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

Optimizing cardiac status in the preliver transplant candidate

PURPOSE OF REVIEW

Liver transplant is a widely accepted therapy for end-stage liver disease. With advances in our understanding of transplant, candidates are increasingly older with more cardiac comorbidities. Cardiovascular disease also represents a leading cause of morbidity and mortality posttransplant.

RECENT FINDINGS

Preoperative cardiac risk stratification and treatment may improve short-term and long-term outcomes after liver transplant. Importantly, the appropriate frequency of surveillance has not been defined. Optimal timing of cardiac intervention in end-stage liver disease is likewise uncertain.

SUMMARY

The approach to risk stratification of cardiovascular disease in end-stage liver disease is outlined, incorporating the AHA/ACC scientific statement on evaluation of cardiac disease in transplant candidates and more recent expert consensus documents. Further study is needed to clarify the ideal timing and approach for cardiovascular interventions.

An overview of unresolved issues in the perioperative management of liver transplant patients

Over the past decade, the field of solid organ transplantation has undergone significant changes, with some of the most notable advancements occurring in liver transplantation. Recent years have seen substantial progress in preoperative patient optimization protocols, anesthesia monitoring, coagulation management, and fluid management, among other areas. These improvements have led to excellent perioperative outcomes for all surgical patients, including those undergoing liver transplantation. In the last few decades, there have been numerous publications in the field of liver transplantation, but controversies related to perioperative management of liver transplant recipients persist. In this review article, we address the unresolved issues surrounding the anesthetic management of patients scheduled for liver transplantation.

Current Therapy and Liver Transplantation for Portopulmonary Hypertension in Japan

Portopulmonary hypertension (PoPH) and hepatopulmonary syndrome are severe pulmonary complications associated with liver cirrhosis (LC) and portal hypertension. Three key pathways, involving endothelin, nitric oxide, and prostacyclin, have been identified in the development and progression of pulmonary arterial hypertension (PAH). To obtain a good effect with PAH-specific drugs in PoPH patients, it is important to diagnose PoPH at an early stage and promptly initiate therapy. The majority of therapeutic drugs are contraindicated for Child-Pugh grade C LC, and their effects decrease in the severe PAH stage. Among many LC patients, the measurement of serum brain natriuretic peptide levels might be useful for detecting PoPH. Previously, liver transplantation (LT) for PoPH was contraindicated; however, the indications for LT are changing and now take into account how well the PoPH is controlled by therapeutic drugs. In Japan, new registration criteria for deceased-donor LT have been established for PoPH patients. PoPH patients with a mean pulmonary arterial pressure <35 mmHg and pulmonary vascular resistance <400 dyn/s/cm−5 are indicated for LT, regardless of whether they are using therapeutic drugs. Combined with PAH-specific drugs, LT may lead to excellent long-term outcomes in PoPH patients. We aimed to review current therapies for PoPH, including LT.

Struggling Between Liver Transplantation and Portopulmonary Hypertension

Portopulmonary hypertension (PoPH) is a progressive, ultimately fatal cardiopulmonary disease that occurs exclusively in patients with underlying portal hypertensive liver disease. PoPH outcomes are driven by both the severity of underlying liver disease and the degree of cardiac adaptation to elevated pulmonary pressures. The mainstay of treatment in PoPH is targeted pulmonary vascular therapy. Liver transplantation (LT) can be beneficial in some patients, but is associated with considerable risks in the PoPH population, and outcomes are variable. The optimal management strategy for PoPH, LT, or medical therapy alone, is unclear, and further research is needed to help guide clinical decision-making.

Efficacy evaluation of pulmonary hypertension therapy in patients with portal pulmonary hypertension: A systematic review and meta-analysis

Objective: To determine the therapeutic effect of pulmonary arterial hypertension (PAH) agents for portal pulmonary hypertension (POPH).

Design: Systematic review and meta-analysis.

Background: POPH is a serious complication of end-stage liver disease with a low survival rate. Liver transplantation (LT) is an effective treatment. Due to the presence of POPH, some patients cannot undergo LT. After PAH treatment, patients with POPH can obtain good hemodynamics and cardiac function for LT, but there are no standard guidelines.

Methods: Two independent researchers searched PubMed, EMBASE, Cochrane Library, and Web of Science for studies published from inception to 27 September 2022, focusing on the changes in hemodynamics and cardiac function in all patients with POPH to understand the effect of PAH treatment on the entire population of POPH patients. Among these, we specifically analyzed the changes in hemodynamics and cardiac function in moderate and severe POPH patients. After collecting the relevant data, a meta-analysis was carried out using the R program meta-package.

