Portopulmonary hypertension and the liver transplant candidate

Shortness of breath due to portopulmonary hypertension and hepatopulmonary syndrome: diagnostic challenges and complex management approach in frail patients

A 60-year-old woman with a background of frailty, non-alcoholic fatty liver disease (NAFLD), cirrhosis and type 2 diabetes mellitus (T2DM), presented with worsening shortness of breath and a drop in oxygen saturation on sitting and standing up. Her chest X-ray demonstrated evidence of upper lobe venous diversion. Given the hypoxia, she had a computed tomography pulmonary angiography (CTPA) to rule out a pulmonary embolism. The only finding from the CTPA was pulmonary hypertension in the absence of any clots in the lungs. An ultrasound of the abdomen confirmed portal hypertension with splenomegaly and a cirrhotic liver, therefore, an initial diagnosis of portopulmonary hypertension and hepatopulmonary syndrome was made. The patient declined an agitated saline contrast echocardiography. Based on frailty she was not deemed to be a suitable candidate for a liver transplant and was discharged with a package of care alongside home oxygen therapy with periodic review in the gastroenterology clinic. She was assessed as stable with no new concerns while on home oxygen and diuretics. This case highlights challenges in diagnosing and managing patients with cirrhosis, portopulmonary hypertension and hepatopulmonary syndrome with a background of complex comorbidities and frailty.

Hemodynamic Instability During Liver Transplantation in Patients With End-stage Liver Disease: A Consensus Document from ILTS, LICAGE, and SATA

Hemodynamic instability (HDI) during liver transplantation (LT) can be difficult to manage and increases postoperative morbidity and mortality. In addition to surgical causes of HDI, patient- and graft-related factors are also important. Nitric oxide-mediated vasodilatation is a common denominator associated with end-stage liver disease related to HDI. Despite intense investigation, optimal management strategies remain elusive. In this consensus article, experts from the International Liver Transplantation Society, the Liver Intensive Care Group of Europe, and the Society for the Advancement of Transplant Anesthesia performed a rigorous review of the most current literature regarding the epidemiology, causes, and management of HDI during LT. Special attention has been paid to unique LT-associated conditions including the causes and management of vasoplegic syndrome, cardiomyopathies, LT-related arrhythmias, right and left ventricular dysfunction, and the specifics of medical and fluid management in end-stage liver disease as well as problems specifically related to portal circulation. When possible, management recommendations are made.

Clinical impact of mild to moderate pulmonary hypertension in living-donor liver transplantation

Severe pulmonary hypertension (PHT) is a contraindication to liver transplantation (LT); however, the prognostic implication of mild to moderate PHT in living-donor LT (LDLT) is unknown. The study cohort retrospectively included 1307 patients with liver cirrhosis who underwent LDLT. PHT was defined as a mean pulmonary artery pressure (PAP) of ≥25 mmHg, measured intraoperatively just before surgery. The primary endpoint was graft failure within 1 year after LDLT, including retransplantation or death from any cause. The secondary endpoints were in-hospital adverse events. In the overall cohort, the median Model for End-stage Liver Disease-Sodium (MELD-Na) score was 19, and 100 patients (7.7%) showed PHT. During 1-year follow-up, graft failure occurred in 94 patients (7.2%). Patients with PHT had lower 1-year graft survival (86% vs. 93.4%, P = 0.005) and survival rates (87% vs. 93.6%, P = 0.011). Mean PAP was associated with a high risk of in-hospital adverse events and 1-year graft failure. Adding the mean PAP to the clinical risk model improved the risk prediction. In conclusion, mild to moderate PHT was associated with higher risks of 1-year graft failure and in-hospital events, including mortality after LDLT in patients with liver cirrhosis. Intraoperative mean PAP can help predict the early clinical outcomes after LDLT.

Cardiac and Pulmonary Vascular Risk Stratification in Liver Transplantation

Cardiovascular disease complications are the leading cause of early (short-term) mortality among liver transplant recipients. The increasingly older candidate pool has multiple comorbidities necessitating cardiac and pulmonary vascular disease risk stratification of patients for optimal allocation of scarce donor livers. Arrhythmias, heart failure, stroke, and coronary artery disease are common pretransplant cardiovascular comorbidities and contribute to cardiovascular complications after liver transplant. Valvular heart disease and portopulmonary hypertension present intraoperative challenges during liver transplant surgery. The Cardiovascular Risk in Orthotopic Liver Transplantation score estimates the risk of cardiovascular complications in liver transplant candidates within the first year after transplant.

A Case of Hypopituitarism Complicated by Non-Alcoholic Steatohepatitis and Severe Pulmonary Hypertension

