You are in: eMedicine Specialties > Transplantation > Surgery Liver TransplantationArticle Last Updated: Nov 1, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Cosme Manzarbeitia, MD, Associate Professor of Surgery, Chairman, Division of Transplant Surgery, Director, Liver Transplant and Hepatobiliary Surgery Program, Albert Einstein Medical Center, Thomas Jefferson University Cosme Manzarbeitia is a member of the following medical societies: American Association for the Study of Liver Diseases, American College of Surgeons, American Society of Transplant Surgeons, and International Liver Transplantation Society Editors: Tushar Patel, MD, Associate Professor, Department of Internal Medicine, Texas A&M College of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Youmin Wu, MD, Professor, Department of Surgery, Transplantation Division, University of Arkansas for Medical Sciences; Michael E Zevitz, MD, Assistant Professor of Medicine, Finch University of the Health Sciences, The Chicago Medical School; Consulting Staff, Private Practice; Julian Katz, MD, Clinical Professor of Medicine, Drexel University College of Medicine; Consulting Staff, Department of Medicine, Section of Gastroenterology and Hepatology, Hospital of the Medical College of Pennsylvania Author and Editor Disclosure Synonyms and related keywords: liver transplant, liver transplantation, LT, hepatic transplantation, liver replacement, liver allografting, transplant, orthotopic liver transplantation, OLT, living donor transplant, living-donor transplant, split-liver transplant, split liver transplant, total hepatectomy, cirrhosis, alcoholism, alcohol abuse, alcohol dependence INTRODUCTIONSection 2 of 11
  History of the ProcedureResearch into the possibility of liver transplantation (LT) started before the 1960s with the pivotal baseline work of Thomas Starzl in Chicago and Boston, where the initial LT techniques were researched in dogs. Starzl attempted the first human LT in 1963 in Denver, but a successful LT was not achieved until 1967. In 1970, with an immunosuppressive regimen largely based on steroids and azathioprine, survival rates were dismal—approximately 15% at 1-year follow-up. LT did not become a clinical reality until the early 1980s, after the discovery of cyclosporine, which led to improvements in rejection rates. In 1983, the US National Institutes of Health established, by consensus, that LT was to be considered out of the experimental realm and was to be clinically accepted as definitive therapy for end-stage liver disease (ESLD). Additional improvements in immunosuppression that were instrumental in advancing the science included the discovery of monoclonal antibodies (ie, muromonab-CD3 [OKT3]) in 1986. The combination of improvements in rejection rates and in surgical technique led to an enormous expansion of the field during the 1980s, with expansion from 3 centers in 1982 to more than 120 centers today. In 1999, 4,500 procedures were performed, up from approximately 100 in 1982. Currently, more than 16,000 patients are on the liver waiting list, and slightly more than 6,600 liver transplants were performed in 2006 (United Network for Organ Sharing [UNOS] data as of June 19, 2007).1 Of great importance in this expansion was the development of the University of Wisconsin (UW) solution in 1988, which increased preservation time and allowed for a smoother surgical procedure, avoiding a rushed tour de force in the operating room. Finally, the development of newer immunosuppressants, such as tacrolimus and interleukin (IL)–2 receptor blockers, has paved the way for further growth in this field. All these advances have produced excellent results, with current 1-year patient survival rates of 85-90% and 5-year survival rates of 65-75%. Future advances may include the development of xenotransplantation, which was pioneered by Starzl in 1992, and the development of cloning techniques and their impact on organ availability. ProblemESLD magnitude and organ shortage The following list shows potential International Classification of Diseases, Ninth Revision, Clinical Modification diagnoses that could indicate candidacy for LT. The number of patients hospitalized with these primary and secondary diagnoses is enormous. However, only a small percentage of these patients ultimately are candidates for transplantation because other criteria are also used to determine candidacy. Diagnoses indicating potential candidacy for LT include the following:
The major constraint to meeting the demand for transplants is the availability of donated (cadaver) organs. Several steps have been taken, nationally and locally, to alleviate the organ shortage. National required request laws mandate that families of every medically suitable potential donor be offered the option to donate organs and tissues. In addition, the National Organ Donation Collaborative efforts, currently ongoing, and laws that require all deaths to be reported to organ procurement organizations have resulted in increased organ donations. Rising public awareness about organ transplantation should continue to reduce the organ shortage. Finally, aggressive usage of extended donors and reduced-size, split, and living-related LT continue to expand the organ donor pool, though these efforts still fail to meet the need for organs. FrequencyAccording to the latest US Centers for Disease Control and Prevention sources, cirrhosis remains the 12th leading cause of death for adults in the United States, with 27,013 deaths reported in 2004 and a death rate of nearly 9.2 cases per 100,000 persons.2 This accounts for 1.1% of total deaths. Unfortunately, this number may grossly underestimate the real impact of ESLD because it does not include acute liver failure or other etiologies that may lead to the need for LT (see Problem). EtiologySee Problem. ClinicalPatients present with signs and symptoms of ESLD, which is discussed in more detail in the next section. INDICATIONSSection 3 of 11
Currently, any patient who has chronic or acute liver disease that leads to the inability to sustain a normal quality of life or that results in life-threatening complications should be considered a candidate for LT. The common etiologies and indications for LT in adults can be seen in the red portion of the pie chart shown in Image 2. The red portion represents the hepatocellular group of diseases, ie, those that primarily affect hepatocyte function and, thus, lead to faster clinical deterioration and life-threatening complications. The green portion represents the group of cholestatic diseases, in which the excretory function of the liver is primarily compromised. In these latter cases, synthetic function is preserved for prolonged periods. Additional indications, such as transplantation for metabolic or inherited diseases (eg, familial hypercholesterolemia, amyloidosis), are considered on a case-by-case basis. Clinical presentation As a general rule, the following complications of ESLD warrant LT:
Ascites is associated with a poor prognosis in the mid to short term, especially when it becomes unmanageable with diuretic therapy and requires repeated paracentesis, transjugular intrahepatic portosystemic shunt (TIPS), or insertion of a peritoneovenous shunt. Encephalopathy may develop rather insidiously in most patients and may be difficult to elicit properly upon examination. Clinically, encephalopathy is divided into 4 stages. Of these, the most obviously life-threatening are stages 3 and 4 (somnolence and coma). Synthetic dysfunction is perhaps the earliest manifestation of ESLD, often manifested by decreased albumin levels alone or in combination with prolongation of the prothrombin time and jaundice. In its most severe form, it can lead to severe malnutrition. Portal hypertension can manifest either silently (ie, decreased platelet count, WBC count, or both) or overtly, with variceal bleeding. Other manifestations include the development of hepatocellular carcinoma (HCC), which is common in patients with hepatitis B and C, or severe intractable pruritus. Finally, a controversial indication for transplantation in the face of the organ shortage is in those patients with severe disabling fatigue. In general terms, diseases that cause ESLD do so by affecting either the function of the hepatocyte (eg, hepatocellular diseases) or the excretory function of the biliary system (eg, cholestatic diseases). Their prognoses are different, and their treatment must be individualized. As a general rule, hepatocellular diseases cause a more profound derangement of hepatic synthetic function early in the disease process. Conversely, cholestatic diseases preserve hepatocellular function until more advanced stages of the disease process. Indications for LT can also be broadly categorized into severity of disease indications (ie, the patient's life is immediately threatened without transplantation) and quality of life indications (ie, the patient is permanently disabled, but his or her life is not in immediate danger). While the former obviously mandates urgent transplantation, great expertise is needed to address the latter. CONTRAINDICATIONSSection 4 of 11
