Portopulmonary hypertension: a tale of two circulations

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Portopulmonary Hypertension: A Review of the Current Literature

Portopulmonary hypertension is defined as the development of pulmonary arterial hypertension in the setting of portal hypertension with or without liver cirrhosis. Portal hypertension-associated haemodynamic changes, including hyperdynamic state, portosystemic shunts and splanchnic vasodilation, induce significant alterations in pulmonary vascular bed and play a pivotal role in the pathogenesis of the disease. If left untreated, portopulmonary hypertension results in progressive right heart failure, with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and liver transplantation candidates, right heart catheterisation remains the gold standard for the diagnosis of the disease. Severe portopulmonary hypertension exerts a prohibitive risk to liver transplantation by conferring an elevated perioperative mortality risk. It is important for haemodynamic parameters to correspond with non-severe portopulmonary hypertension before patients can proceed with the liver transplantation. Small uncontrolled studies and a recent randomised controlled trial have reported promising results with vasodilatory therapies in clinical and haemodynamic improvement of patients, allowing a proportion of patients to undergo liver transplantation. In this review, the epidemiology, pathogenesis, diagnostic approach and management of portopulmonary hypertension are discussed. We also highlight fields of ongoing investigation pertinent to risk stratification and optimal patient selection to maximise long-term benefit from currently available treatments.

Transcatheter closure of congenital portosystemic shunts – A multicenter experience

Background:

Congenital portosystemic shunts (CPSS) are rare and present variably with hepatic encephalopathy, pulmonary arteriovenous malformations (PAVMs), and pulmonary hypertension (PH).

Objective:

The objective of the study was to see the feasibility of transcatheter closure of CPSS and their outcome.

Materials and Methods:

We analyzed the data of 24 patients of CPSS who underwent transcatheter closure from five institutions (March 2013 to April 2019). Baseline evaluation included echocardiography with bubble contrast study, ultrasound examination of the abdomen, computed tomography angiogram, and cardiac catheterization with test balloon occlusion of the CPSS. The evaluation showed cyanosis due to PAVM in 12, PH in 8, and respiratory distress in 2. Two had both cyanosis and PH. Criteria for eligibility for complete catheter closure of CPSS included demonstration of intrahepatic portal vein (PV) radicals together with a PV pressure of ≤18 mmHg on occlusion.

Results:

The median age and weight were 8 years (0.5–21) and 19.5 kg (4.2–73), respectively. Transcatheter closure was performed in 21 patients (22 procedures) using a variety of occlusive devices and stent-graft exclusion was done in one patient. Closure was not done in 3 in view of high portal venous pressures and hypoplastic PVs. During the follow-up (median: 42 months and range: 61 days–4.8 years), saturation normalized in 14 patients with PAVM. PH declined in all eight patients who underwent the procedure. Respiratory distress improved in two patients.

Conclusions:

Early and short-term follow-up results of catheter closure of CPSS appear promising. However, further, follow-up is needed to demonstrate long-term effectiveness.

Role of echocardiography in screening for portopulmonary hypertension in liver transplant candidates: a meta-analysis

Objectives

To demonstrate the screening value of echocardiography for portopulmonary hypertension (POPH) in liver transplant candidates.

Design

Systematic review and meta-analysis.

Background

POPH is a complication of end-stage liver disease that adversely affects the outcome of orthotopic liver transplant. There are no specific symptoms in the early stage of POPH. POPH reduce the survival rate of patients with end-stage liver disease specially if they are not diagnosed. Therefore, early detection may improve prognosis. The objective of this study is to explore the screening value of echocardiography on liver transplant candidates for screening of POPH compared to right heart catheterization (RHC).

Method

PubMed, EMBASE and the Cochrane Library were searched by two independent reviewers for potentially eligible studies published up to 30 June 2019 to retrieve data based on per-patient analysis. STATA, Meta-DiSc, and RevMan were applied to perform this meta-analysis.

Results

Our search yielded 1576 studies, of which 11 satisfied the inclusion criteria. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the summary receiver operating characteristic (SROC) curve (AUC) of echocardiography for POPH were 0.85 (95% CI [0.65–0.94]), 0.83 (95% CI [0.73–0.90]), 4.99 (95% CI [3.03–8.21]), 0.19 (95% CI [0.07–0.46]), and 0.91 (95% CI [0.88–0.93]), respectively. Deeks’ funnel plot did not indicate the existence of publication bias (P = 0.66).

Conclusions

Echocardiography, a noninvasive modality, provides superior screening for POPH, but the diagnosis of POPH still requires RHC. PROSPERO registration number CRD42019144589.