BACKGROUND Pulmonary arterial hypertension (PAH), which is caused by increased pulmonary artery pressure, results in right-heart failure and presents with shortness of breath, chest pain, and syncope. PAH has idiopathic, heritable, and drug/toxin causes and is accompanied by other conditions, including connective tissue disease, congenital heart disease, and portal hypertension. Rarely, portal hypertension causes a type of PAH called portopulmonary hypertension (POPH). Portal hypertension can be triggered by liver cirrhosis, which can result from non-alcoholic steatohepatitis (NASH), a metabolic syndrome caused by hypopituitarism. Although an association between hypopituitarism and POPH has been suggested, few reports have described this relationship. CASE REPORT A 43-year-old woman with hypopituitarism received hormone replacement therapy after partial hypothalamic resection at age 4 years. At age 32 years, she developed liver cirrhosis from NASH due to adult growth hormone (GH) deficiency. Despite restarting GH replacement therapy, she refused the required GH doses for economic reasons. She was hospitalized with abdominal pain and dyspnea and was found to have severe POPH. She received PAH-specific therapies, including endothelin receptor antagonist and prostacyclin analog. Pulmonary hypertension improved on day 3 of hospitalization while the cardiac index increased gradually. On day 12, her respiratory status rapidly worsened and percutaneous cardiopulmonary support was applied. On day 18, she died of multiple organ failure and disseminated intravascular coagulation despite intensive care management. CONCLUSIONS Severe PAH, particularly POPH, remains incurable despite the use of PAH-specific therapies and intensive care management. For hypopituitarism patients, careful observation, including of the cardiopulmonary system, can improve the prognosis after completing hormone replacement therapy.

Acute heart failure after liver transplantation: A narrative review

Acute heart failure (AHF) is an under recognized yet potentially lethal complication after liver transplantation (LT) surgery. The increase in incidence of liver transplantation amongst high-risk patients and the leniency in the criteria for transplantation, predisposes these patients to postoperative AHF and the antecedent morbidity and mortality. The inability of conventional preoperative cardiovascular testing to accurately identify patients at risk for post-LT AHF poses a considerable challenge to clinicians caring for these patients. Even if high-risk patients are identified, there is considerable ambiguity in the candidacy for transplantation as well as optimization strategies that could potentially prevent the development of AHF in the postoperative period. The intraoperative and postoperative management of patients who develop AHF is also challenging and requires a well-coordinated multidisciplinary approach. The use of mechanical circulatory support in patients with refractory heart failure has the potential to improve outcomes but its use in this complex patient population can be associated with significant complications and requires a stringent risk-benefit analysis on a case-by-case basis.

Liver transplantation and cardiac illness: Current evidences and future directions

Contraindications to liver transplantation are gradually narrowing. Cardiac illness and chronic liver disease may manifest independently or may be superimposed on each other due to shared pathophysiology. Cardiac surgery involving the cardiopulmonary bypass in patients with Child-Pugh Class C liver disease is associated with a high risk of perioperative morbidity and mortality. Liver transplantation involves hemodynamic perturbations, volume shifts, coagulation abnormalities, electrolyte disturbances, and hypothermia, which may prove fatal in patients with cardiac illness depending upon the severity. Additionally, cardiovascular complications are the major cause of adverse postoperative outcomes after liver transplantation even in the absence of cardiac pathologies. Clinical decision-making has remained an unsettled issue in these clinical scenarios. The absence of randomized clinical studies has further crippled our endeavours for a consensus on the management of patients with end-stage liver disease with cardiac illness. This review seeks to address this complex clinical setting by gathering information from published literature. The management algorithm in this review may facilitate clinical decision making and augur future research.

Combination therapy for severe portopulmonary hypertension in a child allows for liver transplantation

Severe PPHTN is a contraindication to liver transplantation and predicts an abysmal 5-year outcome. It is defined as a resting mPAP >45 mm Hg with a mean pulmonary artery wedge pressure of <15 mm Hg and pulmonary vascular resistance of >3 wood units in the setting of portal hypertension. There have been limited reports of successful treatment of PPHTN leading to successful liver transplantation in adults, and one reported use of monotherapy as a bridge to successful liver transplant in pediatrics. To our knowledge, we describe the first use of combination therapy as a successful bridge to liver transplantation in a pediatric patient with severe PPHTN. This report adds to the paucity of data in pediatrics on the use of pulmonary vasodilator therapy in patients with severe PPHTN as a bridge to successful liver transplantation. Early diagnosis in order to mitigate or avoid the development of irreversible pulmonary vasculopathy that would preclude candidacy for liver transplantation is crucial, but our report demonstrates that combination therapy can be administered safely, quickly, and may allow for successful liver transplantation in patients with severe PPHTN.

International Liver Transplant Society Practice Guidelines: Diagnosis and Management of Hepatopulmonary Syndrome and Portopulmonary Hypertension

Two distinct pulmonary vascular disorders, hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) may occur as a consequence of hepatic parenchymal or vascular abnormalities. HPS and POPH have major clinical implications for liver transplantation. A European Respiratory Society Task Force on Pulmonary-Hepatic Disorders convened in 2002 to standardize the diagnosis and guide management of these disorders. These International Liver Transplant Society diagnostic and management guidelines are based on that task force consensus and should continue to evolve as clinical experience dictates. Based on a review of over 1000 published HPS and POPH articles identified via a MEDLINE search (1985-2015), clinical guidelines were based on, selected single care reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Guidelines are presented in 5 parts; I. Definitions/Diagnostic criteria; II. Hepatopulmonary syndrome; III. Portopulmonary hypertension; IV. Implications for liver transplantation; and V. Suggestions for future clinical research.