Currently accepted absolute contraindications to LT by most programs include HIV positivity, spontaneous bacterial peritonitis (SBP) or other active infection, severely advanced cardiopulmonary disease, extrahepatic malignancy that does not meet cure criteria, active alcohol or substance abuse, and inability to comply with immunosuppression protocols because of psychosocial situations. SBP, sometimes protean in its manifestations (eg, malaise, abdominal discomfort), can be devastating and can cause decompensation in an otherwise stable patient with cirrhosis. The patient may present with encephalopathy, hypotension, fever, leukocytosis, and an elevated WBC count in the peritoneal fluid. The absolute criteria for a diagnosis of SBP are the presence of more than 200-250 polymorphonuclear leukocytes, the identification of bacteria in the fluid by light microscopy, subsequent positive bacterial culture results in the appropriate clinical setting, or a combination thereof. The development of SBP in a patient with cirrhosis is an indicator of a very poor prognosis. If pneumonia or other active infections are present, mortality rates after transplantation are greatly increased. This emphasizes the need to have a high index of suspicion for infection. If any doubt exists about the presence of infection, abdominal paracentesis, chest radiograph, urine analysis, and/or pan cultures may be indicated. In patients with a prior history of drug use, examine arms and legs for evidence of new track marks. Patients with a history of alcohol abuse should have an alcohol level test performed as part of the preoperative workup through contract arrangements and upon admission for transplantation. Secondary liver malignancies are not indications for hepatic replacement because of the universal recurrence of the tumors under immunosuppression. Exceptions to this rule include metastatic neuroendocrine malignancies such as carcinoid tumors. An elicited history of previous malignancy in a transplant candidate should prompt an extensive workup for metastatic disease, staging before and after surgery or therapy, and consultation with an oncologist. Relative contraindications to LT are multiple, and each should be weighed when considering the prospective recipient's severity of illness. While no single relative contraindication alone may prevent a given patient from receiving a liver transplant, these are red flags, which, if multiple or if manifesting in an otherwise high-risk recipient, may proscribe LT. Most commonly, these red flags include patients with chronic renal failure (in which combined liver-kidney transplantation may be required), advanced cachexia, large HCCs (more advanced than stage II, as described by the UNOS-modified American Joint Committee on Cancer [AJCC] classification), medication-resistant hepatitis B virus (HBV) cirrhosis, portal and mesenteric vein thrombosis, history of prior cancer not meeting full AJCC cure criteria, active infections, and multisystem organ failure states. Note that many of these contraindications are program-specific and depend greatly on the volume and experience of each individual program. Age is no longer considered an absolute contraindication. Physiological age, rather than chronological age, dictates the individual's suitability for candidacy. However, careful judgment should be used in allocating donors to these patients, given the organ shortage. With the development of refinements in surgical techniques, selected patients with portal and/or mesenteric venous thrombosis have undergone successful transplantation. The availability of venous jump grafts to restore portal flow permits transplantation in these generally advanced cases. In cases of mesenteric thrombosis, cavoportal hemitransposition may offer a chance of successful liver engraftment in these patients. If studied carefully, all patients with cirrhosis are found to have a certain degree of intrapulmonary shunting. In certain patients, this can be disabling and can lead to hypoxia at rest (hepatopulmonary syndrome). The successful reversal of these shunts after LT makes this an indication rather than a contraindication. However, selection of these candidates must be adequate and precise, with sophisticated and directed pulmonary function testing. The presence of established anatomical portopulmonary hypertension is probably an absolute contraindication for LT, but the situation varies for nonfixed pulmonary hypertension. LT is contraindicated in patients with severe degrees of pulmonary hypertension (mean peak airway pressure of >35), especially if coupled with increased pulmonary vascular resistance. However, for those patients with mild-to-moderate pulmonary hypertension and reasonable right-sided heart function, treatment with vasodilators, prostaglandin, or both allows safe LT. A history of prior abdominal surgery and portosystemic shunts does not preclude successful transplantation, although these factors make it a technical tour de force and dramatically increase blood loss because of existing portal hypertension. Recently, some groups have reported good results with selective shunting or TIPS. The great likelihood of recurrent and aggressive disease precludes transplantation in patients with actively replicating HBV infection. Recently, some groups have tried xenotransplantation in this population, but better results must be obtained prior to using this resource more widely. A subgroup of these patients with a small viral load and/or no active replication but with ESLD may be considered for candidacy. In these patients, the institution of lamivudine or adefovir therapy may render the viral replicative activity undetectable, hence allowing safe transplantation. The emergence of lamivudine-resistant strains may limit the long-term use of these therapies. Very weak and malnourished patients are poor candidates for LT because of an extremely poor reserve. If their nutritional status can be improved by means of total enteral nutrition or total parenteral nutrition, their odds improve. This is difficult to accomplish in the face of a failing liver. Frequently, cirrhosis is associated with development of HCCs. In these patients, transplantation must be performed under strict guidelines and protocols to minimize or prevent recurrence. As a rule, single-lesion HCCs smaller than 5 cm or 3 or fewer lesions (the largest <3 cm), ie, AJCC stages I and II, are associated with less chance of recurrence and survival rates equal to those of patients undergoing transplantation because of nonmalignant conditions. Protocols using chemoembolization have shown promising early results for larger tumors. Finally, the widespread use of chemoembolization protocols while on the waiting list and aggressive radiofrequency ablation may change the indications and therapeutic approaches in the immediate future. WORKUPSection 5 of 11
Lab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
Histologic FindingsDiscussion of all the histopathological findings of the various diseases that lead to ESLD is beyond the scope of this article. In general, they can be classified into 3 broad categories: cirrhosis and fibroticlike states, acute hepatic necrosis, and malignancies. TREATMENTSection 6 of 11