Results: A total of 2,775 literatures were retrieved, and 24 literatures were included. The results showed that in all POPH patients (n = 1,046), the following indicators were significantly improved with PAH agents: mPAP: (MD = −9.11 mmHg, p &lt; 0.0001); PVR: (MD = −239.33 dyn·s·cm−5, p &lt; 0.0001); CO: (MD = 1.71 L/min, p &lt; 0.0001); cardiac index: (MD = 0.87 L/(min·m2), p &lt; 0.0001); 6MWD: (MD = 43.41 m, p &lt; 0.0001). In patients with moderate to severe POPH (n = 235), the following indicators improved significantly with PAH agents: mPAP (MD = −9.63 mmHg, p &lt; 0.0001); PVR (MD = −259.78 dyn·s·cm−5, p &lt; 0.0001); CO (MD = 1.76 L/min, p &lt; 0.0001); Cardiac index: (MD = 1.01 L/(min·m2), p = 0.0027); 6MWD: (MD = 61.30 m, p &lt; 0.0001).

Conclusion: The application of PAH agents can improve cardiopulmonary hemodynamics and cardiac function in patients with POPH, especially in patients with moderate to severe POPH, and the above changes are more positive.

Systematic Review Registration:https://inplasy.com, identifier INPLASY202250034.

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.

Preoperative 2D-echocardiographic assessment of pulmonary arterial pressure in subgroups of liver transplantation recipients

BACKGROUND

The clinical efficacy of preoperative 2D-echocardiographic assessment of pulmonary arterial pressure (PAP) has not been evaluated fully in liver transplantation (LT) recipients.

METHODS

From October 2010 to February 2017, a total of 344 LT recipients who underwent preoperative 2D-echocardiography and intraoperative right heart catheterization (RHC) was enrolled and stratified according to etiology, disease progression, and clinical setting. The correlation of right ventricular systolic pressure (RVSP) on preoperative 2D-echocardiography with mean and systolic PAP on intraoperative RHC was evaluated, and the predictive value of RVSP > 50 mmHg to identify mean PAP > 35 mmHg was estimated.

RESULTS

In the overall population, significant but weak correlations were observed (R = 0.27; P < 0.001 for systolic PAP, R = 0.24; P < 0.001 for mean PAP). The positive and negative predictive values of RVSP > 50 mmHg identifying mean PAP > 35 mmHg were 37.5% and 49.9%, respectively. In the subgroup analyses, correlations were not significant in recipients of deceased donor type LT (R = 0.129; P = 0.224 for systolic PAP, R = 0.163; P = 0.126 for mean PAP) or in recipients with poorly controlled ascites (R = 0.215; P = 0.072 for systolic PAP, R = 0.21; P = 0.079 for mean PAP).

CONCLUSIONS

In LT recipients, the correlation between RVSP on preoperative 2D-echocardiography and PAP on intraoperative RHC was weak; thus, preoperative 2D-echocardiography might not be the optimal tool for predicting intraoperative PAP. In LT candidates at risk of pulmonary hypertension, RHC should be considered.

Cardiovascular risk stratification in the noncardiac solid organ transplant candidate

PURPOSE OF REVIEW

Solid organ transplantation (SOT) has become a widely accepted therapy for end-stage disease across the spectrum of thoracic and abdominal organs. With contemporary advances in medical and surgical therapies in transplantation, candidates for SOT are increasingly older with a larger burden of comorbidities, including cardiovascular disease (CVD). CVD, in particular, is a leading cause of morbidity and mortality in SOT candidates with end-stage disease of noncardiac organs [1].

RECENT FINDINGS

Identification of coronary artery disease (CAD), heart failure, and valvular disease are important in noncardiac SOT to ensure both appropriate peri-transplant management and equitable organ allocation. Although the American College of Cardiology (ACC) and the American Heart Association (AHA) have published guidelines and recommendations for the perioperative cardiovascular evaluation of patients undergoing noncardiac surgery, the implications of both symptomatic and asymptomatic CVD differ in patients with end-stage organ failure being considered for SOT when compared to the general population.

SUMMARY

Herein, we review the epidemiology, diagnosis, and evidence for the management of CVD in kidney and liver transplantation, combining current guidelines from the 2012 ACC/AHA scientific statement on cardiac disease evaluation in SOT with more contemporary evidenced-based algorithms.

Cardiac and Pulmonary Vascular Risk Stratification in Liver Transplantation

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

Estrogen Signaling and Portopulmonary Hypertension: The Pulmonary Vascular Complications of Liver Disease Study (PVCLD2)

BACKGROUND AND AIMS

Portopulmonary hypertension (POPH) was previously associated with a single-nucleotide polymorphism (SNP) rs7175922 in aromatase (cytochrome P450 family 19 subfamily A member 1 [CYP19A1]). We sought to determine whether genetic variants and metabolites in the estrogen signaling pathway are associated with POPH.