Current Approach to the Diagnosis and Management of Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is a form of pulmonary arterial hypertension occurring in the setting of portal hypertension with or without hepatic cirrhosis. The presence of both portal and pulmonary vascular disease contributes to complicated hemodynamics and therapeutic challenges, though the severities do not appear to correlate directly. Diagnosis of POPH, and distinction from the commonly observed hyperdynamic state of end-stage liver disease, is typically accomplished with an initial screening transthoracic echocardiogram, followed by right heart catheterization for confirmation of hemodynamic parameters. Though few studies have directly evaluated use in POPH, pulmonary artery-directed therapy is the cornerstone of management, along with consideration of liver transplantation. Perioperative and long-term outcomes are variable, but uniformly worse in the setting of uncontrolled pulmonary pressures. Risk stratification and optimal patient selection for these interventions are areas of ongoing investigation.

Pulmonary Hypertension Improves After Orthotopic Liver Transplant in Patients With Chronic Liver Disease

OBJECTIVES

Pulmonary hypertension is a common finding in chronic liver disease patients that has prognostic significance. In this study, we aimed to evaluate the prevalence and severity of pulmonary hypertension in patients undergoing orthotopic liver transplant. We also evaluated pulmonary artery pressure changes after transplant surgery.

MATERIALS AND METHODS

The records of adult patients with chronic liver disease who underwent orthotopic liver transplant at our center between 2004 and 2015 were retrospectively evaluated. Clinical and demographic variables and laboratory data were noted. Transthoracic Doppler echocardiographic examination reports were obtained. Using continuous-wave Doppler examination, systolic pulmonary artery pressure values were calculated. Pulmonary hypertension was defined as systolic pulmonary artery pressure ≥ 30 mm Hg. Among 208 adult patients who underwent orthotopic liver transplant, 203 who had Doppler echocardiographic examination were enrolled.

RESULTS

The mean age of patients was 42.1 ± 14.1 years (range, 16-67 y), and 143 (70.4%) were men. During preoperative assessment, pulmonary hypertension was identified in 47 patients (23.2%), of whom 10 displayed systolic pulmonary artery pressure > 50 mm Hg. Compared with preoperative values of systolic pulmonary artery pressure (46.8 ± 8.4 mm Hg), a significant reduction in mean values (to 39.3 ± 13.3 mm Hg) was observed postoperatively (P = .007).

CONCLUSIONS

The findings of this study indicate that pulmonary hypertension is a common finding in adult chronic liver disease patients undergoing orthotopic liver transplant. A significant improvement occurs in systolic pulmonary artery pressure values following transplant surgery. Regarding the prevalence and prognostic significance of pulmonary hypertension, all patients with chronic liver disease should be evaluated with transthoracic Doppler echocardiography before transplant.

Portopulmonary hypertension in liver transplant candidates

Pulmonary vascular disorders including portopulmonary hypertension (PoPHT) are among the common complications of liver disease and are prognostically significant. Survival is very low without medical treatment and liver transplantation. With advances in medical therapy for elevated pulmonary artery pressure (PAP) and liver transplant surgery, survival of patients with PoPHT and advanced liver disease is significantly improved. Because of the prognostic significance of PoPHT and the limited donor pool, a comprehensive preoperative cardio-pulmonary assessment is of great importance in cirrhotic patients prior to transplant surgery. Therefore, a detailed transthoracic Doppler echocardiographic examination must be an essential component of this evaluation. Patients with mild PoPHT can safely undergo liver transplant surgery. In cases of moderate to severe PoPHT, right heart catheterization (RHC) should be performed. In patients with moderate to severe PoPHT on RHC (mean PAP 35-45 mmHg), vasodilator therapy should be attempted. Liver transplantation should be encouraged in cases that demonstrate a positive response. Bridging therapy with specific pulmonary arterial hypertension treatment agents should be considered until the transplant surgery and should be continued during the peri- and post-operative periods as needed.

Postreperfusion syndrome during liver transplantation

As surgical and graft preservation techniques have improved and immunosuppressive drugs have advanced, liver transplantation (LT) is now considered the gold standard for treating patients with end-stage liver disease worldwide. However, despite the improved survival following LT, severe hemodynamic disturbances during LT remain a serious issue for the anesthesiologist. The greatest hemodynamic disturbance is postreperfusion syndrome (PRS), which occurs at reperfusion of the donated liver after unclamping of the portal vein. PRS is characterized by marked decreases in mean arterial pressure and systemic vascular resistance, and moderate increases in pulmonary arterial pressure and central venous pressure. The underlying pathophysiological mechanisms of PRS are complex. Moreover, risk factors associated with PRS are not fully understood. Rapid and appropriate treatment with vasopressors, volume replacement, or venesection must be provided depending on the cause of the hemodynamic disturbance when hemodynamic instability becomes profound after reperfusion. The negative effects of PRS on postoperative early morbidity and mortality are clear, but the effect of PRS on postoperative long-term mortality remains a matter of debate.

Hemodynamic profile of portopulmonary hypertension

Portopulmonary hypertension (PPHTN) refers to the development of pulmonary arterial hypertension in the setting of portal hypertension with or without chronic hepatic failure. This syndrome is characterized by marked alternations of pulmonary vascular tone and obstruction of pulmonary arterial blood flow. An increased pulmonary blood flow, which is a hallmark of the hyperdynamic circulation of cirrhotic patients, seems to be present in almost all patients who develop PPHTN. The elevations of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) along with the transpulmonary gradient (TPG) have been considered in diagnosing PPHTN. Only a high TPG reflects the severity of obstruction to pulmonary blood flow and differentiates an elevated PAP with concomitant elevated PVR from the situation where the increase in PAP is due only to the hyperdynamic flow and elevated volume. A considerable risk for cardiovascular death arises when PAP increases significantly; this may occur in rapidly evolving syndromes, in very advanced disease, or during a complicated liver transplantation. The distinction between PPHTN and elevated PAP in the context of a hyperdynamic state is of great importance; a PAP increase of hyperkinetic origin, as opposed to PPHTN, is apparently not associated with a high risk for adverse effects during and following liver transplantation.

