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Mohamed Rela

Publications and source records attributed to Mohamed Rela.

At least 37 records · Page 2Linked to original sources
PubMed2004

Pretransplant MELD score and post liver transplantation survival in the UK and Ireland.

It has been shown that the model for end-stage liver disease (MELD) score is an accurate predictor of survival in patients with liver disease without transplantation. Four recent studies carried out in the United States have demonstrated that the MELD score obtained immediately prior to transplantation is also associated with post-transplant patient survival. Our aim was to evaluate how accurately the MELD score predicts 90-day post-transplant survival in adult patients with chronic liver disease in the UK and Ireland. The UK and Ireland Liver Transplant Audit has data on all liver transplants since 1994. We studied survival of 3838 adult patients after first elective liver transplantation according to United Network for Organ Sharing categories of their MELD scores (< or = 10, 11-18, 19-24, 25-35, > or =36). The overall survival at 90-days was 90.2%. The 90-day survival varied according to the United Network for Organ Sharing MELD categories (92.6%, 91.9%, 89.7%, 89.7%, and 70.8%, respectively; P < 0.01). Therefore, only those patients with a MELD score of 36 or higher (3% of the patients) had a survival that was markedly lower than the rest. As a consequence, the ability of the MELD score to discriminate between patients who were dead or alive was poor (c-statistic 0.58). Re-estimating the coefficients in the MELD regression model, even allowing for nonlinear relationships, did not improve its discriminatory ability. In conclusion, in the UK and Ireland the MELD score is significantly associated with post-transplant survival, but its predictive ability is poor. These results are in agreement with results found in the United States. Therefore, the most appropriate system to support patient selection for transplantation will be one that combines a pretransplant survival model (e.g., MELD score) with a properly developed post-transplant survival model.

Adult↗
PubMed2004

Outcomes of liver transplantation in HIV-infected individuals: the impact of HCV and HBV infection.

Liver transplantation (LT) in human immunodeficiency virus (HIV)-positive individuals is considered to be an experimental therapy with limited reported worldwide experience, and little long-term survival data. Published data suggest that the short-term outcome is encouraging in selected patients. Here, we report our experience in 14 HIV-infected liver allograft recipients, and compare outcomes between those coinfected with hepatitis C virus (HCV) and the non-HCV group. A total of 14 HIV-infected patients (12 male, 2 female, age range 26-59 years) underwent LT between January 1995 and April 2003. Indications for LT were HCV (n = 7), hepatitis B virus (HBV; n = 4), alcohol-induced liver disease (n = 2), and seronegative hepatitis (n = 1); 3 patients presented with acute liver failure. At LT, CD4 cell counts (T-helper cells that are targets for HIV) ranged from 124 to 500 cells/microL (mean 264), and HIV viral loads from <50 to 197,000 copies/mL. Nine of 12 patients were exposed to highly active antiretroviral therapy (HAART) before LT. In the non-HCV group (n = 7), all patients are alive, all surviving more than 365 days (range 668-2,661 days). No patient has experienced HBV recurrence, and graft function is normal in all 7 patients. However, 5 of 7 HCV-infected patients died after LT at 95-784 days (median 161 days). A total of 4 patients died of complications due to recurrent HCV infection and sepsis, despite antiviral therapy in 3 of them. A total of 3 patients experienced complications relating to HAART therapy. In conclusion, outcome of LT in HIV-infected patients with HBV or other causes of chronic liver disease indicates that LT is an acceptable therapeutic option in selected patients. However, longer follow-up in larger series is required before a conclusive directive can be provided for HCV / HIV coinfected patients requiring LT.

Adult↗
PubMed2004

Management of neuroendocrine liver metastases.