Medical therapyMedical management before transplantation is aimed at preventing and treating the complications associated with ESLD. Thus, many patients take various medications to control the consequences of liver failure and portal hypertension. These complications include (but are not limited to) ascites, SBP, HRS, encephalopathy, esophageal varices, and intense pruritus. Ascites presents a difficult treatment problem. As a first step, paracentesis should be performed to confirm portal hypertension as the etiology. Initially, salt restriction may be tried, although this is effective in less than 20% of patients. Fluid restriction should be avoided unless patients have gross anasarca, a serum sodium level less than 120 mEq/L, or both. Diuretics remain the mainstay of medical management. The most commonly used are spironolactone, furosemide, and hydrochlorothiazide. Diuretic therapy should be adjusted or discontinued if serum sodium levels fall below 120 mEq/L or if the creatinine level rises to more than 2 mg/dL. Other diuretics that may be used include amiloride, triamterene, or ethacrynic acid. If the ascites become refractory because of an inability to diurese patients and/or the development of electrolyte abnormalities and renal failure, repeat paracentesis may be performed every 2-3 weeks. A TIPS may result in a significant decrease in ascites; however, the risks of ischemic hepatic failure and intractable encephalopathy are higher, which limits its use in patients with cirrhosis classified as Child class C because the morbidity and mortality rates are increased. Other options include using peritoneovenous (LeVeen and SBP manifests in patients with cirrhosis who have ascites as an unexplained clinical deterioration, with or without the classic signs of peritonitis, and is associated with a high mortality rate. Paracentesis findings that are diagnostic include an absolute neutrophil count in the ascitic fluid of greater than 250/µL and positive results from peritoneal fluid cultures. Antibiotic therapy, directed mostly toward gram-negative enteric organisms, should be started early. Secondary peritonitis, such as that due to a perforated viscus, should always be excluded prior to instituting therapy. Prophylactic antibiotics are frequently used in patients with cirrhosis who have severe ascites, previous SBP episodes, or recent variceal bleeding. HRS is present in approximately 10% of hospitalized patients with cirrhosis. HRS is defined as a deterioration of renal function in a patient with advanced cirrhosis, with a creatinine level of more than 1.5 mg/dL, a urine volume of less than 500 mL/d, and a low urinary sodium level (<10 mEq/L). The condition is common in patients with ascites. Before a diagnosis of HRS can be established, other specific causes of renal dysfunction must be excluded. The diagnostic workup frequently includes insertion of a Foley catheter, renal ultrasound, and fluid challenge. Frequently unsuccessful, the medical treatment of HRS has been disappointing. Preliminary data suggest that a TIPS may be useful, but its precise role remains to be defined for this indication. As many as 70% of decompensated patients with cirrhosis have some degree of encephalopathy, ranging from subtle neurological dysfunction to frank coma. Seek and correct potential precipitating causes such as GI bleeding, constipation, infection, medications with CNS effects, or electrolyte abnormalities. If ascites is present, exclude SBP via paracentesis. A search for other reasons, such as portal vein thrombosis or occult HCC, should be made. A TIPS can also lead to severe encephalopathy. In addition to this correction of precipitating causes, treatment is by means of lactulose orally, via nasogastric tube, or through enemas, with doses titrated to achieve both 2-4 soft bowel movements daily and improvement in mental status. Neomycin may be added, although its potential for nephrotoxicity and ototoxicity can limit its usefulness. The usefulness of flumazenil, a benzodiazepine antagonist, remains to be defined. Esophageal variceal bleeding (EVB) is a major cause of morbidity and mortality in patients with ESLD. The mortality rate during the initial EVB incident is as high as 50%, with an additional risk of recurrent bleeding of 70% within the first year. Initial treatment includes aggressive fluid resuscitation, administration of blood products to replace blood loss and/or to correct coagulopathy, and emergent endoscopic evaluation with both diagnostic and therapeutic aims. Intubation may become necessary because of encephalopathy and for airway protection. Patients are usually placed on intravenous octreotide to reduce the portal hypertension, H2 blockers to prevent stress ulceration, and antibiotics for SBP prophylaxis. EVB may manifest overtly, with hematemesis and hemodynamic instability, or more insidiously, with melena, hematochezia, or encephalopathy. After achieving hemodynamic stability, perform an endoscopic evaluation of the upper GI tract with the goals of diagnosis and endoscopic control via rubber band ligation, sclerotherapy, or both. In approximately 5-10% of patients, these maneuvers fail to control bleeding; therefore, consider a TIPS, balloon tamponade, or surgical shunts. Reserve the placement of emergency surgical shunts for patients in Child class A to minimize morbidity and mortality. Pruritus is also common in persons with liver disease, mostly in cholestatic liver diseases such as primary biliary cirrhosis and sclerosing cholangitis, although it is also common in persons with hepatitis C virus (HCV) cirrhosis. In approximately 90% of patients, the condition responds to sequential therapy with use of antihistamines, ursodeoxycholic acid, and cholestyramine. The remaining 10% can be treated with rifampicin, with a significant reduction of pruritus. Because of the potential for bone marrow and hepatic toxicity, regular complete blood cell counts and liver tests are necessary. Opiate antagonists (eg, naloxone, nalmefene, naltrexone) have increasingly been used in the treatment of refractory pruritus. Timing of LT The 1983 consensus from the US National Institutes of Health that finally put LT in the clinical arena stated that in order to be successful, LT had to be offered at an optimal time (see Image 3). Optimal timing of LT is based on the natural history of the disease and the potential for progression over time. Additionally, the patient must be in the system to have the opportunity to undergo transplantation, ie, he or she must be listed with UNOS. All too commonly, patients are referred to the transplantation center late in the stage of their disease, and only then does an immediate sense of urgency arise. This scenario results in accelerated and occasionally incomplete evaluations of very ill patients. If these patients undergo transplantation, they are at a higher MELD score, usually above 30, with a resulting lower survival rate and a much greater cost and length of stay in the hospital and ICU. To avoid this, UNOS revises their organ allocation schemes regularly (see Lab Studies). The issue of transplantation timing is also fraught with challenges and controversies, as outlined in Image 4. To whom these organs should go is another consideration in the timing of LT. An ideal approach maximizes patient benefit and graft survival (see Image 5). This is an ongoing discussion with many perspectives. The right approach is somewhere in the middle, balancing patient outcome and utility. A move toward this has been made with the establishment of minimal listing criteria for entry on the waiting list. The MELD system has been validated clinically both in patients on the waiting list and as a predictor of posttransplant survival. More recent data have revealed that the waiting list mortality for LT in patients with MELD scores of 15 or less is greater than the waiting list mortality, and this has influenced the organ allocation system (UNOS). In the new scheme, organs are first allocated to patients with MELD scores above 15 locally and then regionally, and only then are they offered to local patients with MELD scores below 15. This has resulted in a more equitable sharing of livers for those in greater need and who would derive the greatest benefit (see Image 18 below).