APPROACH AND RESULTS

We performed a multicenter case-control study. POPH patients had mean pulmonary artery pressure >25 mm Hg, pulmonary vascular resistance >240 dyn-sec/cm-5 , and pulmonary artery wedge pressure ≤15 mm Hg without another cause of pulmonary hypertension. Controls had advanced liver disease, right ventricular (RV) systolic pressure <40 mm Hg, and normal RV function by echocardiography. We genotyped three SNPs in CYP19A1 and CYP1B1 using TaqMan and imputed SNPs in estrogen receptor 1 using genome-wide markers. Estrogen metabolites were measured in blood and urine samples. There were 37 patients with POPH and 290 controls. Mean age was 57 years, and 36% were female. The risk allele A in rs7175922 (CYP19A1) was significantly associated with higher levels of estradiol (P = 0.02) and an increased risk of POPH (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.12-4.91; P = 0.02) whereas other SNPs were not. Lower urinary 2-hydroxyestrogen/16-α-hydroxyestrone (OR per 1-ln decrease = 2.04; 95% CI, 1.16-3.57; P = 0.01), lower plasma levels of dehydroepiandrosterone-sulfate (OR per 1-ln decrease = 2.38; 95% CI, 1.56-3.85; P < 0.001), and higher plasma levels of 16-α-hydroxyestradiol (OR per 1-ln increase = 2.16; 95% CI, 1.61-2.98; P < 0.001) were associated with POPH.

CONCLUSIONS

Genetic variation in aromatase and changes in estrogen metabolites were associated with POPH.

Portopulmonary Hypertension: From Bench to Bedside

Portopulmonary hypertension (PoPH) is defined as pulmonary arterial hypertension (PAH) associated with portal hypertension and is a subset of Group 1 pulmonary hypertension (PH). PoPH is a cause of significant morbidity and mortality in patients with portal hypertension with or without liver disease. Significant strides in elucidating the pathogenesis, effective screening algorithms, accurate diagnoses, and treatment options have been made in past 20 years. Survival of PoPH has remained poor compared to IPAH and other forms of PAH. Recently, the first randomized controlled trial was done in this patient population and showed promising results with PAH specific therapy. Despite positive effects on hemodynamics and functional outcomes, it is unclear whether PAH specific therapy has a beneficial effect on long term survival or transplant outcomes. In this review, we will discuss the epidemiology, pathophysiology, clinical and hemodynamic characteristics of PoPH. Additionally, this review will highlight the lacunae in our current management strategy, challenges faced and will provide direction to potentially useful futuristic management strategies.

Vasomodulators and Liver Transplantation for Portopulmonary Hypertension: Evidence From a Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Untreated portopulmonary hypertension (PoPH) carries a poor prognosis. Previous reports have described vasomodulator (VM) therapy and liver transplantation (LT) as treatment options. We aimed to provide summary estimates on the endpoints of pulmonary hemodynamics and survival in patients with PoPH, treated with different modalities.

APPROACH AND RESULTS

We performed a systematic review with meta-analysis of mainly observational and case-control studies describing no treatment, VM, LT, or VM + LT in patients with PoPH. Twenty-six studies (1,019 patients) were included. Both VM and VM + LT improve pulmonary hemodynamics. A substantial proportion of patients treated with VM become eligible for LT (44%; 95% confidence interval [CI], 31-58). Pooled estimates for 1-, and 3-year postdiagnosis survival in patients treated with VM were 86% (95% CI, 81-90) and 69% (95% CI, 50-84) versus 82% (95% CI, 52-95) and 67% (95% CI, 53-78) in patients treated with VM + LT. Of note, studies reporting on the effect of VM mainly included Child-Pugh A/B patients, whereas studies reporting on VM + LT mainly included Child-Pugh B/C. Seven studies (238 patients) included both patients who received VM only and patients who received VM + LT. Risk of death in VM-only-treated patients was significantly higher than in patients who could be transplanted as well (odds ratio, 3.5; 95% CI, 1.4-8.8); however, importantly, patients who proceeded to transplant had been selected very strictly. In 50% of patients, VM can be discontinued post-LT (95% CI, 38-62).

CONCLUSIONS

VM and VM + LT both improve pulmonary hemodynamics and prognosis in PoPH. In a strictly selected subpopulation of cases where LT is indicated based on severe liver disease and where LT is considered safe and feasible, treatment with VM + LT confers a better prognosis. Considering successful VM, 44% can proceed to LT, with half being able to postoperatively stop medication.

Clinical Outcomes after Liver Transplantation in Patients with Portopulmonary Hypertension

BACKGROUND

Portopulmonary hypertension (POPH) is the presence of pulmonary arterial (PA) hypertension in patients with portal hypertension and is associated with significant morbidity and mortality. In a cohort of POPH patients, we describe the clinical outcomes of POPH patients who underwent liver transplantation (LT).

