Hepatopulmonary Syndrome with Right-to-left Shunt in Cirrhotic Patients Using Macro-Aggregated Albumin Lung Perfusion Scan: Comparison with Contrast Echocardiography and Association with Clinical Data

Hepatopulmonary Syndrome: A Comprehensive Review

Hepatopulmonary syndrome (HPS) is defined by abnormally dilated blood vessels and shunts within the lungs, leading to impaired oxygen exchange. This condition results from intricate interactions between the liver, the gastrointestinal system, and the lungs. This complex system primarily affects pulmonary endothelial, immunomodulatory, and respiratory epithelial cells. Consequently, this contributes to pathological pulmonary changes characteristic of HPS. A classification system based on the severity of oxygen deficiency has been proposed for grading the physiological dysfunction of HPS. Contrast-enhanced echocardiography is considered the primary radiological evaluation for identifying abnormal blood vessel dilations within the lungs, which, combined with an elevated alveolar-arterial gradient, is essential for making the diagnosis. Liver transplantation is the sole effective definitive treatment that can reverse the course of the condition. Despite often being symptomless, HPS carries a significant risk of mortality before transplantation, regardless of the severity of liver disease. Meanwhile, there is varying data regarding survival rates following liver transplantation. The adoption of the model for end-stage liver disease (MELD) standard exception policy has notably improved the results for individuals with HPS compared to the period before MELD was introduced. This review offers a summary of the present understanding, highlighting recent advancements in the diagnosis and treatment of HPS. Furthermore, it aims to augment comprehension of the condition's fundamental mechanisms through insights derived from experimental models and translational research.

LTSI Consensus Guidelines: Preoperative Pulmonary Evaluation in Adult Liver Transplant Recipients

The relationship between chronic liver disease and respiratory symptoms and hypoxia is well recognized. Over the last century, three pulmonary complications specific to chronic liver disease (CLD) have been characterized: hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. Apart from that coexisting pulmonary disease like chronic obstructive lung disease and interstitial lung disease also complicate the outcomes after liver transplantation (LT). Assessment for evaluation of underlying pulmonary disorders is essential to improve outcomes in patients with CLD, posted for LT. This consensus guideline of the Liver Transplant Society of India (LTSI) provides a comprehensive review of pulmonary issues in CLD, related and unrelated to underlying liver disease and gives recommendations for pulmonary screening in specific clinical scenarios in adults with chronic liver disease planned for LT. This document also aims to standardize the strategies for preoperative evaluation of these pulmonary issues in this subset of patients. Proposed recommendations were based on selected single case reports, small series, registries, databases, and expert opinion. The paucity of randomized, controlled trials in either of these disorders was noted. Additionally, this review will highlight the lacunae in our current evaluation strategy, challenges faced, and will provide direction to potentially useful futuristic preoperative evaluation strategies.

Hepatopulmonary syndrome complicated by interstitial pneumonia and obesity with normal contrast echocardiography

Diagnosis of hepatopulmonary syndrome complicated by interstitial pneumonia and obesity is difficult because these complications can cause hypoxia. Such patients may not present with typical contrast echocardiography findings.

First presentation of portal hypertension complicated by hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) is a serious complication of chronic liver disease, characterised by portal hypertension and arterial hypoxaemia due to intrapulmonary vascular dilatation. We report an unusual case in which a 27-year-old man had a first presentation of portal hypertension and cirrhosis complicated by HPS. This patient presented with progressive dyspnoea on exertion and deterioration in mobility, with a type 1 respiratory failure and increased oxygen demand. A bubble echocardiogram showed a possible right-to-left shunt, CT aortogram displayed evidence of portal hypertension and cirrhosis, and liver biopsy findings were consistent with alpha-1 antitrypsin deficiency. The patient's increased oxygen demand was subsequently treated with continuous positive airway pressure before he was discharged with 8 L home oxygen. With no current established medical therapy for HPS, the patient was assessed for liver transplantation and a decision was made in favour of this.