Late-onset presentation of ornithine transcarbamylase deficiency in a young woman with hyperammonemic coma

Severe Acute Motor Exacerbations (SAME) across Metabolic, Developmental and Genetic Disorders

Acute presentation of severe motor disorders is a diagnostic and management challenge. We define severe acute motor exacerbations (SAME) as acute/subacute motor symptoms that persist for hours-to-days with a severity that compromise vital signs (temperature, breath, and heart rate) and bulbar function (swallowing/dysphagia). Phenomenology includes dystonia, choreoathetosis, combined movement disorders, weakness, and hemiplegic attacks. SAME can develop in diverse diseases and can be preceded by triggers or catabolic states. Recent descriptions of SAME in complex neurodevelopmental and epileptic encephalopathies have broadened appreciation of this presentation beyond inborn errors of metabolism. A high degree of clinical suspicion is required to identify appropriately targeted investigations and management. We conducted a comprehensive literature analysis of etiologies. Reported triggers are described and classified as per pathophysiological mechanism. A video of six cases displaying multiple SAME with diverse outcomes is provided. We identified 50 different conditions that manifest SAME, some associated with developmental regression. Etiologies include disorders of metabolism: energy substrate, amino acids, complex molecules, vitamins/cofactors, minerals, and neurotransmitters/synaptic vesicle cycling. Non-metabolic neurodegenerative and genetic disorders that present with movement disorders and epilepsy can additionally manifest SAME. A limited number of triggers are grouped here, together with an approach to investigations and general management strategies. Several neurogenetic and neurometabolic disorders manifest SAME. Identifying triggers can help in certain cases narrow the differential diagnosis and guide the expeditious application of targeted therapies to minimize adverse developmental and neurological consequences. This process may inform pathogenesis and eventually improve our understanding of the mechanisms that lead to the development of SAME. © 2024 International Parkinson and Movement Disorder Society.

Late Onset Ornithine Transcarbamylase Deficiency Triggered by an Acute Increase in Protein Intake: A Review of 10 Cases Reported in the Literature

While the urea cycle disorders (UCDs) classically present in the neonatal stage, they have become increasingly recognized as a rare cause of unexplained hyperammonemic encephalopathy in adults. Many metabolic triggers for late-onset UCDs have been described in the literature including excessive protein intake. In this case series, ten such documented cases are reviewed with analysis of patient demographic, protein load, treatment course, and patient outcome. Common delays in treatment include recognition of hyperammonemia as the cause of encephalopathy and initiation of hemodialysis. In only one case was a diet history used to raise suspicion for a metabolic derangement. Metabolic disorders remain an important consideration in adults presenting with encephalopathy not explained by more common etiologies, and recent and remote dietary history may provide valuable information.

Severe hyperammonemia from intense skeletal muscle activity: A rare case report and literature review

RATIONALE

Adult hyperammonemia is most often the result of hepatic dysfunction. Hyperammonemia in the setting of normal hepatic function is a much less common phenomenon and has usually been associated with medications and certain disease states. Here, we present an unusual case of severe hyperammonemia caused physiologically by intense muscle activity in a patient lacking any evidence of liver disease.

PATIENT CONCERNS

A 36-year-old woman was brought to the emergency department for a suicide attempt after being found covered in Lysol and Clorox germicidal bleach. She was noted to be in a state of violent psychosis with extreme agitation and had to be sedated and intubated for airway protection.

DIAGNOSIS AND INTERVENTIONS

Initial labs revealed hyperammonemia, lactic acidosis, and anion gap metabolic acidosis. Aminotransferases, bilirubin, and creatine kinase (CK) were normal. Renal function, prothrombin time, activated partial thromboplastin time, and international normalized ratio were also unremarkable and remained so at 24 hours. Ethyl alcohol, acetaminophen, salicylate, and valproic acid were all undetectable in blood. She received 2 doses of lactulose overnight, with a subsequent bowel movement. Next day, her mentation, serum ammonia level, and lactic acid level were back to normal, and she was extubated. Aminotransferases and CK levels were elevated but improved with supportive care. A detailed history and relevant biochemical investigations were unremarkable for any other etiology of hyperammonemia including the common inborn errors of metabolism (IEM). The combination of clinical findings of extreme skeletal muscle activity along with hyperammonemia and lactic acidosis, and subsequently rhabdomyolysis in the setting of unremarkable history and otherwise normal hepatic function strongly suggest the myokinetic origin of hyperammonemia in the patient.

