Hepatopulmonary syndrome and portopulmonary hypertension: a report of the multicenter liver transplant database

Successful Anesthesia Management of Pediatric Living Donor Liver Transplant With Mild Bilateral Pulmonary Artery Stenosis Due to Alagille Syndrome: A Case Report

Alagille syndrome is an autosomal-dominantinherited disease characterized by intrahepatic bile duct involvement, congenital heart disease, eye anomalies, skeletal and central nervous system involvement, kidney anomalies, and facial appearance. Liver transplant is the only treatment option for patients with end-stage liver disease and Alagille syndrome. Bilateral peripheral pulmonary artery stenosis is a contraindication for liver transplant due to high mortality, and the decision for liver transplant in patients with bilateral peripheral pulmonary artery stenosis is extremely challenging for anesthesiologists andtransplant surgeons.Wepresent a 2-year-oldfemale patient with successful anesthetic management of a pediatric living donor liver transplant with mild bilateral pulmonary artery stenosis, mild aortic stenosis, and mitral regurgitation due to Alagille syndrome. Anesthesiologists should know the underlying pathophysiological condition and perform a comprehensive preoperative evaluation to determine the correct anesthesia plan in patients with Alagille syndrome who will undergo liver transplants to treat multiple system disorders. Successful perioperative management of Alagille syndrome requires effective communication and collaboration between specialists through a multidisciplinary team approach.

Outcomes of liver transplantation for hepatopulmonary syndrome in patients with concomitant respiratory disease

BACKGROUND & AIMS

Concomitant respiratory disease is a common finding in patients with hepatopulmonary syndrome (HPS). Among patients who underwent liver transplantation (LT) for HPS, we compared characteristics and outcome of patients with versus without concomitant respiratory disease.

METHODS

This single center retrospective observational study included patients with HPS who underwent LT between 1999 and 2020.

RESULTS

During the study period, 32 patients with HPS received a LT; nine (28%) with concomitant respiratory disease of whom one required a combined lung-liver transplantation. Patients with concomitant respiratory disease had higher PaCO2 (38 vs. 33 mm Hg, p = .031). The 30-day postoperative mortality was comparable, but the estimated cumulative probability of resolution of oxygen therapy after LT in HPS patients with versus those without concomitant respiratory disease was lower: 63% versus 91% at 12 months and 63% versus 100% at 18 months (HR 95% CI .140-.995, p = .040). In addition to the presence of concomitant respiratory disease (p = .040), history of smoking (p = .012), and high baseline 99mTcMAA shunt fraction (≥20%) (p = .050) were significantly associated with persistent need of oxygen therapy. The 5-year estimated cumulative probability of mortality in patients with concomitant respiratory disease was worse: 50% versus 23% (HR 95% CI .416-6.867, p = .463).

CONCLUSIONS

The presence of a concomitant respiratory disease did not increase the short-term postoperative mortality after LT in patients with HPS. However, it resulted in a longer need for oxygen therapy.

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.

Temporal Trends in Portopulmonary Hypertension Model for End-stage Liver Disease Exceptions and Outcomes

Model for end-stage liver disease (MELD) exception criteria for portopulmonary hypertension (POPH) were created to prioritize patients for liver transplant before POPH progression. Little is known about trends in POPH exception frequency, disease severity, pulmonary hypertension treatment patterns, or outcomes since the POPH MELD exception began.

Incidental finding of elevated pulmonary arterial pressures during liver transplantation and postoperative pulmonary complications

BACKGROUND

In patients with end stage liver disease (ESLD) scheduled for liver transplantation (LT), an intraoperative incidental finding of elevated mean pulmonary arterial pressure (mPAP) may be observed. Its association with patient outcome has not been evaluated. We aimed to estimate the effects of an incidental finding of a mPAP > 20 mmHg during LT on the incidence of pulmonary complications.

METHODS

We examined all patients who underwent a LT at Paul-Brousse hospital between January 1,2015 and December 31,2020. Those who received: a LT due to acute liver failure, a combined transplantation, or a retransplantation were excluded, as well as patients for whom known porto-pulmonary hypertension was treated before the LT or patients who underwent a LT for other etiologies than ESLD. Using right sided pulmonary artery catheterization measurements made following anesthesia induction, the study cohort was divided into two groups using a mPAP cutoff of 20 mmHg. The primary outcome was a composite of pulmonary complications. Univariate and multivariable logistic regression analyses were performed to identify variables associated with the primary outcome. Sensitivity analyses of multivariable models were also conducted with other mPAP cutoffs (mPAP ≥ 25 mmHg and ≥ 35 mmHg) and even with mPAP as a continuous variable.

RESULTS

Of 942 patients who underwent a LT, 659 met our inclusion criteria. Among them, 446 patients (67.7%) presented with an elevated mPAP (mPAP of 26.4 ± 5.9 mmHg). When adjusted for confounding factors, an elevated mPAP was not associated with a higher risk of pulmonary complications (adjusted OR: 1.16; 95%CI 0.8-1.7), nor with 90 days-mortality or any other complications. In our sensitivity analyses, we observed a lower prevalence of elevated mPAP when increasing thresholds (235 patients (35.7%) had an elevated mPAP when defined as ≥ 25 mmHg and 41 patients (6.2%) had an elevated mPAP when defined as ≥ 35 mmHg). We did not observe consistent association between a mPAP ≥ 25 mmHg or a mPAP ≥ 35 mmHg and our outcomes.

CONCLUSION

Incidental finding of elevated mPAP was highly prevalent during LT, but it was not associated with a higher risk of postoperative complications.

