days (median, 39 days). Four patients with aplastic anemia received intravenous antithymocyte globulin (ATG) or antilymphocyte globulin (ALG). Median recovery period of granulopoiesis was 62 days (range, 27-115 days). Two made a full recovery, one had myelodysplasia, and one with unresponsive disease died of septic complications. Four did not receive ATG/ALG, two had aplastic anemia, and two had bone marrow suppression. Three underwent liver transplantation, and all four resumed granulopoiesis. One child who underwent liver transplantation died of sepsis with chronic rejection. Median recovery of granulopoiesis was 99 days (range, 20-153 days). CONCLUSIONS: Bone marrow failure occurs in 10.7% of children with acute liver failure. It sometimes occurs in association with non-A, non-B, non-C hepatitis and parvovirus B19 infection. Treatment with ATG/ALG is successful and is well tolerated in most cases.

Adolescent↗
PubMed2000

Mycobacterium tuberculosis infection in pediatric liver transplant recipients.

OBJECTIVES: To study the incidence, clinical presentation, management, complications and outcome of tuberculosis in pediatric liver transplant recipients. METHODS: A retrospective review of the medical records of children who underwent liver transplantation between 1991 and 1998. RESULTS: Mycobacterium tuberculosis infection occurred in 6 of 254 (2.4%) children undergoing liver transplantation between 1991 and 1998. Cough, pyrexia and poor appetite were common presentations; one-half had normal chest radiographs. The median time to confirmation of diagnosis was 8 months (range, 1 to 17 months). Tests contributing to diagnosis included: Ziehl-Neelsen (ZN) stain (2 patients), M. tuberculosis polymerase chain reaction (1 patient), Mantoux test (1 patient) and histopathology (4 patients). Family health screening was productive for 4 patients. Duration of treatment varied from 9 to 18 months. Isoniazid-induced hepatitis was observed in 2 patients but resolved with dose reduction. Two patients died while receiving treatment, one of Klebsiella spp. septicemia and the other of pulmonary hemorrhage. CONCLUSIONS: Tuberculosis after liver transplantation has a significant morbidity and mortality. Pretransplantation a personal and family history of tuberculosis must be sought, and screening of patients and their families should be considered. Standard regimens incorporating isoniazid and rifampin are effective, but regular monitoring of liver function is essential to detect drug-induced hepatotoxicity.

Adolescent↗
PubMed2000

Congenital absence of the portal vein in liver transplantation for biliary atresia.

BACKGROUND: Extrahepatic biliary atresia is the most common indication for liver transplantation in children. Coexistent congenital anomalies are common (25%), but the combination of polysplenia syndrome (10%) and absence of portal vein is rare. AIMS: We report a case of successful reduced size liver transplantation on a 13-month-old girl with extrahepatic biliary atresia, polysplenia syndrome and congenital absence of the portal vein. METHODS: Technical and post-operative problems related to absence of the portal vein and polysplenia are described and the literature reviewed. RESULTS: The donor portal vein was successfully anastomosed to the confluence of the superior mesenteric vein and splenic vein. The child is well with good graft function at a follow-up of 20 months. CONCLUSION: Absence of the portal vein and polysplenia syndrome is not a contraindication for liver transplantation although an increased post-operative morbidity may be expected.

Biliary Atresia↗
PubMed1999

An investigation into the risk of air embolus during veno-venous bypass in orthotopic liver transplantation.

After observing micro-bubble activity in the venovenous bypass system during liver transplantation, an experiment was designed to investigate the origin of these bubbles and to define the conditions under which they occurred. Using a Biomedicus constrained vortex pump and a customized circuit design, microbubble activity was measured in saline and blood media during varying pre- and post-head pressures. The data show that air emboli can be generated from this pump and the rate at which they develop is directly related to the pre- and post-head pressure and hematocrit.

Anastomosis, Surgical↗
PubMed1999

Splenic artery aneurysm and orthotopic liver transplantation.

Splenic artery aneurysms are a rare but potentially fatal complication after liver transplantation. We report three cases presenting in a 12-month period in adult patients who underwent transplantation for chronic liver disease. Doppler ultrasound of the splenic artery should be performed in all patients with cirrhosis and portal hypertension who are being assessed for liver transplantation. The aneurysm can be ligated at the time of transplantation.

Adult↗