Adult-to-adult living related liver transplantation: initial experience.

The number of adult patients on the liver transplantation waiting lists is growing steadily. Adult living related liver transplantation (LRLT) represents the ultimate means to expand the donor pool. The success of this model of "small for size" grafting relies on strict donor and recipient selection. The choice of the graft (2 left and 4 right hepatectomies) was made on the minimal ratio between estimated graft and recipient body weights (0.8-1%), necessary to meet the recipient's metabolic demands. Our experience with six adults is reported. Donor morbidity was minimal (one wound infection); there was no mortality. Four (66%) recipients are doing well, two died of infectious complications. All recipients had a complicated post-transplant course. Due to its complexity, both in donor and recipient, LRLT should only be developed very carefully in experienced liver transplant centers.

Hemodynamic changes in patients with Alagille's syndrome during orthotopic liver transplantation.

UNLABELLED: Children with Alagille's syndrome are at increased perioperative risk during orthotopic liver transplantation due to the cardiopulmonary abnormalities and the hemodynamic changes associated with this procedure. We studied 16 children with Alagille's syndrome who underwent 21 orthotopic liver transplantations. Peripheral pulmonary stenosis was present in all subjects. Right ventricular pressures were increased in 15 cases. Caval clamping resulted in a mean decrease of 15 +/-9 mm Hg in systolic blood pressure, 5 +/- 3 mm Hg in mean pulmonary artery pressure, and 4 +/- 3 mm Hg in central venous pressure. Systolic blood pressure decreased by 16 +/- 13 mm Hg, whereas mean pulmonary artery pressure and central venous pressure increased by 3 +/- 4 mm Hg and 1 +/- 4 mm Hg, respectively, at portal vein unclamping. There was no correlation between severity of pulmonary artery stenosis and hemodynamic changes. Veno-venous bypass used in four cases resulted in smaller hemodynamic changes. Time to extubation and duration of intensive care unit stay were unrelated to severity of pulmonary artery stenosis. IMPLICATIONS: Some children with Alagille's syndrome require liver transplantation. In our study, associated pulmonary artery stenosis did not dramatically increase perioperative risk. Veno-venous bypass decreased intraoperative hemodynamic changes in these patients.

Pharmacokinetics of tacrolimus (FK506) in paediatric liver transplant recipients.

The pharmacokinetics of intravenous and oral tacrolimus was assessed in paediatric liver transplant patients at two centers in Europe. Sixteen patients, age 0.7 to 13 years, participated in the study; 12 patients were evaluable for intravenous pharmacokinetics, and 16 for oral. Intravenous tacrolimus was given as a continuous 24 h infusion (mean 0.037+/-0.013 mg/kg/day), and oral tacrolimus was given in 2 doses per day (mean 0.152+/-0.015 mg/kg). Whole blood samples for the intravenous pharmacokinetic profile were taken before initiation of the first infusion, 4, 8, 12 and 24 h post-infusion, and every 24 h thereafter until intravenous administration was discontinued. During the 12 h wash-out period between intravenous and oral administration, samples were taken every 3 h. Samples for the oral pharmacokinetic profile were taken immediately before the first oral dose and 0.5, 0.75, 1, 2, 2.5, 3, 4, 6, 8, 10 and 12 h post-administration. Non-compartmental procedures were used to characterise the pharmacokinetic parameters. Mean estimates for clearance and terminal half-life were 2.3+/-1.2 ml/min/kg and 11.5+/-3.8 h, respectively, following intravenous tacrolimus. The mean bioavailability of oral tacrolimus was 25+/-20%. A strong correlation was observed between AUC and trough whole blood levels of tacrolimus (r=0.90). The clearance was approximately 2-fold higher than that previously observed in adults; this could explain the higher dosage requirements in children.

Pediatric liver transplantation: from the full-size liver graft to reduced, split, and living related liver transplantation.