METHODS

Retrospectively collected data from a prospectively assembled cohort of all consecutive POPH adults evaluated in three transplant centers from 1996 to 2019.

RESULTS

From a cohort of 228 POPH patients, 50 patients underwent LT. Significant hemodynamic improvement after PA-targeted therapy was observed, with 58% receiving only monotherapy pre-transplant. After LT, 21 (42%) patients were able to discontinue and remained off PA-targeted therapy. The 1, 3, and 5 year unadjusted survival rates after LT were 72%, 63% and 60%, respectively. An elevated pulmonary vascular resistance (PVR) before LT was associated with worse survival rate (HR 1.91, 95% CI 1.07-3.74, p=0.04). No survival difference was observed in those granted MELD exception or transplants performed before or after the year 2010.

CONCLUSION

Significant number of POPH patients discontinued PA-targeted therapy after LT. Higher PVR before LT was associated with worse survival, as was monotherapy use. Despite effective PA-targeted therapies, POPH survival outcomes after LT in our cohort were modest and may reflect the need for more aggressive therapy.

Liver transplantation and cardiac illness: Current evidences and future directions

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

Ambrisentan in portopulmonary hypertension: A multicenter, open-label trial

BACKGROUND

Ambrisentan has shown effectiveness in the treatment of Group 1 pulmonary arterial hypertension (PAH). Although portopulmonary hypertension (PoPH) is a subset of Group 1 PAH, few clinical trials have been testing PAH therapies in patients with PoPH. The objective of this study is to evaluate the efficacy and safety of ambrisentan in PoPH.

METHODS

This study is a prospective, multicenter, open-label trial in which treatment-naive patients with PoPH with Child-Pugh class A/B were administered with ambrisentan for 24 weeks, followed by a long-term extension (24-28 weeks). The primary end-points were change in pulmonary vascular resistance (PVR) and 6-minutes walk distance (6MWD) at 24 weeks, whereas secondary end-points included safety, World Health Organization (WHO) functional class (FC) and echocardiographic assessments.

RESULTS

Of the 31 patients, 23 finished 24 weeks of ambrisentan therapy and 19 finished the extension. PVR decreased significantly (mean ± SD) (7.1 ± 5 vs 3.8 ± 1.8 Wood units, p < 0.001), whereas 6MWD remained unchanged (314 ± 94 vs 336 ± 108 m). Other hemodynamic parameters such as right atrial pressure (13 ± 8 vs 9 ± 4 mm Hg, p < 0.05), mean pulmonary arterial pressure (46 ± 13 vs. 38 ± 8 mm Hg, p < 0.01), cardiac index (2.6 ± 0.6 vs. 3.5 ± 0.7 liter/min/m², p < 0.001) showed improvement, whereas pulmonary capillary wedge pressure remained unchanged. Of the 22 patients with WHO FC assessments at baseline and 24 weeks, WHO FC improved significantly (p = 0.005). Most frequent drug-related adverse events were edema (38.7%) and headache (22.5%). One episode of leg edema resulted into the permanent discontinuation of ambrisentan.

CONCLUSIONS

Ambrisentan monotherapy in PoPH improves hemodynamics and FC at 24 weeks; however, it did not show any improvement in 6MWD. These preliminary outcomes should be interpreted with caution (Clinicaltrials.Gov:NCT01224210).

Liver transplantation for severe portopulmonary hypertension: A case report and literature review

BACKGROUND

Portopulmonary hypertension (PoPH) is not uncommon in patients waiting for liver transplantation (LT). Severe PoPH has a very high perioperative mortality rate and is still considered a contraindication for LT. Many patients with liver disease require but cannot receive LT due to severe PoPH and eventually died. We report a patient with severe PoPH who underwent successful LT and had near normal pulmonary pressure without drug treatment.

CASE SUMMARY

A 39-year-old woman was hospitalized with the chief complaint of jaundice and exertional dyspnea and fatigue. Caroli disease and liver cirrhosis was diagnosed 6 years previously. Her liver disease met the criteria for LT. However, right heart catheterization showed that her mean pulmonary artery pressure was increased at 50 mmHg, pulmonary vascular resistance was 460 dyn∙s/cm⁵ and pulmonary artery wedge pressure was 20 mmHg, which may have been the reasons for her chief complaint. The patient was diagnosed with severe PoPH and was not listed for LT immediately. After 5 mo of pharmacotherapy, her severe PoPH was moderate, and she underwent successful LT. Pulmonary artery pressure steadily decreased according to post-operative echocardiographic monitoring and drugs have been discontinued for a month.

CONCLUSION

The safety of LT can be greatly improved by reducing mean pulmonary artery pressure to a low level, and LT may cure PoPH.

