Pediatric Solid Organ Transplantation
Stacee Lerret, RN, PhD, CPNP-AC/PC, CCTC
Gail Stendahl, RN, DNP, CPNP-AC/PC, CCTC
I. INTRODUCTIONOrgan transplantation for end-stage disease in children is the treatment of choice.
A. Longer waiting times for organs are a result of
Critical shortage of potential donor organs
Expansion of acceptable diagnoses for transplantation
Increase in the number of children on the waiting list1
B. Improving graft and patient outcomes has led the transplant community to focus on the quality of life of pediatric recipients.2
C. This chapter will focus on pediatric kidney, liver, heart, and lung transplantation. Small-bowel transplantation is covered in the chapter on Intestine Transplantation.
II. GENERAL PRINCIPLES ACROSS ALL ORGAN TYPESA. Pretransplant evaluation
The child is evaluated by the interdisciplinary transplant team.
Transplant surgeon, organ-specific physician, social worker, psychologist, dietician, pharmacist, transplant coordinator, and other specialists as indicated based on patient disease
Psychosocial evaluation:
Psychosocial screening is performed by the transplant social worker and/or psychologist to identify family or financial problems that may affect transplant outcomes.
The child should be prepared physically, psychologically, and socially.
Specific cultural and religious beliefs are identified and addressed on an individual basis and include issues such as
Dietary requirements
Use of blood products
Beliefs surrounding transplantation
Medical evaluation typically consists of
Laboratory tests (e.g., complete blood cell count, complete metabolic profile)
Infectious disease screening
Review of immunization records
ABO
Human leukocyte antigen (HLA)
Organ-specific diagnostic tests
Indications and contraindications to transplant:
Organ-specific indications for transplant will be discussed in each section.
Contraindications to transplant are similar across all organ types and include the following:
Active infection
Active substance abuse specifically for adolescents
Active refractory seizure disorder
Active malignancy
Irreversible multisystem organ failure
Relative contraindications will vary across centers but may include the following:
Psychiatric illness
Nonadherence with medical regimen in the pre-evaluation phase
History of substance abuse
Profound neurological devastation
B. Psychosocial support
Emotional support, reassurance, and education are important for patients and families throughout the transplant continuum.
Patients/families must be given ample time to verbalize their concerns and ask questions.
C. Education for patient/family awaiting transplantation, including, but not limited to
Evaluation process
Placement on waiting list
Monitoring while on waiting list
Organ matching
Perioperative events:
Preoperative tests/procedures
Insertion of lines, tubes, etc
Postoperative course
Care of incision
Pain management
Physical activity
Posttransplant regimen (medications, side effects, biopsies, etc.)
Postdischarge follow-up
Complications
D. Pretransplant immunizations
Significant morbidity and mortality can result from preventable diseases. When possible, children should be fully immunized prior to transplantation based on age.
Vaccination protocols depend on transplant program guidelines.
Many diseases are prevented by using “live” vaccines.
Live vaccines are contraindicated in immunocompromised individuals; therefore, they should be given before transplantation.
If the child has no antibodies to specific diseases, appropriate vaccination will be administered during the evaluation period.
E. Pretransplant optimization of dental health
A dental examination is an important component of the pretransplant evaluation.
Poor dental hygiene and caries are a potential source of infection in the immunocompromised patient.
It is essential to optimize dental health prior to transplantation.
F. Placement on waiting list
Once the transplant evaluation has been completed, the child will be presented to the interdisciplinary transplant team.
Assessments by members of the interdisciplinary transplant team are reviewed. These members include, but are not limited to, organ-specific surgeons and other physicians (e.g., nephrologist, hepatologist, cardiologist, pulmonologist), transplant coordinators, nurse practitioners, social workers, psychologists, dietitians, pharmacists, anesthesiologists, and other pediatric specialists based on patient need.
Children who meet eligibility criteria can be placed on the deceased donor waitlist in their respective countries, for example:
United States: United Network for Organ Sharing (UNOS)
Europe: Eurotransplant
Children in need of a liver, kidney, or lung transplant may have the option of living donation.
G. Immediate preoperative care
This period can be challenging, particularly when families have been called in for a transplant from a deceased donor.