BACKGROUND: The optimum management of neuroendocrine liver metastases, particularly the role of liver transplantation is ill-defined. Current strategies are based on anecdotal reports and small retrospective studies, rather than prospective data. This, as well as the failure to standardize treatment, has probably contributed to the reported variations in outcome. DATA SOURCES: To formulate a putative management protocol and to reevaluate the role of liver transplantation in patients with neuroendocrine liver metastases, a review of the published literature (Medline search) was conducted. CONCLUSIONS: Isolated hepatic metastases should be resected when suitable. Chemoembolization of liver metastases should precede resection of bulky disease and be used to palliate those with unresectable disease. Radiofrequency ablation is suitable for smaller metastatic lesions (<3 cm diameter) in the liver. Systemic treatment with somatostatin analogues or radioactive metaiodobenzylguanidine (MIBG) is appropriate to reduce symptoms and slow disease progression, but prospective data is required to define their exact roles as adjuvant and therapeutic agents. Although current systemic chemotherapy, applied in isolation, may have a role in patients in whom other therapies have failed, its efficacy remains unproven. Restriction of liver transplantation to the treatment of patients with carcinoid metastases with biologically favorable features, limited tumor bulk and without systemic disease may make transplantation a curative rather than a palliative treatment option in selected patients.

Algorithms↗
PubMed2003

Cadaveric versus living-donor livers: differences in inflammatory markers after transplantation.

BACKGROUND: Prolonged cold storage of organs for transplantation may lead to inflammatory damage upon reperfusion. The aim of this study was to investigate whether organs from living donors experience less damage upon reperfusion than those retrieved from cadaver donors, where cold ischemia times are significantly longer. METHODS: Biopsies were obtained from cadaveric (n=23) and living-related donor (LRD) (n=10) liver transplants before and 2 hours after reperfusion. Cryosections were stained with antibodies against neutrophils, platelets, activated platelets, and endothelium. RESULTS: LRD liver allografts showed minimal changes postreperfusion. In contrast, after reperfusion of cadaver allografts, neutrophil infiltration was detected in 22% and increased expression of von Willebrand factor (vWF), CD41, and P-selectin in 48%, 30%, and 13% of allografts, respectively. In cadaver allografts with deposition of activated platelets expressing either P-selectin or vWF, the cold ischemia time was significantly longer (885 +/- 123 min vs. 608 +/- 214 min, P=0.04; 776.8 +/- 171 min vs. 559.3 +/- 216 min, P=0.01, respectively). Increases in neutrophils and platelets after reperfusion were not significantly associated with clinical events posttransplant. However, in cadaver transplants that experienced early acute rejection, the mean cold ischemia time was significantly longer than in allografts with no rejection (732 +/- 174 min vs. 480 +/- 221 min, P=0.006). CONCLUSIONS: This study demonstrates that in the clinical situation, cold ischemia causes platelet deposition and neutrophil infiltration after reperfusion of cadaveric liver allografts. These early inflammatory events may contribute to make the graft more susceptible to acute rejection.

Adult↗
PubMed2003

Is cholangiography required for ex situ splitting of cadaveric livers?

Anomalous biliary anatomy is encountered frequently and, if not considered at the time of ex situ splitting of a cadaveric liver into left lateral segment and right lobe grafts, right-sided second-order ducts that enter the left system, or the segment IV duct, may be damaged, leading to biliary complications in the recipients. Bench cholangiography facilitates delineation of these anomalies, but if one considers the commonly encountered variations in biliary anatomy, in relation to the correct plane of division of the left hepatic duct (away from the hilum, close to the umbilical fissure), it is possible to avoid inadvertent injury to right-sided sectoral ducts. This approach, combined with careful probing of the ducts and absolute identification of the segment IV duct negates the contribution of cholangiography.

Bile Ducts, Intrahepatic↗
PubMed2003

Living-donor liver transplantation with monosegments.

