Postoperative Care of Pediatric Transplant Recipients

Nutrition

Protein-calorie malnutrition is common in ESLD and adversely affects clinical outcomes. Contributing factors that threaten nutritional status in these patients include the presence of a chronic catabolic state requiring significantly higher calorie intake, the loss of appetite, hormonal imbalances, and poor absorption of essential nutrients. Early diagnosis is important to allow appropriate intervention and prevention of malnutrition-associated complications such as growth stunting and bone fractures. Unfortunately, weight alone is a poor indicator of nutritional status in patients with ascites and organomegaly. Linear growth is a good indicator of long-term nutrition but provides little guidance for acute management. It is important to note that abdominal girth and skinfolds can be falsely increased by ascites and peripheral edema. A thorough assessment and good clinical judgment are needed to reach an accurate evaluation.

Correction of nutritional deficiencies provides a significant challenge, especially when the liver disease is cholestatic and its onset is in the first few months of life. Portal hypertension, organomegaly, and ascites can all contribute to enteral feeding intolerance. Nourishing children with liver disease is a challenging task that requires well-timed nutritional intervention, including oral supplementation with high-calorie formulas, enteral tube feedings, and/or parenteral nutritional supplementation. The goal of these interventions is to provide a balance of macronutrients, micronutrients, and vitamins, all of which are paramount to improving clinical outcomes. A majority of these patients will benefit from the use of MCT-enriched formulas to promote improved calorie absorption. Bone health is important for growing children. Therefore it is essential that mineral and vitamin deficiencies be diagnosed in a timely manner and treated aggressively. These medically complex children are best managed by dedicated multidisciplinary teams.

Fulminant Liver Failure

This multisystemic disorder characterized by sudden and severe hepatic injury can occur in people with no recognized prior liver disease. The heterogeneous nature of the insults may have specific implications for medical management. Loss of hepatic metabolic and immunological function may progress to hepatic encephalopathy, life-threatening cerebral edema, coagulopathy, and in many cases, multisystem organ failure.

The preoperative and postoperative management of fluids, electrolytes, hemodynamics, and cerebral perfusion must be judicious. It may be necessary to place intracranial pressure monitors for optimal management of these patients, but noninvasive monitoring of cerebral arterial flow using repetitive transcranial Doppler examinations is emerging as a useful tool to identify intracranial hypertension. Unfortunately, the risk for cerebral hypertension does not end immediately after a successful LT and can persist into the second and third postoperative days. These patients often have severe coagulation abnormalities placing them at increased risk for intraoperative bleeding. The role of the systemic inflammatory response in the pathogenesis of increased intracranial pressure has been recognized as an important factor; this supports the clinical administration of prophylactic antibiotics to improve outcomes. Extracorporeal liver assist devices have been successfully used in children with the goal of removing circulating toxins that are produced, or not metabolized, by the failing liver. These devices have helped stabilize patients, allowing time for spontaneous regeneration of the native liver or transplantation. In small randomized trials, however, these assist devices have not improved survival and are far from being the standard of care.

Multiorgan Failure

Liver failure often leads to a unique cascade of organ dysfunctions. Emergency LT is often the only effective treatment for severe multiorgan failure with unpredictable complications. Outcomes worsen with increasing organ system failures, use of vasopressors, mechanical ventilation, or renal replacement therapy; all of these are considered markers for high mortality. Multiorgan system support measures are imperative to stabilize patients, permitting time for hepatic regeneration and recovery. This can bridge the patient to organ transplantation by preventing or addressing complications. Although controversial and not universally practiced, delisting should be considered if a meaningful chance of survival is not expected. This ethical cutoff is not well defined, although some have argued that expected 5-year survival should be at 50% for adults, though arguably indications should be extended for children who ultimately gain far more years of survival if the transplant succeeds.

Metabolic Disorders

Patients with inborn errors of metabolism generally have specific deficiencies of one or more enzymes required for substrate metabolism. These deficits lead to various biochemical derangements and clinical manifestations. As a result, these patients require certain medications and dietary restrictions before LT. Some of these disorders require urgent neonatal LT. This further complicates postoperative care because of technical issues and the immature physiologic status of neonates. Some patients with metabolic disease have involvement of other organs, such as brain, heart, or kidney; these problems often affect postoperative tolerance to medications. Patients with metabolic disorders may receive auxiliary partial orthotopic liver transplantation (APOLT). The rationale for this is to provide sufficient donor liver to produce the missing enzymes or proteins, while allowing the recipient to salvage his or her own native liver if the donor liver fails. In addition, should a genetic cure for these disorders emerge with advances in the field, removal of the donor graft can be considered to allow full immunosuppression withdrawal.

Malignancy

Primary liver cancers are rare neoplasms of childhood. Hepatoblastoma remains the most common pediatric primary liver cancer. Aggressive management of these patients with a team approach using neoadjuvant chemotherapy, radical resection, and LT (for locally advanced disease or for recurrence) can lead to excellent outcomes in children. HCC that is limited to the liver can be treated with chemotherapy, local regional therapy, and surgery (including resection or transplantation) with good long-term outcomes as well.

Previous Surgery

The majority of pediatric patients undergoing LT have had previous abdominal surgery. The Kasai portoenterostomy, which is used to ameliorate problems caused by biliary atresia, is the most frequent pretransplant abdominal surgery. It predisposes patients to an increased risk for operative blood loss and inadvertent enterotomies during LT. These intraoperative surgical complications negatively affect patient recovery, patient survival, and graft survival.