The utility of the macro-aggregated albumin lung perfusion scan in the diagnosis and prognosis of hepatopulmonary syndrome in cirrhotic patients candidates for liver transplantation

Background: The macro-aggregated albumin lung perfusion scan (Tc-99m-MAA) is a diagnostic method for hepatopulmonary syndrome (HPS). Aim: To determine the sensitivity of Tc-99m-MAA in diagnosing HPS, to establish the utility of Tc-99m-MAA in determining the influence of HPS on hypoxemia in patients with concomitant pulmonary disease and to determine the correlation between Tc-99m-MAA values and other respiratory parameters. Methods: Data from 115 cirrhotic patients who were eligible for liver transplantation (LT) were prospectively analyzed. A transthoracic contrast echocardiography and Tc-99m-MAA were performed in 85 patients, and 74 patients were diagnosed with HPS. Results: The overall sensitivity of Tc-99m-MAA for the diagnosis of HPS was 18.9% (14/74) in all of the HPS cases and 66.7% (4/6) in the severe to very severe cases. In HPS patients who did not have lung disease, the degree of brain uptake of Tc-99m-MAA was correlated with the alveolar-arterial oxygen gradient (A-a PO 2) (r = 0.32, p < 0.05) and estimated oxygen shunt (r = 0.41, p < 0.05) and inversely correlated with partial pressure of arterial oxygen (PaO2) while breathing 100% O-2 (r = -0.43, p < 0.05). The Tc-99m-MAA was positive in 20.6% (7/36) of the patients with HPS and lung disease. The brain uptake of Tc-99m-MAA was not associated with mortality and normalized in all cases six months after LT. Conclusions: The Tc-99m-MAA is a low sensitivity test for the diagnosis of HPS that can be useful in patients who have concomitant lung disease and in severe to very severe cases of HPS. It was not related to mortality, and brain uptake normalized after LT.