Portopulmonary hypertension and right heart failure in patients with cirrhosis

Portopulmonary hypertension: peculiarities of diagnosis and treatment

Portopulmonary hypertension is defined as the development of pulmonary hypertension secondary to portal one. Its exact prevalence is difficult to determine due to the lack of routine screening in patients with portal hypertension. Hemodynamic changes associated with portal hypertension, including the hyperdynamic state, portosystemic shunts, and splanchnic vasodilation, cause significant disturbances in the pulmonary vasculature and play a key role in the pathogenesis of the disease. Without treatment, portopulmonary hypertension leads to progressive right ventricular failure with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and candidates for liver transplant, right heart catheterization remains the gold standard for disease diagnosis. Treatment of patients with portopulmonary hypertension is aimed at improving cardiac function, reducing pulmonary vascular resistance, and optimizing functional capacity. Pulmonary hypertension-specific therapy, which includes prostacyclin and its receptor agonists, endothelin receptor antagonists, phosphodiesterase inhibitors, and guanylate cyclase stimulators, plays a key role in the treatment of patients with portopulmonary hypertension. Small uncontrolled and recent single randomized controlled trials have reported promising results of vasodilator therapy in terms of clinical and hemodynamic improvement in patients, allowing certain patients to undergo liver transplantation. This review discusses the epidemiology, approach to diagnosis and treatment of patients with portopulmonary hypertension. We used MEDLINE database on the PubMed platform and the Cochrane library to search for literature sources using the keywords: portopulmonary hypertension, portal hypertension, pulmonary hypertension, liver cirrhosis, pulmonary complications.

Mechanisms of Acute Right Ventricular Injury in Cardiothoracic Surgical and Critical Care Settings: Part 2

The right ventricle (RV) is intricately linked in the clinical presentation of critical illness; however, the basis of this is not well-understood and has not been studied as extensively as the left ventricle. There has been an increased awareness of the need to understand how the RV is affected in different critical illness states. In addition, the increased use of point-of-care echocardiography in the critical care setting has allowed for earlier identification and monitoring of the RV in a patient who is critically ill. The first part of this review describes and characterizes the RV in different perioperative states. This second part of the review discusses and analyzes the complex pathophysiologic relationships between the RV and different critical care states. There is a lack of a universal RV injury definition because it represents a range of abnormal RV biomechanics and phenotypes. The term "RV injury" (RVI) has been used to describe a spectrum of presentations, which includes diastolic dysfunction (early injury), when the RV retains the ability to compensate, to RV failure (late or advanced injury). Understanding the mechanisms leading to functional 'uncoupling' between the RV and the pulmonary circulation may enable perioperative physicians, intensivists, and researchers to identify clinical phenotypes of RVI. This, consequently, may provide the opportunity to test RV-centric hypotheses and potentially individualize therapies.

The correlation in echocardiogram to right heart catheterization in identifying pulmonary hypertension as a barrier to liver transplantation

BACKGROUND

Pulmonary hypertension (PH) and portopulmonary hypertension (POPH) can be limitations towards listing for liver transplantation (LT). Our study evaluates the correlation of right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) on transthoracic echocardiogram (TTE) compared to mPAP on right heart catheterization (RHC).

METHODS

We performed a retrospective review of 723 patients who underwent LT evaluation at our institution between 2012 and 2020. Our cohort consisted of patients with RVSP and mPAP measured on TTE. A Wald t-test and area under the curve analysis were used for statistical analyses.

RESULTS

Patients with higher mPAP values on TTE (N=33) did not correlate with mPAP ≥ 35 mmHg on RHC, while patients with higher RVSP values (N=147) on TTE were associated with mPAP ≥ 35 mmHg on RHC. The cutoff value of RVSP ≥ 48 mmHg on TTE was associated with mPAP ≥ 35 mmHg on RHC.