Prevalence and prognostic impact of hepatopulmonary syndrome in patients with unresectable hepatocellular carcinoma undergoing transarterial chemoembolization: a prospective cohort study

BACKGROUND

To determine the prevalence and prognostic impact of hepatopulmonary syndrome (HPS) in patients with unresectable hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE).

METHODS

Fifty-four patients with unresectable HCC undergoing TACE between December 2014 and December 2015 were prospectively screened for HPS and were followed up for a maximum of 2 years or until the end of this prospective study.

RESULTS

Nineteen of the 54 (35.2%) patients were considered to have HPS, including one (5.3%) with severe HPS, nine (47.4%) with moderate HPS, and nine (47.4%) with mild HPS. The median overall survival (OS) was 10.1 (95% confidence interval [CI], 3.9-16.3) months for patients with HPS and 15.1 (95% CI, 7.3-22.9) months for patients without HPS, which is not a significant difference ( P  = 0.100). The median progression-free survival was also not significantly different between patients with and without HPS (5.2 [95% CI, 0-12.8] vs. 8.4 [95% CI, 3.6-13.1] months; P  = 0.537). In the multivariable Cox regression analyses, carbon monoxide diffusing capacity (hazard ratio [HR] = 1.033 [95% CI, 1.003-1.064]; P  = 0.028) and Child-Pugh class (HR = 1.815 [95% CI, 1.011-3.260]; P  = 0.046) were identified to be the independent prognostic factors of OS.

CONCLUSION

Mild or moderate HPS is common in patients with unresectable HCC undergoing TACE, but it does not seem to have a significant prognostic impact.

Cardiac risk stratification of the liver transplant candidate: A comprehensive review

Cardiovascular diseases (CVD) form a principal consideration in patients with end-stage liver disease (ESLD) undergoing evaluation for liver transplant (LT) with prognostic implications in the peri- and post-transplant periods. As the predominant etiology of ESLD continues to evolve, addressing CVD in these patients has become increasingly relevant. Likewise, as the number of LTs increase by the year, the proportion of older adults on the waiting list with competing comorbidities increase, and the demographics of LT candidates evolve with parallel increases in their CVD risk profiles. The primary goal of cardiac risk assessment is to preemptively reduce the risk of cardiovascular morbidity and mortality that may arise from hemodynamic stress in the peri- and post-transplant periods. The complex hemodynamics shared by ESLD patients in the pre-transplant period with adverse cardiovascular events occurring in only some of these recipients continue to challenge currently available guidelines and their uniform applicability. This review focusses on cardiac assessment of LT candidates in a stepwise manner with special emphasis on preoperative patient optimization. We hope that this will reinforce the importance of cardiovascular optimization prior to LT, prevent futile LT in those with advanced CVD beyond the stage of optimization, and thereby use the finite resources prudently.

The Edge of Unknown: Postoperative Critical Care in Liver Transplantation

Perioperative care of patients undergoing liver transplantation (LT) is very complex. Metabolic derangements, hypothermia, coagulopathy and thromboses, severe infections, and graft dysfunction can affect outcomes. In this manuscript, we discuss several perioperative problems that can be encountered in LT recipients. The authors present the most up-to-date information regarding predicting and treating hemodynamic instability, coagulation monitoring and management, postoperative ventilation strategies and early extubation, management of infections, and ESLD-related pulmonary complications. In addition, early post-transplant allograft dysfunction will be discussed.

Hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a pulmonary vascular complication of liver disease, which adversely affects prognosis. The disease is characterised by intrapulmonary vascular dilatations and shunts, resulting in impaired gas exchange. A complex interaction between the liver, the gut and the lungs, predominately impacting pulmonary endothelial cells, immune cells and respiratory epithelial cells, is responsible for the development of typical pulmonary alterations seen in HPS. Liver transplantation is the only therapeutic option and generally reverses HPS. Since the implementation of the model for end-stage liver disease (MELD) standard exception policy, outcomes in patients with HPS have been significantly better than they were in the pre-MELD era. This review summarises current knowledge and highlights what’s new regarding the diagnosis and management of HPS, and our understanding of pathogenesis based on experimental models and translational studies.

Mending the Model for End-Stage Liver Disease: An in-depth review of the past, present, and future portopulmonary hypertension Model for End-Stage Liver Disease exception

Patients with portopulmonary hypertension (POPH) have an increased cardiovascular and overall mortality risk when undergoing liver transplantation (LT). However, such risk is not captured in their Model for End-Stage Liver Disease (MELD) laboratory score. POPH MELD exception criteria were established in 2006 with the aim of prioritizing these patients for LT prior to pulmonary hypertension (PH) progression and eventual right heart failure. The original criteria emphasized a posttreatment, pre-LT mean pulmonary arterial pressure (mPAP) of <35 mm Hg and pulmonary vascular resistance (PVR) <400 dynes-s-cm^-5 or <5 Wood units (WU). Since 2006, there have been important advances in the treatment of POPH with pulmonary arterial hypertension (PAH)-targeted therapies and newer evidence regarding LT outcomes and risk factors for perioperative mortality. Specifically, PVR rather than mPAP has been shown to be more strongly associated with outcomes, including mortality. In addition, among treated patients with POPH, mPAP may be persistently elevated related to an elevated cardiac output or other factors that do not necessarily reflect POPH disease severity. Thus, in February 2021, the Organ Procurement and Transplantation Network approved proposed modifications to POPH MELD exception criteria, now allowing either of the following posttreatment, pre-LT hemodynamic profiles: mPAP less than 35 mm Hg and posttreatment PVR less than 400 dynes-s-cm^-5 (or less than 5 WU) or mPAP greater than or equal to 35 mm Hg and less than 45 mm Hg and posttreatment PVR less than 240 dynes-s-cm^-5 (or less than 3 WU). This article reviews the history of the POPH MELD exception criteria, describes the recent modifications to the exception criteria and the evidence supporting them, and highlights unanswered questions and areas for future research.