OUTCOME

The patient recovered well with supportive care and was discharged on day 5.

LESSONS

This unique case illustrates the important role of skeletal muscle in the human metabolism of ammonia. In our discussion, we also elucidate the underlying pathophysiology, with the objective of improving clinician understanding of various differential diagnoses.

Adult Presentation of Ornithine Transcarbamylase Deficiency: 2 Illustrative Cases of Phenotypic Variability and Literature Review

Ornithine transcarbamylase (OTC) deficiency is an X-linked recessive disorder that usually presents in the neonatal period. Late-onset presentation of OTC can cause mild to severe symptoms. We describe laboratory and clinical findings of late-onset presentations of OTC deficiency. We conducted a literature search using search terms "ornithine transcarbamylase deficiency," "late onset presentation," and "hyperammonemia" from January 1, 1987, to December 31, 2016, was performed. Only papers published in English were included. We searched on PubMed, MEDLINE, and Google Scholar. We also present 2 OTC deficiency cases. A total of 30 adult cases had late-onset presentation of OTC deficiency reported. The majority were women (57%) with a median age of 37 years. The median level of ammonia was 308 mmol/L and the mortality rate was 30%. Our case 1 was a 40-year-old woman who succumbed to neurologic complications after a hyperammonemia crisis following an increased protein intake. Our case 2 was a 43-year-old woman with seizures associated with increased ammonia levels. Our 2 case reports show the wide phenotypic variability and severity in late-onset presentation of OTC ranging from seizures to cerebral herniation. Our literature review is the first to detail published laboratory and neurologic sequelae of late-onset OTC deficiency.

Advances in urea cycle neuroimaging: Proceedings from the 4th International Symposium on urea cycle disorders, Barcelona, Spain, September 2013

Our previous imaging research performed as part of a Urea Cycle Rare Disorders Consortium (UCRDC) grant, has identified specific biomarkers of neurologic injury in ornithine transcarbamylase deficiency, OTCD. While characterization of mutations can be achieved in most cases, this information does not necessarily predict the severity of the underlying neurological syndrome. The biochemical consequences of any mutation may be modified additionally by a large number of factors, including contributions of other enzymes and transport systems that mediate flux through the urea cycle, diet and other environmental factors. These factors likely vary from one patient to another, and they give rise to heterogeneity of clinical severity. Affected cognitive domains include non-verbal learning, fine motor processing, reaction time, visual memory, attention, and executive function. Deficits in these capacities may be seen in symptomatic patients, as well as asymptomatic carriers with normal IQ and correlate with variances in brain structure and function in these patients. Using neuroimaging we can identify biomarkers that reflect the downstream impact of UCDs on cognition. This manuscript is a summary of the presentation from the 4th International Consortium on urea cycle disorders held in, Barcelona, Spain, September 2, 2014.

[Adult-onset rare diseases]

The present paper is focusing on rare diseases manifesting in late childhood or adulthood. A part of these syndromes are not of genetic origin, such as relatively or absolutely rare infections, autoimmune diseases, tumours, or diseases due to rare environmental toxic agents. In addition, even a large proportion of genetic disorders may develop in adulthood or may have adult forms as well, affecting are almost each medical specialization. Examples are storage disorders (e.g. adult form of Tay-Sachs disease, Gaucher-disease), enzyme deficiencies (e.g. ornithin-transcarbamylase deficiency of the urea cycle disorders), rare thrombophilias (e.g. homozygous factor V. Leiden mutation, antithrombin deficiency), or some rare monogenic disorders such as Huntington-chorea and many others. It is now generally accepted that at least half of the 6-8000 "rare diseases" belong either to the scope of adult-care (e.g. internal medicine, neurology), or to "age-neutral" specialities such as ophtalmology, dermatology etc.).