CONCLUSIONS

Our data suggest that RVSP compared to mPAP on TTE is a better indicator for mPAP ≥ 35 mmHg on RHC. RVSP can be used as a marker on echocardiography for identifying patients with a higher likelihood of PH being a barrier to LT listing.

Portopulmonary Hypertension: Management and Liver Transplantation Evaluation

Portopulmonary hypertension (POPH) affects 5% to 6% of patients with advanced liver disease and accounts for 5% to 15% of pulmonary arterial hypertension (PAH) cases. Compared with idiopathic PAH, POPH is associated with significantly worse survival. Recent studies have improved our understanding of the role of both PAH therapy and liver transplantation (LT) in the management of POPH and their impact on overall prognosis. We performed a review of the published literature to summarize the available evidence and guidelines regarding the diagnosis and management of POPH. POPH is defined by the presence of precapillary PH in the context of portal hypertension. POPH is associated with increased perioperative risk at the time of LT, which can be stratified by mean pulmonary arterial pressure and pulmonary vascular resistance. Screening with echocardiography is recommended in all LT candidates to facilitate detection and treatment of POPH. Despite a paucity of evidence, POPH is treated similarly to idiopathic PAH with PAH therapy. These therapies are associated with improved pulmonary hemodynamics and facilitation of safe LT. LT can result in improvement or resolution of POPH in half of patients and has been associated with improved survival in highly selected patients. The prognosis in POPH is poor and is impacted by the severity of both PH and liver disease. Management with a combination of PAH therapy and LT in selected patients has been associated with improved pulmonary hemodynamics and survival.

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.

Mechanisms of the ascites volume differences between patients receiving a left or right hemi-liver graft liver transplantation: From biofluidic analysis

BACKGROUND AND OBJECTIVE

Post-transplant refractory ascites (RA) is common in patients receiving living donor liver transplantation (LDLT) using a left hemi-liver graft than in those using a right hemi-liver graft. However, there is currently no clear mechanism explaining the effect of grafts on ascites drainage. The purpose of this study is to analyze the values of blood flow parameters in the portal vein under different grafts using computational fluid dynamics (CFD) to interpret the relationship between portal pressure values with ascites drainage.

METHODS

In this work, ascites drainage was counted in 30 patients who underwent left-sided liver transplantation and 26 patients who underwent right-sided liver transplantation. The portal vein flow models of the transplanted liver under different flow rates were established based on computed tomography (CT) images and finite element theory. Ascites drainage and blood flow parameters were qualitatively compared.

RESULTS

The results show that the ascites drained from patients who received LDLT with a left hemi-liver is three times as that with a right hemi-liver. The simulation results show that the coefficient of the pressure-velocity curve of the left-liver is 1.7 times of the right-liver under the same hydrodynamic conditions, which qualitatively agrees with the clinical data. Moreover, the streamline of the transplanted left liver shows more vortexes compared with the right liver, which is a major reason for the left liver's higher pressure value.

CONCLUSION

This clinical phenomenon is reproduced and comprehensively explained by the hemodynamic parameters of the portal vein. This work establishes the relationship between portal pressure values and floating water drainage, and offers a new way for physicians to predict postoperative risks intuitively.

Evaluation of right ventricular function during liver transplantation with transesophageal echocardiography

BACKGROUND

The pathophysiology of advanced liver cirrhosis may induce alterations in the circulatory system that may be challenging for the anesthesiologist to manage intraoperatively, and perioperative cardiovascular events are associated with worse outcomes in cirrhotic patients undergoing liver transplantation. It remains controversial whether right ventricular function is impaired during this procedure. Studies using transesophageal echocardiography for quantitative analysis of the right ventricle remain scarce in this setting, yielding conflicting results. The aim of this study was to perform a quantitative assessment of right ventricular function with two parameters derived from transesophageal echocardiography during liver transplantation.