Evaluation of pulmonary arterial stiffness and comparison with right ventricular functions in patients with cirrhosis preparing for liver transplantation

OBJECTIVE

Pulmonary complications are common in patients with liver cirrhosis. Devolopment of pulmonary hypertension (PH) is associated with a poor prognosis in these patients. Pulmonary arterial stiffness (PAS) is considered an early sign of pulmonary vascular remodeling. The aim of this study is to investigate PAS and compare it with right ventricular (RV) functions in patients with cirrhosis who are scheduled for liver transplantation.

METHODS

The study included 52 cirrhosis patients (mean age 51.01 ± 12.18 years, male gender 76.9%) who were prepared for liver transplantation and 59 age and sex matched (mean age 51.28 ± 13.63 years, male gender 62.7%) healthy individuals. Patients with left ventricular ejection fraction (LVEF) less than 55%, ischemic heart disease, more than mild valvular heart disease, chronic pulmonary disease, congenital heart disease, rheumatic disease, moderate to high echocardiographic PH probability, rhythm or conduction disorders on electrocardiography were excluded from the study. In addition to conventional echocardiographic parameters, PAS value, pulmonary vascular resistance (PVR) and RV ejection efficiency was calculated by the related formulas with transthoracic echocardiography (TTE).

RESULTS

Demographic characteristics and cardiovascular risk factors of the groups were similar. PAS, PVR, and sPAP values were found to be significantly higher in the patient group (20.52 ± 6.52 and 13.73 ± 2.05; 1.43 ± 0.15 and 1.27 ± 0.14; 27.69 ± 3.91 and 23.37 ± 3.81 p < 0.001, respectively). RV FAC and RV Ee were significantly lower and RV MPI was significantly higher in the patient group (45.31 ± 3.85 and 49.66 ± 3.62, p < 0.001; 1.69 ± 0.35 and 1.85 ± 0.23, p = 0.005; 0.39 ± 0.07 and 0.33 ± 0.09, p = 0.001, respectively). PAS was significantly correlated with RV FAC and MPI (r = -0.423, p < 0.001; r = 0.301, p = 0.001, respectively).

CONCLUSIONS

Increased PAS in cirrhosis patients may be associated with early pulmonary vascular involvement. Evaluation of RV functions is important to determine the prognosis in these patients. FAC, MPI, and RV Ee measurements instead of TAPSE or RV S' may be more useful in demonstrating subclinical dysfunction. The correlation of PAS with RV FAC and MPI may indicate that RV subclinical dysfunction is associated with early pulmonary vascular remodeling in patients with liver cirrhosis.

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.

A Case of Severe Tricuspid Valve Regurgitation in a Patient Undergoing Orthotopic Liver Transplantation: Whether to Proceed, or Not

A 38-year-old male presented for orthotopic liver transplantation complicated by new-onset torrential tricuspid regurgitation before incision. Subclinical volume overload and functional tricuspid regurgitation created a challenging scenario in which the benefits of expeditious transplant were weighed against the risks of allograft congestion and failure. Intraoperative transesophageal echocardiography proved critical in diagnosing severe tricuspid regurgitation and guided clinical decision making. In this article, we describe the intraoperative presentation of acutely elevated right heart pressures and the subsequent management of this patient prior to ultimately successful liver transplantation.

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.

Ratio of Mixed Venous Oxygen Saturation-to-Pulmonary Capillary Wedge Pressure: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

BACKGROUND

Hemodynamic values from right heart catheterization aid diagnosis and clinical decision-making but may not predict outcomes. Mixed venous oxygen saturation percentage and pulmonary capillary wedge pressure relate to cardiac output and congestion, respectively. We theorized that a novel, simple ratio of these measurements could estimate cardiovascular prognosis.

METHODS

We queried Veterans Affairs' databases for clinical, hemodynamic, and outcome data. Using the index right heart catheterization between 2010 and 2016, we calculated the ratio of mixed venous oxygen saturation-to-pulmonary capillary wedge pressure, termed ratio of saturation-to-wedge (RSW). The primary outcome was time to all-cause mortality; secondary outcome was 1-year urgent heart failure presentation. Patients were stratified into quartiles of RSW, Fick cardiac index (CI), thermodilution CI, and pulmonary capillary wedge pressure alone. Kaplan-Meier curves and Cox proportional hazards models related comparators with outcomes.

RESULTS

Of 12 019 patients meeting inclusion criteria, 9826 had values to calculate RSW (median 4.00, interquartile range, 2.67-6.05). Kaplan-Meier curves showed early, sustained separation by RSW strata. Cox modeling estimated that increasing RSW by 50% decreases mortality hazard by 19% (estimated hazard ratio, 0.81 [95% CI, 0.79-0.83], P<0.001) and secondary outcome hazard by 28% (hazard ratio, 0.72 [95% CI, 0.70-0.74], P<0.001). Among the 3793 patients with data for all comparators, Cox models showed RSW best associated with outcomes (by both C statistics and Bayes factors). Furthermore, pulmonary capillary wedge pressure was superior to thermodilution CI and Fick CI. Multivariable adjustment attenuated without eliminating the association of RSW with outcomes.

