Portopulmonary hypertension and the issue of survival

Pulmonary Arterial Pressure Management Based on Oral Medicine for Pediatric Living Donor Liver Transplant With Portopulmonary Hypertension

Pediatric living donor liver transplantation (LDLT) in patients with advanced portopulmonary hypertension (PoPH) is associated with poor prognoses. Recently, novel oral medications, including endothelin receptor antagonists (ERAs), phosphodiesterase 5 (PDE5) inhibitors, and oral prostacyclin (PGI2) have been used to treat PoPH. Pediatric patients with PoPH who underwent LDLT from 2006 to 2016 were enrolled. Oral pulmonary hypertension (PH) medication was administered to control pulmonary arterial pressure (PAP). Four patients had PoPH. Their ages ranged from 6 to 16 years, and their original diseases were biliary atresia (n = 2), portal vein obstruction (n = 1), and intrahepatic portal systemic shunt (n = 1). For preoperative management, 2 patients received continuous intravenous PGI2 and 2 oral medications (an ERA alone or an ERA and a PDE5 inhibitor), and 2 received only oral drugs (an ERA and a PDE5 inhibitor). One patient managed only with intravenous PGI2 died. In the remaining 3 cases, intravenous PGI2 or NO was discontinued before the end of the first postoperative week. Postoperative medications were oral PGI2 alone (n = 1), an ERA alone (n = 1), or the combination of an ERA and a PDE5 inhibitor (n = 1). An ERA was the first-line therapy, and a PDE5 inhibitor was added if there was no effect. New oral PH medications were effective and safe for use in pediatric patients following LDLT. In particular, these new oral drugs prevent the need for central catheter access to infuse PGI2.

Anesthetic Considerations in Transplant Recipients for Nontransplant Surgery

As solid organ transplantation increases and patient survival improves, it will become more common for these patients to present for nontransplant surgery. Recipients may present with medical problems unique to the transplant, and important considerations are necessary to keep the transplanted organ functioning. A comprehensive preoperative examination with specific focus on graft functioning is required, and the anesthesiologist needs pay close attention to considerations of immunosuppressive regimens, blood product administration, and the risk benefits of invasive monitoring in these immunosuppressed patients. This article reviews the posttransplant physiology and anesthetic considerations for patients after solid organ transplantation.

Survival in portopulmonary hypertension: Outcomes of the United Kingdom National Pulmonary Arterial Hypertension Registry

BACKGROUND

Portopulmonary hypertension (PoPH) is a rare condition associated with poor survival, and the effect of modern therapies that target pulmonary arterial hypertension (PAH) on long-term outcome is unknown. This study investigated the baseline characteristics and survival in the cohort of patients diagnosed with PoPH in the United Kingdom National Pulmonary Hypertension Service.

METHODS

A retrospective review was conducted of all incident treatment-naïve patients with PoPH within the United Kingdom national registry diagnosed between January 2001 and December 2010.

RESULTS

Patients with PoPH (n = 110) had survival rates of 85%, 60%, and 35% at 1, 3, and 5 years. The prevalence of PoPH was 0.85 cases/1 million. Mean age at diagnosis was 53 ± 12 years, with a balanced distribution in gender. Alcohol (n = 57) and hepatitis C (n = 10) were the most common causes of portal hypertension. Phosphodiesterase V inhibitors were the most frequently used targeted therapy, in 63.6% (n = 70) of patients, endothelin receptor antagonists were used in 10% (n = 11) and prostacyclin analogs in 12.7% (n = 14). Univariate and multivariate analysis of baseline characteristics did not demonstrate a significant influence of severity of portal hypertension or liver cirrhosis, World Health Organization Functional Class, cardiopulmonary hemodynamics, or year of diagnosis on survival.

CONCLUSIONS

Survival of patients with PoPH remains poor despite targeted therapy and worse than patients with idiopathic PAH. The benefit of PAH therapies in PoPH on long-term morbidity and mortality outcomes needs further consideration and study.

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

Portopulmonary hypertension (PoPH) refers to the condition that pulmonary arterial hypertension (PAH) occur in the stetting of portal hypertension. The development of PoPH is thought to be independent of the severity of portal hypertension or the etiology or severity of liver disease. PoPH results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. Untreated PoPH is associated with a poor prognosis. As PoPH is frequently asymptomatic or symptoms are generally non-specific, patients should be actively screened for the presence of PoPH. Two-dimensional transthoracic echocardiography is a useful non-invasive screening tool, but a definitive diagnosis requires invasive hemodynamic confirmation by right heart catheterization. Despite a dearth of randomized, prospective data, an ever-expanding clinical experience shows that patients with PoPH benefit from therapy with PAH-specific medications including with endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and/or prostanoids. Due to high perioperative mortality, transplantation should be avoided in those patients who have severe PoPH that is refractory to medical therapy.

