Hepatopulmonary syndrome--response to liver transplantation--new insights into an old problem

OPTN policy regarding prioritization of patients with hepatopulmonary syndrome: does it provide equitable organ allocation?

United Network for Organ Transplantation (UNOS) policy 3.6.4.5.1 provides exception points to patients diagnosed with hepatopulmonary syndrome (HPS) to compensate for their reported increased mortality risk. We compared pre- and posttransplant and overall outcomes in 255 patients receiving exception points under this policy (HPS policy patients) with 32 358 nonexception control patients listed in the model for end-stage liver disease (MELD) era to determine whether the intent of the policy is being met. Overall, 92.5% of HPS policy patients versus 45.5% of controls had been transplanted, 5.1% versus 31.2% remained on waiting list and 1.5% versus 14.1% had died while awaiting transplant (p < 0.0001 for each comparison). Relative risk (RR) of death for HPS policy patients compared to controls was 0.158 (confidence interval [CI]: 0.059-0.420, p = 0.0002) pretransplant, and 0.827 (CI: 0.587-1.170, p = 0.28) posttransplant. Overall (combined waitlist and posttransplant) RR of death was 0.514 (CI: 0.374-0.707, p = 0.00004) compared with controls. After adjustment for laboratory MELD, overall RR was 0.807 (CI: 0.587-1.110, p = 0.19), indicating that HPS policy patients' mortality risk would be similar to that of controls had they been listed with their laboratory MELD score. HPS policy patients have a significant pretransplant survival advantage over standard liver transplant candidates because of the exception points awarded, and have similar posttransplant survival. Better criteria for diagnosing and grading of HPS are required.

The hepatopulmonary syndrome

The hepatopulmonary syndrome is a disease entity seen in association with liver failure and other disease entities. It is a devastating consequence of liver failure that results in a significant morbidity for affected patients. Currently, there are no identified medications that ameliorate the symptoms of hypoxemia in this disease state. Recent research, however, has begun to unravel the pathobiology of the vascular dilations that arise in the lungs of patients with liver failure. In this article, a compendium of current knowledge is presented, as well as the contemporary methods for identifying and treating patients.