It is essential that the transplant team explain what will happen in the perioperative and immediate postoperative periods, such as
Preoperative procedures:
Insertion of tubes, lines, wires, etc
Anticipated length of surgery
Operating room (OR) waiting room; periodic updates by member of surgical team
Transfer from the operating room to the postanesthesia care unit (PACU) or intensive care unit (ICU)
Postoperative pain management
H. Postoperative pain assessment and management
Pain assessment and management
Assessment is patient centered, ongoing, and dependent on the child’s stage of development.
Infants and toddlers:
Monitor vital signs.
Observe for change in behavior:
Characteristics of child’s cry
Body movement
Facial expression
Preschoolers may be able to use a FACES scale or simple Likert scale indicating 0 (no pain) to 10 (worst pain in their life).
Although school-age children and adolescents can use a self-report visual analog scale, it is important to monitor them for physiologic and behavioral indicators of pain.
Explain all procedures using age-appropriate language.
Patient-controlled analgesia (PCA):
Allows the patient or nurse to administer small doses of opioids in addition to a continuous infusion
Appropriate with guidance from the pain management team
Common side effects to observe for when opioids are administered via the epidural/IV route include
Respiratory depression
Facial pruritus
Urinary retention
Nausea and vomiting
III. PEDIATRIC KIDNEY TRANSPLANTATIONA. Overview: Renal transplant in children
According to current United Network for Organ Sharing (UNOS) data3:
718 children 0 to 17 years old underwent kidney transplantation in 2015 in the United States.
More than 1,000 children continue to wait for a new kidney on the waiting list.3
B. Indications and contraindications
Causes of renal failure in children are different than those of adulthood.4
Diagnoses leading to end-stage renal disease include (Table 17-1):
Glomerulonephritis
TABLE 17-1 Diagnoses Leading to End-Stage Organ Disease in Children
Lung Diseases
Kidney Diseases
Alveolar proteinosis
Bronchiectasis
Bronchopulmonary dysplasia
Cystic fibrosis
Interstitial lung disease
Pulmonary hypertension
Renal dysplasia/hypoplasia/aplasia
Obstructive uropathy
Focal segmental glomerulosclerosis
Reflux pyelonephritis
Henoch-Schönlein purpura
Bilateral Wilms’ tumor
Liver Diseases
Biliary atresia
Alpha-1 antitrypsin deficiency
Wilson’s disease
Alagille’s syndrome
Acute liver failure
Viral hepatitis
Glycogen storage disease
Liver tumor (hepatoblastoma)
Heart Disease
Congenital heart disease such as hypoplastic left heart syndrome
Cardiomyopathies
Cardiac tumors
Focal segmental glomerulosclerosis (FSGS)
Polycystic kidney disease
Pyelonephritis
Rarely, metabolic disease such as cystinosis
Bilateral Wilms’ tumor
Incidence is age dependent:
In the younger child, the cause is more commonly congenital.
In the older child, glomerulonephritis or FSGS is more frequently the cause.
Contraindications to kidney transplantation are listed above in the “all organ section.”
Timing of kidney transplantation:
Transplantation may be considered when the glomerular filtration rate (GFR) is approximately 30 mL/min per 1.73 m2.5
Internationally, there are differences in practice:
Some countries promote preemptive transplantation.
Some countries do not promote living donor transplantation.
C. Pretransplant evaluation
Blood tests:
ABO (blood type)
Human lymphocyte antigen (HLA) typing
Panel of reactive antibodies (PRA)
See the Basics in Transplant Immunology chapter for an explanation of HLA typing and PRA.
Complete metabolic profile
Complete blood cell count (CBC) with differential
Coagulation studies:
Prothrombin time (PT) and partial thromboplastin time (PTT)
Consider thrombophilia screen:
Arterial or venous thrombosis can cause graft failure in the immediate postoperative period, usually within the first 2 to 3 days.2
Screening includes2
Anticardiolipin antibodies
Factor V Leiden
Antilupus coagulant
Protein C
Protein S
The genetic component methylenetetrahydrofolate reductase (MTHFR)
Patients found to have a clotting tendency or genetic predisposition to coagulation are treated with anticoagulants immediately after the transplant surgery.
Treatment may continue for approximately 6 months thereafter depending on the transplant center protocol.