The neuropsychiatry of inborn errors of metabolism

A number of metabolic disorders that affect the central nervous system can present in childhood, adolescence or adulthood as a phenocopy of a major psychiatric syndrome such as psychosis, depression, anxiety or mania. An understanding and awareness of secondary syndromes in metabolic disorders is of great importance as it can lead to the early diagnosis of such disorders. Many of these metabolic disorders are progressive and may have illness-modifying treatments available. Earlier diagnosis may prevent or delay damage to the central nervous system and allow for the institution of appropriate treatment and family and genetic counselling. Metabolic disorders appear to result in neuropsychiatric illness either through disruption of late neurodevelopmental processes (metachromatic leukodystrophy, adrenoleukodystrophy, GM2 gangliosidosis, Niemann-Pick type C, cerebrotendinous xanthomatosis, neuronal ceroid lipofuscinosis, and alpha mannosidosis) or via chronic or acute disruption of excitatory/inhibitory or monoaminergic neurotransmitter systems (acute intermittent porphyria, maple syrup urine disease, urea cycle disorders, phenylketonuria and disorders of homocysteine metabolism). In this manuscript we review the evidence for neuropsychiatric illness in major metabolic disorders and discuss the possible models for how these disorders result in psychiatric symptoms. Treatment considerations are discussed, including treatment resistance, the increased propensity for side-effects and the possibility of some treatments worsening the underlying disorder.

Successful early management of a female patient with a metabolic stroke due to ornithine transcarbamylase deficiency

BACKGROUND

Ornithine transcarbamylase deficiency (OTC-D) is a urea cycle disorder caused by dysfunction of ornithine transcarbamylase, which frequently leads to hyperammonemia. Hyperammonemia represents a medical emergency requiring prompt treatment to reduce plasma ammonia levels and prevent severe neurological damage, coma, and death, particularly in patients with acute decompensation-related coma. The clinical symptoms of OTC-D can manifest themselves either at an early stage, which is often associated with severe symptoms, or in later life (late-onset OTC-D), when symptoms may be less severe. There is currently little agreement over diagnostic signs of the condition or the most appropriate therapeutic approach. Hyperammonemia is usually treated with ammonia scavengers, continuous venovenous hemodialysis, and dietary changes. N-carbamylglutamate is approved for the treatment of hyperammonemia in N-acetylglutamate synthetase deficiency and may have efficacy in other urea cycle disorders.

METHODS/RESULTS

Here, we report a 13-year-old girl who was diagnosed with OTC-D at the age of 3 years. On this occasion, the patient presented with vomiting, lethargy, and mental confusion. Despite biochemical parameters being within normal ranges, she was comatose within a few hours. She was promptly treated with a combined therapy of continuous venovenous hemodialysis and N-carbamylglutamate, resulting in a gradual normalization of clinical symptoms within 30 hours. No neurological damage was apparent at 18 months after treatment.

CONCLUSIONS

This case demonstrates that clinical benefits can be obtained by beginning aggressive treatment of OTC-D within a few hours of the onset of severe neurological symptoms even in the absence of altered biochemical markers.

A novel mutation of the ornithine transcarbamylase gene leading to fatal hyperammonemia in a liver transplant recipient

Ornithine transcarbamylase (OTC) deficiency (OTCD) is an X-linked urea cycle disorder. Being an X-linked disease, the onset and severity of the disease may vary among female carriers. Some of them start to develop the disease early in life, whereas others remain asymptomatic throughout their lives. Our patient was a 42-year-old man who developed severe hyperammonemia and fatal brain edema after receiving a right lobe graft from an asymptomatic female living donor with unrecognized OTCD. The donor developed hyperammonemia and disturbed level of consciousness that was managed successfully by hemodialysis. Molecular testing of the OTC gene in the donor revealed a heterozygous nonsense mutation (c.429T>A) in exon 5.