Appraising cardiac dysfunction in liver transplantation: an ongoing challenge

End-stage liver disease (ESLD) is a multisystemic disease that adversely and mutually aggravates other organs such as the heart. Cardiac dysfunction in ESLD encompasses a spectrum of disease that could be aggravated, precipitated or be occurring hand-in-hand with coexisting aetiological factors precipitating cirrhosis. Additionally and more complexly, liver transplantation, the curative modality of ESLD, is responsible for additional intra- and postoperative short- and long-term cardiac morbidity. The phenotypic distinction of the different forms of cardiac dysfunction in ESLD albeit important prognostically and therapeutically is not allowed by the current societal recommendations, due to conceptual, and methodological limitations in the appraisal of cardiac function and structure in ESLD and in designing studies that are based on this appraisal. This review comprehensively discusses the spectrum of cardiac dysfunction in ESLD, discusses the limitations of the current appraisal of cardiac dysfunction in ESLD, and proposes a hypothetical approach for studying cardiac dysfunction in liver transplant candidates.

Role of cardiovascular intervention as a bridge to liver transplantation

End stage liver disease (ESLD) is associated with many specific derangements in cardiovascular physiology, which influence perioperative outcomes and may profoundly influence diagnostic and management strategies in the preoperative period. This review focuses on evidence-based diagnosis and management of coronary, hemodynamic and pulmonary vascular disease in this population with an emphasis on specific strategies that may provide a bridge to transplantation. Specifically, we address the underlying prevalence of cardiovascular disease states in the ESLD population, and relevant diagnostic criteria thereof. We highlight traditional and non-traditional predictors of cardiovascular outcomes following liver transplant, as well as data to guide risk-factor based diagnostic strategies. We go on to discuss the alterations in cardiovascular physiology which influence positive- and negative-predictive values of standard noninvasive testing modalities in the ESLD population, and review the data regarding the safety and efficacy of invasive testing in the face of ESLD and its co-morbidities. Finally, based upon the totality of available data, we outline an evidence-based approach for the management of ischemia, heart failure and pulmonary vascular disease in this population. It is our hope that such evidence-driven strategies can be employed to more safely bridge appropriate candidates to liver transplant, and to improve their cardiovascular health and outcomes in the peri-operative period.

Living-donor liver transplantation for congenital biliary atresia with porto-pulmonary hypertension and moderate or severe pulmonary arterial hypertension: Kyoto University experience

Porto-pulmonary hypertension with moderate or severe pulmonary arterial hypertension (PAH) is viewed as a contraindication to liver transplantation (LT) because of associated poor outcomes; however, patients with biliary atresia (BA) are generally good candidates for LT. Ten patients with moderate/severe PAH underwent living-donor liver transplantation (LDLT) at our institution; eight of these patients had BA and were the focus of this study. Preoperative therapies, including prostaglandin (PG)I2 , were introduced. When mean pulmonary arterial pressure (mPAP) after treatment was <40 mmHg or initial mPAP without therapy was <35 mmHg, we performed an acute volume challenge test to evaluate right ventricular function. LDLT was performed when mPAP after anesthetic induction was confirmed at ≤35 mmHg. Six patients had favorable responses to preoperative treatment and catheter testing, but two patients showed poor responses. The two patients with poor responses had poor clinical courses with unstable mPAP after LDLT. The other six patients had successful courses with well-controlled mPAP, and PGI2 was withdrawn or weaned following LDLT. Survival did not significantly differ between the eight BA recipients with moderate/severe PAH and 77 age-matched BA recipients without PAH from the same time period. LDLT has major benefits for BA patients with well-controlled PAH.

Management of portopulmonary hypertension: New perspectives

Portopulmonary hypertension (PPHTN) is a known complication of cirrhosis. Moderate-to-severe PPHTN implies an extremely poor prognosis. It occurs in 5%-10% of patients referred for liver transplantation (LT), and probably with an higher incidence in patients with large portosystemic shunts. Patients with moderate-to-severe pulmonary hypertension have been previously excluded from LT because of the extremely high surgical risk and since the post-transplant outcome reported was poor. Recently, new perspectives in the management of patients with portopulmonary hypertension are emerging. In fact, some pulmonary vasoactive drugs have become routine in the treatment of patients with idiopathic pulmonary hypertension. These drugs, particularly epoprostenol, have been recently introduced in the treatment of patients with PPHTN, and have been shown to be effective in reducing pulmonary artery pressure as well as pulmonary vascular resistances. Furthermore, recent studies seem to demonstrate that treatment with pulmonary vasoactive drugs could allow liver transplantation with acceptable surgical risks and excellent survival. Although there are not large series nor prospective studies addressing this topic, the clinical scenario of patients with PPHTN seems to be positively changing.