Pulmonary manifestations of chronic liver disease: a comprehensive review

Hepatopulmonary syndrome (HPS) and porto-pulmonary hypertension (PoPH) represent relatively common pulmonary vascular complications of advanced liver disease. Despite distinct differences in their pathogenetic background, both clinical states are characterized by impaired arterial oxygenation and limited functional status, and are associated with increased pre-transplantation mortality. Accumulation of ascitic fluid in the pleural cavity, known as hepatic hydrothorax (HH), is another frequent manifestation of decompensated cirrhosis, which may cause severe respiratory dysfunction, depending on the volume of the effusion, the rapidity of its development and its resistance to therapeutic measures. Orthotopic liver transplantation constitutes the only effective treatment able to resolve the pulmonary complications of liver disease. A prioritization policy for liver transplantation has evolved over the past years regarding advanced stages of HPS, yielding favorable outcomes regarding post-transplantation survival and HPS resolution. In contrast, severe PoPH is associated with poor post-transplantation survival. Hence, liver transplantation is recommended only for patients with PoPH and an acceptable reduction in pulmonary pressure values, after receiving PoPH-targeted vasodilating therapy. This review focuses on basic pathogenetic and diagnostic principles and discusses the current therapeutic approaches regarding HPS, PoPH, and HH.

Impact of liver damage on blood-borne variables and pulmonary hemodynamic responses to hypoxia and hyperoxia in anesthetized rats

BACKGROUND

Liver disorders may be associated with normal pulmonary hemodynamic, hepatopulmonary syndrome (HPS), or portopulmonary hypertension (POPH). In this study, we aimed to investigate the effect of the severity of liver dysfunctions on blood-borne variables, and pulmonary hemodynamic during repeated ventilation with hyperoxic and hypoxic gases.

METHODS

Female Sprague Dawley rats were assigned into four groups of Sham (n = 7), portal vein ligation (PPVL, n = 7), common bile duct ligation (CBDL, n = 7), and combination of them (CBDL+ PPVL, n = 7). Twenty-eight days later, right ventricular systolic pressure (RVSP) and systemic blood pressure were recorded in anesthetized animals subjected to repeated maneuvers of hyperoxia (O₂ 50%) and hypoxia (O₂ 10%). Besides, we assessed blood parameters and liver histology.

RESULTS

Liver histology score, liver enzymes, WBC and plasma malondialdehyde in the CBDL+PPVL group were higher than those in the CBDL group. Also, the plasma platelet level in the CBDL+PPVL group was lower than those in the other groups. On the other hand, the serum estradiol in the CBDL group was higher than that in the CBDL+PPVL group. All the above parameters in the PPVL group were similar to those in the Sham group. During ventilation with hyperoxia gas, RVSP in the CBDL+PPVL group was higher than the ones in the other groups, and in the CBDL group, it was more than those in the PPVL and Sham groups. Hypoxic pulmonary vasoconstriction (HPV) was not detected in both CBDL+PPVL and CBDL groups, whereas, it retained in the PPVL group.

CONCLUSION

Severe liver damage increases RVSP in the CBDL+PPVL group linked to the high level of ROS, low levels of serum estradiol and platelets or a combination of them. Furthermore, the high RVSP at the noted group could present a reliable animal model for POPH in female rats.

Current and emerging imaging techniques in the diagnosis and assessment of pulmonary hypertension

INTRODUCTION

Pulmonary hypertension (PH) is a challenging condition to diagnose and treat. Over the last two decades, there have been significant advances in therapeutic approaches and imaging technologies. Current guidelines emphasize the importance of cardiac catheterization; however, the increasing availability of non-invasive imaging has the potential to improve diagnostic rates, whilst providing additional information on patient phenotypes. Areas covered: This review discusses the role of imaging in the diagnosis, prognostic assessment and follow-up of patients with PH. Imaging methods, ranging from established investigations (chest radiography, echocardiography, nuclear medicine and computerized tomography (CT)), to emerging modalities (dual energy CT, magnetic resonance imaging (MRI), optical coherence tomography and positron emission tomography (PET)) are reviewed. The value and limitations of the clinical utility of these imaging modalities and their potential clinical application are reviewed. Expert commentary: Imaging plays a key role in the diagnosis and classification of pulmonary hypertension. It also provides valuable prognostic information and emerging evidence supports a role for serial assessments. The authors anticipate an increasing role for imaging in the pulmonary hypertension clinic. This will reduce the need for invasive investigations, whilst providing valuable insights that will improve our understanding of disease facilitate a more targeted approach to treatment.

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.

Differential diagnosis of hepatopulmonary syndrome (HPS): Portopulmonary hypertension (PPH) and hereditary hemorrhagic telangiectasia (HHT)

Hepatopulmonary syndrome (HPS) is a severe complication of advanced liver disease associated with an extremely poor prognosis. HPS is diagnosed in 4-47% of patients with cirrhosis and in 15-20% of candidates for liver transplantation. In addition, severe hypoxia is associated with a high risk of complications of liver transplantation (a 30% chance during the first 90 days) and increases the gap between transplantation and improving arterial oxygenation. The pathogenesis of HPS is not fully understood, and no effective pharmacological treatment has been developed yet. Currently, the treatment of choice for HPS is orthotopic liver transplantation. Non-specific clinical criteria and the lack of standardized diagnostic criteria for determining HPS can lead to diagnostic errors. Portopulmonary hypertension and hereditary hemorrhagic telangiectasia, also known as Osler-Weber-Rendu syndrome, are pulmonary complications of liver disease which should be differentially diagnosed from HPS.