Pulmonary Complications of Portal Hypertension

The most common pulmonary complications of chronic liver disease are hepatic hydrothorax, hepatopulmonary syndrome, and portopulmonary hypertension. Hepatic hydrothorax is a transudative pleural effusion in a patient with cirrhosis and no evidence of underlying cardiopulmonary disease. Hepatic hydrothorax develops owing to the movement of ascitic fluid into the pleural space. Hepatopulmonary syndrome and portopulmonary hypertension are pathologically linked by the presence of portal hypertension; however, their pathophysiologic mechanisms are significantly different. Hepatopulmonary syndrome is characterized by low pulmonary vascular resistance secondary to intrapulmonary vascular dilatations and hypoxemia; portopulmonary hypertension features elevated pulmonary vascular resistance and constriction/obstruction within the pulmonary vasculature.

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

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

Intraoperative Management to Prevent Cardiac Collapse in a Patient With a Recurrent, Large-volume Pericardial Effusion and Paroxysmal Atrial Fibrillation During Liver Transplantation: A Case Report

BACKGROUND

Pericardial effusion is a common feature of end-stage liver disease. In this case report we describe the intraoperative management of recurrent pericardial effusion, without re-pericardiocentesis, to prevent circulatory collapse during a critical surgical time-point; that is, during manipulation of the major vessels and graft reperfusion.

METHODS

A 47-year-old woman with hepatitis B was scheduled to undergo deceased donor liver transplantation (LT). A large pericardial effusion was preoperatively identified using transthoracic echocardiography (TTE). The patient also had paroxysmal atrial fibrillation. Two days before surgery, preemptive pericardiocentesis was performed and the 1150-mL effusion was drained. Intraoperatively, recurrence of the large pericardial effusion was identified using transesophageal echocardiography (TEE). During inferior vena cava manipulation, the surgeon consulted the anesthesiologist to evaluate the hemodynamic changes in the patient. After 3 attempts, the transplant team was able to determine the most appropriate anastomosis site, defined as that with the least impact on cardiac function. To prevent the development of severe postreperfusion syndrome, 10% MgSO₄ (2 g) was gradually infused 20 minutes before portal vein declamping, and immediately before graft reperfusion a 100-μg bolus of epinephrine was administered.

RESULTS

During graft reperfusion, there was no evidence of heart chamber collapse or flow disturbance, as seen on the TEE findings. Postoperatively, the patient recovered completely and was discharged from the hospital. Six months after surgery, there was no sign of pericardial effusion on follow-up TTE.

CONCLUSION

Our intraoperative strategy may prevent cardiac collapse in patients with pericardial effusion detected during LT. Intraoperative TEE plays an important role in guiding hemodynamic management.

Treatment Barriers in Portopulmonary Hypertension

Portopulmonary hypertension (PoPH) is a form of pulmonary arterial hypertension (PAH) that can develop as a complication of portal hypertension. Treatment of PoPH includes PAH-specific therapies, and in certain cases, such therapies are necessary to facilitate a successful liver transplantation. A significant number of barriers may limit the adequate treatment of patients with PoPH and explain the poorer survival of these patients when compared to patients with other types of PAH. Until recently, only one randomized controlled trial has included PoPH patients, and the majority of treatment data have been derived from relatively small observational studies. In the present article, we review some of the barriers in the treatment of patients with PoPH and implications for liver transplantation.

Does Portopulmonary Hypertension Impede Liver Transplantation in Cirrhotic Patients? A French Multicentric Retrospective Study

BACKGROUND

Portopulmonary hypertension is defined by the presence of pulmonary arterial hypertension associated with portal hypertension. Its presence is a major stake for cirrhotic patients requiring liver transplantation (LT), with increased postoperative mortality and unpredictable evolution after transplantation. The aim was to study outcomes after liver transplantation in patients with portopulmonary hypertension and to identify factors associated with normalization of pulmonary hypertension.

METHODS

Patients with portopulmonary hypertension who underwent LT between 2008 and 2016 in 8 French centers were retrospectively included. Pulmonary artery pressure was established by right heart catheterization before and after LT. Primary endpoint was the normalization of pulmonary artery pressure after LT.

RESULTS

Twenty-three patients who received liver transplant between 2008 and 2016 were included. Two (8.7%) patients died in the immediate posttransplant period from right heart failure. With appropriate vasoactive medical treatment and LT, pulmonary arterial pressure was normalized in 14 patients (60.8%), demonstrating recovery from portopulmonary hypertension. In univariate analysis, the use of vasoactive combination therapy was the only prognostic factor for pulmonary arterial hypertension normalization after LT.

CONCLUSIONS

Treatment of portopulmonary hypertension with a combination of vasoactive drugs allows LT with acceptable postoperative cardiovascular-related mortality and normalization of pulmonary hypertension in the majority of the patients.