Lipid profile
Infectious disease screening to include
Cytomegalovirus (CMV)
Epstein-Barr virus (EBV)
Hepatitis B virus (HBV) and hepatitis C virus (HCV)
Tuberculosis (TB) skin test:
Purified protein derivative (PPD) skin test
Measles, mumps, rubella (MMR) titers
Varicella-zoster virus (VZV) titers
Human immunodeficiency virus (HIV) viii. Toxoplasmosis5
Syphilis by testing rapid plasma reagin (RPR) or venereal disease research laboratory (VDRL)
Urinalysis and urine culture
Renal ultrasound
Additional tests: Potential recipients also may be screened with the following:
Audiologic examination
Bone age films
Ophthalmologic examination
Chest radiograph
Electrocardiogram (ECG)
Echocardiogram
Children with bladder problems require additional evaluation prior to transplantation:
Poor bladder function can cause kidney damage to the newly transplanted kidney; therefore, the nature and extent of bladder abnormalities must be determined.
This evaluation can include ultrasound, voiding cystourethrogram (VCUG), and/or urodynamics.
Bladder function tests must be carried out with the patient awake because sedatives will affect the bladder and confound the test results.
Renal failure secondary to reflux nephropathy, obstructive uropathy, or neuropathic bladder may demonstrate abnormalities that affect continence and bladder capacity.
Corrective action may include
Double voiding. This is a method that can be used to help with urinary retention. Double voiding consists of an initial urination and then a second attempt within 5 minutes.
Initiating self-catheterization.
Bladder augmentation. This is done when a piece of the bowel or stomach is added to the bladder in order to increase the volume of the bladder.
Treatment, including surgical correction, is done prior to transplantation to ensure the bladder function is optimized.
Occasionally, the surgical procedure is performed after transplantation.
D. Placement on the waiting list
Time is the main factor in waiting for a kidney transplant as kidneys are allocated based on recipient length of time on waitlist.
Patients are either active or inactive on the waitlist.
Pediatric candidates accrue waiting time upon listing and receive additional time if dialysis was started prior to listing.
There is no GFR requirement with children in order to place on waitlist.
E. Pediatric organ allocation
Refer to adult kidney transplant chapter.
The Kidney Donor Profile Index (KDPI) score can help predict how a particular kidney is expected to function.
F. Waitlist management
While on the waitlist, children receive dialysis as indicated and are seen by the transplant team as dictated by disease severity.
G. Care of the pediatric transplant candidate
Scheduled appointments with dialysis and transplant teams to assure optimal health
Routine monitoring of nutritional status and risk for infection
H. Immediate preoperative care or perioperative management
If the child has been dialysis dependent, a dialysis session may be necessary immediately prior to transplantation to optimize fluid and electrolyte balance.
Baseline vital signs: temperature, blood pressure, and heart and respiratory rates
Preoperative tests may include
ECG
Chest radiograph
Blood tests (chemical profile, clotting screen, complete blood cell count)
Urinalysis and microscopy
Type and cross for blood
Calculation of a child’s body surface area (BSA) is essential for accurate prescribing and administration of medication.
BSA = height × weight/3,600
Administration of preoperative medications per program-specific protocols, such as
Induction immunosuppressive agents
Monoclonal antibody, steroids, calcineurin inhibitors, or antiproliferative agents
I. Surgical Procedure
The main blood vessels used in kidney transplantation are
Inferior vena cava (IVC)
Aorta
Iliac arteries and veins
Placement of kidney:
Older children (typically >3 years) will have the donor kidney implanted in an extraperitoneal position.
Donor vessels are anastomosed to the iliac vessels.
Infants or small children have the kidney placed intraperitoneally.
Donor blood vessels are anastomosed directly to the aorta and the IVC.
Following reperfusion, the donor ureter is anastomosed to the bladder.
Native kidneys usually are not removed prior to renal transplantation because removing the native kidneys has been noted to increase the rate of surgicalrelated morbidity.
Clinical situations that may involve removing native kidneys in a child include
Severe or poorly controlled hypertension to prevent damage to the new kidney
Polycystic kidney disease owing to space issues
J. Posttransplant care
In the immediate postoperative period, emphasis will be on monitoring for posttransplant complications.
Regular recording of vital signs (Table 17-2).
Frequency is determined by program-specific protocols.
Observations include
Blood pressure
Heart and respiratory rates
Core/peripheral temperature
Pulse oximetry
Central venous pressure (CVP) monitoring
Intake and output initially recorded hourly including
Intravenous (IV) infusions
Blood loss from drains and surgical incision
Output via urinary catheter and/or emesis
Perfusion of the kidney is evaluated immediately postoperatively using Doppler ultrasound depending on the center specific transplant protocol.
Hemodynamic stability is a priority and is monitored closely.