Successful venoarterial extracorporeal membrane oxygenation for prolonged hepatopulmonary syndrome following pediatric liver transplantation: A case report and review of the literature

HPS is a major complicating feature of end-stage liver disease. Diagnosis is clinical, and LT is the only definitive treatment. While the general impression is that HPS improves quickly after transplantation, it may not always be the case. We describe the smallest reported child with HPS prior to LT and requiring prolonged venoarterial extracorporeal membrane oxygenation after LT; especially as it is a rare occurrence, physician managing such cases should be aware of the circumstances under which HPS may require specific treatment.

Onset ages of hepatopulmonary syndrome and pulmonary hypertension in patients with biliary atresia

PURPOSE

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) are extrahepatic complications of biliary atresia (BA). Their detection is sometimes delayed, which may result in missed opportunities for liver transplantation. The aim of this study was to determine the onset ages of HPS and PoPH in BA patients.

METHODS

BA patients followed at our institution were identified. Patients visited our clinic for routine blood work, as well as regular electrocardiography, chest X-rays, and arterial blood gas tests. Lung perfusion scintigraphy and cardiac ultrasound were performed to diagnose HPS. Cardiac catheterization was conducted to diagnose PoPH.

RESULTS

The study population consisted of 88 BA patients. The median follow-up duration was 11.6 years (range 0.8-26.0 years). Six patients (6.8%) developed HPS and three patients (3.4%) developed PoPH. The median age of onset of HPS was significantly younger than that of PoPH (HPS: 4 years, PoPH: 15 years, P < 0.019). Two patients (66%) with PoPH died, while all patients with HPS survivied.

CONCLUSION

The onset of HPS was significantly earlier than that of PoPH. The mortality rate was high in patients with PoPH. Teenagers with BA should receive routine cardiac echocardiograms to detect PH in its early stages.

Long-term outcome in liver transplantation candidates with portopulmonary hypertension

Portopulmonary hypertension (PoPH) is diagnosed in 2-6% of liver transplantation (LT) candidates. We studied outcomes of candidates for LT suffering from PoPH. Data were collected retrospectively from a prospective registry. Pulmonary hemodynamic variables were collected at the time of PoPH diagnosis, at last evaluation before LT, and within 6 months and beyond 6 months after LT. Forty-nine patients (35 males, 48 ± 8 years) were analyzed (median Model for End-Stage Liver Disease score 20). At baseline, mean pulmonary artery pressure (mPAP) was 44 ± 10 mm Hg (range 26-73 mm Hg), cardiac index was 3.5 ± 0.9 L/min/m² , and pulmonary vascular resistance was 5.6 ± 2.8 Wood units. Hemodynamic reassessment performed in 35 patients who were treated with pulmonary arterial hypertension-targeted therapies before LT resulted in significant decreases in both mPAP (36 ± 7 versus 47 ± 10 mm Hg, P < 0.0001) and pulmonary vascular resistance (3.0 ± 1.4 versus 6.1 ± 3.1 Wood units, P < 0.0001). Fourteen patients (29%) died without having had access to LT. Thirty-five patients underwent LT and were followed up for a median of 38 months. Eight patients (23%) died after LT including 5 due to PoPH (after 1 day to 6 months). Among survivors (n = 27), all patients treated with intravenous epoprostenol were weaned off post-LT, and endothelin receptor antagonist or phosphodiesterase type 5 inhibitors were continued in 15/27 patients (55%). At last evaluation, 20/27 patients (74%) had mPAP <35 mm Hg and 8 of them (30%) had mPAP <25 mm Hg. Overall survival estimates after LT were 80%, 77%, and 77% at 6 months, 1 year, and 3 years, respectively.

CONCLUSION

Stabilization or reversibility of PoPH seems to be an attainable goal using the combination of pulmonary arterial hypertension-targeted therapies and LT in patients who are transplantation candidates. (Hepatology 2017;65:1683-1692).

Anesthesia for Patients with Concomitant Hepatic and Pulmonary Dysfunction

Hepatic function and pulmonary function are interrelated with failure of one organ system affecting the other. With improved therapies, patients with concomitant hepatic and pulmonary failure increasingly enjoy a good quality of life and life expectancy. Therefore, the prevalence of such patients is increasing with more presenting for both emergent and elective surgical procedures. Hypoxemia requires a thorough evaluation in patients with end-stage liver disease. The most common etiologies respond to appropriate therapy. Portopulmonary hypertension and hepatopulmonary syndrome are associated with increased perioperative morbidity and mortality. It is incumbent on the anesthesiologist to understand the physiology of liver failure and its early effect on pulmonary function to ensure a successful outcome.