CONCLUSIONS

In a large national database, RSW was superior to conventional right heart catheterization indices at assessing risk of mortality and urgent heart failure presentation. This simple calculation with routine data may contribute to clinical decision-making in this population.

ICU and Hospital Outcomes in Patients with Hepatopulmonary Syndrome Undergoing Liver Transplantation

PURPOSE

There are limited data regarding hospital and intensive care unit (ICU) outcomes in patients with hepatopulmonary syndrome (HPS) following liver transplantation (LT).

METHODS

Data were retrospectively collected from consecutive HPS adult patients who underwent LT and were immediately admitted to the ICU at three transplant centers with shared management protocols, from 2002 to 2018. Demographic, clinical, surgical, laboratory, and outcome data were extracted.

RESULTS

We identified 137 patients (74 male, 54%), with a median age at LT of 58 years (IQR: 52-63). One hundred and 31 (95.6%) patients were admitted to the ICU on invasive mechanical ventilation (MV). The median time on invasive MV in the ICU was 12 hours (IQR: 5-28) and 97 patients (74%) were extubated within 24 hours of ICU admission. The median highest positive end expiratory pressure and fraction of inspired oxygen (FiO₂) were 7 (IQR: 5-8) and 0.6 (IQR: 0.5-0.7), respectively. 7 patients (5%) developed severe post-transplant hypoxemia. Of all patients, 42 (30.4%) required vasopressors and the median ICU and hospital length of stay (LOS) were 3 (IQR: 1-5) and 10 (IQR: 7-20) days, respectively. The in-hospital mortality rate was 3.6% (5/137). HPS severity was not associated with hospital mortality.

CONCLUSION

Most HPS patients have short durations of MV, ICU, and hospital LOS post-LT. HPS severity does not impact hospital mortality.

Pulmonary Vascular Resistance Predicts Mortality and Graft Failure in Transplantation Patients With Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is a pulmonary vascular disease associated with significant morbidity and mortality in those with liver disease, conferring a higher mortality in patients awaiting liver transplantation (LT). Although not a transplant indication, patients with POPH can experience significant clinical improvement following LT, and those maintaining a mean pulmonary artery pressure (MPAP) <35mm Hg and a pulmonary vascular resistance (PVR) <5 Woods units (WU) are granted additional listing points to expedite LT. The effect of POPH on posttransplant outcomes such as mortality and graft failure, however, is not well defined. We performed a retrospective cohort study of the US Organ Procurement and Transplantation Network database of all adult patients who underwent LT between January 1, 2006, and December 1, 2020. Using adjusted accelerated failure time models, we examined the relationship between a diagnosis of POPH and outcomes following LT and the relationship between pre-LT hemodynamics and post-LT survival (alive with a functioning graft) in patients with POPH. Compared with those undergoing transplants without exception points, patients with POPH had comparable post-LT survival rates but were significantly more likely to have graft failure. Both pre-LT MPAP and PVR predicted post-LT survival in POPH, with a pre-LT PVR of ≥1.6 WU, more than doubling the hazard for mortality (death or a nonfunctioning graft; coefficient, 2.01; standard error, 0.85; hazard ratio, 2.21; P = 0.02). POPH may confer a significantly higher risk of post-LT graft failure compared with patients with cirrhosis without POPH, and a pre-LT PVR of ≥1.6 WU may predict post-LT survival. Further investigation into the relationship between pre-LT hemodynamics, right ventricular function, and post-LT outcomes of mortality and graft failure in POPH is needed.

Supine vs upright exercise in patients with hepatopulmonary syndrome and orthodeoxia: study protocol for a randomized controlled crossover trial

BACKGROUND

The hepatopulmonary syndrome (HPS) is a pulmonary complication of liver disease found in 10 to 32% of patients with cirrhosis and is characterized by intrapulmonary vascular dilatations and abnormal oxygenation. Liver transplantation is the only effective therapy for this disease. Patients with HPS have significant exercise limitations, impacting their quality of life and associated with poor liver transplant outcomes. Many patients with HPS exhibit orthodeoxia-an improvement in oxygenation in the supine compared to the upright position. We hypothesize that exercise capacity will be superior in the supine compared to the upright position in such patients.

METHODS

We propose a randomized controlled crossover trial in patients with moderate HPS (PaO₂ < 80 mmHg) and orthodeoxia (supine to upright PaO₂ decrease > 4 mmHg) comparing the effect of supine vs upright position on exercise. Patients with pulmonary hypertension, FEV1/FVC ratio < 0.65, significant coronary artery disease, disorders preventing or contraindicating use of a cycle ergometer, and/or moderate or severe ascites will be excluded. Participants will be randomized to cycle ergometry in either the supine or upright position. After a short washout period (a minimum of 1 day to a maximum of 4 weeks), participants will crossover and perform an exercise in the alternate position. Exercise will be performed at a constant work rate of 70-85% of the predicted peak work rate until the "stopping time" is reached, defined by exhaustion, profound desaturation, or safety concerns (drop in systolic blood pressure or life-threatening arrhythmia). The primary outcome will be the difference in the stopping time between exercise positions, compared with a repeated measures analysis of variance method with a mixed effects model approach. The model will be adjusted for period effects. P < 0.05 will be considered statistically significant.

DISCUSSION

HPS patients have hypoxemia leading to significant exercise limitations. If our study is positive, a supine exercise regimen could become a routine prescription for patients with HPS and orthodeoxia, enabling them to exercise more effectively. Future studies could explore the corresponding effects of a supine exercise training regimen on physiologic variables such as long-term exercise capacity, quality of life, dyspnea, and liver transplantation outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration and Results System (PRS) NCT04004104 . Registered on 1 July 2019.