Surgical therapyThe different techniques used for liver replacement are discussed at length in the following paragraphs. Preoperative detailsDuring multiorgan procurements, the goal of management is to maintain physiologic stability (ie, oxygenation, perfusion) so that the organs are in the best possible condition at harvest. Donors are brain dead and, thus, do not require an anesthetic, although they may still exhibit visceral, somatic, and autonomic reflexes. Additionally, the anesthesiologist may be asked to administer certain medications (eg, mannitol, furosemide, heparin) as part of the organ procurement protocol. In general, the goal is to provide supportive care during the procurement to avoid any insult to the organ(s) being harvested. Anesthetic management during the organ implantation procedure follows the same general provisions as for other procedures, ie, hypnosis, amnesia, analgesia, neuromuscular blockade, and hemodynamic stability. A rapid-sequence induction is used. Nasal intubation is avoided because of the potential for severe epistaxis. Isoflurane in air plus a narcotic is the usual anesthetic technique, and long-acting drugs, such as pancuronium, lorazepam, and methadone, may be used. Nitrous oxide is avoided because of its effect on enteric distension. Regional anesthesia for postoperative analgesia is contraindicated because of actual or potential coagulopathies. Besides the standard intraoperative monitors, arterial and pulmonary artery catheters are placed. In some centers, transesophageal echocardiography is added if questions arise concerning cardiac function or to help detect significant pulmonary emboli after reperfusion. An oral gastric tube is inserted, which later may be changed to a nasogastric tube. Intraoperatively, the Rapid Infusor System (RIS; Haemonetics Corporation, Venovenous bypass is used to divert inferior vena cava and portal blood flow around the retrohepatic portion of the inferior vena cava when it is clamped. Cannulas are usually placed in the femoral vein and the right internal jugular or axillary vein. A third cannula is inserted intraoperatively into the recipient's native portal vein. Blood from the femoral and portal cannulas is then pumped via a centrifugal bypass pump toward the internal jugular or axillary vein cannula. Placement of these cannulas can be accomplished percutaneously or via direct cutdown. The right internal jugular cannula also serves as the infusion site for the RIS. These cannulae are not needed if bypass is not a requirement of the surgical procedure. After reperfusion, inotropics, vasoconstrictors, calcium chloride, and nitroglycerin should be immediately available. Epinephrine, norepinephrine, and phenylephrine are the agents most commonly used at the author's institution. Nitroglycerin is occasionally needed after reperfusion if pulmonary artery pressures are elevated. Transfusion of blood products is often required in LT. Packed red blood cells and fresh frozen plasma (FFP) are administered via the RIS. Platelets and cryoprecipitate are generally administered via a peripheral or central vein after proper filtration. Other important intraoperative considerations include the use of antibiotics, immunosuppression, cytoprotection, and adequate temperature homeostasis. Prophylactic antibiotics are used frequently and dosed around the operative procedure, which can be quite lengthy. After complete revascularization of the allograft, methylprednisolone (1 g) is administered as immunoinduction. In addition, prostaglandin E1 is administered at a rate of 0.3-0.6 mg/kg/h in the postanhepatic portion of the surgery as a hepatic and renal cytoprotective agent, adjusted to blood pressure levels. Finally, maintenance of temperature is important because it plays a vital role in optimizing the function of the coagulation system. Methods to achieve this include maintenance of room temperature, warm air blankets, fluid warming via the RIS, low fresh gas flow rates, and heat-moisture exchangers. If the venovenous bypass circuit is used, a heating element may be placed in-line. Intraoperative detailsThe 3 elements involved in a successful LT are donor procurement, recipient implantation, and surgical coordination of these 2 procedures. The donor operationDonor availability is made known to the transplantation center with a suitable recipient, usually with a certain margin of time. The allocation follows the rules of UNOS. Surgical coordination of both the donor and the recipient operations is made when declaration of death, proper consent, and adequacy of the donor liver are evaluated and found to be adequate for the prospective recipient. The donor team is then transported to the donor's hospital. The donor operation proceeds in cooperation with any other procurement teams present. A long midline incision from the suprasternal notch to the pubis is performed to gain full exposure to the abdomen. The chest is opened via a median sternotomy. This maneuver properly exposes the intrathoracic structures, allowing both cardiac and pulmonary organ harvest; it also allows easier hepatic dissection and extraction for the abdominal surgeon. The dissection starts with the mobilization of the liver by dividing its ligamentous attachments. Sequentially, the left triangular and falciform ligaments are divided with the aid of electrocautery and are joined in the midline. Next, the gallbladder is emptied of its bile content by incising it at the fundus and irrigating it with warm saline until the returns are clear. Attention is then directed toward the hepatic hilum, which is carefully examined and palpated by placing a finger in the Winslow foramen to assess for the presence or absence of anatomic variations. The following are the most frequently encountered variations:
The importance of identifying these abnormalities is that any of these replaced or substituted trunks may contribute a significant amount, if not all, of the arterial blood supply to the respective lobe; therefore, preserve them whenever possible. Also, the presence of an aberrant left branch means that the dissection will be more tedious and delicate in order to preserve the left gastric artery, the main origin of this aberrant branch, alongside the lesser gastric curvature. Similarly, a right substituted or replaced branch requires the delicate dissection of the SMA up to the point of its origin in the aorta. At this point in the operative procedure, a decision is made to either proceed in the usual fashion or resort to the rapid flush technique. This depends on the stability of the donor. For stable donors, the hepatic hilum is dissected systematically, dividing and ligating successively the right gastric artery and the gastroduodenal artery. The other branches of the celiac trunk are isolated and tied, ie, the splenic artery on the superior edge of the pancreas and the left gastric artery along the upper lesser curvature of the stomach; the ties are cut long for posterior identification. The free edge of the common bile duct is exposed laterally and isolated, ligating the distal portion and transecting it. This normally allows dissection of the common hepatic artery upward and the pancreatic edge downward, thus bringing into view the anterior surface of the portal vein. Mild blunt dissection is used to separate the anterior portal surface from the pancreas, with care to not injure minor tributaries. This allows visualization of the splenic, superior, and inferior mesenteric veins and cannulation of the splenic vein with the portal cannula for the portal flush afterward. To do this, the size of the cannula is adjusted to the size of the vein (introduced after appropriate venotomy) and is secured with ties. After the portal cannula is in place, attention is directed to the infrarenal aorta, which is dissected free near its bifurcation; during this step, the inferior mesenteric artery is divided near its origin to obtain a proper segment of aorta for cannulation. Isolation of the supraceliac aorta follows by retracting the esophagus to the left and the previously mobilized left hepatic lobe to the right, thus exposing and dividing the diaphragmatic crura. This is used later as the site for cross-clamping. The scenario is now set for perfusion of the organs. The donor is heparinized with 20,000-30,000 IU of heparin, the aortic cannula is introduced in the infrarenal aorta, the distal aorta is tied, and the suprarenal aorta is clamped. The organs are then perfused with ice-cold UW solution, and the suprahepatic vena cava is vented in the pericardial space. At this point, the cold, topical, iced solution is poured in the abdomen for surface cooling. Some surgeons also vent the vena cava via the infrarenal portion. Removal of the liver then proceeds. The suprahepatic vena cava is taken along with a generous patch of diaphragm. The left gastric