[Portopulmonary hypertension: Updated review]

Portopulmonary hypertension (PPH) is a rare condition worldwide, although epidemiological data are unknown in Mexico. However, chronic liver diseases are very prevalent in Mexico. PPH is the 4th subtype in frequency in the group of pulmonary arterial hypertension. Its diagnosis is made within 2 scenarios: patients with suspected pulmonary hypertension and candidates for orthotopic liver transplantation (OLT). Both echocardiogram and a right cardiac catheterisation are crucial for diagnosis in both cases. PPH is a challenge for OLT, since it can significantly increase perioperative mortality. The use of specific therapy is the cornerstone of this disease, as a measure to improve the outcome of those who become candidates for OLT with moderate to severe PPH. It is important to recognise that PPH can be a contraindication to OLT. The role of lung-liver transplantation or heart-lung-liver transplantation as a measure to heal pulmonary vascular disease in patients with PPH is still uncertain.

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.

Cardiac volume overload and pulmonary hypertension in long-term follow-up of patients with a transjugular intrahepatic portosystemic shunt

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPSS) cause haemodynamic changes in patients with cirrhosis, yet little is known about long-term cardiopulmonary outcomes.

AIM

To evaluate the long-term cardiopulmonary outcome after TIPSS.

METHODS

We evaluated cardiopulmonary parameters including echocardiography during long-term follow-up after TIPSS. Results at 1-5 years after TIPSS were compared to those of cirrhotic controls. Pulmonary hypertension (PH) diagnoses rates were included. Endothelin 1, thromboxane B2 and serotonin were measured.

RESULTS

We found significant differences 1-5 years after TIPSS compared to pre-implantation values: median left atrial diameter (LAD) increased from 37 mm [interquartile range (IQR): 33-43] to 40 mm (IQR: 37-47, P = 0.001), left ventricular end-diastolic diameter (LV-EDD) increased from 45 mm (range: 41-49) to 48 mm (IQR: 45-52, P < 0.001), pulmonary artery systolic pressure (PASP) increased from 25 mmHg (IQR: 22-33) to 30 mmHg (IQR: 25-36, P = 0.038). Comparing results 1-5 years post-implantation to the comparison cohort revealed significantly higher (P < 0.05) LAD, LV-EDD and PASP values in TIPSS patients. PH prevalence was higher in the shunt group (4.43%) compared to controls (0.91%, P = 0.150). Thromboxane B2 levels correlated with PASP in the TIPSS cohort (P = 0.033). There was no transhepatic gradient observed for the vasoactive substances analysed.

CONCLUSIONS

TIPSS placement is accompanied by long-term cardiovascular changes, including cardiac volume overload, and is associated with an increased rate of pulmonary hypertension. The need for regular cardiac follow-up after TIPSS requires further evaluation.

Pharmacological treatment of HIV-associated pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a rare but severe disease that results from chronic obstruction of small pulmonary arteries, leading to right ventricular failure and, ultimately, death. One established risk factor for the development of PAH is HIV infection. The presence of PAH is an independent risk factor for mortality in HIV-infected patients. This article will focus on HIV-associated PAH (HIV-PAH) with special considerations to the available treatments. With the approval of the soluble guanylate cyclase stimulator riociguat, a new drug class has become available in addition to the already existing prostanoids, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. Guidelines for the treatment of idiopathic PAH and guidelines for antiretroviral therapy should be followed for the treatment of HIV-PAH.

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.

Intrapulmonary vascular dilatations are common in portopulmonary hypertension and may be associated with decreased survival

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH) are pulmonary vascular complications of portal hypertension with divergent clinicopathologic features and management. The presence of intrapulmonary vascular dilatations (IPVDs), detected by agitated saline contrast-enhanced transthoracic echocardiography (cTTE), is an essential feature of HPS but is not typically characteristic of POPH. Although IPVDs have been reported rarely in POPH, the prevalence and significance of this finding have not been systematically studied. We conducted a retrospective chart review of 80 consecutive patients diagnosed with POPH from January 1, 2002 to June 30, 2014 with documentation of cTTE findings, pulmonary hemodynamics, oxygenation, and survival. A total of 34 of the 80 patients (42%) underwent cTTE during initial diagnosis of POPH. IPVDs were detected in 20/34 patients (59%); intracardiac shunting was detected in 9/34 patients (26%; 4 also had IPVDs); and 9 patients (26%) had negative cTTE with no evidence of IPVD or intracardiac shunting. Patients with IPVD had decreased survival as compared to those without IPVD (P = 0.003), a trend that persisted after exclusion of liver transplant recipients (P =  0.07). The IPVD group had a trend toward higher Model for End-Stage Liver Disease score with and without incorporating sodium (MELD or MELD-Na; P = 0.05 for both). The right ventricular index of myocardial performance (RIMP) was lower in the IPVD group (median, 0.4 versus 0.6; P = 0.006). Patients with moderate or large IPVDs (n = 6) had worse oxygenation parameters (partial pressure of arterial oxygen, diffusing capacity of the lung for carbon monoxide, and alveolar-arterial oxygen gradient) as compared to the rest of the cohort. Unexpectedly, IPVDs were frequently documented in POPH and associated with decreased survival. To further understand this observation, we recommend screening for IVPD in all patients with POPH.