Fluid balance:
If the child is polyuric, hypovolemia may occur rapidly.
If the child is oliguric, hypervolemia may develop.
Oliguria is defined as a urine output i1 mL/kg/h in infants and <0.5 mL/kg/h in children.
Initially, the IV fluid regimen includes 100% replacement of urine output with 0.45% normal saline.
Close observation of respiratory rate and effort is necessary to monitor for pulmonary edema, especially in the oliguric patient.
TABLE 17-2 Typical Postoperative Observations
Kidney
Liver
Heart-Lung
General observation
Y
Y
Y
Temperature (core +/- peripheral)
Y
Y
Y
Blood pressure
Y
Y
Y
Heart rate
Y
Y
Y
Respiratory rate
Y
Y
Y
CVP
Y
Y
Y
Pulse oximetry
Y
Y
Y
Pulmonary artery catheter measurement
N
N
Y
Telemetry/epicardial pacemaker
N
N
Y
Fluid balance
Y
Y
Y
Wound site
Y
Y
Y
Daily weights
Y
Y
Y
If the child is hyponatremic or has a urinary sodium >100 mmol/L:
Urinary replacement fluid should be alternated between 0.45% and 0.9% normal saline.
Urinary sodium, potassium, and creatinine levels can assist with fluid management and should be assessed regularly based on individual center guidelines.
CVP measurement is continuous.
Maintain in the range of + 4 to + 8 cm H2O with IV infusion of either 4.5% albumin or 0.9% saline.
Low CVP can be indicative of hypovolemia, which can lead to poor graft perfusion.
Hypovolemia may be presumed if
There is a gap of ≥2°C between the core and peripheral temperature.
The child is hypertensive and has a low CVP.
Hypovolemia can be corrected by
Administering 5 to 10 mL/kg of 0.45% albumin over 0.5 to 1 hour with close monitoring of CVP changes.
Repeating albumin infusion as clinically necessary.
Dopamine may be administered to maintain cardiac output and increase allograft perfusion.
Observation for excessive bleeding via the wound site, catheter, or abdominal drain is vital.
The abdominal drain remains in place for the first few days postoperatively until minimal drainage is observed.
The bladder urinary catheter remains on gravity drainage for a time period determined by center protocols, but usually for 4 days.
If the patient suddenly becomes oliguric, assess for a blocked catheter.
Observe the patient for pallor, hypotension, and tachycardia.
Monitor laboratory data at the frequency determined by transplant program protocols.
Chemistry profile:
Hypocalcemia may occur in the very early postoperative period in children with
A long history of dialysis therapy
Poorly controlled hyperparathyroidism
CBC and differential
Venous blood gas
Immunosuppressant trough levels
K. Organ-specific posttransplant complications
Complications after renal transplant can be divided into immediate, early, and late complications.
Immediate complications relate to the intraoperative period and include
Hyperacute rejection
Obstruction
Thrombus
Delayed graft function
Acute tubular necrosis (ATN):
Major cause of delayed or primary nonfunction in kidney transplant recipients.
Results from damage to the proximal tubular membranes.
May last for variable periods from hours up to several weeks.
Long cold ischemic times in the donor kidney are considered a predisposing factor for ATN.
Children with ATN present with oliguria prior to becoming anuric.
Close observation of serum potassium levels is vital as an anuric patient will quickly become hyperkalemic.
Dialysis therapy is required.
During prolonged periods of ATN, serial renal biopsies are performed to assess kidney function and monitor for rejection.
Management of ATN includes avoiding nephrotoxic drugs and conservative fluid replacement to prevent hypervolemia.
Early complications-often related to surgical issues:
Bleeding:
Bleeding can occur at the site of the vascular anastomosis or arterial branches.
Bleeding is manifested clinically as
Tachycardia
Hypotension
Falling CVP
Abdominal distension
Pain
Oliguria
Replacement of blood volume and surgical intervention are necessary to control the bleeding.
Thrombus:
Children younger than 5 years are at highest risk for vascular thrombosis secondary to low flow states.
Arterial thrombosis presents with sudden anuria and is often irreversible resulting in graft loss.
Renal artery stenosis:
Diagnosed when the Doppler ultrasound demonstrates turbulent flow
Clinical symptoms are
Hypertension that is difficult to control with or without erythrocytosis
Deteriorating renal function
Renal vein thrombosis:
More common in young recipients
Can often be treated with heparin
Clinical presentation includes
Gross hematuria
Graft swelling
Deterioration of graft function
Wound dehiscence
Lymphocele:
Lymphoceles are collections of lymph that occur when the lymphatic system is cut intraoperatively.