Echocardiography in liver transplant candidates

Involvement of the cardiovascular system in patients with end-stage liver disease (ESLD) is well recognized and may be seen in several scenarios in adult liver transplantation (LT) candidates. The hemodynamic effects of ESLD may result in apparent heart disease, or in some instances may mask cardiac disease. Alternatively, cardiac disease can occasionally be the underlying etiology of ESLD. LT imposes significant hemodynamic stresses, with cardiovascular complications accounting for considerable perioperative mortality and morbidity. Pre-operative assessment of the cardiac status of LT candidates is thus critically important for risk stratification and management. Cardiac imaging plays an integral role in the assessment of LT candidates. In this review, we discuss the role of cardiac imaging, including transthoracic echocardiography with Doppler and contrast enhancement, noninvasive functional assessment for routine pre-operative assessment of coronary artery disease, and transesophageal echocardiography in select cases to aid in intra-operative fluid management and monitoring in LT candidates.

Living-donor liver transplantation for moderate or severe porto-pulmonary hypertension accompanied by pulmonary arterial hypertension: a single-centre experience over 2 decades in Japan

BACKGROUND

Candidates for orthotopic liver transplantation (OLT) often have porto-pulmonary hypertension (PPHTN) with pulmonary arterial hypertension (PAH). Poor outcomes of PPHTN contraindicate OLT. There are no guidelines for living-donor liver transplantation (LDLT) in PPHTN patients.

METHODS

We present our experiences of LDLT in six patients with moderate or severe PPHTN, along with our institutional guidelines. Three had liver cirrhosis and three were non-cirrhotic. Catheterization studies were undertaken before, during and after LDLT, and the mean pulmonary arterial pressure (mPAP), cardiac output (CO), pulmonary vascular resistance and total peripheral resistance (TPR) were monitored.

RESULTS

The results showed significant differences in CO and TPR between cirrhotic and non-cirrhotic patients before, during and after LDLT. Cirrhotic patients showed systemic hyperdynamic state. Two cirrhotic patients showed poor responses to pre-transplant treatment, and continued to have increased PAH and poor clinical courses after LDLT. LDLT has an advantage of flexible timing of LT. Currently in our institution, PPHTN patients with mPAP <40 mmHg are registered for LDLT after treatment and catheterization. However, LDLT is performed when mPAP is ≤35 mmHg, leading to improved outcomes.

CONCLUSION

PPHTN patients with well-controlled PAH, or secondary PAH resulting from porto-systemic shunts, may be appropriate candidates for LDLT after careful considerations.

Cirrhotic cardiomyopathy and hepatopulmonary syndrome: prevalence and prognosis in a series of patients

Hepatopulmonary syndrome (HPS) is of prognostic value in patients awaiting for orthotopic liver transplantation (OLT), but little is known about the effect of cirrhotic cardiomyopathy (CCM). The aim of the present study was to estimate the prevalence and possible relation between respiratory and cardiac abnormalities in a same series of patients awaiting OLT. Special attention was paid to the prognostic value of CCM in comparison to HPS. Eighty-three patients were included (19 females, 64 males; 52.1 ± 10.0 yrs). All had lung function testing with arterial blood gases and echocardiographic evaluation at rest with a contrast echocardiography in case of arterial oxygenation defect. To estimate the presence of CCM, patients underwent a complete left and right echocardiography and Doppler examination. Complete echocardiographic assessment could be obtained in 64 of the 83 patients of the study. HPS was observed in 16.9% (14/83) and CCM in 23.4% (15/64) of patients. There was a tendency of more serious adverse events before and after OLT in patients with HPS in comparison to others but CCM was not of prognostic value. HPS and CCM were frequent in these patients awaiting OLT but both abnormalities were not found in the same patients. CCM was neither related to death before OLT nor to death or serious adverse events after OLT.

Evaluation of cardiac manifestations in pediatric liver transplant candidates

Knowledge concerning the involvement of the cardiovascular system in children awaiting liver transplant is limited. Therefore, no guidelines have been established on evaluating this group of patients for cardiac disease. This review examines the diverse cardiovascular manifestations of liver disease in children. We also discuss the available testing and its applicability in screening for cardiac disease in this vulnerable population.

Evaluation of liver transplant candidates: A pulmonary perspective

Chronic liver disease is one of the leading causes of mortality and morbidity in the worldwide adult population. Liver transplant is the gold standard therapy for end-stage liver disease and many patients are on the waiting list for a transplant. A variety of pulmonary disorders are encountered in cirrhotic patients. Pleura, lung parenchyma, and pulmonary vasculature may be affected in these patients. Hypoxemia is relatively common and can be asymptomatic. Hepatopulmonary syndrome should be investigated in hypoxic cirrhotic patients. Gas exchange abnormalities are common and are generally correlated with the severity of liver disease. Both obstructive and restrictive types of airway disease can be present. Abnormal diffusion capacity is the most frequently observed pulmonary function disorder in patients with cirrhosis. Hepatic hydrothorax is another finding which is usually seen in conjunction with, but occasionally without ascites. Portopulmonary hypertension is a complication of long standing liver dysfunction and when severe, is accepted as a containdication to liver transplant. Since respiratory disorders are common and have significant impact on postoperative outcome in patients undergoing liver transplant, a careful preoperative pulmonary assessment is important.