METHODS

Nineteen adult patients of both genders undergoing liver transplantation were evaluated in this observational study. The exclusion criteria were age under 18 or above 65 years old, fulminant hepatic failure, hepatopulmonary syndrome, portopulmonary hypertension, cardiopulmonary disease, and contraindications to the transesophageal echocardiogram. Right ventricular function was assessed at five stages during liver transplantation: baseline, hepatectomy, anhepatic, postreperfusion, and closure by measuring tricuspid annular plane systolic excursion and right ventricular fractional area change obtained with transesophageal echocardiography.

RESULTS

Right ventricular function was found to be normal throughout the procedure. The tricuspid annular plane systolic excursion showed a trend toward a decrease in the anhepatic phase compared to baseline (2.0 ± 0.9 cm vs. 2.4 ± 0.7 cm; P = 0.24) but with full recovery after reperfusion. Right ventricular fractional area change remained nearly constant during all stages studied (minimum: 50% ± 10 at baseline and anhepatic phase; maximum: 56% ± 12 at postreperfusion; P = 0.24).

CONCLUSIONS

Right ventricular function was preserved during liver transplantation at the time points evaluated by two quantitative parameters derived from transesophageal echocardiogram.

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.

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.

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Pulmonary Vascular Complications of Liver Disease

Pulmonary vascular disease is a frequent complication of chronic liver disease and portal hypertension, affecting up to 30% of patients. There are two distinct pulmonary vascular complications of liver disease: hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH). HPS affects 25% of patients with chronic liver disease and is characterized by intrapulmonary vasodilatation and abnormal arterial oxygenation. HPS negatively impacts quality of life and is associated with a 2-fold increased risk of death compared to controls with liver disease without HPS. Angiogenesis, endothelin-1 mediated endothelial dysfunction, monocyte influx, and alveolar type 2 cell dysfunction seem to play important roles in disease pathogenesis but there are currently no effective medical therapies. Fortunately, HPS resolves following liver transplant (LT) with improvements in hypoxemia. POPH is a subtype of pulmonary arterial hypertension (PAH) characterized by an elevated mean pulmonary arterial pressure and pulmonary vascular resistance in the setting of normal left-sided filling pressures. POPH affects 5% to 6% of patients with chronic liver disease. Although the pathogenesis has not been fully elucidated, endothelial dysfunction, inflammation, and estrogen signaling have been identified as key pathways involved in disease pathogenesis. POPH is typically treated with PAH targeted therapy and may also improve with liver transplantation in selected patients. This article highlights what is currently known regarding the diagnosis, management, pathobiology, and outcomes of HPS and POPH. Ongoing research is needed to improve understanding of the pathophysiology and outcomes of these distinct and often misunderstood pulmonary vascular complications of liver disease. © 2021 American Physiological Society. Compr Physiol 11:1-22, 2021.

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.

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.

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.

Transjugular intrahepatic portosystemic shunt (TIPS): current indications and strategies to improve the outcomes

Transjugular intrahepatic portosystemic shunt (TIPS) represents a very effective treatment of complications of portal hypertension. Established indications to TIPS in cirrhotic patients include portal hypertensive bleeding and refractory ascites. Over the years additional indications have been proposed, such as the treatment of vascular disease of the liver, hepatic hydrothorax, hepatorenal syndrome and bleeding from ectopic varices. Indications under evaluation include treatment of portal hypertension prior to major abdominal surgery and treatment of portal vein thrombosis. In spite of these advances, there are still uncertainties regarding the appropriate workup for patients to be scheduled for TIPS. Moreover, prevention and management of post-TIPS complications including hepatic encephalopathy and heart failure are still suboptimal. These issues are particularly relevant considering aging in TIPS candidates in Western countries. Correct selection of patients is mandatory to prevent complications which may eventually frustrate the good hemodynamic results and worsen the patient's quality of life or even life expectancy. The possible role of small diameter TIPS to prevent post-procedural complications is discussed.