Living donor liver transplantation from an asymptomatic mother who was a carrier for ornithine transcarbamylase deficiency

Liver transplantation (LT) has been adopted as a radical treatment for ornithine transcarbamylase deficiency (OTCD), yielding favorable outcomes. Despite the fact that it is an inheritable disease, a blood relative who is heterozygous for the disorder must sometimes be used as a liver donor for living donor LT. There is ongoing discussion regarding the use of heterozygous donors, however, to our knowledge, no cases where donation was determined based on the Ornithine transcarbamylase (OTC) activity before LT have been reported. Between May 2001 and April 2011, 17 patients were indicated for living donor LT because of OTCD at our facility. There were three cases with heterozygous donor candidate (17.6%). All heterozygous candidates underwent a liver biopsy to measure their OTC activity before LT and made efforts to secure the safety of the both donor and recipient. Two of 3 candidates had headaches sometimes, and their activity was less than 40%, and thus they were not employed as the donor. One candidate with 104.4% activity was employed, yielding favorable outcomes. Our current experience supported the effectiveness of our donation criteria, however it is necessary to collect sufficient data on a large number of patients to confirm the safety of the procedure.

Early clinical manifestations and eating patterns in patients with urea cycle disorders

OBJECTIVES

To characterize dietary habits and eating patterns in patients with a urea cycle disorder (UCD), and to identify dietary habits that may serve as clues to lead to earlier diagnosis of these disorders.

STUDY DESIGN

This was a retrospective study of clinical and dietary data from hospital records of all patients with UCD (n = 90) attending the Royal Children's Hospital in Melbourne between 1972 and 2010.

RESULTS

Protein aversion, food refusal, frequent vomiting, poor appetite, and adverse reaction to high-protein-containing foods were documented in the majority of patients with available detailed dietary protein intake data. Fourteen of the 90 admissions for metabolic deterioration in which information regarding the precipitating factor(s) were available were directly related to protein intake (5 higher and 9 lower than prescribed).

CONCLUSION

Protein aversion is a common feature of UCD and may serve as a diagnostic clue in patients presenting with food refusal, recurrent vomiting, behavioral problems, mental retardation, and "unexplained" episodes of altered consciousness. Dietary history should be included in the investigation of these symptoms, which might lead to earlier diagnosis. Metabolic decompensation is more frequently related to low energy/protein intake than to high protein intake in these patients. Special attention should be given to protein aversion, which often leads to eating patterns that make it difficult for a patient to achieve the prescribed daily protein requirement.

Peripartum management of two parturients with ornithine transcarbamylase deficiency

Ornithine transcarbamylase deficiency is a rare X-linked disorder in which female carriers are usually heterozygous for the ornithine transcarbamylase deficiency gene. In pregnancy it has been associated with altered mental status, seizures, coma and death, especially in the postpartum period. We report the management of labor and delivery in two parturients with known ornithine transcarbamylase deficiency. Both patients were maintained on arginine, citrulline and sodium phenylacetate therapy with restricted protein intake during pregnancy. Neuraxial techniques were used for pain relief in labor and anesthesia for operative delivery. A dextrose infusion provided caloric intake during labor and perioperatively.

Hyperammonemic coma in an ornithine transcarbamylase mutation carrier following antepartum corticosteroids

Women who are carriers of the ornithine transcarbamylase (OTC) mutation are at risk for developing hyperammonemia during the postpartum period and at times of metabolic stress. We present a unique case of hyperammonemic coma occurring in an OTC mutation carrier during the antepartum period. Multiple factors, including the administration of antenatal corticosteroids, likely precipitated this critical condition. Clinicians should be aware of this life-threatening clinical presentation and be prepared to identify, treat, and prevent hyperammonemia in affected individuals.