Between 1984 and 1996, the authors performed 499 liver transplants in 416 children less than 15 years old. The overall patient survival at 10 years was 76.5%. It was 71.3% for the 209 children grafted in 1984-1990; 78.5% for biliary atresia (n = 286), 87.3% for metabolic diseases (n = 59), and 72.7% for acute liver failure (n = 22). The 5-year survival was 73.6% for the 209 children grafted in 1984-1990 and 85% for the 206 grafted in 1991-1996. Scarcity of size-matched donors led to the development of innovative techniques: 174 children who electively received a reduced liver as a first graft in our center had a 5-year survival of 76% while 168 who received a full-size graft had a survival of 85% (NS). Results of the European Split Liver Registry showed 6-month graft survival similar to results obtained with full-size grafts collected by the European Liver Transplant Registry. Extensive use of these techniques allowed the mortality while waiting to be reduced from 16.5% in 1984-1990 to 10% in 1991-1992. It rose again to 17% in 1993, leading the authors to develop a program of living related liver transplantation (LRLT). The legal and ethical aspects are analyzed. Between July 1993 and October 1997, the authors performed 53 LRLTs with 90% survival. In elective cases, a detailed analysis was made of the 45 children listed for LRLT between July 1993 and March 1997 and the 79 registered on the cadaveric waiting list during the same period. Mortality while waiting was 2% and 14.5% for the LRLT and cadaveric lists, respectively. The retransplantation rate was 4.6% and 16.1% for LRLT and cadaveric transplants, respectively. Overall post-transplant survival was 88% and 82% for children who received a LRLT or a cadaveric graft, respectively. Overall survival from the date of registration was 86% and 70% (P < 0.05) for LRLT or cadaveric LT respectively. The 2-year post-transplant survival in children less than 1 year of age at transplantation was 88.8% and 80. 3% with a LRLT or cadaveric graft, respectively; patient survival after 3 months post-transplant was 95.8% and 91.9% for stable children waiting at home, 93.7% and 93.7% in children hospitalized for complications of their disease, and 89.5% and 77.7% for children hospitalized in an intensive care unit at the time of transplantation for children who received a LRLT or cadaveric graft, respectively. It is concluded that LRLT seems to be justified for multidisciplinary teams having a large experience with reduced and split liver grafting.

Clinical pharmacokinetics of Neoral in pediatric recipients of primary liver transplants.

Pediatric liver transplant recipients constitute a population characterized by a particularly unpredictable and poor bioavailability of cyclosporin (CyA). Even though several adult studies show that the new oral formulation of CyA, Neoral (NEO), produces better bioavailability and blood level predictability, few data describe its pharmacokinetics in children. We performed a complete analysis of the pharmacokinetics of NEO in ten small children after primary liver transplantation. Three pharmacokinetic profiles were set up with data obtained from tests taken during i.v. administration of CyA, after the first oral NEO dose, and after the last NEO dose before discharge from the hospital. The mean half-lives obtained were 8.1, 7.7, and 6.9 h, respectively, and the bioavailabilities were 22% and 21% for the first and last NEO doses. A large interpatient variability was observed. This was due, in part, to episodes of diarrhea that interfered with the pharmacokinetic evaluation and, in part, to the variability of post-transplant hepatic function. There was a good correlation between CyA trough levels and their related AUCs for both NEO profiles (r = 0.93 and r = 0.74, respectively). We conclude that, even though the pediatric OLT population remains more unpredictable than that of adults, NEO has a relatively rapid half-life and a remarkably improved bioavailability.

Management of intra-abdominal organ injury following blunt abdominal trauma in children.

OBJECTIVE: To evaluate the strategy of a combined diagnostic and therapeutic approach in children with intra-abdominal organ injury following blunt abdominal trauma. DESIGN: Retrospective clinical study. SETTING: Pediatric intensive care unit of an university hospital. PATIENTS: 38 children with documented intra-abdominal injury. INTERVENTION: Initial non-surgical treatment by a team of pediatric intensivists, radiologists and surgeons. MEASUREMENTS AND RESULTS: Physical examination, oriented blood and urine tests, plain abdominal film, abdominal ultrasound (US) and computed tomography (CT) with contrast. US documented intra-abdominal fluid in 30 and initial organ lesion in 14 out of 31 patients evaluated. Abdominal CT demonstrated the precise organ lesion in 34 out of 36 patients examined with solid organ lesion. Early laparotomy was needed in 7 because of severe shock, pneumoperitoneum and ruptured diaphragm, and delayed surgery in 6 patients. All 38 patients regained a normal life. CONCLUSIONS: The stepped diagnostic approach combined with initial non-surgical treatment by a team provided accurate diagnosis and appropriate treatment. Abdominal US, by demonstrating free intra-abdominal fluid is very sensitive to detect patients with intra-abdominal organ injury, CT scan with contrast is needed to give precise information of specific organ lesions.

Developmental changes in effects of histamine on segmental pulmonary vascular resistances.