Perioperative Management of the Liver Transplant Recipient

Perioperative management of the liver transplant recipient is a team effort that requires close collaboration between intensivist, surgeon, anesthesiologist, hepatologist, nephrologist, other specialists, and hospital staff before and after surgery. Transplant viability must be reassessed regularly and particularly with each donor organ. Regular discussions with patient and family facilitate realistic determinations of goals based on patient aspirations and clinical realities. Early attention to hemodynamics with optimal resuscitation and judicious vasopressor support, respiratory care designed to minimize iatrogenic injury, and early renal support is key. Preoperative and postoperative nutritional support and physical rehabilitation should remain a focus.

The efficacy of serum brain natriuretic peptide for the early detection of portopulmonary hypertension in biliary atresia patients before liver transplantation

Severe portopulmonary hypertension (POPH) is a contraindication for liver transplantation (LT) because of the high risk of postoperative heart failure. The early detection of POPH is important for patients with biliary atresia (BA). Brain natriuretic peptide (BNP) is known to be correlated with liver fibrosis in patients with liver cirrhosis. The aim of this study was to elucidate the efficacy of BNP measurement for the follow-up of patients with BA. Thirty-two patients with BA were identified from September 2011 to December 2016. As indices of liver fibrosis/cirrhosis, APRI (P < .0001), FIB-4 (P < .0001), Child-Pugh score (P < .0001), IV collagen (P = .0005), and hyaluronic acid (P = .0291) had high or moderate correlations with BNP. Patients with splenomegaly, esophageal varices, liver fibrosis, and collateral veins had significantly higher BNP levels than those without. Patients diagnosed with POPH had significantly higher BNP levels in comparison with those patients without (P = .0068). In contrast, PELD/MELD scores showed an almost negligible correlation with the BNP level. LT was successful in 3 asymptomatic BA patients with POPH who had high BNP levels despite the low PELD/MELD scores. In conclusion, routine serum BNP surveillance can be easy to predict asymptomatic POPH. This may help to identify POPH before it reaches a stage that would contraindicate LT.

Morphologic and Functional Changes in Right-Sided Cardiac Chambers in Patients With Chronic Liver Disease and Normal Pulmonary Artery Pressure

OBJECTIVES

To investigate the effects of chronic liver disease (CLD) on the structural and functional characteristics of right-sided heart chambers in patients with normal pulmonary artery pressure.

METHODS

Fifty-one patients with known CLD but without pulmonary hypertension or other cardiovascular conditions were consecutively enrolled, along with 25 age- and sex-matched participants. Patients with CLD were classified according to the Model of End-Stage Liver Disease score and Child-Pugh classification. Right ventricular (RV) and right atrial (RA) dimensions, indices of RV systolic/diastolic function, and myocardial strain were measured by standard echocardiographic methods.

RESULTS

Patients in the study group had similar RV end-diastolic, end-systolic, and RA dimensions compared to controls. Similarly, neither the conventional indices of RV systolic/diastolic function nor the strain imaging findings were different between groups (P > .05). Only RV free wall thickness was significantly higher in the study group (mean ± SD, 4.15 ± 0.64 versus 3.75 ± 0.37 mm; P < .001). Right ventricular end-diastolic diameter (P = .018; r = 0.334) and RA area (P = .017; r = 0.335) had a significant correlation with RV free wall thickness in patients with CLD. Patients treated with beta blockers were found to have a significant reduction in mean RV free wall strain compared to patients who did not receive beta blocker treatment (-20.37 ± 6.6 versus -24.07 ± 6.52; P = .04).

CONCLUSIONS

Patients with CLD had increased RV free wall thickness despite normal systolic pulmonary pressure, presumably secondary to cirrhotic cardiomyopathy. In the absence of pulmonary hypertension, however, cirrhotic cardiomyopathy did not cause impaired RV systolic or diastolic function.

