Portopulmonary hypertension: state of the art: Concise Review

Portopulmonary hypertension is an uncommon but treatable pulmonary vascular consequence of portal hypertension, which can lead to significant morbidity and mortality. Portopulmonary hypertension results from excessive pulmonary vasoconstriction and vascular remodeling that eventually leads to right-heart failure and death if left untreated. Although pulmonary vascular disease in these patients may be asymptomatic or associated with subtle and nonspecific symptoms (dyspnea, fatigue and lower extremity swelling), it should be looked for especially if patients are potential candidates for liver transplantation. Patients with clinical suspicion of portopulmonary hypertension should undergo screening testing, specifically echocardiography. Right heart catheterization remains the gold standard for the diagnosis. The existence of moderate to severe disease poses higher risks and challenges for liver transplantation. The disease has a substantial impact on survival and requires focused pharmacological therapy. New and evolving medical therapies, such as prostanoids (intravenous, inhaled or oral), endothelin receptors antagonists, phosphodiesterases inhibitors, combination therapy and other experimental drugs might change the natural course of the disease. Case reports and cases series have been published regarding the efficacy and safety of pharmacological therapy, but randomized, controlled multicenter trials are urgently needed. Liver transplantation is not the treatment of choice for portopulmonary hypertension, but after optimal hemodynamic and clinical improvement with medical therapy as a bridge, liver transplant can be considered an option in selected patients.     

Portopulmonary hypertension: An update

Portopulmonary hypertension represents a serious lung vascular disorder, defined as the presence of pulmonary arterial hypertension that is associated with portal hypertension, with or without the presence of significant liver disease. Transthoracic echocardiography represents the single best initial tool for the diagnostic evaluation in portopulmonary hypertension, and right heart catheterization remains the gold standard for definitive diagnosis. Despite the lack of randomized controlled trials in portopulmonary hypertension, some therapies have demonstrated improvements in cardiopulmonary haemodynamics and right ventricular function as described in case reports and case series. Specialists should be able to recognize indications and contraindications for liver transplantation in the setting of portopulmonary hypertension, and this review focuses on the appropriate diagnostic approach and current advances in medical therapies. Recognition of patients eligible for liver transplantation is needed to improve quality of life and survival.     

Portopulmonary hypertension

The development of pulmonary arterial hypertension in the setting of portal hypertension is known as portopulmonary hypertension. Portal hypertension is thought to predispose patients to disturbances in the homeostatic regulation of numerous neurohumoral and vasoactive mediators that induce the development of pulmonary arterial hypertension. Portopulmonary hypertension is pathologically indistinguishable from idiopathic pulmonary arterial hypertension and is characterized by the development of vasoconstriction, vascular remodeling, and thrombosis within the pulmonary vasculature. Although described in patients with both cirrhotic and noncirrhotic portal hypertension, portopulmonary hypertension is most prevalent among patients with end-stage liver disease, and its severity seems to be independent of the etiology or severity of liver disease. All liver transplant candidates must be screened for the presence of portopulmonary hypertension because of the high perioperative mortality risk of liver transplantation associated with this condition. Primary screening for portopulmonary hypertension consists of Doppler-estimated pulmonary artery systolic pressure measurement during echocardiography. However, the diagnosis of portopulmonary hypertension is based on unique hemodynamic criteria as determined by right heart catheterization. Untreated portopulmonary hypertension portends a poor prognosis, and the efficacy of current treatment modalities is limited. At present, the primary goals of therapy are to provide symptomatic relief, prolong survival, and improve pulmonary hemodynamics to facilitate safe and successful liver transplantation.     

Hepatopulmonary syndrome and portopulmonary hypertension

The pulmonary complications of end-stage liver disease include hepatopulmonary syndrome and portopulmonary hypertension. The etio-pathogenesis of these conditions is as yet unclear. Hepatopulmonary syndrome is a gas exchange abnormality and usually manifests as hypoxemia secondary to intra-pulmonary vascular shunts. These shunts can be demonstrated by echocardiography using agitated saline injections, and quantitated by lung perfusion scans. Liver transplantation is the treatment of choice for hepatopulmonary syndrome, and there are no effective pharmacological therapies. Portopulmonary hypertension is a hemodynamic problem which manifests as fatigue and right sided cardiac failure. Several vasoactive agents have been used to lower mean pulmonary arterial pressures. Portopulmonary hypertension is a relative contraindication to liver transplantation.     