artery is dissected back, as is the splenic artery. The duodenum is kocherized, and fingers are placed behind the pancreas; the portal vein is dissected back, and its tributaries are divided. The SMA is felt through the pancreatic parenchyma, is dissected free, and is placed on traction with aid of a clamp. Sharp dissection proceeds to the left of the SMA and is carried down to the aorta; then, dissection from left to right is performed to identify potential right branches. The celiac trunk is then removed along with a generous Carrel patch of aorta. After the hepatic hilar dissection is completed, the inferior vena cava is divided above the renal veins and is taken along with the bisected right adrenal vein. The remaining attachments of the liver and its hilar structures are carefully divided, and the organ is removed and taken to the back table for an immediate flush. This general procedure is modified in cases of aberrant vessels to include dissection of the left gastric artery along the lesser curvature of the stomach (for left branches), or the SMA is included in the Carrel patch and is dissected very carefully from left to right to avoid injury to accessory right branches. In unstable donors, the portal system is cannulated first, prior to the hilar dissection, via the superior mesenteric vein in the inframesocolic space; the aortic control and cannulation quickly follow, and, after cross-clamping the supraceliac aorta, cold flushing is performed. Thereafter, hilar dissection and removal of the liver is performed in an asanguinous field. Exquisite care must be exercised to avoid injury to the vessels or biliary structures. Once removed from the body, the liver is again flushed with 1 L of UW on the back table. After the organ has been properly flushed and packed, the internal iliac arteries and veins of the donor are procured for potential use as grafts. Transportation to the recipient's hospital immediately follows, in close coordination with the recipient's preparation. The recipient implantationBack-table allograft preparation Prior to engraftment, the donor liver is removed from ice and prepared for implantation in a back-table procedure. In this procedure, the superfluous tissues that accompany organs removed en bloc are trimmed, and, if any vascular reconstruction is necessary, it is performed. The aim of the vascular reconstruction procedures, usually arterial, is to provide a single common inflow vessel of sufficient length so that only one anastomosis needs to be performed in the recipient. All vessels are then tested for patency and integrity by flushing with sterile preservation solution. The donor iliac arteries and veins routinely procured at the termination of the donor operation are also prepared for use, if necessary, as venous or arterial grafts in the recipient. Full liver recipient procedure The goals of an orthotopic LT operation are to remove the diseased liver (total hepatectomy) and then replace it with a healthy liver in exactly the same location. The recipient hepatectomy could result in massive bleeding; therefore, paying careful attention to the meticulous gentle handling of tissues and having a strict systematic approach to hemostasis at all times are crucial. Proper usage of venovenous bypass and blood products can optimize this part of the operation, thus decreasing morbidity rates. A bilateral subcostal incision with a midline extension to the xiphoid process is routinely used (ie, "Mercedes-Benz" incision). After mobilizing and dividing the round and falciform ligaments, a large self-retaining upper abdominal retractor is placed (see Image 6). The ligamentous attachments of the liver (ie, left triangular, right triangular, and gastrohepatic ligaments) are then dissected to mobilize the liver in its entirety. Dissection of the hilar structures then proceeds (see Image 7), with systematic ligation of the hepatic artery, cystic duct, and common hepatic duct. The portal vein is then cleaned of surrounding tissue from the level of the head of the pancreas up to its bifurcation into right and left branches. The hepatic artery is now formally dissected proximal to the gastroduodenal artery, exposing the common hepatic artery to allow for subsequent anastomosis. The gastroduodenal artery is left untied to avoid distal thrombosis or dissection, which may happen if this is ligated. Venovenous bypass may now be initiated (see Image 8). Whether and when to start bypass depends on the degree of portal hypertension, the extent of previous surgery with vascularized adhesions, and the degree of bleeding within the operative field, notoriously from the retroperitoneum. Thus, initiation of bypass may occur early or late during the hepatectomy phase, as judged by the operating surgeon. Once bypass is initiated, the remaining attachments to the liver can be divided rapidly and the liver can be removed, leaving both upper and lower caval cuffs for later anastomosis. Depending on the degree of bleeding and the size of the donor liver to be implanted, the bare area of the liver may be oversewn. Following this, the vena caval cuffs are shaped for anastomosis. Implantation and caval techniques
After achievement of adequate hemostasis, biliary reconstruction can begin. If the recipient bile duct is of normal caliber and is free of intrinsic disease, a donor-to-recipient duct-to-duct reconstruction can be performed over an indwelling T-tube stent that is exteriorized through a separate stab wound incision. If the 2 ends of the bile duct can be tailored to meet perfectly without redundancy and are of similar caliber, this end-to-end reconstruction can be performed without a T-tube. If the patient's native bile duct is diseased or if the duct is too small, the bile duct of the donor is anastomosed to a defunctionalized Roux-en-Y loop of jejunum over an internal stent (see Image 12). Cholangiography is performed to confirm a technically sound biliary reconstruction and may be performed through the T-tube or via the cystic duct. With this completed, closing the abdomen after leaving 3 closed suction drains above and below the liver concludes the operation. Recipient procedure (special cases)
Partial liver recipient procedures While the number of LTs has grown exponentially, the number of organ donors has not kept pace with the growing number of candidates. This widening gap between supply and demand has led to higher mortality rates among candidates on the waiting list. In attempts to narrow this gap, transplantation centers have broadened their donor selection criteria and have begun to use innovative surgical techniques such as reduced-size LT, split LT, and living-donor LT. Reduced-size LT was introduced in the mid 1980s to provide size-matched grafts for pediatric patients. In reduced-size LT, a cadaveric liver procured using standard techniques is resected on the back table to create a smaller graft. The liver allograft can be tailored based on the recipient's body size. Right lobe grafts, left lobe grafts, or left lateral segment grafts can be created. The rest of the liver is discarded. In living-donor LT (see Image 13), part of the liver from a living donor is resected and transplanted into a recipient. The technique was first used for pediatric recipients and has now been extended to the adult recipient population because of excellent results and established donor safety. In pediatric recipients, either left lateral segments or full left lobes usually suffice. For adults, right lobe grafts are necessary to ensure enough liver volume. This new procedure provides many advantages to the recipient because of the elective nature of the procedure (usually before severe hepatic decompensation) and the assurance of a healthy donor organ with a short ischemia time, resulting in better graft quality than with cadaveric liver allografts. Technical problems in the recipient, such as hepatic artery thrombosis and biliary leaks, were observed initially but have decreased dramatically with increasing experience in technique and recipient selection. For the donors, the advantage is mainly psychological. Because living-donor LT subjects a healthy individual to major surgery, donor safety is essential and informed consent is crucial. The American Society of Transplant Surgeons published guidelines for living-donor transplantation. The risks and benefits of the living-donor operation must be explained to the donor, the recipient, and their immediate families. In addition, donors should be thoroughly evaluated by an unbiased physician. The workup should include a full medical, psychosocial, and anatomical evaluation of prospective donors. Finally, although the donor operation has been associated with low morbidity and mortality rates, long-term follow-up is necessary to confirm the safety of this procedure for donors, especially for donors of right lobe grafts.