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.

Successful Liver Transplant Complicated by Severe Portopulmonary Hypertension After an Initial Aborted Attempt: Case Report and Review of Treatment Options

Good right ventricular function and responsiveness to vasodilator therapy are the most important prerequisites for successful liver transplant in patients with portopulmonary hypertension. A patient with portopulmonary hypertension and good right ventricular function presented for deceased-donor liver transplant. Pulmonary arterial pressure was controlled with epoprostenol and sildenafil preoperatively. After anesthesia induction, pulmonary arterial pressure increased significantly and the procedure was aborted. Additional medical treatment included aggressive vasodilator therapy and the transplant was successfully performed 1 month later. During the procedure, elevations in pulmonary arterial pressure responded to a combination of inhaled nitric oxide, intravenous milrinone and nitroglycerin, and optimization of mechanical ventilation.

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.

"Porto-pulmonary hypertension: a comprehensive review"

Porto-pulmonary hypertension (PoPH) is a rare but threatening vasculopathy, defined by the presence of pulmonary arterial hypertension (PAH) in the setting of portal hypertension. Although most commonly observed in cirrhotic patients, those with non-cirrhotic portal hypertension are also at risk of developing it. Little is known about the mechanisms by which PAH develop in patients with portal hypertension, but genetic factors, pulmonary vascular wall shear stress, and a dysregulation of vasoactive, proliferative and inflammatory mediators might be involved. PoPH is estimated to occur in 3 to 10% of patients with end-stage liver disease, although its frequency is not related to the severity of liver dysfunction or the degree of portal hypertension. Moderate-to-severe PoPH portends an extremely poor prognosis. Presentation is highly variable, therefore a high index of suspicion is required to establish the diagnosis. PoPH should be screened by transthoracic echocardiography (TTE) in cirrhotic patients presenting with dyspnoea as well as in all patients being evaluated for liver transplantation (LT) regardless of their symptoms. If TTE shows elevated pulmonary pressures, patients should undergo right heart catheterisation, which is required for the definitive diagnosis of PoPH. Without LT, the overall 5-year mortality in PoPH patients is 70%, but it should not be considered an indication for LT. Moderate-to-severe PoPH contraindicates LT, since it is associated with a prohibitively increased intra and postoperative mortality. However, there is now evidence supporting the use of PAH-specific therapies pre-LT in order to improve pulmonary haemodynamic measurements, so the procedure can then be performed with significantly lower risks.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Portopulmonary hypertension

Portopulmonary hypertension (POPH) is defined as pulmonary arterial hypertension (PAH) complicated by portal hypertension, with or without advanced hepatic disease. Significant percentage of patients with cirrhotic liver disease has high cardiac output and subsequently elevated pulmonary arterial pressures (PAP). However, patients with POPH develop a progressive increase in pulmonary vascular resistance (PVR), which is generally lower than that observed in other forms of PAH.

The prognosis of untreated patients with POPH is very poor and the outcome of liver transplant (LT) in those patients is determined by the degree of severity of the associated pulmonary hemodynamics.

In this narrative review, we describe the clinical presentation of POPH, the pathobiology, and the clinical implication of pulmonary hemodynamics. We also provide evidence-based recommendations for the diagnosic and management approaches of POPH.

Hepatopulmonary syndrome and portopulmonary hypertension

Hepatopulmonary syndrome and portopulmonary hypertension are 2 of many diseases that affect the lungs in patients with liver disease. The 2 vascular conditions are often confused. We review both hepatopulmonary syndrome and portopulmonary hypertension to better understand their pathophysiologies, clinical presentations, tools to aid in differentiating and diagnosing the disease states, treatment options, and influences on patient prognosis. We also consider patient viability for liver transplantation.