Hepatopulmonary syndrome and portopulmonary hypertension

Liver disease affects the lungs. The majority of patients exhibit mild to moderate arterial hypoxaemia essentially attributable to an alteration in ventilation/perfusion matching and limited by an increase in ventilation. A minority (some 10%) of patients exhibit a "hepatopulmonary syndrome" defined by severe hypoxaemia with arterial PO2 below 60 mm Hg, dyspnoea, cyanosis, digital clubbing, orthodeoxia, platypnoea and demonstrable pulmonary vascular dilatations causing a true pulmonary shunt and a diffusion/perfusion imbalance. The hepatopulmonary syndrome is incurable but resolves over time after liver transplantation. An even lower proportion of patients, approximately 1%, develop pulmonary hypertension. Clinically this "portopulmonary hypertension" resembles primary pulmonary hypertension, with dyspnoea and fatigue as the main symptoms, histopathology and response to prostacyclin therapy. Portopulmonary hypertension is irreversible. Liver transplantation mortality in patients with portopulmonary hypertension ranges from 50 to 100%. The common cause of the hepatopulmonary syndrome and portopulmonary hypertension is portal hypertension and portosystemic shunting, indicating that vasoactive and angiogenetic factors originating from the liver normally control the pulmonary circulation.     

Successful management of portopulmonary hypertension with beraprost

Portopulmonary hypertension is a complication of chronic liver disease, which has significant effects on survival and prognosis. Although the pathogenesis of pulmonary arterial hypertension has been well known, portopulmonary hypertension is often underestimated in patients with chronic liver disease. Every clinician who manages patients with chronic liver disease complaining of dyspnea should consider portopulmonary hypertension because this disorder requires special treatment. Herein, a 40-year-old woman with liver cirrhosis who complained of dyspnea on exercise is presented. She was diagnosed with portopulmonary hypertension by echocardiography and right-heart catheterization. Beraprost was used to reduce the pulmonary arterial pressure and improve the symptoms. Her symptoms were improved after 2 weeks, and improved symptoms and reduced pulmonary arterial pressure were sustained for 18 months.     

Portopulmonary hypertension

Portopulmonary hypertension is a common condition in patients who have portal hypertension. This article reviews the definition and clinical presentation of this disorder and outlines our current understanding of its pathophysiology. A diagnostic approach is provided , and novel medical therapies that are being investigated to treat this condition are discussed. Finally, the safety of liver transplantation in patients who have portopulmonary hypertension is reviewed.     

Severe portopulmonary hypertension after liver transplantation in a patient with preexisting hepatopulmonary syndrome

BACKGROUND: Portopulmonary hypertension and hepatopulmonary syndrome have been considered mutually exclusive pulmonary vascular disorders in liver disease states. METHODS: This current report describes a middle-aged patient, a candidate for liver transplantation, diagnosed with hepatopulmonary syndrome on the basis of clinical, echocardiographic and gas exchange criteria. Unusually high pulmonary pressures were observed at liver transplantation, performed 6 months after the initial diagnosis of hepatopulmonary syndrome. Three months later, the patient developed severe pulmonary hypertension and died of right ventricular failure during a second attempted liver transplantation. Postmortem histologic findings in the lung confirmed the presence of plexogenic pulmonary arteriopathy. CONCLUSION: This case illustrates the potential occurrence of hepatopulmonary syndrome and portopulmonary hypertension in the same patient, suggesting that the presence of hepatopulmonary syndrome may not preclude the development of portopulmonary hypertension.     

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-tosevere 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.     

Sildenafil decreased pulmonary arterial pressure but may have exacerbated portal hypertension in a patient with cirrhosis and portopulmonary hypertension

Portopulmonary hypertension is a recognized but uncommon complication of cirrhosis. Liver transplantation may be contraindicated in patients with severe portopulmonary hypertension. In order to decrease the pulmonary arterial pressure, intravenous administration of epoprostenol has been shown to provide substantial beneficial results in these patients. Additionally, a recent case report demonstrated that long-term oral administration of sildenafil decreased pulmonary arterial pressure, but its effects on splanchnic hemodynamics were not measured. We report on a patient with cirrhosis and portopulmonary hypertension and the changes in the hemodynamic status after an oral administration of sildenafil. This case report clearly delineates that sildenafil decreases pulmonary arterial pressure but may exacerbate portal hypertension and hyperdynamic circulation in patients with cirrhosis and portopulmonary hypertension.     