Majority are asymptomatic.
Larger lymphoceles can cause obstruction and hydronephrosis.
Diagnosis is made by Doppler ultrasound or nuclear medicine renal scan examination.
Treatment depends on whether the lymphocele is causing obstruction or dysfunction.
Treatment is by percutaneous aspiration.
May be drained on a single occasion.
May require an indwelling drainage system.
Drainage that continues long-term may require surgical fenestration.
Infection:
Predisposing factors:
Immunosuppressive agents
Hypoalbuminemia
Prevention-prophylactic antibiotics:
Administered at the time of surgery.
Prophylactic antibiotics are typically discontinued after 3 doses.
Signs of infection and/or impaired wound healing include, but are not limited to
Redness
Purulent discharge
Dehiscence
Pyrexia
Diagnosis: swab for microscopy, culture, and sensitivities
Treatment:
Initially broad-spectrum coverage is provided for both aerobic and anaerobic organisms.
Once a specific organism is identified, the appropriate agent is ordered (antiviral, antifungal, or antibacterial).
Urinary leak:
Another potential complication after renal transplantation is a urinary leak at the ureterovesical anastomosis.
Clinical signs include
Unexplained fever
Abdominal pain
Decreased urinary output
Elevated creatinine
Wound drainage
Treatment
Urine leaks are treated with long-term indwelling urinary catheters, or surgical intervention for minor leaks.
Obstruction at the anastomotic site:
Can occur any time after transplantation
Presents as oliguria or elevation of BUN and/or creatinine
Treatment requires surgery:
Acute rejection (See section on Rejection below)
Late complications:
Chronic rejection (See section on Rejection below).
Refer to the chapter on Transplant Complications: Noninfectious Diseases for additional information.
L. Rejection
Types of rejection:
Acute cellular rejection:
Children with rejection present with
Decreased urine output
Increased weight
Hypertension
Increased creatinine levels
Pain over the graft area
Other clinical signs of acute rejection include
Proteinuria or hematuria
Antibody-mediated (humoral) rejection:
Frequently referred to as “vascular” rejection
Always involves blood vessels
Chronic rejection:
Characterized by slow and progressive increase in creatinine
Frequently associated with hypertension and proteinuria
Causes may include
Inadequate immunosuppression
Nonadherence to immunosuppression regimen
Associated with recipients who have had multiple episodes of acute rejection
Treatment typically includes
Increasing the primary immunosuppressive agent dose to achieve a higher drug level
Adjuvant immunosuppressive agents in addition to increase in primary immunosuppressive agent
As renal function continues to deteriorate, the child experiences symptoms of chronic renal failure.
May require phosphate binders, vitamin D administration, and erythropoietin to manage anemia
Diagnosis of rejection:
A definitive diagnosis of rejection can only be made by histopathologic examination of renal tissue following a biopsy (See section on Biopsy and postbiopsy monitoring below)
Grading of rejection:
Banff criteria allow standardization of the diagnosis and rejection grade.
See Table 17-3 for specific Banff criteria.6
Treatment of rejection:
Acute cellular rejection:
Acute cellular rejection is typically treated with methylprednisolone according to individual center protocol.
Additional immunosuppression agents such as antithymoctye globulin (Thymoglobulin; Atgam) may be used for rejection unresponsive to methylprednisolone.
Antibody-mediated rejection:
Choice of therapy depends on program-specific protocols as well as patient-specific considerations based on pretransplant induction therapy.
Treatment may include IVIG and/or plasmapheresis antibody therapy, depending on program-specific protocols.
TABLE 17-3 Banff Criteria Grading of Rejection in Renal Transplant Recipients | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
M. Biopsy and postbiopsy monitoring
Indications for biopsy include
Primary nonfunction of the kidney.
A >10% rise over the previous day’s creatinine level.
Individual center protocols may include surveillance or routine biopsies.
Preparation for biopsy:
Explain procedure to parents and child.
Ensure that informed consent is signed by parents.
Obtain laboratory tests as ordered.
Clotting screen including prothrombin time (PT)/international normalized ratio (INR)
Type and cross of blood:
At least one unit of blood should be available in case of bleeding after biopsy.
