Echocardiographic versus Angiographic Measurement of the Patent Ductus Arteriosus in Extremely Low Birth Weight Infants and the Utility of Echo Guidance for Transcatheter Closure.

BACKGROUND: Transthoracic echocardiography (TTE) is increasingly utilized for guiding transcatheter closure of patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. The objectives of this study were to compare PDA size measurements by TTE with angiographic measurements and to describe TTE techniques used in guiding transcatheter PDA closure (TCPC) in ELBW infants. METHODS: One hundred twenty-five consecutive ELBW infants (gestational age < 27 weeks, birth weight < 1 kg) who underwent TCPC before 8 weeks of age under TTE guidance were included. Patent ductus arteriosus sizes were measured from the procedural TTE and angiograms retrospectively by blinded observers. The TTE PDA diameters at the aortic (ED1) and pulmonary end (ED2) were compared with the corresponding angiographic diameters (CD1 and CD2). The TTE PDA lengths, obtained by two techniques (EL1, a straight line between ED1 and ED2; and EL2, a curvilinear line along the PDA), were compared with the PDA length by angiography (CL). Transthoracic echocardiography was used to guide accurate device positioning within the PDA. RESULTS: The procedure weight was 600-1,460 g. The TTE and angiographic PDA diameters were comparable (mean ED1 vs CD1 = 4.5 ± 0.68 vs 4.4 ± 0.85 mm, P = .26; and mean ED2 vs CD2 = 3.1 ± 0.72 vs 3.2 ± 0.94 mm, P = .14). The angiographic length was underestimated by EL1 by 2.6 ± 1.6 mm (P < .0001), while EL2 estimated it better (mean EL2 vs CL = 11.0 ± 1.83 vs 10.8 ± 2.15 mm; P = .40). Transcatheter PDA closure was successful in 100% of the cases using TTE guidance. There were no intraprocedural complications. CONCLUSIONS: Transthoracic echocardiography guidance during TCPC in ELBW infants eliminates the need for aortograms via femoral arterial access, preventing the complications associated with it. Transthoracic echocardiography PDA measurements are comparable to angiographic measurements, thereby assisting in appropriate device size selection.

Hemodynamic and clinical consequences of early versus delayed closure of patent ductus arteriosus in extremely low birth weight infants.

OBJECTIVES: To describe changes in hemodynamics, respiratory support, and growth associated with transcatheter PDA closure (TCPC) in ELBW infants, stratified by postnatal age at treatment. STUDY DESIGN: This is an observational study of ELBW infants who underwent TCPC at ≤4 weeks (Group-1; n = 34), 4-8 weeks (Group-2; n = 33), and >8 weeks of age (Group-3; n = 33). Hemodynamic assessment was performed during TCPC. Multivariate Cox-proportionate-hazard modeling was used to identify factors associated with respiratory severity score (RSS) > 2 for >30 days following TCPC. RESULTS: In comparison with Group-1, Group-3 infants had higher pulmonary vascular resistance (PVRi = 3.3 vs. 1.6 WU*m2; P = 0.01), less weight gain between 4 and 8 weeks of age (16 vs. 25 g/day) and took longer to achieve RSS < 2 (median 81 vs. 20 days; P = 0.001). RSS > 2 for >30 days was associated with TCPC > 8 weeks (OR = 3.2, 95% CI: 1.75-5.8; p = 0.03) and PVRi ≥ 3 (OR = 4.5, 95% CI: 2.7-8.9; p < 0.01). CONCLUSION: ELBW infants may benefit from PDA closure within the first 4 weeks of life in order to prevent early onset pulmonary vascular disease, promote faster growth, and for quicker weaning of ventilator and oxygen support.

Live broadcast of transcatheter PDA closure in a 700 grams ELBW infant during the International PDA Symposium.

OBJECTIVE: The objective of this article is to describe a live case transmission of transcatheter closure of a patent ductus arteriosus (PDA) in an extremely low birth weight (ELBW) infant during the first International PDA Symposium conducted in Memphis, Tennessee. SETTING: A multidisciplinary team approach including audiovisual specialists, information technology specialists, physicians, nurses, and other health care specialists was required to perform the transcatheter PDA closure (TCPC) in an ELBW infant at LeBonheur Children's Hospital and the procedure was broadcast live to the attendees at the International PDA Symposium allowing for a two-way audiovisual discussion during the procedure. PATIENT: The patient was a 14 days old 24-week premature ELBW infant, who weighed 700 g at the time of the procedure. The patient was requiring mechanical ventilation secondary to pulmonary hemorrhage. The PDA measured 4 mm in diameter and 12 mm in length. INTERVENTIONS: TCPC was performed safely without any procedural complications using a specialized minimally invasive technique. OUTCOME MEASURES: The patient was weaned off the ventilator in < 7 days after the procedure. The child was discharged 9 weeks after the procedure (35 weeks' corrected gestation) weighing 2.2 kg, on full oral feeds and no supplemental oxygen. RESULTS: The successful TCPC allowed for this child to have an uneventful hospital course. The case also highlights the technical nuances involved in setting up the live transmission. CONCLUSIONS: This case demonstrated to the audience in the International PDA Symposium the feasibility and safety of performing TCPC in an ELBW infant. Live cases are useful in exhibiting the nuances involved in any new technique and allows for best learning experience.