Consequences of delayed surgical closure of patent ductus arteriosus in very premature infants.

Background: Surgical closure of ductus arteriosus is commonly indicated in premature newborns. The aim of this study was to assess short-term and mid-term effects of delayed surgical closure of the ductus arteriosus on respiratory and digestive outcome in extremely preterm infants.

Methods: We retrospectively studied 58 infants less than 28 weeks gestational age who underwent surgical closure of ductus arteriosus between January 1997 and December 2002. Nine infants with intrauterine growth restriction and major congenital malformation were excluded from the study. Criteria for surgical closure of ductus arteriosus were: (1) medical treatment failure (ie, indomethacin or ibuprofen) and (2) hemodynamically patent ductus arteriosus: systemic arterial pressure less than gestational age in mm Hg, heart failure, left atrial-aortic root ratio greater than 1.6, mean velocity in the left pulmonary artery greater than 0.6 m/s, and ductus arteriosus diameter greater than 3 mm. Infants were divided into two groups: (1) the early group who had surgery before 21 days of life (n = 31), and (2) the late group who had surgery after 21 days of life (n = 27). Preoperative and postoperative criteria were compared between the two groups (ie, gestational age, birth weight, hemodynamic, ventilatory, and echographic [left atrial-aortic root ratio, mean velocity in the left pulmonary artery] parameters).

Results: Preoperative gestational age and birth weight did not differ between the two groups. In the early group, gestational age was 26 weeks (range, 23 to 28 weeks and birth weight was 800 g (range, 630 to 1,240 g). In the late group, gestational age was 26 weeks (range, 24 to 28 weeks) and birth weight was 840 g (530 to 1,130 g). Hemodynamic, ventilatory, and echographic parameters were similar in both groups. Rate of bronchopulmonary dysplasia was similar in both groups. However, at 24 hours post surgery, median FiO2 was higher in the late group (28% [range, 21% to 65%]) than in early group (21% [range, 21% to 60%]) (p < 0.05). Furthermore, full oral feeding was acquired later in the late group (57 days of life [range, 30 to 136 days]) than in the early group (37 days of life [range, 27 to 84 days]) (p < 0.01), and body weight at 36 weeks of post-conceptional age was higher in the early group at 1,800 g (range, 1,250 to 2,750 g) than in the late group at 1,607 g (1,274 to 2,200 g) (p < 0.05).

Conclusions: Our findings show that early surgical closure of the ductus arteriosus (< 3 weeks of life) is associated with shortened delay for full oral feeding and improved body growth when compared with late surgical closure (> 3 weeks of life).