In mature animals histamine infusion typically causes an H1-mediated increase and H2-mediated decrease in pulmonary vascular resistance (PVR). Moreover, low histamine concentrations can cause H1-mediated relaxation of vascular strips in mature animals, and in newborn animals histamine infusion causes only H1-mediated decreases in PVR. The mechanisms responsible for the different H1-mediated responses are unknown. We used an inflow-outflow occlusion technique to identify the sites of H1- and H2-mediated responses in lungs of developing lambs. Histamine was infused at 1.0 and 10.0 micrograms.kg-1.min-1 in control and H1- and H2-blocked lungs of newborn and juvenile lambs under "normoxic" and hypoxic conditions and in hypoxic H2-blocked lungs of mature sheep. In newborns histamine caused significant H1-mediated decreases in resistance across the arterial (delta Pa) and middle (delta Pm) segments of the circuit during both normoxia and hypoxia. In normoxic juveniles low-dose histamine caused H1-mediated decreases in the resistance across delta Pa and delta Pm, but the resistances across delta Pm rose above baseline at the higher dose. The venous segment exhibited only a high-dose increase in resistance. During hypoxia, the high-dose H1-mediated pressor response of delta Pm was attenuated compared with that during normoxia; however, the increase in venous resistance was unaffected. In hypoxic mature sheep, no low dose H1-mediated decrease in segmental resistances was seen, but at the higher dose an increase in all resistances occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Developmental changes in vascular responses to histamine in normoxic and hypoxic lamb lungs.

This study of newborn (3-10 day old) and juvenile (6-8 mo old) in situ isolated lamb lungs was undertaken to determine whether 1) histamine receptor blockade accentuates hypoxic pulmonary vasoconstriction more in newborns than in juveniles, 2) histamine infusion causes a decrease in both normoxic pulmonary vascular resistance and hypoxic pulmonary vasoconstriction in newborns, and 3) the H1-mediated dilator response to infused histamine in newborns is due to enhanced dilator prostaglandin release. Pulmonary arterial pressure (Ppa) was determined at baseline and in response to histamine (infusion rates of 0.1-10.0 micrograms.kg-1 min-1) in control, H1-blocked, H2-blocked, combined H1- and H2-blocked, and cyclooxygenase-inhibited H2-blocked lungs under "normoxic" (inspired O2 fraction 0.28) and hypoxic (inspired O2 fraction 0.04) conditions. In newborns, H1-receptor blockade markedly accentuated baseline hypoxic Ppa, and H2-receptor blockade caused an increase in baseline normoxic Ppa. In juveniles, neither H1 nor H2 blockade altered baseline normoxic or hypoxic Ppa. Histamine infusion caused both H1- and H2-mediated decreases in Ppa in normoxic and hypoxic newborn lungs. In juvenile lungs, histamine infusion also caused H2-mediated decreases in Ppa during both normoxia and hypoxia. During normoxia, histamine infusion caused an H1-mediated increase in normoxic Ppa in juveniles as previously seen in mature animals; however, during hypoxia there was an H1-mediated decrease in Ppa at low doses of histamine followed by an increase in Ppa. Combined histamine-receptor blockade markedly reduced both dilator and pressor responses to histamine infusion. Indomethacin failed to alter the H1-mediated dilator response to histamine in newborns.(ABSTRACT TRUNCATED AT 250 WORDS)

Intensive care for children after orthotopic liver transplantation.

We report our experience in the management of children after orthotopic liver transplantation (OLT). From 03/84 to 04/87 50 patients (pts) were transplanted. Mean age was 4 3/12 years (8/12 to 13 2/12) and mean body weight 14.7 kg (5.8 to 40). Hospital mortality was 14%. Problems related to the surgery included: Abdominal complications: bleeding (8 pts), infection (18 pts), ascites and fistula (1 pt), need for secondary abdominal surgery (10 patients). Respiratory problems: lobar atelectasis (11 pts), right diaphragmatic paralysis (2 pts) and right pleural effusion (11 pts). Problems related to immunosuppression included: Bacterial infection (29 pts) fungal infection (5 pts), one patient died of disseminated cytomegalovirus infection. Side effect of cyclosporin A (CsA) were systemic blood hypertension (S.B.H.) (47 pts), sinusal bradycardia (37 pts), associated to SBH (24 pts), hypertensive encephalopathy (2 pts). Generalized seizures (2 pts in the absence of SBH). Renal side effects of CsA were hypercreatininemia, decreased sodium bicarbonate and hyperkaliemia. The nephrotoxicity of CsA was favoured by the use of other nephrotoxic drugs such as aminoglycosides, amphotericin B. Edematous pancreatitis was observed in 3 patients and related to the use of large doses of steroids. Problems related to the functioning of the graft included: Primary non-function of the graft (4 pts), hepatic artery thrombosis (8 pts) and severe acute rejection unresponsive to therapy (1 pt); these situations needed to be recognised early in order to organize a second OLT. Other causes of hepatic dysfunction were: portal vein thrombosis (1 pt), biliary tract obstruction (2 pts), angiocholitis (3 pts), right hepatic lobe necrosis (2 pts). Acute hepatic insufficiency in 7 children.(ABSTRACT TRUNCATED AT 250 WORDS)