Not all donors are suitable for split procedures. Donors should be older than 50 years and should be hospitalized for less than 3 days with perfect liver function, minimal pressor support, and no steatosis. The final decision of whether a liver is suitable for splitting should be made in the operating room. Similarly, recipients should be selected carefully. Relatively stable patients in Child class B or C tolerate split-related complications better. Postoperative detailsICU careFollowing LT, the function of the new liver is monitored closely in an ICU setting. Elevations of liver enzymes, notoriously transaminases (ie, aspartate aminotransferase, alanine aminotransferase), early on are reflective of preservation injury (cold preservation). On occasion, these enzyme levels rise sharply. If they are higher than 2000, the overall viability function of the liver should be monitored carefully to assess the need for retransplantation. Usually, the liver enzyme levels normalize very quickly, typically within a week of transplantation. The bilirubin level follows a similar pattern of early rise and delayed clearing. However, if the preservation injury is severe, this elevation can persist for 2-3 weeks and can be accompanied by a significant rise in alkaline phosphatase levels. Platelet counts usually decrease in the first week after LT and recover during the second week. This may be caused by platelet sequestration in the liver and spleen due to preservation injury. Once the liver has recovered, as manifested by the return of bilirubin to normal levels, the platelet count increases. Recovery in a typical patient is rapid, as is discharge to the floor, usually within 2-3 days. However, if the graft has suffered severe preservation injury, return to normality may lag. Treatment is mostly supportive, with the goal of maintaining stable hemodynamics while the liver recovers. In extreme cases, termed primary graft nonfunction, the new liver never recovers and urgent retransplantation is required. Floor careAfter the patient's medical condition has stabilized and graft function is stable, he or she is transferred from the ICU to the floor transplant unit. At this time, tests are performed to assure adequacy of the new connections. A duplex Doppler ultrasound helps check for patency of the vascular anastomoses and the presence of abnormal fluid collections. If a tube is present, a T-tube cholangiogram is performed to assure adequate biliary drainage and to exclude leaks. During the patient's stay on the floor unit, his or her laboratory studies, medications, nutritional status, and exercise tolerance are monitored. As soon as patients are able, discharge instructions begin to prepare them for going home. Most patients with severe ESLD have a very low albumin level prior to transplantation. After successful LT, the albumin level slowly rises to normal levels. This explains the generalized edema that patients may experience following transplantation, which begins to disappear once albumin levels start to normalize. Follow-upUpon leaving the hospital, the patient receives a schedule of follow-up clinic visits for laboratory tests and checkups. The idea is to track clinical progress and to detect potential complications (eg, rejections, infections) as early as possible. Patients are instructed to notify the transplantation team if they have any prolonged illness, fever, nausea, vomiting, or diarrhea or if they experience any unusual symptoms or adverse effects potentially related to the immunosuppressants. Immunosuppression regimensFollowing transplantation, all patients are placed on immunosuppressive drugs to prevent rejection of the new liver. These medications are usually started in the operating room and are continued thereafter. The dose of the immunosuppression agent needed varies from patient to patient depending on the likelihood of rejection. Immunosuppression must be balanced carefully against the patient's own immune system. Adjusting the dose specifically for each patient helps avoid the risk of postoperative infections, tumor development, and liver rejection. The dose of immunosuppression agents varies between patients and may vary with time in a particular patient. This explains the requirement of frequent blood drawing, especially early after transplantation, because absorption, metabolism, and dose requirements of these drugs can vary significantly from day to day in the early posttransplant period. As time passes, the amount of immunosuppression needed to prevent organ rejection usually decreases. Immunosuppression therapy is not without risk and must be monitored closely. Immunosuppression management is based on the following principles:
In-depth discussion of the pharmacology of immunosuppressive medications is beyond the scope of this article, although certain points are worth mentioning. Induction immunosuppression is not commonly used after LT, although the recent introduction of the newer IL-2 receptor-blocking antibody preparations, daclizumab (Zenapax) and basiliximab (Simulect), may change this approach in the future. Maintenance immunosuppression is usually based on a calcineurin inhibitor (ie, cyclosporine A or tacrolimus) and corticosteroids. These may be combined with newer antimetabolite compounds (eg, mycophenolate) or antiproliferative agents (eg, sirolimus, rapamycin) with the goal of decreasing steroid and/or calcineurin inhibitor use. The most important toxicities are related to steroids (eg, osteopenia, diabetes, cushingoid syndromes). Calcineurin inhibitor use is fraught mostly with neurotoxicity and nephrotoxicity. Finally, the antimetabolites can cause cytopenias, and sirolimus (rapamycin) has been associated with poor wound healing, hepatic artery thrombosis, cytopenias, and severe hyperlipidemia (see Image 15). Cyclosporine (Sandimmune, Neoral) Cyclosporine is a highly lipid-soluble drug that is extensively bound to plasma proteins. It is metabolized in the liver by cytochrome P-450 enzymes. Excretion is mainly biliary, with only trace amounts excreted unchanged in urine. Interactions with other drugs generally arise from effects on the pharmacokinetic characteristics of cyclosporine and from additive pharmacologic or toxic effects. Cyclosporine can be administered by double-route therapy (PO and IV). Patients who have undergone kidney transplantations can usually be maintained on oral therapy alone. Patients who have undergone LT, who sustain longer GI dysfunction after the operation, are maintained on double-route therapy longer. The decision to switch to oral therapy depends on the status of cyclosporine drug levels and liver function. Oral cyclosporine is now available in an emulsified form (Neoral), which has overcome many of the problems of absorption observed initially. Capsules are available in 25- and 100-mg sizes. Cyclosporine toxicity is manifested by hypertension, tremulousness, hypertrichosis, gingival hyperplasia, and nephrotoxicity with hyperkalemia and/or renal tubular acidosis. A low serum magnesium level potentiates cyclosporine neurotoxicity and may result in seizures. Liver function may also be impaired by cyclosporine, but this is less common than nephrotoxicity. Cyclosporine can produce acute and chronic nephrotoxicity. The most common cause of a rise in BUN and creatinine levels after transplantation is cyclosporine toxicity, which responds promptly to a reduction in dosage. Every effort is made to reduce cyclosporine doses to the lowest levels possible. Cyclosporine levels are measured by the TDx monoclonal assay. Careful clinical assessment of the patient for adverse effects of cyclosporine (eg, tremulousness, hypertension, hyperkalemia, gum enlargement or soreness, elevated creatinine level, liver dysfunction not attributable to other causes) remains the best guide to dosage. In general, TDx 12-hour trough levels of 450-550 ng/mL for liver recipients on triple therapy are expected during the early posttransplant period, with decreasing levels in the weeks after transplantation. Cyclosporine also has toxic effects on the CNS. Intravenous cyclosporine may cause seizures. The magnesium level must be kept greater than 2 to prevent adverse effects, including paranoid delusions and hallucinations. Oral