Changes in pulmonary artery size before and after total cavopulmonary connection.

OBJECTIVE

To assess changes in size of the central pulmonary arteries following a total cavopulmonary connection (TCPC).

DESIGN

A retrospective analysis of the angiographic diameters of the central pulmonary arteries, expressed as z scores, in infancy before the TCPC and 3.5 (0.9) years (mean (SD)) later. Analysis of the relation between the pulmonary arteriolar resistance and the z scores at follow up.

SETTING

Tertiary referral centre.

PATIENTS

32 patients who had TCPC from February 1990 to July 1993.

RESULTS

The patients were divided into two groups (n = 16) depending on their preoperative flow ratio: group I, Qp/Qs < or = 1; group II, Qp/Qs > 1. At the initial study in infancy the mean z scores in group I were -6.0 for the right pulmonary artery (RPA) and -9.6 for the left pulmonary artery (LPA); in group II the respective values were -2.7 and -3.0. Before the TCPC the values increased to 0.5 (RPA) and -0.5 (LPA) in group I, and to 8.8 (RPA) and 8.2 (LPA) in group II. At follow up the z scores decreased to -2.4 (RPA) and -4.9 (LPA) in group I, and to 2.2 (RPA) and -0.7 (LPA) in group II. The changes in pulmonary artery diameters were significant for both groups (p < 0.02). Following the TCPC, no significant difference in pulmonary arteriolar resistance index was found between patients with relatively small pulmonary arteries (z score RPA + LPA < or = 0) and those with relatively large pulmonary arteries (z score RPA + LPA > 0).

CONCLUSIONS

Creation of a TCPC results in a significant reduction in size of the central pulmonary arteries. At a mean interval of 3.5 years following the TCPC, however, there was no significant difference in pulmonary arteriolar resistance index between patients with smaller and larger central pulmonary arteries.