Perioperative management of liver surgery-review on pathophysiology of liver disease and liver failure

An increasing number of patients present for liver surgery. Given the complex pathophysiological changes in chronic liver disease (CLD), it is pivotal to understand the fundamentals of chronic and acute liver failure. This review will give an overview on related organ dysfunction as well as recommendations for perioperative management and treatment of liver failure-related symptoms.

Hospital and intensive care unit management of decompensated pulmonary hypertension and right ventricular failure

Pulmonary hypertension and concomitant right ventricular failure present a diagnostic and therapeutic challenge in the intensive care unit and have been associated with a high mortality. Significant co-morbidities and hemodynamic instability are often present, and routine critical care unit resuscitation may worsen hemodynamics and limit the chances of survival in patients with an already underlying poor prognosis. Right ventricular failure results from structural or functional processes that limit the right ventricle’s ability to maintain adequate cardiac output. It is commonly seen as the result of left heart failure, acute pulmonary embolism, progression or decompensation of pulmonary hypertension, sepsis, acute lung injury, or in the perioperative setting. Prompt recognition of the underlying cause and institution of treatment with a thorough understanding of the elements necessary to optimize preload, cardiac contractility, enhance systemic arterial perfusion, and reduce right ventricular afterload are of paramount importance. Moreover, the emergence of previously uncommon entities in patients with pulmonary hypertension (pregnancy, sepsis, liver disease, etc.) and the availability of modern devices to provide support pose additional challenges that must be addressed with an in-depth knowledge of this disease.

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

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

Hepatopulmonary Syndrome and Portopulmonary Hypertension: Implications for Liver Transplantation

Hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PoPH) represent serious pulmonary complications of advanced liver diseases. Orthotopic liver transplantation (OLT) is capable of completely resolving the underlying abnormalities associated with HPS. On the other hand, post-OLT response in patients with PoPH is less predictable, although heavily influenced by pre-OLT mean pulmonary arterial pressure. It remains the case that the opportunity to reverse 2 potentially fatal organ dysfunctions in the liver and the lung make HPS and PoPH more than worthy for further clinical investigations.

Anesthesia for Liver Transplantation

The provision of anesthesia for a liver transplant program requires a dedicated team of anesthesiologists. Liver transplant anesthesiologists must have an understanding of liver physiology and anatomy; the spectrum of clinical disease associated with liver dysfunction; the impact of warm and cold ischemia times, surgical techniques in liver transplantation, and the impact of ischemia-reperfusion syndrome; and optimal practices to protect the liver. The team must provide a 24-hour service, be actively involved in the selection committee process, and stay current with advances in the subspecialty.

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.

Anesthesia for Patients with Concomitant Hepatic and Pulmonary Dysfunction

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

Consensus conference on TIPS management: Techniques, indications, contraindications

The trans jugular intrahepatic Porto systemic shunt (TIPS) is no longer viewed as a salvage therapy or a bridge to liver transplantation and is currently indicated for a number of conditions related to portal hypertension with positive results in survival. Moreover, the availability of self-expandable polytetrafluoroethylene (PTFE)-covered endoprostheses has dramatically improved the long-term patency of TIPS. However, since the last updated International guidelines have been published (year 2009) new evidence have come, which have open the field to new indications and solved areas of uncertainty. On this basis, the Italian Association of the Study of the Liver (AISF), the Italian College of Interventional Radiology-Italian Society of Medical Radiology (ICIR-SIRM), and the Italian Society of Anesthesia, Analgesia and Intensive Care (SIAARTI) promoted a Consensus Conference on TIPS. Under the auspices of the three scientific societies, the consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Bergamo on June 4th and 5th, 2015. The final statements presented here were graded according to quality of evidence and strength of recommendations and were approved by an independent jury. By highlighting strengths and weaknesses of current indications to TIPS, the recommendations of AISF-ICIR-SIRM-SIAARTI may represent the starting point for further studies.