BACKGROUND: Living-donor liver transplantation is now an established technique to treat children with end-stage liver disease. Implantation of left-lateral segment grafts can be a problem in small infants because of a large-for-size graft. We report 10 cases of transplantation using monosegment grafts from living donors. METHOD: Of 506 children transplanted between June 1990 and June 2002, 10 patients (median age 196 days, median weight 5.9 kg) received monosegment living-donor liver transplants. The indication for using this technique was infants with an estimated graft-to-recipient weight ratio of over 4.0%. RESULTS: Graft and patient survival was 80.0%. There were no differences in donor operation time and blood loss between monosegmentectomy and left-lateral segmentectomy (n=281). Monosegmental transplantation had a high incidence of vascular complications (20.0%). CONCLUSION: Monosegmental living- donor liver transplantation is a feasible option with satisfactory graft survival in small babies with liver failure.

Adult↗
PubMed2003

Leukocyte infiltration and inflammatory antigen expression in cadaveric and living-donor livers before transplant.

BACKGROUND: There is evidence to indicate that organs obtained from cadaveric donors may be injured as a result of inflammatory events occurring at around the time of brain death. The aim of this study was to investigate whether there are differences in the expression of proinflammatory molecules between cadaveric and living-donor livers before transplant and to determine whether there is any association with donor factors and posttransplant graft function. METHODS: A comparison of biopsies obtained before implantation from cadaveric (n=22) and living-related donor (LRD) (n=10) livers was performed. Cryostat tissue sections were stained with antibodies to leukocyte subpopulations, adhesion molecules, and human leukocyte antigen class II antigens. RESULTS: Significantly higher levels of CD3+ lymphocytes (1.5%+/-0.8% vs. 0.5%+/-0.3%; P=0.00004), CD68+ monocytes and macrophages (4.0%+/-1.2% vs. 2.7%+/-0.6%; P=0.0003), and Fas-ligand staining (4.2%+/-2.6% vs. 1.5%+/-1.1%; P=0.0003) were detected in cadaveric livers compared with LRD livers before transplantation. Furthermore, higher levels of intercellular adhesion molecule-1 expression were detected in cadaveric donor livers and found to be associated with longer periods of ventilation (P=0.01), infection in the donor (P=0.013), and administration of dopamine (P=0.03). Although there were no differences in neutrophil infiltration between cadaveric and LRD livers, significantly higher levels were found in cadaveric donors with infection (P=0.01). CONCLUSION: This study demonstrates that inflammatory changes occur in cadaveric donor livers and are associated with events occurring during the period of intensive care. These proinflammatory changes did not seem to affect the short-term clinical outcome of cadaveric liver allografts but may contribute to alloimmune responses and impairment of graft function in the long term.

Antigens, CD↗
PubMed2003

Successful segmental auxiliary liver transplantation from a non-heart-beating donor: implications for split-liver transplantation.

BACKGROUND: Liver transplantation (LT) using grafts from non-heart-beating donors (NHBDs) has been shown to be a successful practice. Recently reported primary nonfunction rates are similar to those of LT using grafts from brain-dead donors. METHOD: We report the use of an NHBD liver, which was cut into a right-lobe graft and implanted as an auxiliary partial orthotopic liver transplant for acute liver failure in a 11-year-old child. The warm ischemia time was 21 minutes, and the cold ischemia was 8 hours. RESULTS: Initial graft function was excellent, and the child is well, with normal liver function 2 months posttransplant. CONCLUSION: Reduction and splitting of livers from NHBDs for transplantation is a realistic option, provided there is careful selection of the graft.

Cadaver↗
PubMed2003

Non-heart-beating versus cadaveric and living-donor livers: differences in inflammatory markers before transplantation.