Predictive Value of Intraoperative Pulmonary Vascular Resistance in Liver Transplantation

We aimed to evaluate the association between intraoperative pulmonary vascular resistance (PVR) and clinical outcome of liver transplantation (LT). Cardiovascular involvement of end-stage liver disease is relatively common, and hemodynamic instability during LT can be fatal to recipients. However, the clinical impact of intraoperative PVR in LT remains undetermined. A total of 363 adult recipients with intraoperative right heart catheterization from January 2011 to May 2016 were analyzed. Patients were divided into 2 groups according to PVR. Two separate analyses were performed according to the time point of measurement: at the beginning and at the end of LT. The primary outcome was all-cause death or graft failure during the follow-up period. Increased PVR was observed in 11.8% (43/363) of recipients at the beginning and 12.7% (46/363) of recipients at the end of LT. PVR at the beginning of LT had no significant effect on the rate of death or graft failure in the multivariate analysis (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.64-2.38; P = 0.52). In contrast, PVR at the end of LT was significantly associated with death or graft failure during the overall follow-up period (HR, 2.00; 95% CI, 1.13-3.54; P = 0.02). In conclusion, PVR at the end of LT, rather than the beginning, is associated with clinical outcome. Larger trials are needed to support this finding.

Transesophageal ultrasonography during orthotopic liver transplantation: Show me more

The first perioperative transesophageal echocardiography (TEE) guidelines published 21 years ago were mainly addressed to cardiac anesthesiologists. TEE has since expanded its role outside this setting and currently represents an invaluable tool to assess chamber sizes, ventricular hypertrophy, and systolic, diastolic, and valvular function in patients undergoing orthotopic liver transplantation (OLT). Right-sided microemboli, right ventricular dysfunction, and patent foramen ovale (PFO) are the most common intra-operative findings described during OLT. However, left ventricular outflow tract obstruction and left ventricular ballooning syndrome are more difficult to recognize and less frequent. Transesophageal ultrasonography (TEU) during OLT is also underused. Its applications are as follows: (1) assistance in the difficult placement of pulmonary arterial catheters; (2) help with catheterization of great vessels for external veno-venous bypass placement; (3) intra-operative evaluation of surgical liver anastomosis patency, if feasible, through the liver window; and (4) intra-operative investigation of "acute hypoxemia" due to pulmonary and cardiac issues using trans-esophageal lung ultrasound (TELU). The aims of this review are as follows: (1) to summarize the uses of TEE and TEU throughout all phases of OLT, and (2) to describe other new feasible applications.

Multidisciplinary approach to cardiac and pulmonary vascular disease risk assessment in liver transplantation: An evaluation of the evidence and consensus recommendations

Liver transplant (LT) candidates today are older, have greater medical severity of illness, and have more cardiovascular comorbidities than ever before. In addition, there are specific cardiovascular responses in cirrhosis that can be detrimental to the LT candidate. Cirrhotic cardiomyopathy, a condition characterized by increased cardiac output and a reduced ventricular response to stress, is present in up to 30% of patients with cirrhosis, thus challenging perioperative management. Current noninvasive tests that assess for subclinical coronary and myocardial disease have low sensitivity, and altered hemodynamics during the LT surgery can unmask latent cardiovascular disease either intraoperatively or in the immediate postoperative period. Therefore, this review, assembled by a group of multidisciplinary experts in the field and endorsed by the American Society of Transplantation Liver and Intestine and Thoracic and Critical Care Communities of Practice, provides a critical assessment of the diagnosis of cardiac and pulmonary vascular disease and interventions aimed at managing these conditions in LT candidates. Key points and practice-based recommendations for the diagnosis and management of cardiac and pulmonary vascular disease in this population are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

Predictors of Waitlist Mortality in Portopulmonary Hypertension

BACKGROUND

The current Organ Procurement Transplantation Network policy grants Model for End-Stage Liver Disease (MELD) exception points to patients with portopulmonary hypertension (POPH), but potentially important factors, such as severity of liver disease and pulmonary hypertension, are not included in the exception score, and may affect survival. The purpose of this study was to identify significant predictors of waitlist mortality in patients with POPH.

METHODS

We performed a retrospective cohort study of patients in the Organ Procurement and Transplantation Network database with hemodynamics consistent with POPH (defined as mean pulmonary arterial pressure >25 mm Hg and pulmonary vascular resistance [PVR] ≥240 dynes·s·cm) who were approved for a POPH MELD exception between 2006 and 2014. Using a Cox proportional hazards model, we identified predictors of waitlist mortality (or removal for clinical deterioration).