Current Approach to the Diagnosis and Management of Portopulmonary Hypertension

Portopulmonary hypertension (POPH) is a form of pulmonary arterial hypertension occurring in the setting of portal hypertension with or without hepatic cirrhosis. The presence of both portal and pulmonary vascular disease contributes to complicated hemodynamics and therapeutic challenges, though the severities do not appear to correlate directly. Diagnosis of POPH, and distinction from the commonly observed hyperdynamic state of end-stage liver disease, is typically accomplished with an initial screening transthoracic echocardiogram, followed by right heart catheterization for confirmation of hemodynamic parameters. Though few studies have directly evaluated use in POPH, pulmonary artery-directed therapy is the cornerstone of management, along with consideration of liver transplantation. Perioperative and long-term outcomes are variable, but uniformly worse in the setting of uncontrolled pulmonary pressures. Risk stratification and optimal patient selection for these interventions are areas of ongoing investigation.

Report of the 22nd Annual Congress of the International Liver Transplantation Society

The 2016 Annual Congress of the International Liver Transplantation Society was held in Seoul, South Korea in May. The 22nd Congress marked the largest multidisciplinary liver transplantation meeting in Asia since 2010. The principal themes were living donation, allocation, immunosuppression, machine preservation, novel treatment of hepatitis C, and expansion of the deceased-donor allograft pool. This report presents select abstracts from the scientific sessions within the context of the published literature to serve as a quick reference.

Anesthesia Patients with Concomitant Cardiac and Hepatic Dysfunction

Anesthesia and surgery in patients with hepatic and cardiac dysfunction poses a challenge for anesthesiologists. It is imperative to optimize these patients perioperatively. Cirrhosis is associated with a wide range of cardiovascular abnormalities. Cirrhotic cardiomyopathy is characterized by blunted contractile responsiveness or systolic incompetence, and/or diastolic dysfunction. In liver disease, anesthetic drug distribution, metabolism, and elimination may be altered. Among patients with liver disease, propofol is a reasonable anesthetic choice and cisatracurium is the preferred neuromuscular blocker. Regional anesthesia should be used whenever appropriate if not contraindicated by coagulopathy, because it reduces the need for systemic analgesia.

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.

Transoesophageal echocardiography during liver transplantation

Liver transplantation (LT) has become the standard of care for patients with end stage liver disease. The allocation of organs, which prioritizes the sickest patients, has made the management of liver transplant candidates more complex both as regards their comorbidities and their higher risk of perioperative complications. Patients undergoing LT frequently display considerable physiological changes during the procedures as a result of both the disease process and the surgery. Transoesophageal echocardiography (TEE), which visualizes dynamic cardiac function and overall contractility, has become essential for perioperative LT management and can optimize the anaesthetic management of these highly complex patients. Moreover, TEE can provide useful information on volume status and the adequacy of therapeutic interventions and can diagnose early intraoperative complications, such as the embolization of large vessels or development of pulmonary hypertension. In this review, directed at clinicians who manage TEE during LT, we show why the procedure merits a place in challenging anaesthetic environment and how it can provide essential information in the perioperative management of compromised patients undergoing this very complex surgical procedure.

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.

Meeting report of the 2014 joint international congress of the International Liver Transplantation Society, Liver Intensive Care Group of Europe, and European Liver and Intestinal Association

The 2014 Annual Meeting of the International Liver Transplantation Society was held in London, England. This was the 20th meeting of the Society and was marked by a joint meeting including the European Liver and Intestinal Association as well as the Liver Intensive Care Group of Europe. The meeting included symposia, invited lectures, debates, oral presentations, and posters. The principal themes were living donation, expanding the deceased donor pool, machine preservation, and new oral therapies for hepatitis C virus. This report highlights the scientific discussions of this meeting.

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

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

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

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

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.

Study of liver cirrhosis over ten consecutive years in Southern China

AIM: To investigate the etiology and complications of liver cirrhosis (LC) in Southern China.

