OBJECTIVEThe development status of pulmonary artery is one of the most important criteria for decision-making strategy and predicting postoperative outcome in congenital heart disease with decreased pulmonary blood flow. Currently, Nakata index and McGoon index have been used as morphologic index in evaluating the development status of pulmonary artery. Those indices have some shortcoming. It was recently found that pulmonary veins index is a more precise morphological indicator of pulmonary blood flow and development status of pulmonary vessels. This study aimed to explore an index of evaluating pulmonary blood stream and the development of pulmonary vessels, as a criterion for surgical decision-making strategy.

METHODSThe diameters of left and right pulmonary arteries and pulmonary veins were measured on DSA films in 74 patients with congenital heart disease with decreased pulmonary blood flow, The correlative analysis was done between Nakata index, McGoon index, pulmonary vein index (PVI) and postoperative outcome which were the length of stay in ICU, duration of mechanical ventilation and dose of inotropic drugs.

RESULTSExcellent correlations between the size of pulmonary veins and pulmonary arteries were found, the correlation between left pulmonary veins and distal portion of left pulmonary artery was 0.73, between left pulmonary veins and proximal portion of left pulmonary artery was 0.72, right pulmonary veins and distal portion of right pulmonary artery was 0.67, and right pulmonary veins and proximal portion of right pulmonary artery was 0.71. The length of stay in ICU, duration of mechanical ventilation and dose of inotropic drugs correlated well with PVI (r = -0.51, -0.478, and -0.693). Compared with Nakata index and McGoon index, PVI was a better criterion for evaluating the developmental status of the whole pulmonary vessels. In the right ventricular outlet reconstruction patients, the McGoon index for patients with low cardiac output syndrome (LCOS) was 1.36 +/- 0.51, and 1.97 +/- 0.58 for patients without LCOS (t = 2.347, P < 0.05), the Nakata index for patients with LCOS was 164 +/- 106 mm(2)/m(2) and 269 +/- 124 mm(2)/m(2) for patients without LCOS (t = 2.218, P < 0.05), the PVI for patients with LCOS was 152 +/- 77 mm(2)/m(2) and 273 +/- 125 mm(2)/m(2) for patients without LCOS (t = 2.936, P < 0.01), pulmonary vessel index of patients with LCOS was less than that of those without LCOS. When PVI was < or = 180 mm(2)/m(2), postoperative hemodynamics was unstable, the frequency of low cardiac output syndrome and mortality significantly increased.

CONCLUSIONSThe development of pulmonary arteries and pulmonary veins correlated with each other. PVI is a precise morphological indicator of pulmonary blood flow and development of pulmonary vessels. It is a helpful indicator to decide surgical strategy.