Cirrhotic Multiorgan Syndrome

Patients with cirrhosis and portal hypertension are at an increased risk of the development of circulatory dysfunction that may potentially result in multiple organ failure. Apart from the liver, this may involve the heart, lungs, kidneys, the immune system, the adrenal glands, and other organ systems. As the disease progresses, the circulation becomes hyperdynamic, and signs of cardiac, pulmonary, and renal dysfunction are observed, in addition to reduced survival. Infections and an altered cardiac function known as cirrhotic cardiomyopathy may be precipitators for the development of other complications such as hepatorenal syndrome. In patients with chronic organ dysfunction, various precipitating events may induce an acute-on-chronic renal failure and acute-on-chronic liver failure that negatively affect the prognosis. Future research on the pathophysiologic mechanisms of the complications and the precipitating factors is essential to understand the basics of the treatment of these challenging conditions. The aim of the present review is to focus on the development and precipitating factors of various organ failures in patients with decompensated cirrhosis.

Complications of cirrhosis. A 50 years flashback

In patients with cirrhosis and portal hypertension, it is largely the frequency and severity of complications relating to the diseased liver, degree of portal hypertension and hemodynamic derangement that determine the prognosis. It can be considered as a multiple organ failure that apart from the liver involves the heart, lungs, kidneys, the immune systems and other organ systems. Progressive fibrosis of the liver and subsequent metabolic impairment leads to a systemic and splanchnic arteriolar vasodilatation. With the progression of the disease development of portal hypertension leads to formation of esophageal varices and ascites. The circulation becomes hyperdynamic with cardiac, pulmonary as well as renal consequences for dysfunction and reduced survival. Infections and a changed cardiac function known as cirrhotic cardiomyopathy may be involved in further aggravation of other complications such as renal failure precipitating the hepatorenal syndrome. Patients with end-stage liver disease and related complications as for example the hepatopulmonary syndrome can only radically be treated by liver transplantation.

Outcomes of liver transplantation for porto-pulmonary hypertension in model for end-stage liver disease era

Porto-pulmonary hypertension (POPH), once considered an absolute contraindication for liver transplantation (LT), has become a more accepted indication because of the evolution of treatment with prostacyclin analogues, phosphodiesterase inhibitors and endothelin receptor antagonists. An exception model for end stage liver disease (MELD) score of 22 is assigned to candidates with documentation of effective treatment. We examined the post-transplant outcomes of patients who received LT for POPH with exception.

METHODS

Scientific Registry of Transplant Recipients data on 34,318 adult (≥ 18 years) deceased donor LT recipients transplanted between March 1, 2002 and August 31, 2010 were reviewed. The diagnosis of POPH was ascertained from MELD exception forms. Patients were followed from the time of transplant until the earlier occurrence of death or end of the follow-up period. Cox regression was used to evaluate the predictors of post-LT mortality and graft failure.

RESULTS

During the study period, 34,318 patients received deceased donor LT. Seventy eight out of 34,318 patients were transplanted for POPH with MELD exception. The 1-year adjusted risks of patient death and graft failure for patients transplanted under exception rules for POPH were significantly higher than with POPH adult recipients who did not receive exception points (death:hazard ratio [HR] = 2.25, p = 0.005 and graft failure HR = 1.96, p = 0.012).

CONCLUSIONS

This study of national data suggests that treated POPH continues to be associated with inferior early post-transplant outcomes.

Long-term follow-up of portopulmonary hypertension patients after liver transplantation

