Hepatopulmonary syndrome and portopulmonary hypertension in the model for end-stage liver disease (MELD) era

Abstract

Key Points 1. How do physicians decide which patients with pulmonary vascular disease will benefit from liver transplantation? 2. Studies on patients with pulmonary vascular disease are limited and the findings and recommendations may not apply to all practice sites. 3. All patients with hypoxemia, liver disease, and pulmonary vasodilation do not have hepatopulmonary syndrome (HPS). 4. Not all patients with hepatopulmonary syndrome will benefit from liver transplantation. 5. The mean pulmonary artery pressure (mPAP) may not be an accurate predictor of mortality in patients with portopulmonary hypertension. T he transplant community continues to expend considerable effort constructing organ allocation protocols that will reduce deaths on the transplant waiting list. However, the effects of hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN) on waiting list mortality and patient outcome are not fully understood. This creates a decisional dilemma as physicians try to determine if potential recipients with coexistent pulmonary vascular diseases should undergo transplantation and what priority they should be given for surgery. Because pulmonary vascular disease in transplant candidates is relatively rare, case reports and single institutional studies are the most common source of outcome data for these patients. The pressure to optimize organ allocation demands that investigators develop practice recommendations based upon this limited information. Thus, physicians question whether patient outcomes and recommendations from these studies are predictive in their own practices. HPSThe triad of liver disease, arterial deoxygenation while breathing room air and evidence of intrapulmonary vascular dilation defines HPS. 1 Although the pathophysiology of HPS is not well understood, it is clear that there is a causative relationship between hypoxemia due to HPS and liver disease. This relationship is the theoretic basis for suggesting liver transplantation could be an effective intervention. However, early results of transplantation in HPS patients were disappointing and reinforced opinions that HPS was of such significant risk to the patient and donor graft function that severe hypoxemia caused by HPS (partial pressure of arterial oxygen [PaO 2 ] Ͻ 50 mm Hg) should be considered as an absolute contraindication to liver transplantation. 2 Subsequent reports of improved survival following liver transplantation caused physicians to reconsider HPS as a contraindication and speculate that liver transplantation may be effective in reversing hypoxemia caused by HPS. This thinking persisted, culminating in recommendations that patients with hypoxemia due to HPS receive additional priority on the waiting list for liver transplantation. 3 Recent evidence that shows HPS independently increases morbidity and mortality in patients with cirrhosis waiting for transplantation adds support to current policies that recommend increasing transplant priority. 4 However, markedly different estimates in the prevalence of disea...

OPTN Policy Regarding Prioritization of Patients with Hepatopulmonary Syndrome: Does It Provide Equitable Organ Allocation?

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Liver transplantation for pulmonary vascular complications of pediatric end-stage liver disease

“…Fortunately, current UNOS criteria permit liver allocation score exceptions for significant hypoxemia associated with HPS. Therefore, timely diagnosis is critical in getting these patients listed because they generally do not have PELD/MELD scores that warrant transplantation [29,30].…”

Emergency versus elective living-donor liver transplantation: a comparison of a single center analysis

“…Aging is known to be related to immunodeficiency [26] as a result of dysfunction of T cells. The pathogenesis of low preoperative PaO 2 /FiO 2 ratios could be multifactorial, including atelectasis caused by pleural effusion, adult respiratory distress syndrome (ARDS), and hepatopulmonary syndrome (HPS), and these easily lead to pulmonary infection [27].…”