METHODS: In this retrospective, cross-sectional study, we identified cases of liver cirrhosis admitted between January 2001 to December 2010 and reviewed the medical records. Patient demographics, etiologies and complications were collected, and etiological changes were illustrated by consecutive years and within two time periods (2001-2005 and 2006-2010). All results were expressed as the mean ± SD or as a percentage. The χ² test or Student’s t-test was used to analyze the differences in age, gender, and etiological distribution, and one-way analysis of variance was applied to estimate the trends in etiological changes. We analyzed the relationship between the etiologies and complications using unconditioned logistic regression, and the risk of upper gastrointestinal bleeding (UGIB) and hepatocellular carcinoma (HCC) in the major etiological groups was evaluated as ORs. A P value less than 0.05 was considered significant. Statistical computation was performed using SPSS 17.0 software.

RESULTS: In this study, we identified 6719 (83.16%) male patients and 1361 (16.84%) female patients. The average age of all of the patients was 50.5 years at the time of diagnosis. The distribution of etiological agents was as follows: viral hepatitis, 80.62% [hepatitis B virus (HBV) 77.22%, hepatitis C virus (HCV) 2.80%, (HBV + HCV) 0.58%]; alcohol, 5.68%; mixed etiology, 4.95%; cryptogenic, 2.93%; and autoimmune hepatitis, 2.03%; whereas the other included etiologies accounted for less than 4% of the total. Infantile hepatitis syndrome LC patients were the youngest (2.5 years of age), followed by the metabolic LC group (27.2 years of age). Viral hepatitis, alcohol, and mixed etiology were more prevalent in the male group, whereas autoimmune diseases, cryptogenic cirrhosis, and metabolic diseases were more prevalent in the female group. When comparing the etiological distribution in 2001-2005 with that in 2006-2010, the proportion of viral hepatitis decreased from 84.7% to 78.3% (P < 0.001), and the proportion of HBV-induced LC also decreased from 81.9% to 74.6% (P < 0.001). The incidence of mixed etiology, cryptogenic cirrhosis, and autoimmune diseases increased by 3.1% (P < 0.001), 0.5% (P = 0.158), and 1.3% (P < 0.001), respectively. Alcohol-induced LC remained relatively steady over the 10-year period. The ORs of the development of UGIB between HBV and other major etiologies were as follows: HCV, 1.07; alcohol, 1.89; autoimmune, 0.90; mixed etiology, 0.83; and cryptogenic, 1.76. The ORs of the occurrence of HCC between HBV and other major etiologies were as follows: HCV, 0.54; alcohol, 0.16; autoimmune, 0.05; mixed etiology, 0.58; and cryptogenic, 0.60.

CONCLUSION: The major etiology of liver cirrhosis in Southern China is viral hepatitis. However, the proportions of viral hepatitis and HBV are gradually decreasing. Alcoholic LC patients exhibit a greater risk of experiencing UGIB, and HBV LC patients may have a greater risk of HCC.

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

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Living-donor liver transplantation for congenital biliary atresia with porto-pulmonary hypertension and moderate or severe pulmonary arterial hypertension: Kyoto University experience

Porto-pulmonary hypertension with moderate or severe pulmonary arterial hypertension (PAH) is viewed as a contraindication to liver transplantation (LT) because of associated poor outcomes; however, patients with biliary atresia (BA) are generally good candidates for LT. Ten patients with moderate/severe PAH underwent living-donor liver transplantation (LDLT) at our institution; eight of these patients had BA and were the focus of this study. Preoperative therapies, including prostaglandin (PG)I2 , were introduced. When mean pulmonary arterial pressure (mPAP) after treatment was <40 mmHg or initial mPAP without therapy was <35 mmHg, we performed an acute volume challenge test to evaluate right ventricular function. LDLT was performed when mPAP after anesthetic induction was confirmed at ≤35 mmHg. Six patients had favorable responses to preoperative treatment and catheter testing, but two patients showed poor responses. The two patients with poor responses had poor clinical courses with unstable mPAP after LDLT. The other six patients had successful courses with well-controlled mPAP, and PGI2 was withdrawn or weaned following LDLT. Survival did not significantly differ between the eight BA recipients with moderate/severe PAH and 77 age-matched BA recipients without PAH from the same time period. LDLT has major benefits for BA patients with well-controlled PAH.

