Page 1582 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 115: The Transplant Patient 1101

commonly on the first postoperative day, but may occur up to several After the biliary tree and vascular structures have been imaged using
weeks following surgery. Thrombosis is the most common early ultrasonography, a liver biopsy will help confirm the diagnosis of acute
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complication, with stenosis and pseudoaneurysm formation generally rejection. As is the case in any solid-organ transplant recipient, treat-
developing later in the patient’s course. Hepatic artery thrombosis is the ment of acute rejection should be aggressive and must be instituted
second most significant cause of liver graft failure after primary non- promptly. For liver transplant recipients, therapy usually involves anti-
function in the immediate posttransplant period. The presentation of thymocyte globulin and increased or pulsed doses of methylpredniso-
hepatic artery thrombosis has been associated with hepatic artery recon- lone. Fortunately, with the advent of more potent immunosuppressive
struction with an interposition graft to the supraceliac aorta. There agents, acute rejection has decreased in incidence but still affects 15% to
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may also be an increased risk of hepatic artery thrombosis with the use 25% of liver transplant patients. 102
of sirolimus. The clinical picture of this complication can vary from the Chronic rejection can occur months to years after transplant. Chronic
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asymptomatic rise in liver enzymes to fulminant hepatic failure. Urgent rejection of the liver presents clinically as progressive cholestasis and
laparotomy and revision of the hepatic artery anastomosis is required if histologically with mononuclear infiltration of the allograft, vascular
this complication develops, and unfortunately retransplantation is often abnormalities, and fibrosis. These findings are most commonly seen as
necessary if hepatic necrosis has occurred. part of the vanishing-bile-duct syndrome; treatment is often unsuccess-
Portal vein thrombosis develops less frequently and may present ful and may require retransplantation.
more insidiously. Ascites may be seen to develop or worsen, and variceal Primary Disease Recurrence: Recurrence of the primary disease is not
bleeding (usually from preexisting varices) may ensue. Thrombectomy uncommon posttransplant. Autoimmune diseases, hepatitis C, and
and anastomotic revision can be successful if this complication is diag- hepatocellular carcinoma can recur posttransplantation. Reactivation
nosed early.
HBV or HCV infection in the recipient and resultant allograft infection
Biliary Leaks: Biliary complications occur in approximately 15% of remains a major challenge. For HBV, most patients receive a combina-
patients following orthotopic liver transplantation. Of these, bile leak is tion of pretransplant antiviral therapy followed by hepatitis B immu-
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the most common early complication. Symptoms are nonspecific, and can noglobulin (HBIg) and an antiviral to suppress replication of the virus
include fever, abdominal discomfort, and signs of peritoneal irritation. in the postoperative setting. These therapies are generally continued
Though ultrasound may demonstrate an intra-abdominal fluid collec- indefinitely, and have resulted in allograft and patient survival rates sim-
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tion, cholangiography will provide a definitive diagnosis. Endoscopic ilar to those of patients not infected with HBV. Combination therapy
insertion of biliary stents can sometimes provide satisfactory results, has reduced the recurrence of HBV to less than 10% with a significant
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but surgical repair of the leak may be required. The risk of biliary leak improvement in patient and graft survival. Transplantation of an
depends on the type of reconstruction with duct-to-duct anastomosis felt HCV patient with a new graft is likely to become reinfected with HCV
to have a slightly less risk given that there is preservation of the sphincter given that effective antiviral therapies are lacking. These patients in
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of Oddi to prevent reflux of contents into the bile duct. Hepatic artery turn have been shown to have poorer graft and patient survival rates.
thrombosis, prolonged cold and warm ischemic times, CMV infection, Recipient outcomes will depend on whether it is a newly acquired viral
primary sclerosing cholangitis, ABO mismatch, and donation after strain, whether it is a reactivation of their previous strain, and if there is
cardiac death are other risk factors for the development of biliary leak. evidence of immunity and the previous response to antiviral therapy. 106
Biliary strictures and stones typically appear later in the postopera- Hepatocellular carcinoma recurrence was especially common with
tive period. Obstructions usually can be managed endoscopically or poorly differentiated tumors; however, with better patient selection
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through the use of interventional radiology techniques, but surgical criteria, those patients with hepatocellular carcinoma undergoing trans-
correction is sometimes necessary. Strictures typically develop at the plant have a better prognosis and lower risk of recurrent disease.
anastomotic site, and are likely the result of local ischemia. These may Renal Dysfunction: Following the liver transplant procedure, renal
present as cholestasis or possibly as overt cholangitis. Balloon dilation of dysfunction is frequently observed, and postoperative renal failure
the stricture with or without stent placement usually is successful treat- can be severe enough to require renal replacement therapy in 13%
ment, but surgical revision and even retransplantation may be required. of patients. Kidney function generally improves and only 5% of
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Rejection: Rejection of the hepatic allograft is usually not seen until about 1 patients require chronic hemodialysis following liver transplant. 108
to 2 weeks following the procedure, and most often manifests as fever, right The most common precipitant is intravascular volume depletion
upper quadrant pain, and reduced bile pigment and volume. However, the resulting in prerenal azotemia. Intraoperative hypotension, low cardiac
most sensitive marker of early rejection is a rise in serum transaminase output syndromes, immunosuppressive therapies, sepsis, abdominal
(AST/ALT) levels and bilirubin. A rise in total white blood count may also compartment syndrome, and contrast-induced nephropathies can also
develop. Liver biopsy remains the gold standard for the diagnosis of rejec- contribute to renal injury posttransplant. Hepatorenal syndrome is a
tion. The most important consideration when elevation of these serum reversible cause of renal failure that arises in patients with advanced
enzymes occurs early in the postoperative course is the exclusion of one of cirrhosis. Liver transplant can lead to complete renal recovery; however,
the various mechanical complications (such as vascular compromise, bili- the rates are variable.
ary obstruction, and primary graft nonfunction). Table 115-15 outlines the Pulmonary Complications: Hepatopulmonary syndrome (HPS) is char-
differential diagnosis of transaminitis posttransplant. acterized by pulmonary vascular vasodilation and shunting in a patient
with cirrhosis. It is defined by the presence of liver dysfunction and
TABLE 115-15 Differential Diagnosis of Elevated Transaminases Post-Liver intrapulmonary vasodilation resulting in abnormal gas exchange. It has
Transplant been estimated that up to 10% to 30% of patients with cirrhosis have
some degree of HPS. No effective medical therapies beyond transplant
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Etiology Timing (Early <30 days)
exist. Resolution posttransplant is variable with persistent shunting
Postsurgical inflammation Early (should be resolving in a few days with a downward trend) seen up to 14 months in some reviews. It was previously believed that
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Primary graft nonfunction Early patients with severe HPS should be excluded from transplant (defined
as preoperative arterial oxygen content <50 mm Hg); however, recent
Hyperacute/acute rejection Early evidence has demonstrated that the survival in those with HPS and
Biliary complications Early/late (primarily cholestatic pattern) severe HPS is higher than originally demonstrated and that, with careful
Vascular complications Early/late preoperative evaluation, many patients with HPS may benefit from liver
transplantation. However, these patients often have protracted post-
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Primary disease recurrence Late requirements and poorly tolerate
operative ICU courses with high Fi O 2

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