Ornithine transcarbamylase deficiency presenting as hepatitis

Ornithine transcarbamylase deficiency is an inborn error of metabolism that commonly presents as hyperammonemia in neonates. We present a case of a 2-year-old girl who was referred to a pediatric emergency department for evaluation of hepatitis, an uncommon presentation of ornithine transcarbamylase deficiency. Recognition of late presentations of this disease is important for survival and neurological outcome.

[Ornithine transcarbamylase deficiency in adult]

INTRODUCTION

Ornithine transcarbamylase (OTC) deficiency is a X-linked inherited disorder characterized by hyperammoniemic encephalopathy in male neonates. However, there is an increased evidence of late-onset disease, including in adults.

CASE REPORTS

A 23-year-old woman presented with vomiting, somnolence, confusion and hyperammonemia. Familial history revealed OTC deficiency in three brothers and one sister, but urinary orotic acid level was normal at birth in the reported patient who therefore was considered as mutation-free. The mother was asymptomatic but had cognitive defect and moderate mental deficiency. Molecular biology demonstrated that both our patient and her mother were heterozygous for complete OCT deletion.

CONCLUSION

OCT deficiency could be diagnosed in adult patients at any age and clinical features are various, including hyperammonemic encephalopathy, psychiatric disorders or mental deficiency.

Brain imaging in urea cycle disorders

Urea cycle disorders (UCD) represent a group of rare inborn errors of metabolism that carry a high risk of mortality and neurological morbidity resulting from the effects of accumulation of ammonia and other biochemical intermediates. These disorders result from single gene defects involved in the detoxification pathway of ammonia to urea. UCD include deficiencies in any of the six enzymes and two membrane transporters involved in urea biosynthesis. It has previously been reported that approximately half of infants who present with hyperammonemic coma in the newborn period die of cerebral edema; and those who survive 3days or more of coma invariably have intellectual disability [1]. In children with partial defects there is an association between the number and severity of recurrent hyperammonemic (HA) episodes (i.e. with or without coma) and subsequent cognitive and neurologic deficits [2]. However, the effects of milder or subclinical HA episodes on the brain are largely unknown. This review discusses the results of neuroimaging studies performed as part of the NIH funded Rare Diseases Clinical Research Center in Urea Cycle Disorders and focuses on biomarkers of brain injury in ornithine transcarbamylase deficiency (OTCD). We used anatomic imaging, functional magnetic resonance imaging (fMRI), diffusion-tensor imaging (DTI), and (1)H/(13)C magnetic resonance spectroscopy (MRS) to study clinically stable adults with partial OTCD. This allowed us to determine alterations in brain biochemistry associated with changes in cell volume and osmolarity and permitted us to identify brain biomarkers of HA. We found that white matter tracts underlying specific pathways involved in working memory and executive function are altered in subjects with OTCD (as measured by DTI), including those heterozygous women who were previously considered asymptomatic. An understanding of the pathogenesis of brain injury in UCD is likely to advance our knowledge of more common disorders of liver dysfunction.

[Ornithine transcarbamylase deficiency in adolescence and adulthood: first manifestation with life-threatening decompensation]

BACKGROUND

Ornithine transcarbamylase (OTC) deficiency is the most frequent innate disorder of the urea cycle and is X-chromosome linked. The disease normally manifests itself shortly after birth and is fatal when untreated. Due to the different expression and X-chromosomal inheritance the manifestation of symptoms can appear later particularly in girls and young women. The first symptoms are non-specific signs of elevated cerebral pressure as a result of a hyperammonemia, which range from nausea and headache up to cerebral herniation with fatal outcome. Measurement of plasma ammonia levels is a simple yet important screening test for patients with unexpected stupor or delirium.

CASE REPORTS

The two case reports show the clinical range from acute decompensation with acute cerebral herniation followed by fatal outcome to recovery under emergency therapy without substantial neurological deficits.

