Risk factors for hemodynamically-unrelated cystic periventricular leukomalacia in very low birth weight premature infants

Background and Purpose: Periventricular leukomalacia (PVL) is one of the most important complications of prematurity, but its cause remains unclear. This study investigated the risk factors for hemodynamically-unrelated cystic PVL in very low birth weight (VLBW) premature infants. Methods: VLBW premature infants admitted to the neonatal intensive care unit from 1998 through 2002 were included in this retrospective study. Infants who had congenital lethal anomalies or who died before a cranial scan could be done were excluded. All VLBW infants received serial cranial ultrasound examinations to screen for cystic PVL during hospitalization. Infants with cystic PVL were divided into those with or without a hemodynamic event of sufficient severity to potentially cause cystic PVL. The charts of all included infants were reviewed and relevant clinical parameters were analyzed. Results: Cystic PVL occurred in 20 VLBW infants (6.9%) during the study period. Four of these infants (20%) had hemodynamic events before the development of cystic PVL and 16 (80%) had hemodynamically-unrelated cystic PVL. Univariate analysis showed that infants with hemodynamically-unrelated cystic PVL were more likely to have symptomatic patent ductus arteriosus (PDA) [p < 0.01] and bronchopulmonary dysplasia (BPD) [p < 0.01]. However, logistic regression indicated VLBW premature infants with BPD combined with symptomatic PDA (odds ratio, 8.92; 95% confidence interval, 2.55-31.20; p < 0.01) were at greatest risk for development of hemodynamically-unrelated cystic PVL. Conclusion: BPD and symptomatic PDA were more common in infants with hemodynamically-unrelated cystic PVL, although the reasons for these associations were unclear. Serial cranial scans are strongly suggested for VLBW premature infants with BPD and symptomatic PDA to screen for the development of cystic PVL.