Echocardiography for the detection of portopulmonary hypertension in liver transplant candidates: an analysis of cutoff values

Portopulmonary hypertension (POPH), a complication of chronic liver disease, may be a contraindication to liver transplantation (LT) because of the elevated risk of peritransplant and posttransplant morbidity and mortality. Because POPH is frequently asymptomatic, screening with echocardiography is recommended. The only reliable technique, however, for diagnosing POPH is right heart catheterization (RHC). The aims of this study were to evaluate the current estimated systolic pulmonary artery pressure (sPAP) cutoff value of 30 mm Hg and to determine a better cutoff value. One hundred fifty-two patients underwent pretransplant echocardiography between January 2005 and December 2010. These echocardiographic results were compared with pulmonary artery pressures measured during the pretransplant workup or at the beginning of the transplantation procedure (both by catheterization). With a cutoff value of 30 mm Hg, 74 of the 152 patients met the criteria for POPH on echocardiography, although the diagnosis was confirmed in only 7 patients during catheterization; this resulted in a specificity of 54%. It would have been more accurate to use a cutoff value of 38 mm Hg, which had a maximal specificity of 82% and, at the same time, guaranteed a sensitivity and negative predictive value of 100%. With the incorporation of the presence or absence of right ventricular dilatation, the specificity even increased to 93% for this new cutoff value. In conclusion, the prevalence of POPH was 4.6% among LT candidates in this study. We can recommend that LT candidates with an sPAP > 38 mm Hg should be referred for RHC. With the cutoff value increased from 30 to 38 mm Hg, the number of patients undergoing invasive RHC during their evaluation could be safely reduced.

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.

The characteristics of respiratory function and pulmonary hemodynamics in patients with portal hypertension

OBJECTIVE

To investigate the respiratory function and pulmonary hemodynamics in patients with portal hypertension (PHT).

METHODS

A total of 148 patients with PHT were divided into three groups according to Child-Pugh classification. Results of blood biochemistry test, lung function test, arterial blood gas analysis, free portal pressure (FPP) and pulmonary hemodynamics measurements of the three Child-Pugh grade groups were compared with those of the control group.

RESULTS

The overall incidence of arterial hypoxemia was 27.0% in PHT patients. Arterial oxygen tension (PaO(2) ) had a significant negative correlation with FPP (r=-0.76, P<0.01) and Child-Pugh grade (r=-0.42, P<0.01), as well as a positive correlation with systemic vascular resistance (SVR, r=0.24, P=0.01). Alveolar-arterial oxygen difference (A-aDO(2) ) increased in Child-Pugh grade C group when compared with Child-Pugh grade A and B groups (P<0.05). Restrictive impairment of lung function was seen in Child-Pugh grade C group. Direct measurement of the hemodynamics in PHT patients revealed a hyperdynamic disturbance in both systemic and portal venous systems, and was illustrated in pulmonary circulation as an increase of mean pulmonary arterial pressure (MPAP) and pulmonary arterial wedged pressure (PAWP) as well as a decrease of pulmonary vascular resistance (PVR).

CONCLUSIONS

  High output and low resistance are the key characteristics of pulmonary circulation in PHT patients and the decrease of PVR can be detected even when liver function is still compensated.

Clinical manifestations of portal hypertension

The portal hypertension is responsible for many of the manifestations of liver cirrhosis. Some of these complications are the direct consequences of portal hypertension, such as gastrointestinal bleeding from ruptured gastroesophageal varices and from portal hypertensive gastropathy and colopathy, ascites and hepatorenal syndrome, and hypersplenism. In other complications, portal hypertension plays a key role, although it is not the only pathophysiological factor in their development. These include spontaneous bacterial peritonitis, hepatic encephalopathy, cirrhotic cardiomyopathy, hepatopulmonary syndrome, and portopulmonary hypertension.

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.

Portopulmonary hypertension: from diagnosis to treatment

Portopulmonary hypertension is a form of pulmonary arterial hypertension that has gained interest in recent years with the development of liver transplantation techniques and new pulmonary vasodilator therapies. Portopulmonary hypertension is defined as pulmonary artery hypertension associated with portal hypertension with or without advanced hepatic disease. Echocardiography plays a major role in screening for portopulmonary hypertension but right heart catheterization remains the gold standard for diagnosis. The treatment of patients with portopulmonary hypertension consists of general measures that apply to all patients that carry the diagnosis of pulmonary hypertension and specific vasodilator therapies. These new therapies showed encouraging results in patients who would otherwise have a contraindication for liver transplantation. The review presents a summary of the current knowledge on the epidemiology, diagnosis, treatment and prognosis of patients with portopulmonary hypertension.

HIV infection and pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare but severe disease that results from chronic obstruction of small pulmonary arteries, leading to right ventricular failure and, ultimately, death. One established risk factor for the development of PAH is HIV infection. In comparison with the incidence of idiopathic PAH in the general population (1-2 per million), HIV-infected patients have a 2500-fold increased risk of developing PAH. The presence of PAH is an independent risk factor for mortality in patients with HIV infection, and in most cases death is causally related to PAH rather than to other complications of HIV infection. This article will focus on HIV-PAH with special considerations to epidemiology, pathogenesis, clinical presentation, diagnostic approach and available treatments.

Management of cardiopulmonary complications of cirrhosis

Advanced portal hypertension accompanying end-stage liver disease results in an altered milieu due to inadequate detoxification of blood from splanchnic circulation by the failing liver. The portosystemic shunts with hepatic dysfunction result in an increased absorption and impaired neutralisation of the gastrointestinal bacteria and endotoxins leads to altered homeostasis with multiorgan dysfunction. The important cardiopulmonary complications are cirrhotic cardiomyopathy, hepatopulmonary syndrome, portopulmonary hypertension, and right-sided hydrothorax.