The Prognostic Role of Right Ventricular Stroke Work Index during Liver Transplantation

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan–Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12–1.36, p < 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15–1.37, p < 0.001). Kaplan–Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

Impact of hypoxemia on pediatric liver transplantation for hepatopulmonary syndrome

BACKGROUND

The treatment of choice for patients with cirrhosis and HPS is LT. The clinical manifestations associated with hypoxemia result in limitations and a poor health-related quality of life of affected patients. The present report aims to study the differences in outcomes between patients with PaO₂  < 50 mm Hg and those with PaO₂  ≥ 50 mm Hg.

METHODS

This was a retrospective study of 21 patients under 18 years of age conducted from 2001 to 2018; the patients were divided into 2 groups: G1-PaO₂  ≥ 50 mm Hg, 11 patients, and G2-PaO₂  < 50 mm Hg, 10 patients. Demographic, clinical, laboratory, and perioperative data; outcome variables; and post-transplant survival were compared between the groups.

RESULTS

In total, 2/11 (18.2%) patients in G1 and 8/10 (80%) patients in G2 required supplemental oxygen therapy at home (P = .005). Patients in G2 required prolonged MV (median 8.5 days in G2 vs 1 day in G1, P = .015) and prolonged ICU and hospital stays (P = .002 and P = .001, respectively). Oxygen weaning time was longer in G2 (median 127.5 days) than in G1 (median 3 days; P = .004). One (9.1%) patient in G1 and three (30%) patients in G2 died (P = .22). The survival at 90 months was 90.9% in G1 and 70% in G2 (P = .22).

CONCLUSION

The survival between groups was similar. Patients with very severe HPS required a longer MV time, longer ICU and hospital stays, and a longer O₂ weaning time than those with mild, moderate, or severe HPS.

Outcomes of liver transplantation in patients with hepatopulmonary syndrome in the pre and post-MELD eras: A systematic review

BACKGROUND

The lack of large hepatopulmonary syndrome cohorts undergoing liver transplantation (LT) has resulted in limited information about post-LT outcomes and expectations.

METHODS

The long and short-term outcomes of LT in patients with hepatopulmonary syndrome (HPS) were evaluated before and after the implementation of Model for Endstage Liver Disease (MELD) score in 2002, granting exception points for patients with HPS. PubMed/Medline, Embase, Web of Science and Scopus databases were searched for published and unpublished studies from 01/1990 to 04/2019. Studies that included HPS patients who underwent LT and reported post-LT outcomes and HPS severity were reviewed. After reviewing the full text of 1421 articles, 30 were included in the pre-MELD era (before 2002) and 60 in the post-MELD era.

RESULTS

A total of 598 patients (210 children and 388 adults) with HPS who underwent LT were included in this systematic review. In children, 5-year survival probability was similar in the pre and post-MELD groups (85.7% vs. 97.4; p = 0.09). Median post-transplant PaO2 in room air was higher in the post-MELD group (71 [53-87] vs. 97 [80-108] mmHg: p = 0.008). In adults, 5-year survival probability was higher in the post-MELD era (73 vs. 87.3%; p = 0.008). Median post-transplant PaO2 in room air was higher in post-MELD group (75 [63-85] vs. 87 [75-95] mmHg; p = 0.001)..

CONCLUSIONS

After MELD exception implementation, survival rates and post-transplant oxygenation improved in adult patients with HPS who underwent liver transplantation, whereas only post-transplant oxygenation improved in children.

Portopulmonary hypertension: prognosis and management in the current treatment era - results from the REHAP registry

BACKGROUND

Portopulmonary hypertension (PoPH) is a rare condition with poorer survival compared to idiopathic/familial pulmonary arterial hypertension (IPAH/FPAH).

AIMS

To compare the characteristics, survival, prognostic factors and management of PoPH and IPAH/FPAH patients and to assess the impact of treatment on survival of PoPH patients.

METHODS

Analysis of data of prevalent and incident PoPH patients enrolled in the Spanish registry of PAH (REHAP) from January 1998 to December 2017 and comparison with IPAH/FPAH patients. Variables analysed: patient and disease (PAH and liver) characteristics, first-line PAH-targeted therapy, causes of death, prognostic factors and survival (according to aetiology and treatment in PoPH patients).

RESULTS

Compared to IPAH/FPAH patients (n = 678), patients with PoPH (n = 237) were predominantly men, older and had better functional class and higher prevalence of ascites. Haemodynamics were better. Biomarkers for heart failure were worse. Age- and sex-adjusted 5-year survival rate from diagnosis was 49.3% for PoPH patients and 68.7% for IPAH patients (P < 0.001). Treated PoPH had better survival than non-treated. PAH- and liver-related causes accounted for 30.2% and 24.7% of deaths in PoPH patients. PoPH patients were less likely to receive first-line PAH-targeted therapy and this was associated with greater mortality. Increasing age, worse exercise capacity and ascites were independent prognostic factors of poorer survival; first-line oral monotherapy was associated with improved survival. Eight (3.4%) PoPH patients underwent liver transplantation.

CONCLUSIONS

PoPH patients are undertreated and show poorer survival than IPAH/FPAH patients. First-line treatment with PAH-targeted therapy was associated with better survival. Presence of ascites was a predictor of mortality.