Diagnosis of portopulmonary hypertension in candidates for liver transplantation: a prospective study

Portopulmonary hypertension represents a major risk factor for transplantation; therefore, preoperative detection is crucial. The aims of this study were to determine (1) whether Doppler echocardiography performed at evaluation is a reliable tool for detecting portopulmonary hypertension and (2) the incidence of acquired portopulmonary hypertension profile after evaluation. One hundred sixty-five patients had Doppler echocardiography and right heart catheterization at evaluation over a 9-year period. All patients had a prospective follow-up, and the results of catheterization at evaluation were compared with those obtained at the time of transplantation. Seventeen of 165 patients met the criteria for portopulmonary hypertension on Doppler echocardiography. Portopulmonary hypertension was confirmed by catheterization in 10 patients and ruled out in 7. There were no false negatives for echocardiography. Mean pulmonary artery pressure was significantly higher during the initial phase of transplantation than at evaluation (17.8 +/- 4.3 vs. 20.3 +/- 5.5 mm Hg, respectively, P <.0001), and there was no significant correlation between values obtained at these 2 time points. Three patients showed to have acquired portopulmonary hypertension profile while waiting for a graft within time intervals ranging from 2.5 to 5 months. In conclusion, Doppler echocardiography is a highly sensitive tool for detecting portopulmonary hypertension. However, because this technique has a poor positive predictive value, right heart catheterization is recommended for confirming portopulmonary hypertension. In addition, the absence of portopulmonary hypertension at evaluation does not exclude the occasional occurrence of acquired portopulmonary hypertension profile after listing.     

门脉性肺动脉高压的诊断与治疗进展

门脉性肺动脉高压是伴或不伴晚期肝病患者在门静脉高压基础上出现以肺动脉压升高和肺血管阻力增加为特点的疾病。门脉性肺动脉高压显著增加患者病死率。目前尚无明确有效的治疗药物,肝移植是唯一有效的治疗手段。本文重点介绍了门脉性肺动脉高压的流行病学、发病机制、临床表现、诊断、治疗及预后情况。     

Intravenous iloprost bridging to orthotopic liver transplantation in portopulmonary hypertension.

Portopulmonary hypertension (PPHTN) is associated with poor prognosis and high perioperative mortality after orthotopic liver transplantation. This study documents the first case of a patient with PPHTN who was successfully bridged to orthotopic liver transplantation with i.v. iloprost, a stable prostacyclin analogue. The PPHTN had resolved completely 4 months after successful transplantation. In conclusion, portopulmonary hypertension is a relative contraindication to orthotopic liver transplantation, which should be attempted only if pulmonary haemodynamics improve with prostanoids. In this context, iloprost may be a valuable alternative to epoprostenol.     

Pulmonary vascular complications in portal hypertension and liver disease: A concise review

Chronic liver disease and/or portal hypertension may be associated with one of the two pulmonary vascular complications: portopulmonary hypertension and hepatopulmonary syndrome. These pulmonary vascular disorders are notoriously underdiagnosed; however, they have a substantial negative impact on survival and require special attention in order to understand their diagnostic approach and to select the best therapeutic options. Portopulmonary hypertension 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. On the other hand, abnormal intrapulmonary vascular dilations, profound hypoxemia, and a wide alveolar-arterial gradient are the hallmarks of the hepatopulmonary syndrome, resulting in difficult-to-treat hypoxemia. The aim of this review is to summarize the latest pathophysiologic concepts, diagnostic approach, therapy, and prognosis of portopulmonary hypertension and hepatopulmonary syndrome, as well as to discuss the role of liver transplantation as a definitive therapy in selected patients with these conditions.     

Portopulmonary hypertension: distinctive hemodynamic and clinical manifestations

Portopulmonary hypertension is now recognized as one of the pulmonary complications of chronic liver disease. However, previous studies reported that the incidence ranged from 0.25% to 2%, excluding fortuitous coincidence. In this study, we aimed to determine the variant hemodynamic and clinical features of portopulmonary hypertension in an area with a high prevalence of viral cirrhosis. After reviewing the hemodynamic data of 322 patients with portal hypertension admitted to the Taipei Veterans General Hospital between 1987 and 1999, we found 10 with portopulmonary hypertension. The overall incidence was, therefore, 3.1% in all patients with portal hypertension. Most of the patients with portopulmonary hypertension experienced exertional dyspnea. The survival times ranged from 2 to 86 months. In our series, most of the patients who died, died of complications related to cirrhosis and portal hypertension, but not of complications related to pulmonary hypertension. This study suggested that portopulmonary hypertension was not a frequent complication in cirrhotic patients and was not associated with an adverse outcome. Received: June 15, 2000 / Accepted: September 8, 2000     