Portopulmonary hypertension

Portopulmoanry hypertension (POPH) is a form of pulmonary arterial hypertension (PAH) associated with portal hypertension with or without underlying chronic liver disease. POPH is increasingly recognized and recent evidence suggests that it is one of the leading causes of PAH. The pathophysiology of POPH is poorly understood although the pathological changes in pulmonary vasculature in advanced POPH are similar to those seen in idiopathic pulmonary hypertension. The prognosis in patients with liver disease who also suffer from significant POPH is considered to be poor. Higher degree of pulmonary artery pressure (PAP) may preclude a patient from liver transplant as mortality in these patients is high. The treatment with vasodilator therapy has shown to improve both hemodynamics and clinical outcome in POPH in retrospective studies and in some case series. The aim of medical management is to bring PAP <35 mmHg that may make a patient with POPH and advanced liver disease eligible for liver transplant, which otherwise would have been denied because of high PAP.

Survival of Chinese patients with pulmonary arterial hypertension in the modern treatment era

BACKGROUND

In a previous study of Chinese patients with idiopathic pulmonary arterial hypertension (IPAH) in the nontargeted therapy era (defined as the time before 2006 when new pulmonary arterial hypertension-specific drugs were not available in China), we reported 1- and 3-year survival estimates of only 68% and 39%, respectively. However, it is not yet known whether the survival of patients with pulmonary arterial hypertension is improved in the modern treatment era (defined in China as after 2006).

METHODS

A retrospective cohort study was undertaken in 276 consecutive patients with newly diagnosed incident IPAH and connective tissue disease-related pulmonary arterial hypertension (CTDPAH) who were referred between 2007 and 2009. Baseline characteristics and survival rates in the two groups were compared.

RESULTS

The 1- and 3-year survival estimates were 92.1% and 75.1%, respectively, in patients with IPAH, and 85.4% and 53.6%, respectively, in patients with CTDPAH. Patients with CTDPAH had a significantly lower mean pulmonary artery pressure, more pericardial effusion, and more severe impairment of the diffusion capacity of the lung for carbon monoxide than patients with IPAH. A diagnosis of CTDPAH, World Health Organization functional class III or IV, single-breath diffusion capacity of the lung for carbon monoxide < 80% predicted, and the presence of pericardial effusion were independent predictors of mortality. The 1- and 3-year survival rates of male patients were 93.5% and 77.5%, respectively, in those with IPAH, and 71.1% and 47.4%, respectively, in those with CTDPAH.

CONCLUSIONS

The survival rates of patients with pulmonary arterial hypertension have improved in China in the modern treatment era, despite the high costs of treatment and financial constraints. However, the survival rates of patients with CTDPAH are inferior to those of patients with IPAH. Our study also indicates poorer survival rates in male patients with CTDPAH.

Pulmonary complications of cirrhosis

Pulmonary vascular complications of liver disease comprise two distinct clinical entities: hepatopulmonary syndrome (HPS-microvascular dilatation and angiogenesis) and portopulmonary hypertension (POPH-vasoconstriction and remodeling in resistance vessels). These complications occur in similar pathophysiologic environments and may share pathogenic mechanisms. HPS is found in 15% to 30% of patients with cirrhosis and its presence increases mortality and the risks of liver transplantation, particularly when hypoxemia is present. Contrast echocardiography and arterial blood gas analysis are required to establish the diagnosis. No medical therapies are available, although liver transplantation is effective in reversing the syndrome. POPH is found in 4% to 8% of patients undergoing liver transplantation evaluation, and the presence of moderate to severe disease significantly increases perioperative transplant mortality. Transthoracic echocardiography is recommended for screening and right-heart catheterization is required to establish the diagnosis. Medical therapies are increasingly effective in improving pulmonary vascular hemodynamics in POPH and may result in better perioperative outcomes.

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.

Safety and efficacy of ambrisentan for the treatment of portopulmonary hypertension

BACKGROUND

Ambrisentan is a selective endothelin-receptor antagonist that is approved by the US Food and Drug Administration for the treatment of pulmonary arterial hypertension. We describe hemodynamic responses and clinical outcomes of patients with portopulmonary hypertension (POPH) treated with ambrisentan.

METHODS

In this observational study, we prospectively identified and followed consecutive adult patients with POPH who received monotherapy with ambrisentan ≤ 10 mg daily from January 2007 until December 2009. Liver enzymes were assessed monthly. Pulmonary hemodynamic responses were assessed using echocardiograms and right-sided heart catheterizations.