RESULTS

One hundred ninety adults were included. Age (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.00-1.08; P = 0.0499), initial native MELD score (HR, 1.11; 95% CI, 1.05-1.17; P < 0.001), and initial PVR (HR, 1.12 per 100 dynes·s·cm; 95% CI, 1.02-1.23; P = 0.02) were the only significant univariate predictors of waitlist mortality and remained significant predictors in a multivariate model, which had a c-statistic of 0.71. PVR and mean pulmonary arterial pressure were not significant predictors of posttransplant mortality.

CONCLUSIONS

Both the severity of liver disease and POPH (as assessed by MELD and PVR, respectively) were significantly associated with waitlist, but not posttransplant, mortality in patients with approved MELD exceptions for POPH. Both factors should potentially be included in the POPH MELD exception score to more accurately reflect waitlist mortality risk.

Respiratory Complication in Liver Disease

Cirrhosis, the twelfth leading cause of death, accounts for 1.1% of all deaths in the United States. Although there are multiple pulmonary complications associated with liver disease, the most important complications that cause significant morbidity and mortality are hepatopulmonary syndrome, hepatic hydrothorax, and portopulmonary hypertension. Patients with cirrhosis who complain of dyspnea should be evaluated for these complications. This article reviews these complications.

Perioperative Care of the Liver Transplant Patient

With the evolution of surgical and anesthetic techniques, liver transplantation has become "routine," allowing for modifications of practice to decrease perioperative complications and costs. There is debate over the necessity for intensive care unit admission for patients with satisfactory preoperative status and a smooth intraoperative course. Postoperative care is made easier when the liver graft performs optimally. Assessment of graft function, vigilance for complications after the major surgical insult, and optimization of multiple systems affected by liver disease are essential aspects of postoperative care. The intensivist plays a vital role in an integrated multidisciplinary transplant team.

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

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

Pulmonary hypertension's variegated landscape: a snapshot

The many types of pulmonary hypertension (PH) are so protean in their biological origin, histological expression, and natural history that it is difficult to create a summary picture of the disease, or to easily compare and contrast characteristics of one type of PH with another. For newcomers to the field, however, such a picture would facilitate a broad understanding of PH. In this paper, we suggest that four characteristics are fundamental to describing the nature of various types of PH, and that taken together they define a number of patterns of PH expression. These characteristics are histopathology, developmental origin, associated clinical conditions, and potential for resolution. The “snapshot” is a way to concisely display the ways that these signal characteristics intersect in select specific types of PH, and is an effort to summarize these patterns in a way that facilitates a “big picture” comprehension of this disease.

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.

Postreperfusion syndrome during liver transplantation

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

The Art and Science of Diagnosing and Treating Lung and Heart Disease Secondary to Liver Disease

Patients with chronic liver disease are at risk of extrahepatic complications related to cirrhosis and portal hypertension, as well as organ-specific complications of certain liver diseases. These complications can compromise quality of life, while also increasing morbidity and mortality before and after liver transplantation. Patients with chronic liver disease are at risk for pulmonary complications of hepatopulmonary syndrome and portopulmonary syndrome; the cardiac complication fall under the general concept of cirrhotic cardiomyopathy, which can affect systolic and diastolic function, as well as cardiac conduction. In addition, patients with certain diseases are at risk of lung and/or cardiac complications that are specific to the primary disease (ie, emphysema in α-1-antitrypsin deficiency) or occur with increased incidence in certain conditions (ie, ischemic heart disease associated with nonalcoholic steatohepatitis). This article focuses on the epidemiology, clinical presentation, pathogenesis, treatment options, and role of transplantation for lung and heart diseases secondary to liver disease, while also highlighting select liver diseases that directly affect the lungs and heart.

Portopulmonary Hypertension in Liver Disease Presenting in Childhood

OBJECTIVE

Portopulmonary hypertension (POPH) is a known complication of cirrhosis in adults, but there is little information on its incidence and outcome in children with liver disease. We report 14 patients with POPH and present a synthesis of the medical literature.

METHODS

Diagnosis of POPH in the 14 patients was based on right-sided heart catheterization displaying mean pulmonary artery pressure (mPAP) >25 mmHg, indexed pulmonary vascular resistances >3 Wood units · m, and pulmonary wedge pressure <15 mmHg. A literature review added 84 patients.

RESULTS

In our unit, POPH was found in 0.5% of the children with portal hypertension, 0.9% of the children with end-stage liver disease awaiting transplantation, and 3 children with congenital portosystemic shunts (CPSSs). Analysis of 98 reported patients, including the 14 presented here, showed the cause of liver disease to be chronic liver disease or portal cavernoma in 76 instances (34 with a history of surgical portosystemic shunt) and CPSS in 22 instances. There was a precession with proven hypoxemia caused by hepatopulmonary syndrome in 6 patients. Median survival was 3 months in 56 untreated patients. An 80% 5-year probability of survival in 42 patients was treated by CPSS closure, pulmonary vasodilators, and/or liver transplantation. Mean pretransplant mPAP was 34 and 49 mmHg in transplant survivors and nonsurvivors, respectively.