Portopulmonary hypertension (POPH) occurs in 5.3% to 8.5% of patients with advanced liver disease. The rate of survival in the absence of orthotopic liver transplantation (OLT) is reportedly 38% at 3 years and 28% at 5 years. Moderate to severe POPH [mean pulmonary artery pressure (MPAP) ≥ 35 mm Hg] is associated with a perioperative mortality rate of 50%. Single-center series have demonstrated the feasibility and short-term efficacy of OLT after POPH is controlled with vasodilators, but long-term outcomes have not been reported. Our aim was to determine graft and patient survival rates and the effects of OLT on pulmonary hypertension (PHT) in patients undergoing transplantation for POPH at our center. Four hundred eighty-eight adult patients underwent transplantation between June 2004 and January 2011, and 7 underwent transplantation for POPH after their MPAP was reduced to ≤35 mm Hg with vasodilators. These 7 patients included 3 men and 4 women with ages ranging from 39 to 54 years at the time of OLT. All patients received IV EPO or inhaled EPO during the perioperative period, and all were weaned off EPO over the course of 3 days to 8 months. Both the graft and patient survival rates were 85.7% after a median follow-up of 7.8 years. One patient had recurrent hepatitis C virus cirrhosis and recurrent POPH and died from multiorgan failure unrelated to PHT. Four of the remaining 6 patients required oral vasodilator therapy for persistent PHT. Only 2 of the 7 patients (4.4 and 8.5 years after OLT) did not have PHT. In conclusion, patients with POPH responsive to vasodilator therapy may have excellent long-term graft and patient survival after OLT. Despite the alleviation of portal hypertension by OLT, most patients have persistent or recurrent PHT that can be controlled with oral vasodilators.

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.

Portopulmonary hypertension: an update

Portopulmonary hypertension (POPH) is a serious complication of cirrhosis that is associated with mortality beyond that predicted by the Model for End-Stage Liver Disease (MELD) score. Increased pulmonary vascular resistance (PVR) may be initiated by pulmonary vasoconstriction, altered levels of circulating mediators, or shear stress, and can eventually lead to the classic vascular remodeling (plexiform lesion) that characterizes POPH. Portal hypertension is a prerequisite for the diagnosis of POPH, although the severity of pulmonary hypertension is unrelated to the severity of portal hypertension or the nature or severity of liver disease. POPH precludes liver transplantation (LT) unless the mean pulmonary artery pressure (MPAP) can be reduced to a safe level. The concept of an acceptable pressure has changed: we now consider both MPAP and PVR in the diagnosis, and we include the transpulmonary pressure gradient so that we can factor in fluid overload and left ventricular failure. Pulmonary vasodilator therapy includes oral, inhaled, and parenteral agents, and one or more of these agents may significantly lower pulmonary artery pressures to the point that LT becomes possible. The United Network for Organ Sharing recommends MELD exception points for patients with medically controlled POPH, but this varies by region. Patients who undergo LT need specialized intraoperative and postoperative management, which includes the availability of intraoperative transesophageal echocardiography for assessing right ventricular function, and rapidly acting vasodilators (eg, inhaled nitric oxide and/or epoprostenol). Published case series suggest excellent outcomes after LT for patients who respond to medical therapy.

Successful outcomes following living donor liver transplantation for portopulmonary hypertension

Pulmonary arterial hypertension (PAH) associated with portal hypertension [portopulmonary hypertension (PPHTN)] occurs in 2% to 10% of patients with advanced liver disease and carries a very poor prognosis without treatment. Most hepatic transplantation centers consider moderate to severe PPHTN to be a contraindication to liver transplantation because of the high rate of perioperative complications. We present 3 patients with PPHTN who were managed with intravenous prostacyclin therapy followed by living donor liver transplantation (LDLT). These individuals demonstrated subsequent resolution of their pulmonary hypertension and were weaned off all PAH-specific medical therapy. We present their demographics, clinical courses, and hemodynamics. We discuss the potential indications for LDLT and risks with respect to this patient population. Limitations of the Model for End-Stage Liver Disease scoring system and outcome data for this patient population are reviewed. Future studies should be directed toward better defining indications for LDLT in patients with PPHTN, improving medicosurgical management, and assessing long-term outcomes.

Pulmonary hypertension after liver transplantation: case presentation and review of the literature

Hepatopulmonary syndrome and portopulmonary hypertension are the most common pulmonary vascular complications in patients with cirrhosis. Usually but not universally mutually exclusive, they each may present prior to liver transplantation and, if severe enough, may be a contraindication to transplant. However, there have been a number of case reports describing patients developing pulmonary hypertension de novo after liver transplantation. This report describes one such patient from our institution and reviews the medical literature describing this unusual clinical entity.

Pulmonary hypertension is associated with reduced patient survival after kidney transplantation

INTRODUCTION

Pulmonary hypertension (PH) is common in patients on dialysis where it is associated with reduced survival. The possible association between PH and kidney transplant recipient survival has not been previously evaluated.

METHODS

In this retrospective study, we screened for PH pretransplant in 215 transplant candidates using cardiac echocardiography and measurements of right ventricular systolic pressure (RVSP).