BACKGROUND: Liver transplantation from non-heart-beating donors (NHBD) has been reintroduced into clinical practice to increase the donor pool; however, little is known about the immune status of NHBD livers. The aim of this study was to assess intragraft cell populations and inflammatory markers in NHBD and to compare the findings with cadaveric and living-related donor (LRD) livers. METHODS: Biopsy specimens were obtained from controlled NHBD (n=9), conventional cadaveric (n=22), and living-donor (n=10) livers at the end of cold storage. Cryostat sections were stained for monocytes-macrophages, T lymphocytes, and intercellular adhesion molecule (ICAM)-1. RESULTS: The levels of leukocyte infiltration in NHBD reflected those found in conventional cadaver donors and were significantly higher than in LRD livers. Similar levels of CD68+ monocytes-macrophages were detected in cadaver (4.0+/-1.2%) and NHBD livers (4.6+/-1.2%) and were significantly greater than in the LRD livers (2.6+/-0.5%, P<0.01). Furthermore, the levels of T lymphocytes in NHBD (1.1+/-0.6%) and cadaver donors (1.5+/-0.8%) were similar, and were higher than in LRD (vs. 0.47+/-0.3%, P<0.05). Twelve of 22 (60%) cadaver livers had high levels of ICAM-1 expression (grade 3), compared with only 1 of 10 (10%) LRD livers (P=0.02). Four of nine (44%) controlled NHBD livers expressed high levels of ICAM-1. CONCLUSIONS: The results demonstrate that livers obtained from controlled NHBD before transplantation are similar to conventional cadaver donors regarding the level of leukocyte infiltration. Nevertheless, lower levels of ICAM-1 were detected in NHBD, suggesting less exposure to inflammatory mediators than conventional cadaver donor livers.

Adult↗
PubMed2003

Human hepatocyte isolation and relationship of cell viability to early graft function.

Hepatocyte transplantation is emerging as an additional modality of treatment for patients with acute liver failure or liver-based metabolic disorders. The procedure requires isolation of high-quality hepatocytes from unused donor livers. Hepatocytes were isolated from 20 donor livers (11 right lobes, 3 left lateral segments, 6 whole livers) using a collagenase perfusion technique. Cell viability (median 56%, range 13-95%) and yield (median 1.4 x 10(9) cells, range 2.0 x 10(6)-1.8 x 10(10) cells) varied according to the tissue available. Fatty livers rejected for transplantation gave lower cell viability (median 45%, range 25-59%). There was a significant correlation between age of donor (median 21 years, range 7-66 years) and viability of isolated hepatocytes in vitro (r = -0.683, p = 0.001). The 13 segments of livers were from reduced/split grafts used for clinical transplantation in 9 children and 4 adults. There was no significant correlation between in vitro cell viability and clinical parameters including intensive care stay, serum aspartate aminotransferase,and international normalized ratio (in the first 7 days), and allograft rejection or other early posttransplant complications, in patients transplanted with the corresponding tissue.

Adolescent↗
PubMed2002

Long-term outcome of liver retransplantation in children.

BACKGROUND: Retransplantation of the liver is the only means of prolonging survival in children whose initial graft has failed. Patient and graft survival rates after retransplantation in most series have been inferior to rates after first transplantation. PATIENTS AND METHODS: Of 450 pediatric liver transplantations performed between January 1990 and March 2001, 50 were first retransplantations, 9 were second retransplantations, and 1 was a third retransplantation. The overall retransplantation rate was 13.3% (median age at retransplantation 4 years and median weight 15 kg). The median post-retransplantation follow-up was 73 (range, 6-139) months. RESULTS: Kaplan-Meier patient survival rates for the group (n=50) were 71.7%, 64.7%, and 64.7% at 1, 3, and 5 years, respectively. Graft survival rates were 65.6%, 56.7%, and 56.7% at 1, 3, and 5 years, respectively. This is significantly worse than rates for children undergoing first liver transplantation. There were 17 deaths, of which 9 occurred in the first month. Biliary complications occurred in 5 (10%) patients and vascular complications in 6 (12%). Improved patient and graft survival rates were observed in the later phase of the program, although the difference was not significant. Higher preoperative serum creatinine (P=0.001) and serum bilirubin (P=0.02) levels were associated with a higher postoperative mortality. CONCLUSION: Results of retransplantation in children remain inferior to those after first transplantation. There is a trend toward improving results. Liver retransplantation makes an important contribution to overall survival in children.

