Portopulmonary hypertension

Pulmonary hypertension due to high cardiac output

Pulmonary hypertension (PH) is usually associated with a normal or decreased cardiac output (CO). Less commonly, PH can occur in the context of a hyperdynamic circulation, characterized by high CO (>8 L/min) and/or cardiac index ≥4 L/min/m² in the setting of a decreased systemic vascular resistance. PH due to high CO can occur due to multiple conditions and in general remains understudied. In this review article we describe the pathophysiology, etiology, diagnosis, hemodynamic characteristics, and management of PH in the setting of high CO. It is important to recognize this distinct entity as PH tends to improve with treatment of the underlying etiology and PH specific therapies may worsen the hemodynamic state.

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.

Portopulmonary Hypertension: From Bench to Bedside

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

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

BACKGROUND AND AIMS

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

APPROACH AND RESULTS

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

CONCLUSIONS

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

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.

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

BACKGROUND

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

CASE SUMMARY

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

CONCLUSION

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

Hepatopulmonary Disorders: Gas Exchange and Vascular Manifestations in Chronic Liver Disease

This review concentrates on the determinants of gas exchange abnormalities in liver-induced pulmonary vascular disorders, more specifically in the hepatopulmonary syndrome. Increased alveolar-arterial O₂ difference, with or without different levels of arterial hypoxemia, and reduced diffusing capacity represent the most characteristic gas exchange disturbances in the absence of cardiac and pulmonary comorbidities. Pulmonary gas exchange abnormalities in the hepatopulmonary syndrome are unique encompassing all three pulmonary factors determining arterial PO₂ , that is, ventilation-perfusion imbalance, increased intrapulmonary shunt and oxygen diffusion limitation that, combined, interplay with two relevant nonpulmonary determinants, that is, increased total ventilation and high cardiac output. Behind the complexity of this lung-liver association there is an abnormal pulmonary vascular tone that combines inhibition of hypoxic pulmonary vasoconstriction with a reduced (or blunted) hypoxic vascular response. The pathology and pathobiology include the presence of intrapulmonary vascular dilatations with or without pulmonary vascular remodeling, i.e. angiogenesis. Liver transplantation, the only effective therapeutic approach to successfully improve and resolve the vast majority of complications induced by the hepatopulmonary syndrome, along with a large list of frustrating pharmacologic interventions, are also reviewed. Another liver-induced pulmonary vascular disorder with less gas exchange involvement, such as portopulmonary hypertension, is also considered. © 2018 American Physiological Society. Compr Physiol 8:711-729, 2018.

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.

Relationship between portopulmonary hypertension and splenectomy: Mayo Clinic experience and review of published works

AIM

Portopulmonary hypertension is a serious complication of portal hypertension that can lead to right heart failure and death. To our knowledge, an association between portopulmonary hypertension and prior splenectomy has not been described previously. The goals of this study were to describe the frequency of splenectomy in portopulmonary hypertension and compare selected parameters between portopulmonary hypertension subgroups.

METHODS

This is a retrospective analysis of patients diagnosed with portopulmonary hypertension between 1 January 1988 and 30 June 2015 at Mayo Clinic (Rochester, MN, USA). We compared age, sex, right ventricle systolic pressure by echocardiography, and right heart catheterization measurements/calculations among subgroups of portopulmonary hypertension patients with splenectomy and/or autoimmune liver disease (autoimmune hepatitis/primary biliary cirrhosis/primary sclerosing cholangitis).

RESULTS

The cohort consisted of 141 patients, of whom 8 (6%) had a history of splenectomy prior to the development of portopulmonary hypertension. Twenty-seven (19%) portopulmonary hypertension patients had autoimmune liver disease, and 5 of 8 (62.5%) splenectomized portopulmonary hypertension patients had autoimmune liver disease. No significant difference was noted in right heart catheterization measurements/calculations between splenectomized and non-splenectomized portopulmonary hypertension patients. Right ventricle systolic pressure by echocardiography was significantly higher in those splenectomized.

CONCLUSIONS

Prior history of splenectomy in portopulmonary hypertension was 6% in this cohort. The combination of autoimmune liver disease and splenectomy in portopulmonary hypertension was not uncommon. History of splenectomy in patients with portal hypertension and/or autoimmune liver disease may have clinical implications.

Acute right ventricular failure after orthotopic liver transplantation

The interdependence between the heart and liver in maintaining hemodynamic stability during the perioperative period of either orthotopic heart (OHT) or liver (OLT) transplantation is important. The pre-transplant hemodynamic changes that occur in patients with end-stage liver disease (ESLD) can include decreased systemic vascular resistance, poor ventricular response to stress and increased cardiac output (CO). Concomitant pulmonary disorders are often present in ESLD. Portopulmonary hypertension (PoPHTN) is an important marker for increased mortality in liver transplant patients. The pathophysiologic mechanisms specific to PoPHTN have been compared with other known forms of pulmonary hypertension, including primary pulmonary hypertension, and has been found to fall within a spectrum of disorders related to factors both due to intrinsic liver failure [with resultant portal hypertension and hepatopulmonary syndrome (HPS)] as well as pulmonary vascular remodeling. We present a 47-year-old Caucasian female with ESLD secondary to non-alcoholic steatohepatitis and HPS. Our current case demonstrates the difficulty in managing patients with acute pulmonary hypertension after OLT. Review of the contemporary literature demonstrated a total of eight case reports of post-transplant severe pulmonary hypertension thought to be due to a combination of either HPS or PoPHTN. This case highlights the complexities of patient management in the acute setting after OLT. Furthermore, it demonstrates the intricate role of careful preoperative evaluation and screening in patients undergoing workup for solid organ transplantation.