Portopulmonary hypertension and hepatopulmonary syndrome

Portopulmonary hypertension (POPH) and hepatopulmonary syndrome (HPS) are two frequent complications of liver disease, with prevalence among liver transplant candidates of 6% and 10%, respectively. Both conditions result from a lack of hepatic clearance of vasoactive substances produced in the splanchnic territory. Subsequently, these substances cause mainly pulmonary vascular remodeling and some degree of vasoconstriction in POPH with resulting elevated pulmonary pressure and right ventricular dysfunction. In HPS the vasoactive mediators cause intrapulmonary shunts with hypoxemia. Medical treatment is disappointing overall. Whereas liver transplantation (LT) results in the disappearance of HPS within six to twelve months, its effect on POPH is highly unpredictable. Modern strategies in managing HPS and POPH rely on a thorough screening and grading of the disease’s severity, in order to tailor the appropriate therapy and select only the patients who will benefit from LT. The anesthesiologist plays a central role in managing these high-risk patients. Indeed, the important hemodynamic and respiratory modifications of the perioperative period must be avoided through continuation of the preoperatively initiated drugs, appropriate intraoperative monitoring and proper hemodynamic and respiratory therapies.

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

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

Portopulmonary hypertension

Portopulmonary hypertension (POPH) is the presence of pulmonary arterial hypertension in patients with portal hypertension. Among liver transplant (LT) candidates, reported incidence rates of POPH range from 4.5% to 8.5%. In patients with LT, intraoperative death and immediate post-LT mortality are feared clinical events when transplantation is attempted in the setting of untreated, moderate to severe POPH; therefore, POPH precludes LT unless the mean pulmonary artery pressure can be reduced to a safe level and right ventricular function optimized. Specific pulmonary artery vasodilator medications seem effective in reducing pulmonary artery pressures and improving right ventricular function and survival.

Management of portopulmonary hypertension: New perspectives

Portopulmonary hypertension (PPHTN) is a known complication of cirrhosis. Moderate-to-severe PPHTN implies an extremely poor prognosis. It occurs in 5%-10% of patients referred for liver transplantation (LT), and probably with an higher incidence in patients with large portosystemic shunts. Patients with moderate-to-severe pulmonary hypertension have been previously excluded from LT because of the extremely high surgical risk and since the post-transplant outcome reported was poor. Recently, new perspectives in the management of patients with portopulmonary hypertension are emerging. In fact, some pulmonary vasoactive drugs have become routine in the treatment of patients with idiopathic pulmonary hypertension. These drugs, particularly epoprostenol, have been recently introduced in the treatment of patients with PPHTN, and have been shown to be effective in reducing pulmonary artery pressure as well as pulmonary vascular resistances. Furthermore, recent studies seem to demonstrate that treatment with pulmonary vasoactive drugs could allow liver transplantation with acceptable surgical risks and excellent survival. Although there are not large series nor prospective studies addressing this topic, the clinical scenario of patients with PPHTN seems to be positively changing.

Advances in transplantation 1940-2014

The history of medicine is that what was inconceivable yesterday and barely achievable today often becomes routine tomorrow. Liver transplantation began with almost no resources at the same time as the tentative first steps were taken to land a man on the moon. Because human lives would be at stake, both objectives had a sacramental element from the outset: a solemnly binding commitment to perfection. The gift of an organ is really a gift of life, and something as valuable as a life-saving organ is more important to a suffering patient than wealth or power. The concept of a team approach to the care of the transplant patient is an important factor in the development of a successful program. This has resulted in recipient survival rates reaching 90% at one year.