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

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

The clinical characteristics, treatment, and survival of portopulmonary hypertension in Japan

Background

Portopulmonary hypertension (PoPH) refers to the simultaneous presentation of pulmonary arterial and portal hypertension. However, few reports have included the characteristics and treatments for patients with PoPH of Asian population; thus, we investigated the clinical characteristics, treatment, and survival of these patients in a Japanese cohort.

Methods

Pulmonary arterial hypertension (PAH) has been included in the National Research Project on Intractable Disease in Japan; therefore, we extracted data of patients with PoPH from the forms of newly registered cases of the project from 2012 to 2013 (for 2 years), and updated cases of the project in 2013 (Study 1, n = 36 newly registered forms, n = 46 updated forms). Additionally, for Study 2, we performed a retrospective, observational cohort study at Chiba University Hospital (n = 11). We compared the characteristics between patients with PoPH and those with idiopathic/heritable PAH (I/H-PAH).

Results

Both studies showed higher cardiac outputs (COs) and cardiac indexes (CIs), lower pulmonary vascular resistance (PVR), and less treated with combination therapy in patients with PoPH than those with I/H-PAH. In Study 2, the overall and disease-specific survival between PoPH and I/H-PAH were similar. Conversely, many patients (45%) had to change their PAH-specific medicine because of adverse effects.

Conclusion

As seen in western countries, Japanese patients with PoPH showed higher COs and CIs, better exercise tolerance, and lower PVRs than patients with I/H-PAH. Further studies are needed to improve PoPH treatments.

Keeping Patients with End-Stage Liver Disease Alive While Awaiting Transplant: Management of Complications of Portal Hypertension

Complications of portal hypertension such as gastroesophageal variceal hemorrhage, ascites, and spontaneous bacterial peritonitis, as well as pulmonary complications, are often responsible for diminished quality of life, excess morbidity and mortality, increased health care resource use and expenditure, and dropout from the liver transplant (LT) waiting list. Therefore, the care of LT candidates on the waiting list must be centered on anticipation and prompt intervention for these complications.

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.

High-flow nasal cannula oxygen therapy: Alternative respiratory therapy for severe post-transplant hypoxemia in children with hepatopulmonary syndrome

Severe post-transplant hypoxemia, which is defined as <50 mm Hg of the partial pressure of oxygen in arterial blood/fraction of inspired oxygen (P/F) ratio, is a major post-operative complication with high mortality rates in patients with hepatopulmonary syndrome (HPS). Non-invasive positive pressure ventilation therapy and mechanical ventilation are options for respiratory support of patients with severe post-transplant hypoxemia. However, these therapies are associated with several problems, such as compliance, ventilator-associated pneumonia, and lung injury. We here firstly described two children with HPS who developed severe post-transplant hypoxemia (lowest post-operative P/F ratio, 49.7 and 34.0 mm Hg, respectively) that was successfully managed with high-flow nasal cannula (HFNC) oxygen therapy and vasodilation drugs without adverse complications or necessity of reintubation. We consider that HFNC oxygen therapy could become a safe alternative respiratory therapy or be added to the other such as inhaled nitric oxide (iNO), methylene blue (MB), inhaled epoprostenol, embolization of abnormal pulmonary vessels, and combination of iNO and MB for severe post-transplant hypoxemia in children with HPS.

Outcomes of Liver Transplantation in Treated Portopulmonary Hypertension Patients With a Mean Pulmonary Arterial Pressure ≥35 mm Hg

Portopulmonary hypertension (POPH), pulmonary arterial hypertension (PAH) that develops in the setting of portal hypertension, affects 5%–6% of patients with liver disease and is associated with significant morbidity and mortality. A mean pulmonary arterial pressure (mPAP) threshold of 35 mm Hg is used to stratify perioperative risk and liver transplant eligibility in treated POPH patients but does not take into account the specific factors that contribute to the pressure elevation.

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.

Pulmonary Complications in Candidates for Liver Transplantation

The liver plays a pivotal role in maintaining the homeostasis of various organ systems. Also, end-stage liver disease and its complications are major causes of morbidity and mortality among adults. Individuals who develop a chronic liver disease are at increased risk of progression to multi-organ dysfunction, including the pulmonary system. The clinical complications of pulmonary problems related to the presence of liver disease range from mild (such as hypoxemia) to life-threatening diseases (such as portopulmonary hypertension and hepatopulmonary syndrome). Herein, the major pulmonary complications related to liver cirrhosis and considerations for performing liver transplantation are reviewed.

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.

Pharmacologic therapy for pulmonary artery hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is a disease that carries a significant mortality left untreated. This article aims to review pharmacotherapeutics for PAH.

RECENT FINDINGS

PAH-specific therapies have evolved over the last three decades and have expanded from one therapy in the 1990s to 14 FDA-approved medications. Current therapies are directed at restoring the imbalance of vasoactive mediators that include nitric oxide, endothelin and prostacyclin. Although these agents are effective as monotherapy, recent trials have promulgated the strategy of upfront combination therapy. The availability of oral prostacyclin agonists has also allowed for expanded treatment options. Risk assessment is vital in guiding therapy for PAH patients. There is ongoing focus on targeting pathological mechanisms of the disease via novel therapies and repurposing existing drugs.

SUMMARY

There is an array of medications available for the treatment of PAH. Prudent combination of therapies to maximize treatment effect can improve morbidity and mortality. This article reviews the data supporting these therapies and attempts to outline an approach to patient management.