Adolescent↗
PubMed2002

Orthotopic liver transplantation for unresectable hepatoblastoma.

BACKGROUND: The outcome of treatment for advanced hepatoblastoma has recently improved after the introduction of preoperative or pre- and postoperative cisplatin-containing chemotherapy combined with complete surgical excision. The role of liver transplantation in a population of patients who have received this regimen has not been clearly defined. METHODS: Orthotopic liver transplantation (OLT) was performed in 13 children, aged 5 months to 11 years (median 27 months), who were assessed with unresectable hepatoblastoma, and whose pretreatment extent-of-disease was based on radiologic findings of group III (n=11) and group IV (n=2). One child with a multifocal tumor showed pulmonary metastases at presentation, but, according to radiologic studies, the deposits resolved with chemotherapy before liver transplantation. One other child showed exophytic extension of the primary tumor infiltrating the porta hepatis and body of the pancreas. All 13 patients received preoperative chemotherapy to reduce the size of the primary tumor(s) and to treat metastatic spread. RESULTS: Twelve children underwent elective OLT; all are alive and show normal graft function at a mean follow-up of 33 months (range 1-108). One child shows evidence of recurrent disease in the form of pulmonary metastases. One child underwent emergency OLT for acute liver failure after (incomplete) extended right hepatectomy and died from respiratory failure, with no evidence of recurrent tumor 3 weeks posttransplant. CONCLUSIONS: Liver transplantation is an effective treatment for unresectable unifocal or multifocal hepatoblastoma confined to the liver. A multidisciplinary approach to the management of hepatoblastoma, with thoughtful collaboration between pediatric oncologists, hepatologists, and liver surgeons, is essential.

Adolescent↗
PubMed2002

Auxiliary partial orthotopic liver transplantation in acute liver failure due to hepatitis B.

Auxiliary partial orthotopic liver transplantation is an alternative therapeutic modality in acute liver failure, wherein the capacity of native liver to regenerate is preserved. A case of acute liver failure due to hepatitis B in an 18-year-old male patient treated with an auxiliary left lateral segment graft is described. There was no recurrence of hepatitis B in the auxiliary graft and the patient cleared the virus after 9 months whilst receiving lamivudine. Immunosuppression was withdrawn at 14 months, and the auxiliary graft atrophied secondary to hepatic arterial conduit thrombosis, possibly precipitated by immunosuppression withdrawal. The native liver regenerated completely, and the patient is well and off immunosuppressive and antiviral therapy 3 years after transplantation. Auxiliary partial orthotopic liver transplantation is an attractive treatment option in acute liver failure due to hepatitis B infection and allows a life free of long-term immunosuppression.

Acute Disease↗
PubMed2002

Liver transplantation for Budd-Chiari syndrome.

BACKGROUND: Budd-Chiari syndrome (BCS) is a clinical condition characterized by hepatic venous outflow obstruction secondary to an underlying systemic predisposition to thrombosis. METHODS: We reviewed our experience of 19 adult patients who underwent orthotopic liver transplantation for BCS from April 1988 to May 1999 to assess their long-term outcome and specific complications related to this procedure. RESULTS: Of these patients, 13 presented with chronic and 6 with acute liver failure. At presentation predisposing factors included polycythemia rubra vera in five, an undefined myeloproliferative disorder in four, essential thrombocythemia in two, presence of lupus anticoagulant in one, antiphospholipid antibody positivity in one, post-gestational in one, oral contraceptive pill in one, and idiopathic in four. Five patients had undergone previous porto-systemic shunt. Of the 19 patients, 16 are alive at a median follow-up of 89 months (range 1-119) with 2 patients developing disease recurrence at 4 months and 7 years posttransplant, respectively. Four patients have been retransplanted: one for progressive graft dysfunction due to nodular regenerative hyperplasia secondary to azathioprine toxicity, two for hepatic artery thrombosis (one soon after and the other 47 months posttransplant), and one for recurrent BCS. Three patients have died: one from an intra-abdominal bleed secondary to acute hemorrhagic pancreatitis 8 years posttransplant, another from acute myeloid leukemia at 6 years posttransplant, and the third patient from graft failure secondary to severe rejection 1 month posttransplant. CONCLUSION: Liver transplantation for BCS provides good long-term survival with acceptable morbidity. Long-term survival may be prejudiced by progression of the underlying hematological disorders.