RESULTS

Sixty-eight percent of patients had normal RVSP (<35 mm Hg), 47 (22%) had mild to moderately elevated RVSP (36-50), and 22 (10%) had markedly elevated RVSP more than 50 suggestive of severe PH. Time on dialysis was the strongest correlate of an elevated RVSP (r=0.253, P<0.001) and this relationship was independent of other variables. Elevated RVSP was observed in 25%, 25%, 38%, and 58% of patients not on dialysis, on dialysis for less than 1 year, more than 1 to 2 years, or more than 2 years, respectively. An RVSP more than 50 was associated with significantly reduced posttransplant survival (hazard ratio =3.75 [1.17-11.97], P=0.016). This relationship seemed to be independent of other variables including older age, reduced left ventricular ejection fraction, low serum albumin, and delayed graft function.

CONCLUSION

These analyses suggest for the first time that pretransplant PH correlates with patient survival after kidney transplantation.

The impact of treatment of portopulmonary hypertension on survival following liver transplantation

Pulmonary hypertension in the setting of cirrhosis and portal hypertension is known as portopulmonary hypertension (PPHTN). Moderate or severe PPHTN is uncommon, but has a poor prognosis and is considered to be a contraindication to liver transplantation. We assessed the impact of vasodilation therapy on pulmonary hemodynamics and outcome after liver transplant in these patients. Eighty-six patients evaluated for liver transplant between 1997 and 2005 had an estimated right ventricular systolic pressure >40 mm Hg or a clinical suspicion of PPHTN. Right heart catheterization confirmed PPHTN in 30 patients (ten mild, eight moderate, and 12 severe). Sixteen of the 20 with moderate-to-severe pulmonary hypertension (mPAP >or= 35) were otherwise considered suitable liver transplant candidates and were treated with vasodilation therapy. mPAP fell to less than 35 mm Hg in 12 patients (75%) and 11 of them then underwent orthotopic liver transplantation. One- and five-year survivals in the transplanted patients were 91% and 67%, respectively. Nine of 11 were off vasodilator therapy after a median of 9.2 months following transplantation. None of the patients who failed vasodilator therapy survived (median survival, 8 months). Effective pharmacologic control of PPHTN before liver transplant is associated with excellent posttransplant survival that is similar to patients transplanted for other indications.

Successful liver transplantation following medical management of portopulmonary hypertension: a single-center series

Severe portopulmonary hypertension (POPH) is an absolute contraindication to orthotopic liver transplantation (OLT). Vasodilators have been used, but the safety of subsequent transplantation and the reversibility of pulmonary hypertension after transplantation are uncertain. This study examined the feasibility and post-transplant effects of liver transplantation following medical control of POPH. Eight consecutive patients (three females and five males, ages 39-51) with POPH as their only contraindication to transplantation were treated with continuous intravenous epoprostenol. Liver transplantation was considered if the mean pulmonary artery pressure (PAM) was lowered to <35 mmHg. Epoprostenol 2-8 ng/kg/min successfully improved hemodynamics in seven of eight patients, usually within 6.5 months of initiating therapy. PAM declined from an average of 43-33 mmHg (p=0.03); mean pulmonary vascular resistance declined from 410 to 192 dyn s cm-5 (p=0.01) and cardiac output increased from 6.6 to 10 L/min (p=0.02). Six of the seven responders were actively listed for liver transplantation. Two died on the waiting list; the remaining four were transplanted and remain alive and well 9-18 months post-OLT-two without vasodilators, and two on oral medication. We conclude that pulmonary vasodilators permit safe liver transplantation in some cases, and that POPH may be reversible after transplantation.

Cardiopulmonary complications in chronic liver disease

Patients with cirrhosis and portal hypertension exhibit characteristic cardiovascular and pulmonary hemodynamic changes. A vasodilatatory state and a hyperdynamic circulation affecting the cardiac and pulmonary functions dominate the circulation. The recently defined cirrhotic cardiomyopathy may affect systolic and diastolic functions, and imply electromechanical abnormalities. In addition, the baroreceptor function and regulation of the circulatory homoeostasis is impaired. Pulmonary dysfunction involves diffusing abnormalities with the development of the hepatopulmonary syndrome and portopulmonary hypertension in some patients. Recent research has focused on the assertion that the hemodynamic and neurohumoral dysregulation are of major importance for the development of the cardiovascular and pulmonary complications in cirrhosis. This aspect is important to take into account in the management of these patients.