Pulmonary Complications in Patients with Liver Cirrhosis

Patients with advanced chronic liver diseases, particularly with decompensated liver cirrhosis, can develop specific pulmonary complications independently of any pre-existing lung disease. Especially when dyspnea occurs in combination with liver cirrhosis, patients should be evaluated for hepato-pulmonary syndrome (HPS), porto-pulmonary hypertension (PPHT), hepatic hydrothorax and spontaneous bacterial empyema, which represent the clinically most relevant pulmonary complications of liver cirrhosis. Importantly, the pathophysiology, clinical features, diagnosis and the corresponding therapeutic options differ between these entities, highlighting the role of specific diagnostics in patients with liver cirrhosis who present with dyspnea. Liver transplantation may offer a curative therapy, including selected cases of HPS and PPHT. In this review article, we summarize the pathogenesis, clinical features, diagnostic algorithms and treatment options of the 4 specific pulmonary complications in patients with liver cirrhosis.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Current Status and Implications for Liver Transplantation

PURPOSE OF REVIEW

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) are both pulmonary vascular complications of advanced liver disease; however, these syndromes have distinct pathophysiology, clinical implications, and management.

RECENT FINDINGS

While both conditions are associated with portal hypertension, HPS results from diffuse pulmonary capillary vasodilation and PoPH results from vasoconstriction and vascular remodeling of pulmonary arteries. In HPS, no medical therapies clearly improve outcomes; however, patients have excellent post-LT outcomes with near uniform reversal of hypoxemia. In PoPH, several medical therapies used in idiopathic pulmonary hypertension have been shown improve pulmonary hemodynamics, symptoms, and potentially LT outcomes; however, further study is needed to determine best treatment regimens, long-term outcomes on medical therapy, and role of LT.

SUMMARY

While HPS results in severe hypoxemia that is usually reversible by LT, PoPH patients develop progressive pulmonary hypertension that may improve with medical therapy.

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.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Management in Liver Transplantation in the Horizon 2020

Hepatopulmonary syndrome (HPS) is characterized by intrapulmonary microvasculature dilatation that causes intrapulmonary shunting and leads to a gas exchange abnormality in the presence of liver diseases, which is the most common cause of respiratory insufficiency in these patients. HPS doubles the risk of death, and liver transplantation (LT) is the only curative therapeutic option so it should be considered in patients with severe HPS, with excellent survival rates post-LT. However, pretransplant Pao₂ <45 mm Hg has been associated with an increase in post-transplant morbidity and mortality, but it does not imply a contraindication for LT. The resolution of HPS usually occurs within 6 months post-LT, but it can take 1 year. Portopulmonary hypertension (PoPH) is defined as pulmonary arterial hypertension (PAH) that develops in the setting of portal hypertension with or without liver disease in the absence of other causes of PAH. The prevalence of PoPH is 5% to 10% among liver transplant (LT) candidates. The impact of LT on PoPH is unpredictable. Therefore, despite conferring a high morbidity and mortality, PoPH itself is not an indication for liver transplantation. It may be considered a contraindication for LT in severe cases.

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.

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.

A 44-Year-Old Woman With Sudden Breathlessness, Tightness in Chest, and Hypotension After Extubation in the Early Postoperative Period After Liver Transplantation

CASE PRESENTATION

A 44-year-old woman with Child-Pugh class C cirrhosis due to primary biliary cirrhosis and mild portopulmonary syndrome received a liver transplant. Her basal catheterization showed a mean pulmonary arterial pressure (mPAP) of 28 mm Hg, pulmonary artery occlusion pressure (PAOP) of 8 mm Hg, pulmonary vascular resistance (PVR) of 307 dynes.s.cm^-5, and a cardiac output of 5.2 L/min. The echocardiogram did not reveal right ventricular dilatation (mid-diameter of 34 mm). In surgery, hemodynamic assessment showed an mPAP of 25 mm Hg, PAOP of 6 mm Hg, PVR of 262 dynes.s.cm^-5 and cardiac output of 5.8 L/min. During the anhepatic period, the patient required norepinephrine (0.4 μg/kg/min) but had no complications during reperfusion; throughout surgery, her mPAP was never > 30 mm Hg. At the end of surgery, the brain natriuretic peptide level was 66 pg/mL (< 100 pg/mL). One day following transplantation, the patient remained hemodynamically stable and was therefore weaned from mechanical ventilation. However, 6 h following extubation, she reported breathlessness and tightness in chest, and developed sudden arterial hypotension, oxygen desaturation, and oliguria.

Thermodilution vs Estimated Fick Cardiac Output Measurement in Clinical Practice: An Analysis of Mortality From the Veterans Affairs Clinical Assessment, Reporting, and Tracking (VA CART) Program and Vanderbilt University

Importance

Thermodilution (Td) and estimated oxygen uptake Fick (eFick) methods are widely used to measure cardiac output (CO). They are often used interchangeably to make critical clinical decisions, yet few studies have compared these approaches as applied in medical practice.

Objectives

To assess agreement between Td and eFick CO and to compare how well these methods predict mortality.

Design, Setting, and Participants

This investigation was a retrospective cohort study with up to 1 year of follow-up. The study used data from the Veterans Affairs Clinical Assessment, Reporting, and Tracking (VA CART) program. The findings were corroborated in a cohort of patients cared for at Vanderbilt University, an academic referral center. Participants were more than 15 000 adults who underwent right heart catheterization, including 12 232 in the Veterans Affairs cohort between October 1, 2007, and September 30, 2013, and 3391 in the Vanderbilt cohort between January 1, 1998, and December 31, 2014.

Exposures

A single cardiac catheterization was performed on each patient with CO estimated by both Td and eFick methods. Cardiac output was indexed to body surface area (cardiac index [CI]) for all analyses.