Actuarial Analysis↗
PubMed2002

The role of mitochondria in ischemia/reperfusion injury.

In organ transplantation, ischemia/reperfusion injury is a multifactorial process that leads to organ damage and primary graft dysfunction. Injury to the organ is mediated by a complex chain of events that involves depletion of energy substrates, alteration of ionic homeostasis, production of reactive oxygen species, and cell death by apoptosis and necrosis. There is increasing evidence that mitochondria play a role in this process because of the profound changes experienced during ischemia and reperfusion. Understanding the mechanisms that lead to mitochondrial damage may be important for developing strategies aimed at improving graft outcome. In this review, we examine the role of mitochondria in ischemia/reperfusion injury and the possible mechanisms that may contribute to organ dysfunction.

Animals↗
PubMed2002

Liver transplantation in children.

The results of liver transplantation has improved significantly in the last decade with one year survival figures close to 90% for children with chronic liver disease. This can be attributed to improvement in surgical techniques, better postoperative care and newer immunosuppresive drugs. As a result of this, increasing number of children are referred for transplantation with no significant increase in the number of solid organ donors. The earliest transplants in children were performed using organs from size matched pediatric donors. However, as the pediatric donor numbers were limited, liver reduction techniques were developed to transplant small children before deterioration. Increasing experience with reduced livers led to the development of split liver, living donor and auxiliary liver transplantation. Better management of immunosuppressive drugs and newer agents such as Mycophenolate Mofetil have reduced the incidence of graft loss due to chronic rejection and long-term renal toxicity. The goal for the future will remain to be transplantation without the use of long-term immunosuppression.

Child↗
PubMed2002

Evidence of differential risk for posttransplantation malignancy based on pretransplantation cause in patients undergoing liver transplantation.

Organ transplant recipients are considered to be at greater risk for developing malignancy because of the prolonged immunosuppression associated with organ grafting. The purpose of this study is to determine risk factors, clinical characteristics, and outcomes of de novo nonlymphoid malignancies after liver transplantation from a large single-center series. All patients undergoing liver transplantation at the King's College Hospital (London, UK) between January 1988 and December 1999 were analyzed retrospectively for the development of de novo malignancy in the posttransplantation period. Records were evaluated for age at diagnosis of malignancy, cause of liver disease, interval from transplantation to diagnosis of malignancy, predisposing factors for the development of cancer, immunosuppression regimen, treatment of malignancy, rejection episodes, and patient survival. Of 1,140 patients undergoing 1,271 liver transplantations, 30 patients (2.6%) developed de novo nonlymphoid malignancy after transplantation. Skin cancers were the most common (n = 13), followed by oropharyngeal carcinoma (n = 2), bladder carcinoma (n = 2), acute leukemia (n = 2), breast carcinoma (n = 2), and various other malignancies (n = 9). The mean time of presentation of the malignancy after transplantation was 45.1 +/- 32 months (range, 6 to 133 months), and mean age at diagnosis of malignancy was 55 years (range, 34 to 71 years). The incidence of de novo malignancy was significantly greater in patients who underwent transplantation for alcoholic liver disease compared with other groups (P <.001). Although the incidence of de novo nonlymphoid malignancy after liver transplantation is low, patients who underwent transplantation for alcoholic cirrhosis appear to have an increased risk for developing posttransplantation malignancy.

Adult↗