Anesthesia options:
Renal biopsy can be performed under general anesthesia, conscious sedation, or local anesthesia depending on the age of the child and transplant program protocol.
Procedure:
Usually performed under ultrasonic guidance
Complications:
The nurse should monitor for bleeding from the biopsy site as well as routine postanesthesia complications including nausea and vomiting.
Biopsy results:
May demonstrate any of the following:
Healthy kidney tissue
Resolving ATN
Calcineurin inhibitor (CNI) toxicity
Rejection
N. Summary
Kidney transplantation is
A treatment for end-stage kidney disease where the patient and family trade a life-threatening illness for a posttransplant chronic illness:
Lifelong medication to suppress the immune system
Long-term clinical follow-up
Internationally accepted as the best option for children with end-stage renal failure7
A successful kidney transplant is measured by both patient and graft survival rates.
IV. PEDIATRIC LIVER TRANSPLANTATIONA. Overview
Liver transplantation is the accepted treatment for end-stage liver disease in children.
According to the UNOS database, 580 children 0 to 17 years of age underwent liver transplantation in 2015.3
More than 450 children continue to await liver transplantation.3
Until the mid-1990s, survival rates for children had been limited by the lack of available size-matched donors.
Long waiting periods for an appropriate donor resulted in high mortality rates for patients on the transplant waiting list.
Reduced-size liver transplantation using the right lobe, left lobe, or left lateral segment from a deceased donor was recommended.
Purpose:
To address the issues of small intra-abdominal space
To alleviate the high rates of mortality
Initially, this procedure was used in critically ill children who required immediate transplantation.
Improved survival rates on the liver transplant waitlist were demonstrated as more patients were undergoing transplantation.
Today, multiple procedures exist for transplantation of the smallest recipients including
Living related donor transplants:
Living donors are evaluated by a separate adult transplant team.
Centers that offer this option must consider the ethical dilemma of subjecting a healthy donor to surgery.
Split liver grafts:
Division of a liver graft into two sections resulting in liver transplantation of two individuals
Reduced-size liver grafts:
Surgically modified graft to fit participant
Whole liver grafts
B. Indications and contraindications
Children referred for liver transplantation have end-stage liver disease; see Table 17-1.
Contraindications to liver transplantation are listed above in the “all organ section.”
C. Pretransplant liver evaluation
The child is evaluated by the interdisciplinary transplant team.
Transplant surgeon, hepatologist or gastroenterologist with expertise in liver disease, social worker, psychologist, dietician, pharmacist, transplant coordinator, and other specialists as indicated based on patient disease10
Laboratory tests:
ABO
PT/INR and partial thromboplastin time (PTT)
Comprehensive metabolic panel that typically includes albumin, blood urea nitrogen, calcium, carbon dioxide, chloride, creatinine, glucose, potassium, sodium, total bilirubin, total protein, liver enzymes (alanine aminotransferase [ALT], alkaline phosphatase [ALP], aspartate aminotransferase [AST])
CBC
Lipid panel
Ammonia
Amylase
Lipase
Alpha fetoprotein
Vitamin A, D 25-hydroxy, and E levels
Infectious disease screening:
Herpes simplex virus (HSV)
CMV
Hepatitis viruses A, B, and C
VZV titer
EBV
Syphilis by testing rapid plasma reagin (RPR) or venereal disease research laboratory (VDRL)
Toxoplasmosis antibody
HIV
MMR titers
Diagnostic tests:
EKG and/or echocardiogram
Chest radiograph
Doppler ultrasound of the liver
Computerized tomography (CT) scan or magnetic resonance imaging (MRI) of the liver11
Review of immunization records
D. Placement on waiting list
In the United States, potential recipients are listed by blood type, weight, and labs according to age on the UNOS waiting list.12
The pediatric end-stage liver disease (PELD) score was developed simultaneously with the adult model for end-stage liver disease (MELD) score to create an effective system for donor liver allocation in the United States.
PELD score lists children <12 years of age according to the probability of death within 3 months of listing.
Developed from data derived from a sample of children enrolled in the Studies of Pediatric Liver Transplantation (SPLIT).
Factors included in the PELD score include
INR
Total bilirubin (mg/dL)
Serum albumin (g/dL)
Age at listing, <1 year
Growth failure (based on gender, height, and weight)12
MELD score lists children >12 years of age:
Please refer to Liver Transplantation chapter for details regarding MELD score.