Cardiovascular risk assessment of the liver transplant candidate

Liver transplantation (LT) candidates today are increasingly older, have greater medical acuity, and have more cardiovascular comorbidities than ever before. Steadily rising model for end-stage liver disease (MELD) scores at the time of transplant, resulting from high organ demand, reflect the escalating risk profiles of LT candidates. In addition to advanced age and the presence of comorbidities, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Patients with cirrhosis requiring LT usually demonstrate increased cardiac output and a compromised ventricular response to stress, a condition termed cirrhotic cardiomyopathy. These cardiac disturbances are likely mediated by decreased beta-agonist transduction, increased circulating inflammatory mediators with cardiodepressant properties, and repolarization changes. Low systemic vascular resistance and bradycardia are also commonly seen in cirrhosis and can be aggravated by beta-blocker use. These physiologic changes all contribute to the potential for cardiovascular complications, particularly with the altered hemodynamic stresses that LT patients face in the immediate post-operative period. Post-transplant reperfusion may result in cardiac death due to a multitude of causes, including arrhythmia, acute heart failure, and myocardial infarction. Recognizing the hemodynamic challenges encountered by LT patients in the perioperative period and how these responses can be exacerbated by underlying cardiac pathology is critical in developing recommendations for the pre-operative risk assessment and management of these patients. The following provides a review of the cardiovascular challenges in LT candidates, as well as evidence-based recommendations for their evaluation and management.

Pulmonary hypertension as a predictor of postoperative complications and mortality after liver transplantation

Most transplant centers consider severe pulmonary hypertension (PHT) to be an absolute contraindication for orthotopic liver transplantation (OLT). We retrospectively examined the outcome of 24 patients with PHT (group 1) who underwent OLT compared with 24 matched patients (group 2) without PHT, who also underwent OLT. Based on right cardiac catheterization measurements made after the induction of anesthesia for OLT, PHT was defined as mild or moderate-to-severe if the mean pulmonary arterial pressure exceeded 25 or 35 mm Hg, respectively. The incidence of PHT was 9.8% (24/244); 21/24 PHT patients showed mild and 3/24 moderate PHT. Kaplan-Meier survival analysis did not show a significant difference between the two groups. The incidence of pulmonary infections was significantly greater in group 1 (P < .05). The duration of ventilation and intensive care unit stay was similar in the two groups. Echocardiography detected only the three moderate cases of PHT and not the twenty-one cases of mild PHT. Our analysis suggested that mild PHT was common and did not affect patient outcomes after OLT; moderate or severe PHT was uncommon. The two patients with moderate PHT survived OLT and did not succum to PHT during long-term follow-up.

Portopulmonary hypertension: short review

Portopulmonary hypertension (PoPH) is an underrecognized complication of portal hypertension, related to cirrhosis and noncirrhotic portal hypertension. PoPH has been found in 5-6% of patients with decompensated liver disease and may adversely affect outcome after liver transplantation. The prevalence of PoPH is unrelated to the severity of liver disease but associated with female sex and underlying autoimmune liver disease. Diagnosis of PoPH is based on screening with Doppler echocardiography and confirmation by right-heart catheterization. Treatment options with proven efficacy in idiopathic pulmonary hypertension include endothelin receptor antagonists, prostanoids, and sildenafil. In PoPH, such targeted treatment was found to be safe in small uncontrolled studies but randomized trials demonstrating its benefit are lacking.

Pulmonary complications of cirrhosis

Advanced liver disease and portal hypertension produce various intrathoracic complications that involve the pleural space, the lung parenchyma, and the pulmonary circulation. Dyspnea and arterial hypoxemia are the most common symptoms and signs in patients with such complications. This article focuses on the diagnosis and management of hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. All are pulmonary processes associated with end-stage liver disease that lead to significant morbidity and affect the quality of life of patients who are suffering from liver cirrhosis.

Intraoperative pulmonary hypertension occurred in an asymptomatic patient with pre-existent liver cirrhotic and portal hypertension

Portopulmonary hypertension (PPH) is clinically defined as the development of pulmonary arterial hypertension complicated by portal hypertension, with or without advanced hepatic disease. Physical signs may be absent in mild to moderate PPH and only appear in a hyperdynamic circulatory state. Similar signs of advanced liver disease can be observed in severe PPH, with ascites and lower extremity edema. Pulmonary hypertension is usually diagnosed after anesthetic induction during liver transplantation (LT). We present intraoperative pulmonary hypertension in a 41-year-old male patient with hepatic cirrhosis. Since this patient had no preoperation laboratory data supporting the diagnosises of pulmonary hypertension and was asymptomatic for a number of years, it was necessary to send him to the intensive care unit after operation. Further study should be focued on the diagnosis and treatment of pulmonary arterial hypertension in order to reduce its mortality.

Pulmonary vasodilators--treating the right ventricle

Pulmonary hypertension remains a significant complication of several systemic and cardiothoracic diseases. It is important to emphasize that the hemodynamic relevance relates to the effect of pulmonary hypertension on right ventricular function and right-left ventricular interaction. The goal of pulmonary vasodilation should focus on optimizing right ventricular function and improving systemic perfusion. The properties of an optimum vasodilator include selective pulmonary vasodilation (avoiding systemic vasodilation), rapid onset of action, short half-life, and ease of administration. Inhaled nitric oxide or nebulization of traditional systemically administered agents offers the greatest clinical promise. An additional merit of selective pulmonary vasodilation consists of augmenting oxygenation by improving ventilation perfusion matching.

