diagnosis of primary EBV infection which has reduced the risk of PTLD to less than 3% in the liver transplant population, and less than 10% in the heart transplant population Imaging via CT scan can help screen for enlarged lymph nodes, solid tumors, and other findings concerning for neoplasia If found, and if accessible, biopsy of the disease site is the diagnostic step of choice A PET-CT may help detect occult disease Treatment typically includes minimization or discontinuation of immunosuppression as a first step, to allow the body to resume control of the proliferating B cells Directed therapies with chemotherapeutic regimens including rituximab, cyclophosphamide, and prednisone may then be added If high EBV load is detected, an antiviral agent is typically added as adjunct therapy Clinical Considerations Clinical Recognition Suspicion for PTLD should arise in the setting of a child with a prior EBV infection and an increasing viral load as measured by EBV polymerase chain reaction (PCR) Other presentations include progressive and unremitting gastrointestinal findings (e.g., chronic diarrhea, bloody stool, abdominal pain, anorexia, weight loss), pulmonary symptoms (e.g., chronic cough, shortness of breath), or vague systemic malaise (e.g., fever, feeling unwell, weight loss) Children may be asymptomatic Lymphoproliferative disease can occur in any location, and screening must include the graft (though lesions are rarely intracardiac), lungs, brain, intestine, spleen, liver, lymph nodes, and bone marrow Clinical Assessment Common clinical examination findings may include fever, lymphadenopathy (especially cervical, submandibular, and axillary), sinusitis, tonsillar enlargement, and splenomegaly Initial assessments should target the primary symptomatology: if diarrhea is present, stool should be collected and sent for usual infectious pathogens plus occult (or gross) blood; if respiratory symptoms are present, chest radiograph is indicated; palpable masses or obstructive symptoms require CT imaging All of this must be performed with the advice and participation of the transplant team The diagnosis of PTLD is rarely made in the ED It usually requires a combination of imaging, analysis of tissues (e.g., lymph node, tonsil, liver) for evidence of EBV-transformed B cells and quantitative EBV PCR from blood confirming viral replication With that said, investigations can be initiated in the ED Blood can be sent for EBV PCR if this condition is suspected Specific T-cell studies are used to determine the clonality of the lymphoproliferation and thereby to determine the appropriate therapy, which can range from reduction of immunosuppression and antiviral therapy to specific cytotoxic chemotherapeutic agents In many cases, the PTLD responds to discontinuation of immunosuppressive medications without ensuing allograft rejection Acute, urgent management should focus on the primary symptom constellation and resultant clinical compromise VASCULAR COMPLICATIONS CLINICAL PEARLS AND PITFALLS Vascular complications in liver transplant patients can occur in any of the three vascular anastomoses: hepatic artery, portal vein, and hepatic vein Early hepatic artery thrombosis (HAT) is a surgical emergency as it can lead to graft failure and may require retransplantation Portal vein complications include portal vein thrombosis (PVT) or stenosis and typically present with signs of portal hypertension Cardiac transplant recipients not typically present de novo with postsurgical vascular issues LIVER TRANSPLANTATION Vascular complications can occur in any of the three vascular anastomoses: hepatic artery, portal vein, and hepatic vein Vascular thrombosis remains the most common cause of early postoperative allograft loss Hepatic Artery Thrombosis HAT occurs most often within the first few days following transplantation with a reported incidence between 3% and 10% HAT can present with a variable clinical picture from mild abnormalities in transaminases and lactate dehydrogenase to fulminant allograft failure With graft ischemia, patients may also present with signs of biliary obstruction secondary to associated biliary pathology, or even systemic sepsis Early identification of HAT is key and allows for potential salvage of the hepatic allograft via thrombectomy or possible hepatic artery reconstruction Ultrasound with Doppler is the initial screening modality of choice and is >90% sensitive at detecting early HAT, but confirmation with CT, MRI, or angiogram is necessary Acute HAT with allograft failure is a surgical emergency and requires immediate listing for retransplantation While awaiting transplant, biliary stenting or percutaneous draining may be indicated to manage the biliary complications associated with HAT Late HAT may be asymptomatic or present with progressive biliary stenosis and as such, total bilirubin, alkaline phosphatase, and GGT levels may be elevated With late HAT, arterial collaterals may develop and if there is adequate hepatic blood flow whether through these collaterals or via compensation by the portal vein, then treatment may not be required Imaging with ultrasound followed by CT or angiogram may help to map the hepatic vasculature and collaterals Treatment options of HAT remain fairly limited as anticoagulation and thrombolysis are not typically effective Surgical reconstruction is typically contraindicated as disruption of the collateral supply can precipitate hepatic ischemia with resultant parenchymal necrosis Most cases of HAT ultimately require retransplantation TABLE 125.3 OVERVIEW OF COMPLICATIONS OF SOLID ORGAN TRANSPLANTATION Portal Vein Complications Portal vein complications include abnormalities in portal flow or portal vein obstruction from either portal vein stenosis or PVT Portal vein obstructions occur in approximately 10% of pediatric liver transplant recipients Most cases are symptomatic with portal venous obstruction ultimately resulting in portal hypertension Examination findings might include splenomegaly, ascites, caput medusae, or esophageal varices Clubbing has been described in advanced cases of PVT In severe cases, portal vein obstruction may lead to graft loss PVT may also be clinically silent or provide only subtle clues, especially if collateral formation has occurred For children with collaterals or who develop spontaneous splenorenal shunts, subtle neurologic or behavioral changes may be seen as mesenteric blood becomes diverted around the liver LFTs are largely unremarkable in patients with PVT Transaminases and LDH levels are usually only slightly elevated, and bilirubin, alkaline phosphatase, and ... hepatic artery, portal vein, and hepatic vein Early hepatic artery thrombosis (HAT) is a surgical emergency as it can lead to graft failure and may require retransplantation Portal vein complications... confirmation with CT, MRI, or angiogram is necessary Acute HAT with allograft failure is a surgical emergency and requires immediate listing for retransplantation While awaiting transplant, biliary... from either portal vein stenosis or PVT Portal vein obstructions occur in approximately 10% of pediatric liver transplant recipients Most cases are symptomatic with portal venous obstruction