Other variables include the following:
Although the maximum adult MELD score is 40, there is no minimum or maximum to the PELD score.
Status 1A and 1B listing for children with acute or chronic liver disease meeting certain criteria.
Pediatric donors maintain priority for allocation to pediatric patients.
Regional boards maintain discretion to upgrade patients to higher PELD score or status 1 if the PELD score does not reflect the urgency for transplantation.13
E. Pediatric organ allocation
Organs are allocated to the patients highest on the list indicative of being the sickest patients.
Status 1A, Status 1B, MELD/PELD scoring system
F. Waitlist management
Patients maintain their active status on the waitlist by confirming the MELD/PELD parameters as documented above and outlined in Liver Transplantation chapter on a periodic basis as directed by UNOS guidelines.
G. Care of the pediatric transplant candidate
Children with end-stage liver disease are at risk for several other problems that require management in the pretransplant period.
Reduced caloric intake:
Nutritional support is required in the pretransplant period.
Cholestasis associated with malabsorption deprives the infant/child of essential fat-soluble vitamins (A, D, E, and K).
Other factors that affect caloric intake include
Anorexia that occurs with chronic disease
Increased abdominal pressures associated with organomegaly, ascites, and varices resulting in
Early satiety
Increased incidence of emesis
Management includes the use of increased caloric density formulas with medium chain triglycerides and night time drip feedings via nasogastric or nasojejunal tubes.10
Aggressive nutritional support before transplant improves patient and graft survival.14
Portal hypertension:
Results from:
Increased portal resistance and/or increased portal blood flow
Therapy is directed at management of the major complication, variceal hemorrhage.
Sclerotherapy or banding may be necessary to minimize risk of variceal bleeding.
Encephalopathy:
Elevated ammonia levels play a central role in the development of encephalopathy.
Manifestations:
Altered mental status
Complaints of increased sleeping
Poor school performance
Treatment:
Lactulose is commonly used although it lacks evidence of efficacy.
Bowel decontamination with rifaximin or neomycin.15
H. Immediate preoperative care or perioperative management
Once a donor organ is available, the child is brought to the hospital and preoperative laboratory tests are obtained.
The child is brought into the operating room and intubated.
One to two large-bore catheters and/or central lines are placed.
I. Surgical procedure
The liver transplant procedure takes approximately 8 to 12 hours.
Procurement of the donor liver occurs according to the standard procedure for whole liver transplantation.
The donor liver is prepared at the back table simultaneously with hepatectomy of the native liver by a second surgical team.
In a reduced-size liver transplant, the liver is reduced by lobectomy (right or left) or trisegmentectomy for left lateral segment implants, with ligation of the main vessels and ducts.
The biliary and vascular structures along the cut edge are ligated and the remaining vascular structures are flushed with preservation solution.
Surgical incision
A bilateral subcostal incision is made to visualize major structures
Known as the Mercedes incision
May be an extension of the previous incision if the child underwent a Kasai portoenterostomy for management of biliary atresia
Explantation of the native liver
The vena cava, portal vein, and hepatic artery are crossed clamped prior to hepatectomy.
Hemodynamic instability is a risk during the anhepatic phase secondary to
Decreased intravascular volume
Ongoing fluid and blood losses
Decreased venous return to the heart
Implantation of the allograft
Orthotopic
Vascular anastomoses are generally performed in the following order:
Suprahepatic inferior vena cava
Intrahepatic inferior vena cava
Portal vein
Hepatic artery
Reperfusion of the graft occurs after the portal vein anastomosis.
During reperfusion, massive fluid shifts can result in intestinal edema, third spacing, and renal compromise.
Children generally tolerate the caval clamping and reperfusion well because of collateral circulation
Bile duct reconstruction is performed with an end-to-side roux-en-Y limb of the jejunum.
Two or three Jackson-Pratt drains may be inserted.
Duct-to-duct biliary reconstruction is often performed in children with an adequate biliary tree (recipients diagnosed with metabolic disorders or fulminant hepatic failure).
Other surgical options
Split liver transplantation
Split liver grafts differ from reduced sized grafts in the approach to separating the vascular and biliary structures.
Produce two viable grafts for separate recipients
The goal with this procedure had been to address donor shortages by providing a two-for-one application.
Carries a higher incidence of postoperative complications such as biliary leaks and bleeding
Living related donor transplants
The arterial reconstruction necessary in a living donor liver transplant presents a surgical challenge because of the many normal variants found in the hepatic arterial system.