CONCLUSIONS

POPH is a rare but extremely severe complication of childhood liver disease. Portosystemic shunts, whether congenital or acquired, likely play an important causative role. Early diagnosis is crucial and requires systematic screening by echocardiography in children at risk.

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.

What's new in the treatment of portopulmonary hypertension?

Portopulmonary hypertension (POPH) is a complication of portal hypertension characterized by pulmonary vasoconstriction and vascular remodeling that can lead to right heart failure and death. Differentiation of POPH from other causes of pulmonary hypertension, such as volume overload or a hyperdynamic high flow state, is critical because a diagnosis of POPH has significant implications for liver transplant risk stratification, Model for End Stage Liver Disease exception points, and the use of pulmonary arterial hypertension-(PAH) specific therapy. Currently, there are 12 approved medications for the treatment of PAH in the US, and three of these were approved in 2013. This review will discuss the diagnosis, evaluation and management of POPH and the role of recently approved PAH therapies in the treatment of POPH.

"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.

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.

Effect of PAH specific therapy on pulmonary hemodynamics and six-minute walk distance in portopulmonary hypertension: a systematic review and meta-analysis

Background. Little is known about the effect of pulmonary arterial hypertension (PAH) specific therapy on pulmonary hemodynamics and exercise capacity in patients with portopulmonary hypertension (PoPH) because such patients are usually excluded from randomized clinical trials (RCT) of such therapy. Methods. We searched PUBMED using the terms “(Therapy/Broad (filter)) AND (portopulmonary hypertension).” We included studies that met the following criteria: ≥5 patients, AND PoPH confirmed by right heart catheterization (RHC), AND follow-up RHC data, AND/OR baseline and follow-up 6MWD available. Results. 12 studies met our inclusion criteria. None was a RCT. The baseline mPAP was 48.6 ± 4.4 mmHg, cardiac output (CO) 5.6 ± 0.9 L/min, and pulmonary vascular resistance (PVR) 668.6 ± 219.1 dynes.sec/cm⁵. The baseline 6MWD was 348.2 ± 35.6 meters. The use of PAH specific therapy improved mPAP by 7.54 mmHg (95% CI 10.2 to 4.9), CO by 1.77 L/min (95% CI 1.1 to 2.4), and PVR by 253 dynes.sec/cm⁵ (95% CI 291.4 to 214.6) (n = 135) and 6MWD by 61.8 meters (95% CI 47.5 to 76) (n = 122). Conclusions. The use of PAH specific therapy in PoPH results in significant improvement in both pulmonary hemodynamics and 6MWD.

Clinical implications of the hyperdynamic syndrome in cirrhosis

The hyperdynamic syndrome is a late consequence of portal hypertension in cirrhosis. The principal hemodynamic manifestations of the hyperdynamic syndrome are high cardiac output, and increased heart rate and total blood volume, accompanied by reduced total systemic vascular resistance. Pathophysiology involves a complex of humoral and neural mechanisms that can determine hemodynamic changes, and lead to hyperdynamic circulation. In this review we focus our attention on the manifestations of the hyperdynamic syndrome. Some of these are well described and directly related to portal hypertension (varices, ascites, hepatic encephalopathy, and hepatorenal syndrome), while others, such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy, are less known as clinical manifestations related to cirrhosis and, therefore, merit further investigation.

MELD exceptions for portopulmonary hypertension: current policy and future implementation

Since 2006, waitlist candidates with portopulmonary hypertension (POPH) have been eligible for standardized Model for End-Stage Liver Disease (MELD) exception points. However, there are no data evaluating the current POPH exception policy and its implementation. We used Organ Procurement and Transplantation Network (OPTN) data to compare outcomes of patients with approved POPH MELD exceptions from 2006 to 2012 to all nonexception waitlist candidates during this period. Since 2006, 155 waitlist candidates had approved POPH MELD exceptions, with only 73 (47.1%) meeting the formal OPTN exception criteria. Furthermore, over one-third of those with approved POPH exceptions either did not fulfill hemodynamic criteria consistent with POPH or had missing data, with 80% of such patients receiving a transplant based on receiving exception points. In multivariable multistate survival models, waitlist candidates with POPH MELD exceptions had an increased risk of death compared to nonexception waitlist candidates, regardless of whether they did (hazard ratio [HR]: 2.46, 95% confidence interval [CI]: 1.73-3.52; n = 100) or did not (HR: 1.60, 95% CI: 1.04-2.47; n = 55) have hemodynamic criteria consistent with POPH. These data highlight the need for OPTN/UNOS to reconsider not only the policy for POPH MELD exceptions, but also the process by which such points are awarded.