Portopulmonary hypertension

Portopulmonary hypertension (POPH) refers to the presence of pulmonary arterial hypertension (PAH) in patients with portal hypertension. Pulmonary hypertension in patients with liver disease or portal hypertension can be due to multiple mechanisms, including hyperdynamic (high-flow) state, increased pulmonary venous congestion, and vascular constriction or obstruction of the pulmonary arterial bed. Vascular obstruction to pulmonary arterial flow, reflected by increased pulmonary vascular resistance (PVR), is a key parameter that defines POPH. Among patients with portal hypertension, reported incidence rates of POPH range from 2 to 9%. Long-term survival in cases of POPH is poor. Favorable responses to pulmonary vasodilator/vasomodulatory therapy have been observed, but prospective, randomized trials are lacking. Severe POPH with right ventricular failure despite vasodilator therapy is associated with poor outcomes in the setting of liver transplantation (LT) and is considered a contraindication to LT. The post-LT course of patients with moderate POPH is unpredictable, but most patients can be weaned from PAH-specific therapy over time.     

Clinical risk factors for portopulmonary hypertension

Portopulmonary hypertension affects up to 6% of patients with advanced liver disease, but the predictors and biologic mechanism for the development of this complication are unknown. We sought to determine the clinical risk factors for portopulmonary hypertension in patients with advanced liver disease. We performed a multicenter case-control study nested within a prospective cohort of patients with portal hypertension recruited from tertiary care centers. Cases had a mean pulmonary artery pressure > 25 mm Hg, pulmonary vascular resistance > 240 dynes x second x cm(-5), and pulmonary capillary wedge pressure < or = 15 mm Hg. Controls had a right ventricular systolic pressure < 40 mm Hg (if estimable) and normal right-sided cardiac morphology by transthoracic echocardiography. The study sample included 34 cases and 141 controls. Female sex was associated with a higher risk of portopulmonary hypertension than male sex (adjusted odds ratio = 2.90, 95% confidence interval 1.20-7.01, P = 0.018). Autoimmune hepatitis was associated with an increased risk (adjusted odds ratio = 4.02, 95% confidence interval 1.14-14.23, P = 0.031), and hepatitis C infection was associated with a decreased risk (adjusted odds ratio = 0.24, 95% confidence interval 0.09-0.65, P = 0.005) of portopulmonary hypertension. The severity of liver disease was not related to the risk of portopulmonary hypertension. CONCLUSION: Female sex and autoimmune hepatitis were associated with an increased risk of portopulmonary hypertension, whereas hepatitis C infection was associated with a decreased risk in patients with advanced liver disease. Hormonal and immunologic factors may therefore be integral to the development of portopulmonary hypertension.     

Pulmonale Komplikationen der Leberzirrhose

Hepatopulmonary syndrome, portopulmonary hypertension and hepatic hydrothorax are typical pulmonary complications in patients with liver cirrhosis. Whereas hepatopulmonary syndrome and portopulmonary hypertension represent pulmonary vascular diseases, the development of hepatic hydrothorax is associated with the presence of ascites and phrenic lesions. For severe hepatopulmonary syndrome and refractory hepatic hydrothorax, liver transplantation is the treatment of choice. In severe portopulmonary hypertension specific medical treatment is indicated. In selected patients, beside intravenous prostanoids, oral endothelin receptor antagonists and phosphodiesterase type-5 inhibitors are possible treatment options.     

Hepatopulmonary syndrome and portopulmonary hypertension: recent knowledge in pathogenesis and overview of clinical assessment

Hepatopulmonary syndrome and portopulmonary hypertension are cardiopulmonary complications, which are not infrequently seen in patients with liver disease and/or portal hypertension. These entities are both clinically and pathophysiologically different: the hepatopulmonary syndrome is characterized by abnormal pulmonary vasodilation and right‐to‐left shunting resulting in gas exchange abnormalities, whereas portopulmonary hypertension is caused by pulmonary artery vasoconstriction leading to hemodynamic failure. As both hepatopulmonary syndrome and portopulmonary hypertension are associated with significantly increased morbidity and mortality, and as these patients are commonly asymptomatic, all liver transplantation candidates should be actively screened for the presence of these two complications. The aim of is this review is to provide an overview on the hepatopulmonary syndrome and portopulmonary hypertension with primary focus on diagnosis and recent knowledge regarding pathogenesis and therapeutic targets.     

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 Po PHT and advanced liver disease is significantly improved. Because of the prognostic significance of Po PHT 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 Po PHT can safely undergo liver transplant surgery. In cases of moderate to severe Po PHT, right heart catheterization(RHC) should be performed. In patients with moderate to severe Po PHT on RHC(mean PAP 35-45 mm Hg), 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.