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Patent ductus arteriosus ligation and adverse outcomes: causality or bias?
Dany E Weisz1, Patrick J McNamara2
1Department of Newborn and Developmental Paediatrics, Sunnybrook Health Sciences Centre, Toronto, Canada.
Insights
Patent ductus arteriosus (PDA) ligation in preterm infants may be linked to long-term morbidities. However, confounding factors require cautious interpretation, and surgical ligation remains vital for symptomatic PDA.
Area of Science:
- Neonatal Medicine
- Pediatric Surgery
- Perinatal Research
Background:
- Observational studies link patent ductus arteriosus (PDA) ligation in preterm infants to increased chronic lung disease (CLD), retinopathy of prematurity, and neurodevelopmental impairment.
- A trend towards permissive PDA management exists, but the biological rationale is not fully understood.
- Potential residual bias from confounding by indication, including intraventricular hemorrhage and mechanical ventilation, complicates interpretation of the ligation-morbidity relationship.
Purpose of the Study:
- To critically evaluate the association between PDA ligation and morbidities in preterm infants.
- To assess the impact of confounding factors on the interpretation of observational study findings.
- To inform clinical decision-making regarding PDA management strategies in preterm neonates.
Main Methods:
- Review of observational studies investigating PDA ligation outcomes in preterm infants.
- Analysis of potential confounding variables, including postnatal factors and severity of illness.
- Assessment of the evidence supporting conservative management versus surgical intervention for PDA.
Main Results:
- Observational data suggest associations between PDA ligation and adverse long-term outcomes.
- Insufficient adjustment for critical pre-ligation confounders indicates potential residual bias.
- Persistent symptomatic PDA is associated with increased mortality and CLD.
Conclusions:
- Caution is warranted when interpreting the relationship between PDA ligation and morbidity due to confounding by indication.
- Conservative management may be considered after failed medical PDA closure to reduce surgical interventions.
- Surgical ligation remains an important treatment for preterm infants with persistent symptomatic PDA, balancing risks and benefits.
Abstract:
Observational studies have associated patent ductus arteriosus (PDA) ligation in preterm infants with increased chronic lung disease (CLD), retinopathy of prematurity, and neurodevelopmental impairment at long-term follow-up. Although the biological rationale for this association is incompletely understood, there is an emerging secular trend toward a permissive approach to the PDA. However, insufficient adjustment for postnatal, pre-ligation confounders, such as intraventricular hemorrhage and the duration and intensity of mechanical ventilation, suggests the presence of residual bias due to confounding by indication, and obliges caution in interpreting the ligation-morbidity relationship. A period of conservative management after failure of medical PDA closure may be considered to reduce the number of infants treated with surgery. Increased mortality and CLD in infants with persistent symptomatic PDA suggests that surgical ligation remains an important treatment modality for preterm infants.