THERAPY

Emergency treatment consists of symptomatic securing of vital parameters and an immediate reduction in the ammonia level using high calorie, protein-free nutrition to avoid catabolism together with administration of arginine, benzoate or phenyl butyrate. In cases of coma with severe cerebral edema and the threat of a herniation reaction or excessive ammonia levels, emergency hemodialysis must be immediately carried out.

CONCLUSIONS

In the clinical routine it is extremely important to consider a metabolic defect at an early phase and among others to determine the ammonia level so that the appropriate treatment can be instigated in time.

Neurologic damage and neurocognitive dysfunction in urea cycle disorders

Although the survival of patients who have urea cycle disorders has improved with the use of modalities such as alternative pathway therapy and hemodialysis, neurologic outcome is suboptimal. Patients often manifest with a variety of neurologic abnormalities, including cerebral edema, seizures, cognitive impairment, and psychiatric illness. Current hypotheses of the pathogenesis underlying brain dysfunction in these patients have focused on several lines of investigation, including the role of glutamine in causing cerebral edema, mitochondrial dysfunction leading to energy failure and the production of free radicals, and altered neurotransmitter metabolism. Advances in understanding the pathogenetic mechanisms underlying brain impairment in urea cycle disorders may lead to the development of therapies designed to interfere with the molecular cascade that ultimately leads to cerebral edema and other brain pathological findings.

Hemodialysis for hyperammonemia associated with ornithine transcarbamylase deficiency

Acute hyperammonemia is a medical emergency requiring rapid recognition and treatment to prevent devastating neurologic sequelae. Its varying etiologies include primary hepatic failure, drug toxicity, infection, and inherited disorders of metabolism. Ornithine transcarbamylase (OTC) deficiency is the most common inherited urea cycle disorder and can result in hyperammonemic encephalopathy and coma, often presenting in the newborn or early childhood. Partial deficiencies of the enzyme can present later in adulthood with protean neuropsychiatric signs and symptoms. Early recognition and management of metabolic encephalopathy is crucial to avoid neurologic damage, and may require hemodialysis for rapid removal of ammonia, with adjunctive medications and dietary modifications to decrease endogenous nitrogen production and activate alternate pathways of nitrogen excretion. We present the case of an adult patient with partial OTC deficiency who presented with encephalopathy, coma, and seizures, accompanied by hyperammonemia and treated acutely with hemodialysis.

Acute fatal presentation of ornithine transcarbamylase deficiency in a previously healthy male

Ornithine transcarbamylase (OTC) deficiency is an X-linked urea cycle defect. While hemizygous males typically present with hyperammonemic coma in infancy, reports of rare late-onset presentations exist, with poor outcomes in males up to 58 years old. Relatives with mutations identical to affected patients often remain asymptomatic, and it is likely that environmental and genetic factors influence disease penetrance and expression. Here, we present our investigation of a patient with late-onset presentation, and we emphasize the potential role of environmental and genetic factors on disease expression. The patient was a previously healthy 62-year-old man who developed mental slowing, refractory seizures, and coma over an 8-day period. Interestingly, the patient had recently used home gardening fertilizers and pesticides. Evaluations for drug and alcohol use, infections, and liver disease were negative. Despite aggressive therapy, blood NH₃ concentration peaked at 2,050 μM and the patient died from cerebral edema and cerebellar herniation. Analysis of the OTC gene showed a Pro-225-Thr (P225T) change in exon 7, a mutation that has been previously implicated in OTC deficiency. This case illustrates that OTC deficiency can cause acute, severe hyperammonemia in a previously healthy adult and that the P225T mutation can be associated with late-onset OTC deficiency. We speculate that exposure to organic chemicals might have contributed to the onset of symptoms in this patient. This case also emphasizes that persistent hyperammonemia may cause irreversible neurologic damage and that after the diagnosis of hyperammonemia is established in an acutely ill patient, certain diagnostic tests should be performed to differentiate between urea cycle disorders and other causes of hyperammonemic encephalopathy.