A review of long-term outcome and quality of life of patients after Kasai operation surviving with native livers

Biliary atresia (BA) is a rare neonatal cholestatic disease which leads to progressive obliterative cholangiopathy, resulting in biliary obstruction and jaundice. The standard surgical treatment is hepatoportoenterostomy (Kasai operation). Although approximately 50% of the affected infants would require liver transplantation within the first 2 years of life, the other 50% of the patients can live for years with their native liver, despite the progression of cirrhosis and chronic liver disease. Many of these patients will be affected by long-term complications such as repeated cholangitis, portal hypertension, variceal bleeding, growth problems, biochemical abnormalities, and hepatic osteodystrophy. These morbidities impose a huge impact on the quality of life of the patients and their families. Herein, we performed a comprehensive review on the clinical status and quality of life of long-term survivors of biliary atresia with their native livers, to facilitate meticulous longitudinal follow-up of these patients, and alert caregivers the probable complications to be aware of.

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.

Perioperative Care of the Liver Transplant Patient

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

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

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

Portopulmonary hypertension

Portopulmonary hypertension (PoPH) refers to the condition that pulmonary arterial hypertension (PAH) occur in the stetting of portal hypertension. The development of PoPH is thought to be independent of the severity of portal hypertension or the etiology or severity of liver disease. PoPH results from excessive vasoconstriction, vascular remodeling, and proliferative and thrombotic events within the pulmonary circulation that lead to progressive right ventricular failure and ultimately to death. Untreated PoPH is associated with a poor prognosis. As PoPH is frequently asymptomatic or symptoms are generally non-specific, patients should be actively screened for the presence of PoPH. Two-dimensional transthoracic echocardiography is a useful non-invasive screening tool, but a definitive diagnosis requires invasive hemodynamic confirmation by right heart catheterization. Despite a dearth of randomized, prospective data, an ever-expanding clinical experience shows that patients with PoPH benefit from therapy with PAH-specific medications including with endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and/or prostanoids. Due to high perioperative mortality, transplantation should be avoided in those patients who have severe PoPH that is refractory to medical therapy.

Portopulmonary hypertension in liver transplant candidates

Pulmonary vascular disorders including portopulmonary hypertension (PoPHT) are among the common complications of liver disease and are prognostically significant. Survival is very low without medical treatment and liver transplantation. With advances in medical therapy for elevated pulmonary artery pressure (PAP) and liver transplant surgery, survival of patients with PoPHT and advanced liver disease is significantly improved. Because of the prognostic significance of PoPHT and the limited donor pool, a comprehensive preoperative cardio-pulmonary assessment is of great importance in cirrhotic patients prior to transplant surgery. Therefore, a detailed transthoracic Doppler echocardiographic examination must be an essential component of this evaluation. Patients with mild PoPHT can safely undergo liver transplant surgery. In cases of moderate to severe PoPHT, right heart catheterization (RHC) should be performed. In patients with moderate to severe PoPHT on RHC (mean PAP 35-45 mmHg), vasodilator therapy should be attempted. Liver transplantation should be encouraged in cases that demonstrate a positive response. Bridging therapy with specific pulmonary arterial hypertension treatment agents should be considered until the transplant surgery and should be continued during the peri- and post-operative periods as needed.

Portopulmonary Hypertension in Liver Disease Presenting in Childhood

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A review of differences in cirrhosis between men and women and characteristics of cirrhosis in females

There are differences in the disease susceptibility, natural history of liver disease, complications and treatment response between females and males with cirrhosis. Pre-menopausal status for female patients is protective against viral hepatitis C, non-alcoholic steatohepatitis and primary biliary cirrhosis. Smoking accompanied with drinking is a strong risk factor for cirrhosis and malignancies in women with chronic liver disease. Pregnancy increases the incidence of variceal hemorrhage and hepatic encephalopathy in patients with cirrhosis. The choice of contraceptive measures between patients with liver cirrhosis and normal people is the same. The selection of drugs and surgical treatment in female patients with liver cirrhosis before and after pregnancy complications have obvious differences. The organ distribution of model for end-stage liver disease (MELD) scoring system is detrimental to female patients, but the introduction of new drugs for viral hepatitis C is expected to change this difference.

What do we take consideration in the patient who has an unpredicted severe portopulmonary hypertension in liver transplantation?: a case report

Severe portopulmonary hypertension (PPHT) is considered a contraindication for liver transplantation (LT) because of the associated high mortality and poor prognosis. We report the case of a 57-year-old cirrhotic woman with severe PPHT (mean pulmonary artery pressure [mPAP] > 65 mmHg), who underwent a successful living donor LT. Intra-operative use of inhaled iloprost, milrinone, dobutamine, and postoperative use of inhaled nitric oxide and oral sildenafil failed to lower the pulmonary artery pressure (PAP). The patient responded only to nitroglycerin and drainage of massive ascites. Meticulous intra-operative volume control, which included minimizing blood loss and subsequent transfusion, was carried out. The use of vasopressors, which may have elevated the PAP, was strictly restricted. Intra-operative PAP did not show an increase, and the hemodynamics was maintained within relatively normal range, compared to the preoperative state. The patient was discharged without any complications or related symptoms.

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.