Main Outcomes and Measures

All-cause mortality over 90 days and 1 year after catheterization.

Results

Among 12 232 VA patients (mean [SD] age, 66.4 [9.9] years; 3.3% female) who underwent right heart catheterization in this cohort study, Td and eFick CI estimates correlated modestly (r = 0.65). There was minimal mean difference (eFick minus Td = -0.02 L/min/m2, or -0.4%) but wide 95% limits of agreement between methods (-1.3 to 1.3 L/min/m2, or -50.1% to 49.4%). Estimates differed by greater than 20% for 38.1% of patients. Low Td CI (<2.2 L/min/m2 compared with normal CI of 2.2-4.0 L/min/m2) more strongly predicted mortality than low eFick CI at 90 days (Td hazard ratio [HR], 1.71; 95% CI, 1.47-1.99; χ2 = 49.5 vs eFick HR, 1.42; 95% CI, 1.22-1.64; χ2 = 20.7) and 1 year (Td HR, 1.53; 95% CI, 1.39-1.69; χ2 = 71.5 vs eFick HR, 1.35; 1.22-1.49; χ2 = 35.2). Patients with a normal CI by both methods had 12.3% 1-year mortality. There was no significant additional risk for patients with a normal Td CI but a low eFick CI (12.9%, P = .51), whereas a low Td CI but normal eFick CI was associated with higher mortality (15.4%, P = .001). The results from the Vanderbilt cohort were similar in the context of a more balanced sex distribution (46.6% female).

Conclusions and Relevance

There is only modest agreement between Td and eFick CI estimates. Thermodilution CI better predicts mortality and should be favored over eFick in clinical practice.

Changes in arterial oxygenation after portal decompression in Budd-Chiari syndrome patients with hepatopulmonary syndrome

OBJECTIVES

To evaluate the changes in arterial oxygenation after portal decompression in Budd-Chiari syndrome (BCS) patients with hepatopulmonary syndrome (HPS).

METHODS

From June 2014 to June 2015, all patients with BCS who underwent balloon angioplasty or transjugular intrahepatic portosystemic shunt (TIPS) creation at our institution were eligible for inclusion in this study. Arterial blood gas analysis was performed with the patient in an upright position and breathing room air at 2-3 days and 1 and 3 months after the procedure.

RESULTS

Eleven patients with HPS and 14 patients without HPS were included in this study. The procedure was technically successful in 24 patients. One patient with HPS had technically unsuccessful TIPS creation. Reobstruction or TIPS dysfunction was not detected in any patient within 3 months after the procedure. For patients with HPS, the alveolar-arterial oxygen gradient (A-aO2) remained comparable to baseline 2-3 days after the procedure (-3.2 ± 11.9 mmHg; p = .412), significantly improved 1 month after the procedure (-11.7 ± 6.4 mmHg; p < .001), and then returned to baseline 3 months after the procedure (-1.3 ± 12.5 mmHg; p = .757). For patients without HPS, the A-aO2 remained comparable to baseline at all three time points after the procedure (+1.4 ± 8.3 mmHg, +3.5 ± 8.1 mmHg, and +1.3 ± 8.2 mmHg; p = .543, p = .137, and p = .565).

CONCLUSIONS

Arterial oxygenation transiently improves after portal decompression in BCS patients with HPS.

KEY POINTS

• Intrapulmonary vascular dilation and hepatopulmonary syndrome are common in patients with Budd-Chiari syndrome. • Arterial oxygenation transiently improves after portal decompression in Budd-Chiari syndrome patients with hepatopulmonary syndrome.

Time-dependent reversal of significant intrapulmonary shunt after liver transplantation

BACKGROUND/AIMS

Although the association between intrapulmonary shunt (IPS) and liver cirrhosis is clear, data of repeated contrast echocardiography (CE) before and after liver transplantation (LT) to evaluate factors associated with IPS are limited.

METHODS

Hand-agitated saline was used for CE and, by assessing left-chamber opacification, IPS was classified as grade 0 to 4. Grade 3/4 constituted significant IPS and hepatopulmonary syndrome (HPS) was defined as significant IPS with the arterial partial pressure of oxygen < 70 mmHg.

RESULTS

Before LT, 253 patients underwent CE and the frequency of significant IPS and HPS were 44% (n = 112) and 7% (n = 17), respectively. Child-Pugh score (odds ratio [OR], 1.345; 95% confidence interval [CI], 1.090 to 1.660; p = 0.006) and arterial oxygen content (OR, 0.838; 95% CI, 0.708 to 0.991; p = 0.039) were independent determinants of significant IPS, whereas direct bilirubin (OR, 1.076; 95% CI, 1.012 to 1.144; p = 0.019) was the only variable associated with HPS. Among 153 patients who underwent successful LT, repeated CE was performed in 97 (63%), which showed significant reductions in IPS grade (from 2.6 ± 1.0 to 1.2 ± 1.3, p < 0.001) and the prevalence of significant IPS (from 56% to 20%, p = 0.038). After adjustment for pre-LT IPS grade, time from LT to repeated CE presented negative linear relationship with post-LT IPS grade (r 2 = 0.366, p < 0.001) and was the only determinant of post-LT IPS grade (OR, 1.009; 95% CI, 1.003 to 1.014; p = 0.004).

CONCLUSION

Repeated CE is useful to evaluate intrapulmonary vascular change before and after LT. Reversal of IPS after successful LT is time-dependent and follow-up duration should be considered for accurate assessment of IPS after LT.