RESULTS

We identified 13 patients (seven men) with POPH and began monotherapy with ambrisentan. The median age was 57 (interquartile range [IQR], 52-60). Patients were followed for a median of 613 days (IQR, 385-1,011). The median model for end-stage liver disease score was 10 (IQR, 8.5-15); eight patients had Child-Turcotte-Pugh A classification. Median time on ambrisentan therapy was 390 days (IQR, 363-611). Two patients died, one of advanced hepatocellular carcinoma and one of septic shock following pneumonia. The mean pulmonary artery pressure decreased from a baseline median of 58 mm Hg (IQR, 37-63) to 41 mm Hg (IQR, 27-48) (P = .004). The pulmonary vascular resistance median was reduced from 445 dynes/s/cm(5) (IQR, 329-834) to 174 dynes/s/cm(5) (IQR, 121-361) (P = .008). There was no difference in the longitudinal analysis of liver function tests (aspartate aminotransferase, alanine aminotransferase, total bilirubin, and international normalized ratio) after 12 months of therapy. One patient underwent successful liver transplantation and normalized pulmonary hemodynamic responses after transplantation.

CONCLUSIONS

In this small cohort of patients with moderate to severe pulmonary hypertension in the setting of POPH, we have shown that ambrisentan monotherapy can significantly improve pulmonary hemodynamic responses without adverse effect on hepatic function.

Critical care management of patients before liver transplantation

The critical care management of patients before liver transplantation is aimed at optimizing hepatic and extrahepatic organ function before the transplant operation, with a goal to favorably influence perioperative and postoperative graft and patient outcomes. Critical illness in liver disease can present in the context of acute liver failure or acute on chronic liver failure. The differing pathophysiologic processes underlying these 2 types of liver failure necessitate specific approaches to their intensive care management. In their extreme presentations, both types of liver failure present as multiorgan system failure; and therefore, the critical care management of these entities requires a systematic multiorgan system approach to address hepatic and extrahepatic organ dysfunction. This review provides a multiorgan system-based description of critical care management of acute liver failure and acute on chronic liver failure before liver transplantation.

The complex interrelationships between chronic lung and liver disease: a review

Lung complications may occur as a result of hepatic disease from any cause and represent a highly heterogeneous group of conditions. Early recognition of such complications may be challenging but is crucial both in forming a meaningful differential diagnosis and in avoiding severe sequelae and irreversible damage. Although a number of different pathogenetic mechanisms are likely to be involved, chronic liver dysfunction may cause pulmonary manifestations because of alterations in the production or clearance of circulating cytokines and other mediators. This is likely to be the case in hepatopulmonary syndrome, portopulmonary hypertension and primary biliary cirrhosis, although their pathogenesis remains largely speculative. Moreover, the severity of lung manifestations may or may not correspond to that of liver impairment, making disease outcome often unpredictable. Congenital and inflammatory disorders, however, may primarily affect both the liver and lung. Apart from specific diseases, a number of medications can also result in pulmonary and hepatic toxic effects. This is particularly important with cytokine therapy - used to treat viral hepatitis, among other diseases - because treatment consists of drug discontinuation, which, in turn, may cause reactivation or progression of the underlying disease that the drug was used for. This review summarizes salient diagnostic and therapeutic aspects of these often misdiagnosed conditions and highlights, based on the most recent literature, the need for early referral of such patients to centres with specific expertise in the field. In fact, a multidisciplinary approach involving pulmonologists, hepatologists and, in particularly severe cases, transplant surgeons has been already proven successful.

Pulmonary complications in liver disease

Pulmonary complications of liver disease are poorly understood and often identified late. Abnormalities of the pulmonary vasculature lead to two distinct complications, hepatopulmonary syndrome and portopulmonary hypertension, which differ in their clinical features and management. This article focuses on these two entities.

Pulmonary hypertension in primary biliary cirrhosis: a prospective study in 178 patients

OBJECTIVE. To analyze the incidence, clinical features, and prognosis of patients with primary biliary cirrhosis (PBC) complicated by pulmonary hypertension (PH).

MATERIAL AND METHODS

A total of 178 consecutive PBC patients, who were admitted to Peking Union Medical College Hospital from January 2001 to March 2007, were included in this prospective study. A structured interview, systemic rheumatological examination, laboratory tests (including autoantibodies), and Doppler echocardiography were conducted for each patient and compared between patients with and without PH.

RESULTS

Twenty-one PBC patients (11.8%) had PH. Among them, four patients (19.0%) had moderate to severe PH, and one patient died of right heart failure instead of liver failure. The incidences of Raynaud's phenomenon, interstitial lung disease, Sjögren's syndrome, and portal hypertension, the proportion of patients with a positive anti-SSA, the level of serum IgA, as well as the Mayo risk score in the PH-PBC patients were significantly higher than in the non-PH-PBC group (p = 0.02, 0.001, 0.02, 0.03, 0.006, 0.04 and 0.02, respectively).

CONCLUSIONS

PH, including moderate to severe PH, is not a rare complication of PBC. This complication is closely associated with portal hypertension and immunological dysregulation and indicates a poor prognosis.