Safety and efficacy of combined use of sildenafil, bosentan, and iloprost before and after liver transplantation in severe portopulmonary hypertension

Portopulmonary hypertension (PPHTN) represents a constrictive pulmonary vasculopathy in patients with portal hypertension. Liver transplantation (LT) may be curative and is usually restricted to patients with mild-to-moderate disease severity characterized by a mean pulmonary artery pressure (mPAP < 35 mm Hg). Patients with severe disease (mPAP > 50 mm Hg) are usually excluded from transplantation. We describe a patient with severe PPHTN, initiated on sequential and ultimately combination therapy of prostacyclin, sildenafil, and bosentan (PSB) pretransplantation and continued for 2 years posttransplantation. Peak mPAP on PSB therapy was dramatically reduced from 70 mm Hg to 32 mm Hg pretransplantation, and continued therapy facilitated a further fall in mPAP to 28 mm Hg posttransplantation. The pulmonary vascular resistance index fell from 604 to 291 dyne second(-1) cm(-5). The perioperative mPAP rose to 100 mm Hg following an episode of sepsis and fell with optimization of PSB therapy. In conclusion, this is the first reported patient with severe PPHTN using this combination of vasodilator therapy as a bridge to LT and then as maintenance in the posttransplantation phase. This regimen may enable LT in similar patients in the future, without long-term consequences.

Outcomes of patients with cirrhosis undergoing non-hepatic surgery: Risk assessment and management

The reported mortality rates in patients with cirrhosis undergoing various non-transplant surgical procedures range from 8.3% to 25%. This wide range of mortality rates is related to severity of liver disease, type of surgery, demographics of patient population, expertise of the surgical, anesthesia and intensive care unit team and finally, reporting bias. In this article, we will review the pathophysiology, morbidity and mortality associated with non-hepatic surgery in patients with cirrhosis, and then recommend an algorithm for risk assessment and evidence based management strategy to optimize post-surgical outcomes.

Long-term follow-up of portopulmonary hypertension: effect of treatment with epoprostenol

Moderate to severe portopulmonary hypertension (PPHTN) increases the risks of orthotopic liver transplantation (OLT). Epoprostenol is an effective treatment of PPHTN, but long-term effects on pulmonary hemodynamics or liver function in PPHTN are poorly defined. We sought to describe the long-term effects of treatment with or without epoprostenol on pulmonary hemodynamics, liver biochemistries, and survival in patients with moderate to severe PPHTN at a single center. A large retrospective cohort was identified with moderate to severe PPHTN diagnosed before OLT. Baseline and follow-up pulmonary hemodynamics and liver biochemistries were compared and outcomes assessed. Nineteen patients were treated with epoprostenol and 17 were not treated with epoprostenol. There were significant improvements in mean pulmonary artery pressure (MPAP, 48.4-36.1 mm Hg; P < 0.0001), pulmonary vascular resistance (PVR, 632-282 dynes . s . cm(-5); P < 0.0001), and cardiac output (5.7 to 7.7 L/min; P = 0.0009) with epoprostenol after a median of 15.4 months. Liver biochemistries did not change significantly, and survival did not seem to differ between the 2 groups (hazard ratio, 0.85; P = 0.77). In the epoprostenol group, patients who survived had greater absolute changes in MPAP, transpulmonary gradient, and PVR than those who died. Two patients in the epoprostenol group successfully underwent OLT. Long-term epoprostenol therapy greatly improves pulmonary hemodynamics in patients with PPHTN. Liver biochemistries are not greatly changed. Survival seemed not to differ between treatment groups. A minority of patients treated with epoprostenol will improve sufficiently to undergo OLT.

Portopulmonary hypertension

As a result of the success of orthotopic liver transplantation, there has been increasing interest in the diagnosis and therapeutic options for the pulmonary vascular complications of hepatic disease. These pulmonary vascular complications range from the hepatopulmonary syndrome, which is characterized by intrapulmonary vascular dilatations, to portopulmonary hypertension (POPH), which is characterized by an elevated pulmonary vascular resistance as a consequence of obstruction to pulmonary arterial blood flow. This review concentrates on POPH.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare and debilitating disease characterized by abnormal proliferation and contraction of pulmonary vascular smooth muscle cells. The resulting increase in pressure and pulmonary vascular resistance results in progressive right heart failure, low cardiac output, and ultimately death if left untreated. PAH is defined by a persistent elevation in pulmonary artery pressure with normal left-sided pressures, differentiating it from left-sided heart disease. Symptoms progress from shortness of breath and decreasing exercise tolerance to right heart failure, with peripheral edema and marked functional limitation. Exercise-induced syncope, worsening symptoms at rest, and intractable right heart failure indicate critical disease. PAH may be idiopathic with no identifiable cause or associated with collagen vascular diseases, drugs, HIV, liver disease, and/or congenital heart disease. Familial or genetically mediated PAH accounts for a small percentage of cases. Advances in the understanding of pathobiological pathways that contribute to vascular proliferation and remodeling have resulted in new therapies that improve quality of life and survival. Emerging therapies focus on the nitric oxide, prostacyclin, and endothelin pathways. Nursing interventions are critical to ensure patients' success with these expensive and complex treatments and their optimal adjustment to living with PAH.

