Distensibility of the ductus arteriosus in neonates and young infants undergoing transcatheter closure

Distensibility of the ductus arteriosus in neonates and young infants undergoing transcatheter closure.

Nagasawa K, Muneuchi J, Sugitani Y, Ezaki H, Doi H, Furuta T, Kobayashi M, Watanabe M.Heart Vessels. 2022 Mar;37(3):513-516. doi: 10.1007/s00380-021-01925-9. Epub 2021 Aug 18.PMID: 34406441

Take home points

1. Forty one, term babies with PDA with Qp:Qs 1.53-3.13:1 were evaluated. Thirty-seven (93%) had successful closure. Three had device instability and one had device migration; these four were excluded from analysis. The authors did not further discuss these patients.
2. The following devices were utilized/attempted: ADO (32), ADO-2 (1) and AVP-2 (8), all nitinol devices.
3. Distensibility index, defined as ratio of device center diameter after device deployment to the diameter at the center of the ductus before PDA closure, was evaluated in these babies.
4. Distensibility index measured in each baby with successful closure; the mean distensibility index was 1.28
5. Distensibility index was negatively correlated with age (r= -0.49) and weight (r= -0.53), p<0.01 for both
6. The authors conclude that younger and smaller babies have a more distensible patent ductus, potentially putting those babies at higher risk for embolization

Commentary from Dr. Thomas Zellers (Dallas, USA), section editor of Congenital Heart Disease Interventions and ACHD Journal Watch:

Summary: Forty one babies, 68% female, with a mean gestational age of 38 weeks (37-39 weeks) were evaluated. Mean birth weight was 2.71 kg (2.4-3.03 kg). The mean weight at implant was 5.32 kg (range 4.33-6.93 kg); mean age at implant was 168 days (range 117-260 days).

All patients underwent cardiac catheterization with the plan to implant a closure device. Thirty-seven (93%) were successfully implanted; 3 had unstable devices and one had device embolization but no further information was given about these four patients and they were excluded, likely because the distensibility index could not be calculated. The mean pulmonary arterial pressure was 28 (range 16-60 mmHg) and Qp:Qs was 2.19:1 (range 1.53-3.13).

PDAs were categorized according to the Krischenko criteria: Type A = 29, Type B = 1, Type C = 8, Type D = 1 and Type E = 3. The mean diameters of the PDA at the PA size, center and aortic end were 3.2 (2.2=4.3) mm, 4.7 (3.6-5.7) mm and 7.7 (6.3-9.4) mm, respectively.

Devices attempted or deployed were ADO-1 = 32, ADO-2 = 1, and AVP-2 = 8. After deployment, the CENTER of the device was measured and compared to the pre-implant CENTER diameter of the PDA and a distensibility index was calculated as a ratio of the measurement of the center of the device after implantation to the center of the PDA pre-implantation. The mean distensibility index for the population was calculated at 1.28. The distensibility index negatively correlated with age (r= -0.49) and weight (r= -0.53) with a p value < 0.01 for both. A few of the older (> 200 days) and larger (> 5 kg) patients actually had a distensibility index < 1.

The authors concluded that the younger and lower weighted patients had a more distensible ductus. However, there are several limitations. It is a retrospective evaluation. The measurements of the CENTER of the device and ductus may not have always been correlated exactly as the devices may distort the PDA. The majority of the PDAs were closed with an ADO1, and the retention disc may be pulled fairly far into the ductus, making the center of the ductus more difficult to discern and measure accurately.