Pulmonary hypertension as a predictor of postoperative complications and mortality after liver transplantation

A review of liver dysfunction in the lung transplant patient

Liver dysfunction is an increasingly common finding in patients evaluated for lung transplantation. New or worsening dysfunction in the perioperative period, defined by presence of clinical ascites/encephalopathy, high model for end-stage liver disease (MELD) score, and/or independent diagnostic criteria, is associated with high short- and long-term mortality. Therefore, a thorough liver function assessment is necessary prior to listing for lung transplant. Unfortunately, identification and intraoperative monitoring remain the only options for prevention of disease progression with isolated lung transplantation. Combined lung and liver transplantation may provide an option for definitive long-term management in selecting patients with known liver disease at high risk for postoperative progression. However, experience with the combined operation is extremely limited and indications for combined lung and liver transplant remain unclear. Herein, we present a comprehensive literature review of patients with liver dysfunction undergoing lung transplantation with and without concurrent liver transplant in an effort to illuminate the risks, benefits, and clinical judgement surrounding decision to pursue combined lung-liver transplantation (CLLT). We also argue description of liver function is currently a weakness of the current lung allocation scoring system. Additional algorithms incorporating liver function may aid in risk stratification and decision to pursue combined transplantation.

Clinical Outcomes after Liver Transplantation in Patients with Portopulmonary Hypertension

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Liver transplantation and cardiac illness: Current evidences and future directions

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

The early outcomes of candidates with portopulmonary hypertension after liver transplantation

Background

Portopulmonary hypertension (PPH) was once regarded as a contraindicaton to liver transplantation (LT). However, growing evidence has indicated that PPH patients undergoing LT may show similar outcomes compared to those without PPH, and researchers have recommended it not be an absolute contraindication. Given this controversy, we aimed to identify and review the current evidence on this topic and to provide a comparison of the outcomes after LT between candidates with PPH and those without.

Methods

We systematically searched the MEDLINE, EMBASE and Cochrane Library databases for all studies that compared the outcomes of PPH patients and those without PPH after LT. All studies reporting outcomes of PPH patients versus those without PPH (Control) were further considered for inclusion in this meta-analysis. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to compare the pooled data between PPH and Control groups.

Results

Eleven retrospective trials and one prospective, randomized, controlled trial, involving 37,686 transplant recipients were included. The PPH patients had increased 1-year mortality with an OR of 1.59 (95% CI = 1.26–2.01, P = 0.0001) compared to the control group. There was no significant difference in graft loss and 30-day mortality after LT between the two groups.

Conclusions

Patients with PPH who underwent LT had increased 1-year mortality compared to those without PPH, while graft loss and 30-day mortality were similar. Nevertheless, LT may be a reasonable therapeutic option for some patients with PPH, but further studies are needed to identify those select patients with PPH who would benefit most from LT.

Electronic supplementary material

The online version of this article (10.1186/s12876-018-0797-8) contains supplementary material, which is available to authorized users.

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

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

Pulmonary Hypertension Improves After Orthotopic Liver Transplant in Patients With Chronic Liver Disease

OBJECTIVES

Pulmonary hypertension is a common finding in chronic liver disease patients that has prognostic significance. In this study, we aimed to evaluate the prevalence and severity of pulmonary hypertension in patients undergoing orthotopic liver transplant. We also evaluated pulmonary artery pressure changes after transplant surgery.

MATERIALS AND METHODS

The records of adult patients with chronic liver disease who underwent orthotopic liver transplant at our center between 2004 and 2015 were retrospectively evaluated. Clinical and demographic variables and laboratory data were noted. Transthoracic Doppler echocardiographic examination reports were obtained. Using continuous-wave Doppler examination, systolic pulmonary artery pressure values were calculated. Pulmonary hypertension was defined as systolic pulmonary artery pressure ≥ 30 mm Hg. Among 208 adult patients who underwent orthotopic liver transplant, 203 who had Doppler echocardiographic examination were enrolled.