Monitoring Hepatic and Renal Function

Liver disease represents a serious risk factor for patients requiring anesthesia and surgery. Even subclinical liver disease increases perioperative morbidity and mortality. Perioperative renal dysfunction and failure have similar implications. Thus, detection of early hepatic and renal dysfunction and monitoring of their progress is essential. This article discusses methods for monitoring hepatic and renal function in patients who have high risk for liver or renal injury in the perioperative period.

Hypertension portopulmonaire

INTRODUCTION

Porto-pulmonary hypertension (PoPH) is the association of pulmonary artery hypertension and portal hypertension. The diagnosis of PoPH is based on pulmonary haemodynamic criteria, obtained via right heart catheterisation, including an increase in mean pulmonary arterial pressure (> 25 mmHg) and in pulmonary vascular resistance (> 240 dyn.s.cm-5).

STATE OF THE ART

The exact pathophysiological mechanisms of PoPH are unknown. However, since PoPH has been reported in patients with non-hepatic portal hypertension, the factor that determines the development must be portal hypertension rather than liver disease per se. Moreover, no simple relationship has been identified between the degree of hepatic impairment and the severity of PoPH. The clinical presentation is non-specific with haemodynamic failure occurring at the end stage. As a consequence, screening by annual transthoracic echocardiography is highly recommended in potential liver transplant candidates. Therapy with prostacyclin analogues may partially relieve pulmonary arterial hypertension (PAH). Liver transplantation has an uncertain effect in PoPH and because PoPH is associated with a high perioperative mortality, moderate to severe PoPH remains a contraindication for liver transplantation.

PERSPECTIVES AND CONCLUSIONS

Recent advances in the management of PoPH have improved the prognosis. The safety and efficacy of oral endothelin receptor antagonists and oral phosphodiesterase inhibitors is currently under evaluation. A therapeutic approach utilising combinations of drugs should provide better long-term results.

Portopulmonary Hypertension in the Early Phase Following Liver Transplantation

BACKGROUND

Portopulmonary hypertension (PPH) is a severe complication of liver cirrhosis, which poses a high risk for postliver transplantation (LT) mortality. In most liver transplant centers, severe PPH is viewed as an absolute contraindication for LT, but recent reports challenge this. The purpose of our study was to determine the incidence of PPH, its influence on the 30-day mortality rate following LT and to determine the sensitivity and specificity of Doppler echocardiography and electrocardiography as noninvasive tools to determine PPH.

METHODS

We studied 74 consecutive patients that underwent LT between February 2004 and November 2005. Pulmonary arterial pressure and cardiac index were repeatedly determined during surgery and postoperatively. PPH was defined as mild (mean pulmonary arterial pressure (MPAP) 25-35 mm Hg), moderate (MPAP of 35-45 mm Hg) and as severe (MPAP >45 mm Hg).

RESULTS

The total incidence of PPH was 31% (16 mild, 5 moderate, and 2 severe). There was a tendency towards increased 30-day mortality rate in patients with PPH compared to controls (22% vs. 12%, P=0.1). However, the two patients with the most severe PPH survived. The duration of ventilation and total stay at the intensive care unit did not differ significantly between groups. The positive predictive value of Doppler echocardiography for PPH was 39% and the negative predictive value 90%.

CONCLUSIONS

Mild pulmonary hypertension is common in patients with liver failure, whereas moderate and severe hypertension is not. Severe PPH should not be considered as absolute contraindication for LT.

Successful treatment of portopulmonary hypertension with bosentan: case report

Pulmonary arterial hypertension (PAH) is found in 2-20% of cirrhosis patients who have portal hypertension (portopulmonary hypertension, PPHT). Endothelin (ET), a potent vasoconstrictor, is likely to play a role in the pathogenesis of portal hypertension. We describe the long-term successful use of the dual ET(A)/ET(B) receptor antagonist bosentan in a 43-year-old male with alcohol-related cirrhosis (Child-Pugh A), right ventricular enlargement and dysfunction, respectively, and moderate PAH. Elevated pulmonary arterial pressure was substantially reduced and exercise capacity increased. Improvement was maintained over 2 years, and bosentan treatment continues in this patient. Our report is in line with a series of current reports in PPHT that support the use of bosentan in this subset of PAH patients.

Portopulmonary hypertension

Portopulmonary hypertension (PPHT) is defined as precapillary pulmonary hypertension accompanied by hepatic disease or portal hypertension. Pulmonary hypertension results from excessive pulmonary vascular remodeling and vasoconstriction. These histological alterations have been indistinguishable from those of other forms of pulmonary arterial hypertension. Factors involved in the pathogenesis of PPHT include volume overload, hyperdynamic circulation, and circulating vasoactive mediators. The disorder has a substantial impact on survival and requires focused treatment. Liver transplantation in patients with moderate to severe PPHT is associated with a significantly reduced survival rate. The best medical treatment for patients with PPHT is controversial; most authors currently regard continuous intravenous application of prostacyclin as the treatment of choice for patients with severe PPHT. There is only very limited reported experience with inhaled prostacyclin or its analog, iloprost. Increasing evidence of the efficacy of the endothelin-receptor antagonist bosentan and of the phosphodiesterase-5 inhibitor sildenafil is emerging in highly selected patients with PPHT. In the future, a combination therapy of the above-mentioned agents might become a therapeutic option. Other agents such as beta-blockers seem to be harmful to patients with moderate to severe portopulmonary hypertension. Up-to-date, randomized, double-blind, controlled clinical trials are lacking and are needed urgently.