maintenance therapy has also been found to produce mood depression. Cyclosporine is primarily eliminated from the body by hepatic metabolism, and potent inducers and inhibitors of the cytochrome P-450 hepatic microsomal enzyme system increase or decrease cyclosporine clearance. In general, enzyme-inducing effects occur over a several-week period; when the inducing drug is withdrawn, the effect takes a similar time to reverse. Enzyme inhibition has more rapid clinical effects because drug accumulation begins immediately and may require a reduction in cyclosporine dosage. Liver transplant recipients may need parenteral nutritional support, including intravenous fat emulsions (Intralipid). Cyclosporine is highly lipophilic and binds to serum lipoproteins. Cyclosporine levels should be carefully monitored in patients receiving intravenous fat emulsions. FK506/tacrolimus (Prograf) Tacrolimus is a macrolide antibiotic that shares many characteristics with cyclosporine. It inhibits IL-2, interferon-gamma, and IL-3 production; transferrin and IL-2 receptor expression; mixed lymphocyte reactions; and cytotoxic T generation. Tacrolimus is metabolized by the same cytochrome P-450 system as cyclosporine, and less than 1% appears in the urine after an oral dose. It is highly lipid soluble; but, unlike cyclosporine, oral absorption is not dependent on bile acids. Tacrolimus can be administered by both oral and intravenous routes, although the intravenous route is used infrequently at present because of its greater likelihood of toxicity, especially nephrotoxicity and neurological toxicity. Because the absorption of tacrolimus is more efficient than that of cyclosporine, it can be used as an oral agent very early following LT and does not require clamping of the T-tube to provide adequate absorption and maintenance of levels. The usual recommended oral dose of tacrolimus is 0.15 mg/kg, initially every 12 hours. For adults, the oral maintenance dose is usually in the range of 0.03-0.2 mg/kg/dose. If an intravenous dose is required, it is usually 0.03 mg/kg, with a range of 0.01-0.05 mg/kg every 12 hours as a continuous infusion. Like cyclosporine, tacrolimus toxicity is manifested by nephrotoxicity, neurotoxicity, and hyperglycemia. Nephrotoxicity seems to be as frequent and severe as that observed with cyclosporine and is generally reversible with dosage reduction. Neurotoxicity ranges from mild symptoms (eg, insomnia or somnolence, headaches, tremors) to more severe symptoms (eg, obtundation, seizures, coma). As with nephrotoxicity, neurotoxicity appears to be related to high levels of the drug and resolves with dosage reduction. Hyperglycemia requiring insulin therapy has been reported, but the development of this hyperglycemia does not appear to be dose dependent and its cause is unknown. Other reported adverse effects for patients taking tacrolimus include hypercalcemia, hyperlipidemia, hypercholesterolemia, and alopecia. Low serum magnesium levels have been reported, and the development of hyperkalemia in the face of stable renal function has also been reported. Tacrolimus levels are monitored daily by obtaining trough levels while the patient is hospitalized and at the time of their clinic follow-up visits. Tacrolimus is usually administered at 8 am and 8 pm, with blood levels being drawn between 7 am and 8 am. These levels are measured by the florescent polarization immunoassay analysis, with concentrations of 5-20 mg/mL representing therapeutic levels that appear to avoid most adverse effects. However, careful clinical assessment of the patient for adverse effects, even in the face of what appear to be therapeutic levels, remains the most reliable method for tacrolimus dosing. Although the extensive listing of drug interactions that have been defined for cyclosporine have not been completely elucidated for tacrolimus, they likely will have similar drug interactions. This is because both are metabolized by the cytochrome P-450 hepatic microsomal enzyme system, and any medication that induces or inhibits this system either increases or decreases tacrolimus clearance. Drugs such as ketoconazole, fluconazole, and diltiazem may significantly inhibit tacrolimus clearance; therefore, increase levels and decrease the dosage requirement. Corticosteroids Corticosteroids are used routinely as part of the maintenance protocol for solid organ transplant recipients. Patients with brittle diabetes, advanced osteoporosis, or refractory hypertension who are receiving conventional immunosuppression with cyclosporine and prednisone may have their steroid doses reduced early. Long-term steroid use is associated with many debilitating complications, including refractory hypertension, diabetes, osteoporosis and fractures, hip necrosis, cataracts, acne, and obesity; thus, weaning patients to the lowest effective dose is highly desirable. One of the principal benefits of tacrolimus is that it has permitted patients to be maintained on much lower doses of prednisone than was possible with previous regimens. Steroids are also important in the management of acute rejection (see Acute rejection). Combination therapy with azathioprine (Imuran) or mycophenolate (CellCept) Azathioprine or mycophenolate may be added to cyclosporine- or tacrolimus-steroid therapy. This may be initiated to augment immunosuppression or to permit reducing the dosage of cyclosporine to control toxicity. Therapy is usually started at low doses (~1 mg/kg for azathioprine and 1 g twice daily for mycophenolate) and is gradually increased as tolerated. Leukocyte counts (peripheral WBC count) must be monitored daily because both drugs are bone marrow depressants. Because immunosuppressive agents have significant toxicities, other medications are frequently added to the patients' regimens to either prevent infections or counteract some of these adverse effects. As such, prophylactic perioperative antibiotics are routinely used for 48 hours post-LT. In addition, maintenance antibiotic prophylaxis for infections is frequently instituted for 3-12 months after transplantation, including agents such as trimethoprim-sulfamethoxazole or dapsone (Pneumocystis carinii pneumonia), acyclovir or ganciclovir (herpes viruses), and clotrimazole and/or nystatin (fungal infections, candidal infections). Other commonly prescribed medications include antacids, antiulcer medications, or both. Rejection and allograft dysfunction after transplantationAcute (cellular) hepatic allograft rejection, an attempt by the immune system to attack the transplanted liver and destroy it, can occur in as many as 40% of patients during the first 3 months after transplantation. Acute rejection normally occurs 7-14 days after the operation but can occur earlier or much later. Hyperacute rejection of the liver, comparable to that observed in kidney transplantation, is controversial and difficult to diagnose, but early accelerated rejection certainly occurs. Liver biopsy may be required to distinguish between rejection and viral infection. Rejection is most commonly manifested by malaise, fever, graft enlargement, and diminished graft function. In patients who have undergone LT, a rise in bilirubin and transaminase levels is observed and T-tube biliary drainage may be thin and lighter in color. Acute rejection most commonly first occurs in the second week after transplantation but can occur earlier. Graft biopsy should be performed, if safe, to document rejection. Adult liver biopsies are routinely performed at the bedside with or without ultrasound guidance. With early suspicion and detection, most acute rejection episodes can be treated successfully. Characteristic signs and symptoms of rejection include fatigue, fever, abdominal pain or tenderness, jaundice, dark yellow or orange urine, and/or clay-colored stools. In some instances, a patient may not have any symptoms, but his or her liver function test findings may be abnormal, suggesting that rejection is occurring. Rejection episodes are managed sequentially by pulse steroids, OKT3, and/or the use of mycophenolate or a tacrolimus switch if the patient was on cyclosporine. Retransplantation is the last resort when therapy fails and the patient develops hepatic failure. Chronic rejection The characteristics of