Neurological implications of urea cycle disorders

The urea cycle disorders constitute a group of rare congenital disorders caused by a deficiency of the enzymes or transport proteins required to remove ammonia from the body. Via a series of biochemical steps, nitrogen, the waste product of protein metabolism, is removed from the blood and converted into urea. A consequence of these disorders is hyperammonaemia, resulting in central nervous system dysfunction with mental status changes, brain oedema, seizures, coma, and potentially death. Both acute and chronic hyperammonaemia result in alterations of neurotransmitter systems. In acute hyperammonaemia, activation of the NMDA receptor leads to excitotoxic cell death, changes in energy metabolism and alterations in protein expression of the astrocyte that affect volume regulation and contribute to oedema. Neuropathological evaluation demonstrates alterations in the astrocyte morphology. Imaging studies, in particular (1)H MRS, can reveal markers of impaired metabolism such as elevations of glutamine and reduction of myoinositol. In contrast, chronic hyperammonaemia leads to adaptive responses in the NMDA receptor and impairments in the glutamate-nitric oxide-cGMP pathway, leading to alterations in cognition and learning. Therapy of acute hyperammonaemia has relied on ammonia-lowering agents but in recent years there has been considerable interest in neuroprotective strategies. Recent studies have suggested restoration of learning abilities by pharmacological manipulation of brain cGMP with phosphodiesterase inhibitors. Thus, both strategies are intriguing areas for potential investigation in human urea cycle disorders.

Der Patient mit Ornithintranscarbamylasemangel

Ornithine transcarbamylase deficiency (OTCD) is the most common inborn urea cycle disorder. Patients with OTCD are at risk of acute metabolic decompensation with hyperammonemia and subsequent encephalopathy, coma and death. Symptoms may be triggered by infections, drugs and stress, evoked by trauma, pain, fear, surgery and anaesthesia or by episodes of protein catabolism, i.e. fasting-induced, post partum or during gastrointestinal bleeding. Several specific considerations must be made for anaesthetic and intensive care management in patients with this disease in order to avoid metabolic decompensation. We report the intensive care management of the first manifestation of late-onset OTCD in a 16-year-old girl and a course of inconspicuous general anaesthesia with midazolam, s-ketamine, fentanyl and isoflurane in a 22-year-old girl with known OTCD.

Pediatric Liver Transplantation: Ten Years of Experience in a Multicentric Program in Chile

Liver transplantation is the only treatment for patients with terminal acute and chronic diseases. Liver transplantation was started in Chile in 1985; our pediatric program began in 1993. The aim of this paper work was to present our experience from 1993 through 2004. One hundred and thirty two orthotopic liver transplants (OLT) were performed in children of mean age 5 years and median age 4 years (8 months to 15 years). The most frequent indications were biliary atresia, (43.1%) and acute liver failure (ALF; 20.4%), whose frequent cause was unknown but viral hepatitis A was the second one. A complete liver was transplanted in 59 patients, reduced in 39, split in one, and as an auxiliary liver in another one. Living related liver transplantation was performed in 32 cases (24.2%), of which thirty included segments II and III, and two, a right liver. A terminal arterial anastomosis was performed in 102 (77.2%) recipients and a graft interposition in 32 patients (24.2%). In 16 cases, biliary reconstruction was performed through an enterobiliary anastomosis. Immunosuppression included cyclosporine (Neoral), steroids, and azathioprine with conversion to tacrolimus (Prograf) as indicated. Rejection episodes, which were always biopsy-proven, were treated either with methylprednisolone or with antibodies. Biliary complications were the most frequent (21.4%) and the second cause was vascular complications (13%). Sixty-six patients suffered an acute rejection episode. Actuarial graft survival was 81.3% at 1 year and 72% at 5 years, while actuarial graft survival for ALF was 75.9% at 1 year and 67.8% at 5 years. Our results are comparable to those reported by most international groups.