RESULTS

The mean age of patients was 42.1 ± 14.1 years (range, 16-67 y), and 143 (70.4%) were men. During preoperative assessment, pulmonary hypertension was identified in 47 patients (23.2%), of whom 10 displayed systolic pulmonary artery pressure > 50 mm Hg. Compared with preoperative values of systolic pulmonary artery pressure (46.8 ± 8.4 mm Hg), a significant reduction in mean values (to 39.3 ± 13.3 mm Hg) was observed postoperatively (P = .007).

CONCLUSIONS

The findings of this study indicate that pulmonary hypertension is a common finding in adult chronic liver disease patients undergoing orthotopic liver transplant. A significant improvement occurs in systolic pulmonary artery pressure values following transplant surgery. Regarding the prevalence and prognostic significance of pulmonary hypertension, all patients with chronic liver disease should be evaluated with transthoracic Doppler echocardiography before transplant.

High-resolution CT findings of pulmonary infections after orthotopic liver transplantation in 453 patients

OBJECTIVES

The objective of this study was to review the high-resolution CT (HRCT) findings in patients with pulmonary infection after orthotopic liver transplantation (OLT) and to determine distinguishing findings among the various types of infection.

METHODS

This study included 453 consecutive liver transplant recipients with pulmonary infection, on whom HRCT of the chest was performed within 24 h of the beginning of symptoms and for whom proven diagnosis had taken place within 1 week of the onset of symptoms. Two radiologists analysed the CT images; final decisions regarding the findings were reached by consensus.

RESULTS

Bacterial and viral pneumonia made up the bulk of infections (63.4% and 29.4%, respectively), followed by fungal infiltrates (24.5%). Large nodules were most common in patients with fungal pneumonia, having been seen in 38 (54%) of the 70 patients with fungal pneumonia, 22 (10%) of 220 with bacterial pneumonia (p=0.0059) and 6 (8%) of 78 with viral pneumonia (p=0.0011). The halo sign was also more frequent in patients with fungal pneumonia, having been seen in 38 (54%) of the 70 patients with fungal pneumonia, 17 (8%) of 220 with bacterial pneumonia (p=0.0026) and 7 (9%) of 78 with viral pneumonia (p=0.0015). There was no statistically significant difference in the prevalence of the other HRCT patterns including air-space consolidation, ground-glass attenuation and small nodules among bacterial, viral and fungal infections (all p>0.05).

CONCLUSION

The presence of large nodules with the halo sign is most suggestive of fungal infection after OLT. Other HRCT patterns are not helpful in distinguishing among the various types of infection seen in liver transplant recipients.

Anesthetic considerations for the patient with liver disease

PURPOSE OF REVIEW

An increasing number of patients requiring surgery are presenting with chronic or end stage liver disease. The management of these patients demands anesthesiologists with in-depth knowledge of the consequences of hepatic dysfunction, the effects on other organs, the risk of surgery, and the impact of anesthesia.

RECENT FINDINGS

Chronic or end stage liver disease is associated with an increased risk of perioperative morbidity and mortality. It is essential to preoperatively assess possible hepatic encephalopathy, pleural effusions, hepatopulmonary syndrome, hepatopulmonary hypertension, hepatorenal syndrome, cirrhotic cardiomyopathy, and coagulation disorders. The application of two scoring systems, that is, Child-Turcotte-Pugh and model for end stage liver disease, helps to estimate the risk of surgery. The use of propofol is superior to benzodiazepines as intravenous narcotics. Although enflurane and halothane are discouraged for maintenance of anesthesia, all modern volatile anesthetics appear comparable with respect to outcome. Fentanyl, sufentanil, and remifentanil as opioids and cis-atracurium for relaxation may be the best choices in liver insufficency. Regional anesthesia is valuable for postoperative pain management.

SUMMARY

Current studies have employed different anesthetic approaches in the preoperative and intraoperative management in order to improve outcomes of patients with liver disease.