J. Posttransplant care
In the immediate postoperative period, emphasis will be on monitoring for posttransplant complications.
Monitoring vital signs (see Table 17-2).
Program-specific protocols should be followed.
K. Organ-specific posttransplant complications
The child is taken to the pediatric intensive care unit (PICU), intubated, and monitored for
Hemorrhage:
May occur as a result of preexisting coagulopathy or bleeding at the anastomoses.
Children who have undergone previous abdominal procedures are at higher risk for bleeding and adhesions.
Frequent monitoring of output from the Jackson-Pratt drains is necessary.
Indications of bleeding include
Increasing abdominal girth
Oozing from the suture line
Managing of coagulopathies:
Blood products are used per discretion of the transplant team.
Fluid and electrolyte balance:
Hemodynamic instability may occur in the postoperative period, related to altered renal function and volume losses.
Fluids are administered
On the basis of fluid status, vital signs, CVP, and weight compared to preoperative baseline values
To provide necessary intravascular volume and assure adequate perfusion to the allograft and other vital organs
Adjustments of electrolytes and acid-base balance are made to assure appropriate fluid status.
Patients at risk for cerebral edema require a careful balance between maintaining adequate intravascular volume and avoiding increasing intracranial pressure.
Hyperkalemia and metabolic acidosis are two early signs of vascular graft insufficiency or dysfunction.
Decreased urine output (<1 mL/kg/h) may indicate early graft dysfunction.
Neurologic status: monitor for
Mental status changes
Hepatic coma/encephalopathy
Seizures:
Seizures are rare although they may be result of calcineurin inhibitor toxicity.
Gastrointestinal (GI) status:
A nasogastric tube will be placed to decompress the stomach.
Monitor for nausea, vomiting, and presence of bowel sounds.
Hepatic artery thrombosis (HAT):
Complication occurring in 4% to 6% of pediatric recipients.
A duplex ultrasound of the liver is obtained in the first 12 hours to assess vessel patency.
Diagnosis of HAT in the first 1 to 6 postoperative days is possible with a duplex ultrasound.
If collateral vessels have developed, angiography may be the most definitive test.
Clinical signs of HAT:
Elevated transaminases and bilirubin
Change in mental status
Biliary leak, which may present as abdominal pain, jaundice, or bilious drainage from incision sites/drains
Sepsis
Heparin may be administered in the immediate postoperative period to prevent thromboses.
Management of HAT:
Thrombectomy to restore blood flow
Retransplantation
Portal vein (PV) thrombosis:
May present with enlarging liver or spleen and decreasing platelet counts
May initially be diagnosed by daily liver ultrasound
Biliary complications:
In the immediate postoperative period, a change may be noted in the color of fluid in the Jackson-Pratt drain.
Bacterial contamination is possible if the leak occurs at the roux-en-Y anastomosis.
Diagnosis is made by ultrasound or percutaneous transhepatic cholangiogram.
Treatment involves surgical revision with insertion of a transhepatic biliary stent and broad-spectrum antibiotics.
L. Rejection
Signs of rejection may include
Low-grade fever.
Increased liver enzymes and bilirubin.
There may not be any physical signs or symptoms.
Diagnosis: confirmed with a percutaneous liver biopsy
Types of rejection:
Acute rejection:
Can occur as early as the first week posttransplant; risk of rejection continues lifelong
Treatment:
Chronic rejection:
Frequent cause of graft loss
Underlying causes may be multifactorial including
Multiple episodes of acute rejection
CMV infection
Inconsistent immunosuppressant levels
Biopsy demonstrates bile duct loss with fibrosis and cirrhosis.
Treatment:
Treatment is similar to acute rejection utilizing, increasing immunosuppression per transplant program guidelines.17
M. Liver biopsy and postbiopsy monitoring
Performed under conscious sedation with local anesthesia
Preparation:
Type and cross the child for blood.
Obtain PT and PTT.
Postbiopsy monitoring:
Hemoglobin level should be obtained 4 to 6 hours after the procedure.
The child should remain flat in bed for 4 to 6 hours.
N. Summary
Liver transplantation is
A treatment for end-stage liver disease where the patient and family trade a life-threatening illness for a posttransplant chronic illness
Lifelong medication to suppress the immune system
Long-term clinical follow-up
Future directions focus on immunosuppression withdrawal and continuing to expand the donor pool.18,19
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