chronic rejection in recipients of a liver transplant are progressive bile duct disappearance and obliterative arteriopathy, known as ductopenia, and vanishing bile duct syndrome, which results in progressive jaundice and allograft dysfunction. The ducts suffer direct immunological injury and ischemia from the obliterative arteriopathy caused by antibody-mediated intimal damage of hepatic arterioles. In the late phase of chronic rejection, diffuse hepatic fibrosis occurs. Allograft function deteriorates, marked by cholestasis and, ultimately, loss of synthetic function and portal hypertension. Heavy immunosuppression with tacrolimus, mycophenolate mofetil, and/or sirolimus may reverse chronic rejection in the early phases. Advanced chronic rejection is an indication for retransplantation. Diagnostic tools for allograft dysfunction As Image 16 shows, the etiology of posttransplant allograft dysfunction is multifactorial and multietiological in its origin. Anything, from technical factors to recurrent infections or drug interactions, can ultimately cause allograft dysfunction. Thus, establishing the diagnosis accurately is of prime importance because many of these conditions have diametrically opposed management strategies. For example, if the dysfunction is due to infection, appropriate antibiotics should be used and immunosuppression should be decreased. This is the wrong course of action if the diagnosis is acute rejection. The complete workup of allograft dysfunction (see Image 17) in the adult liver transplant recipient must include all of the tests outlined in the slide. Serial monitoring of liver function test results; pan cultures for bacteria, viruses, and fungi; use of imaging tests (described below); and, ultimately, liver biopsy, are essential for an accurate diagnosis. In terms of radiological imaging, the transplantation team may perform one or more of the following tests and procedures to monitor a patient's transplant:
COMPLICATIONSSection 7 of 11
In uncomplicated cases, recovery from the operation is surprisingly rapid and not unlike that experienced by other general surgical patients. However, early graft dysfunction suggests accelerated rejection, technical complications, or primary graft failure. Primary graft failurePrimary graft failure occurs in approximately 7% of patients and is a very serious complication. The patient decompensates quickly, and a desperate search for a new graft must be initiated. Patients show markedly abnormal liver function, coagulopathy, oliguria, and severe CNS changes (including seizures and status epilepticus). Stage IV coma, alkalosis, hyperkalemia, and hypoglycemia characterize the terminal phase of this acute hepatic decompensation. In these patients, treatment includes avoiding the administration of any potassium, transfusing FFP every 4-6 hours (or as a continuous infusion when necessary), and keeping the gastric pH greater than 5.0. FFP can be administered once the determination of primary nonfunction has been made. A continuous 10% aqueous dextrose solution infusion may be needed to control hypoglycemia. Urgent retransplantation is the solution to this complication if it can be performed before pneumonia or irreversible coma occurs. Prostaglandin infusions may also be used in the setting of primary nonfunction. Biliary complicationsTechnical complications usually involve either biliary or arterial reconstruction. Biliary complications are relatively frequent after LT and are thought to be primarily of ischemic origin. Persistent jaundice with or without drainage of bile through the drains warrants study. Ultrasound and/or abdominal CT scans may show ductal dilation or bile collection. If the patient has a T-tube, obtain a cholangiogram, preferably in the radiology suite. Reexploration is required if a bile leak is present. Obstruction may require reexploration if it cannot be dealt with by percutaneous interventional radiology. Hepatic arterial thrombosisHepatic arterial thrombosis should be considered in any patient who has a sudden high fever and elevation in liver function study results. A positive blood culture finding for Klebsiella species, Escherichia coli, Pseudomonas species, or enterococci in this setting is virtually pathognomonic. Doppler ultrasound is an effective noninvasive method for evaluating hepatic artery patency. If the vessel cannot be seen well or if clinical suggestion is high, arteriography is indicated. Hepatic arterial thrombosis has 3 general patterns of presentation. The first is acute hepatic gangrene with sepsis and fulminant liver failure. Urgent retransplantation is required. The second is delayed bile leak or intrahepatic biloma or bile abscess resulting from ischemic necrosis of the bile ducts. Retransplantation is usually required, especially if the common bile duct is disrupted, but some patients can be controlled, at least temporarily, with percutaneous drainage of intrahepatic collections and antibiotic coverage. The third general pattern is relapsing bacteremia. Some patients, especially small children, can be treated successfully with antibiotic therapy. A full course of intravenous antibiotics is administered, followed by a course of oral suppressive therapy. If the patient remains afebrile with good liver function, retransplantation may be necessary only if chronic ischemic strictures of the biliary tree develop. Other patients have persistent bacteremia and develop liver abscesses, requiring eventual transplantation. Because of the danger of hepatic artery thrombosis, vigorously treating evaluated prothrombin times or low platelet counts with FFP and platelet transfusions is dangerous. Except in patients with active bleeding, platelet counts as low as 50,000/µL and prothrombin times less than 25 seconds are not treated. In addition, at the discretion of the surgeon, patients may be started on aspirin and dipyridamole (Persantine). Infection and feverAggressively evaluate all fever episodes in an immunosuppressed patient with the following routine tests:
The following tests also may be indicated if the above tests fail to identify the source or if the clinical situation dictates:
Even mild infections are a serious threat in immunosuppressed patients. As an adjunct to therapy, immunosuppression must be reduced or even completely stopped temporarily. Bacterial infections are better tolerated with cyclosporine than with azathioprine but still must be treated aggressively. Viral infections account for substantial morbidity and mortality. Herpes infections are treated with a 10- to 14-day course of acyclovir (5-10 mg/kg q8h IV over 1 h). Candidal species in sputum, blood, urine, bile, or drains are an indication for systemic therapy. The presence of candidal species in peritoneal fluid strongly suggests a bile leak or bowel perforation. Cytomegalovirus CMV status (positive or negative) of the donor must be recorded in the recipient's chart, and the CMV titer of the recipient must be ordered as part of the pretransplantation evaluation so the results are available immediately after transplantation. CMV infection is usually observed 3 or more weeks after transplantation and is one of the most common viral infections. CMV infection is often characterized by fever, leukopenia, and malaise. Patients with systemic CMV infections are treated with ganciclovir. The drug appears to be most effective when started early in the course of CMV infection and may be useful for CMV hepatitis, enteritis, and CMV pneumonia. A tissue diagnosis of CMV should be sought, either by characteristic histological findings or by biopsy cultures. Endoscopy is often successful in demonstrating CMV infection, even in patients without GI symptoms. Candidal infections Candidal species (ie, Candida albicans, Candida tropicalis, Candida parapsilosis, Torulopsis glabrata) can cause severe locally or systematically invasive infections in heavily immunosuppressed patients. As a general rule, if candidal species grow from 2 or more sites, even if not from blood (eg, urine, wound), the condition should be managed as a systemic infection. Traditional treatment for systemic candidiasis has been intravenous amphotericin B. Amphotericin must be administered intravenously and has synergistic renal toxicity |
