Pediatric emergency medicine trisk 1036

GGT levels are normal. As a consequence of hypersplenism from portal
hypertension, the platelet count is typically low. Initial imaging with Doppler
ultrasound can be confirmed with CT, MRI, or angiography. Treatment for portal
vein obstruction depends on the etiology. Balloon dilation with stent placement
may be used to repair portal vein stenosis. For PVT, anticoagulation or
thrombolysis may be attempted. When amenable, surgical bypass or shunting to
preserve flow through the liver, such as a Meso-Rex shunt, is preferred. In select
cases, retransplantation may be necessary.

Hepatic Vein Obstruction
Hepatic vein obstruction is a rare complication that occurs more often with
technical variant grafts. It is typically associated with ascites and protein-losing
enteropathy which presents with diarrhea and hypoalbuminemia. Ultrasound with
Doppler is the imaging of choice when a hepatic vein obstruction is suspected. A
venogram should be used to confirm hepatic vein obstruction and venoplasty has
been successful at restoring hepatic venous flow.

Cardiac Vascular Complications
Cardiac transplant recipients do not typically present de novo with postsurgical
vascular issues. Recipients who were transplanted for failed palliation of
congenital heart disease may have stenotic vessels or anastomotic sites that
become narrow over time. Such findings are typically identified during the course
of routine cardiac transplant follow-up and addressed electively.

SURGICAL COMPLICATIONS
CLINICAL PEARLS AND PITFALLS
Surgical complications of liver transplantation are typically related to
vascular and biliary anastomoses and an ultrasound with Doppler
should be obtained if there is suspicion of a surgical complication.
Surgical complications post heart transplant are typically not occult, and
are not likely to present beyond the early postoperative period.

Surgical complications of renal transplant include urinary leak or urinary
tract obstruction.
The high doses of immunosuppression used in the immediate postoperative
period present a risk of wound infection, and certain medications such as
sirolimus may impede wound healing. Overall, most surgical complications are


related to the vascular anastomoses, which are described in more detail in
previous sections.
Biliary anatomy can complicate liver transplantation and recipients who
require more than one biliary anastomosis are at increased risk for biliary leaks.
In addition, graft ischemia whether from increased cold ischemia time or poor
vascular reperfusion can lead to biliary strictures. Patients with surgical
complications may present with a variety of symptoms including fever,
hemodynamic instability, or rise in liver enzymes. Initial management should
focus on hemodynamic stabilization and obtaining directed imaging such as an
ultrasound with Doppler.
Incisional hernia may occur in 5% to 18% of liver transplant recipients and
occur more frequently if there is not a primary fascial closure. Incisional hernias
can be diagnosed on physical examination and assessment of reducibility is
imperative. An incarcerated or nonreducible hernia requires surgical consultation
although most can be medically managed without need for surgery.
In renal transplant patients, urinary leak occurs due to ureteral necrosis, bladder
injury, or obstruction. Urinary obstruction is thought to be caused by clot in the
urinary tract or postoperative edema. It is detected as hydronephrosis on renal
ultrasound.

IMMUNOSUPPRESSANT MEDICATION–RELATED
COMPLICATIONS
CLINICAL PEARLS AND PITFALLS

Long-term use of immunosuppression medications has been
associated with an increased risk for renal insufficiency, hypertension,
diabetes, hyperlipidemia, obesity, lymphoproliferative disease, and
metabolic syndrome.
Common side effects of CNIs include hypertension, renal insufficiency,
lymphoproliferative disease, and seizures. Most side effects improve
with minimizing doses.
Sirolimus is being used more frequently as a renal-sparing primary
immunosuppressive agent with the main side effects being mouth
ulcers, marrow suppression, and hyperlipidemia.
Sirolimus is used in heart transplant recipients as adjunct therapy for
those patients with coronary artery disease, chronic rejection, or
antibody-mediated rejection.


There is potential for complications with all posttransplant medication regimens,
including both from immunosuppression medications as well as other routine
prophylactic medications including aspirin, ganciclovir, trimethoprim
sulfamethoxazole, and ranitidine ( Table 125.4 ). The two main classifications of
immunosuppressant medications used are CNIs (cyclosporine and tacrolimus) and
the purine antagonists or antimetabolites (azathioprine and mycophenolate
mofetil). The typical immunosuppressant medications used in liver
transplantation include corticosteroids, CNIs, and antimetabolites. Similarly, heart
transplant recipients receive maintenance immunosuppression with a CNI and a
purine antagonist; most programs have moved away from chronic steroid use.
Long-term use of immunosuppression medications has been associated with an
increased risk for renal insufficiency, hypertension, diabetes, hyperlipidemia,
lymphoproliferative disease/lymphoma, increased infection risk, obesity, and
metabolic syndrome.
TABLE 125.4

ADVERSE EFFECTS OF IMMUNOSUPPRESSIVE AGENTS a

Corticosteroids are used in both the initial immunosuppression setting as well
as for the treatment of acute cellular rejection. Corticosteroid therapy decreases


inflammatory response by preventing the chemotaxis and recruitment of
mediating lymphocytes. Relatively common acute adverse effects include
hypertension, hyperglycemia (sometimes requiring insulin), psychosis, and joint
pain. Chronic adverse effects include the Cushing syndrome, bone
demineralization, linear growth delay/arrest, adrenal suppression, and cataracts.
CNIs including tacrolimus and cyclosporine are currently the primary longterm immunosuppressant agents for pediatric liver transplant recipients. Common
side effects of tacrolimus include hyperglycemia (sometimes requiring insulin),
anorexia, hypertension, headache, increased creatinine, and renal electrolyte
wasting (particularly magnesium and potassium). Less common adverse effects of
tacrolimus include dermatologic diseases, such as eczema, common warts (the
severity of which can range from mild to disfiguring), and neurotoxicity
(seizures). Many of these side effects are dose dependent. Adverse effects of
cyclosporine are similar to those of tacrolimus, with hypertension, renal injury,
infection, skin problems, PTLD, and seizures. Cyclosporine further causes
cosmetic changes including hirsutism, coarsening of facial features, and gingival
hyperplasia; these findings are not present with tacrolimus use. Renal function is
a primary concern as CNIs contribute to both acute and chronic posttransplant
renal dysfunction. The CNIs, as well as the purine inhibitors, enhance skin
sensitivity to UV irradiation; as such, all patients on immunosuppression are
cautioned to use high SPF sun screen/sun block and cover up when in the sun.
Mycophenolate is an ester of mycophenolic acid with lymphocytic
antiproliferative properties that selectively inhibits proliferation of B and T
lymphocytes by inhibiting de novo purine nucleotide synthesis. Mycophenolate is
used as a short-term or as maintenance adjuvant immunosuppressive therapy.

Common adverse effects include gastrointestinal symptoms, such as diarrhea and
cramping, and marrow suppression. Other effects include vomiting, anorexia,
leukopenia, anemia, and infection.
Azathioprine can be used as an adjuvant immunosuppressive therapy in
combination with a CNI and/or corticosteroid therapy. Azathioprine is rapidly
converted to 6-mercaptopurine, the active form of the drug, which acts as a
lymphocytic antiproliferative by inhibition of purine synthesis. The most common
adverse effect is myelosuppression. Idiosyncratic reactions include drug fever,
hepatotoxicity, and pancreatitis and there is also an increased risk of infection.
Sirolimus is a newer immunosuppressive medication with growing indications
in children. Sirolimus inhibits T-lymphocyte activation and proliferation in
response to antigenic and cytokine stimulation. Sirolimus has been used in the
pediatric transplant population as a single agent or in combination with CNIs. It is