Congenital Heart Interventions

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 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. The following devices were utilized/attempted: ADO (32), ADO-2 (1) and AVP-2 (8), all nitinol devices. 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. Distensibility index measured in each baby with successful closure; the mean distensibility index was 1.28 Distensibility index was negatively correlated with age (r= -0.49) and weight (r= -0.53), p<0.01 for both 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.    

Late Outcomes of Transcatheter Coarctation Intervention in Infants with Biventricular Anatomy. Kurtz JD, Rubio AE, Johnston TA, Morray BH, Jones TK. Pediatr Cardiol. 2022 Mar 10. doi: 10.1007/s00246-022-02865-5. Online ahead of print. PMID: 35274168   Take Home Points: Transcatheter balloon angioplasty and stent implantation are a safe and effective way to treat native and recurrent coarctation of the aorta in infants. There is a high rate of transcatheter and surgical re-intervention in this patient population, especially when stenting was performed. The development and approval of bioresorbable stents could drastically shift the management of coarctation of the aorta away from surgery if they are deliverable through small sheaths. Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch: Coarctation of the aorta (CoA) is a discrete narrowing of the thoracic aorta typically just distal to the left subclavian artery. CoA is common, accounting for 5-8% of congenital heart disease (CHD). Surgical repair is the preferred approach in infants less than 12 months of age at most centers, though there is a recurrent CoA rate of 4-14% (Mery CM, Guzmán-Pruneda FA, Trost JG Jr, et al. Contemporary Results of Aortic Coarctation Repair Through Left Thoracotomy. Ann Thorac Surg 2015; 100:1039., Karamlou T, Bernasconi A, Jaeggi E, et al. Factors associated with arch reintervention and growth of the aortic arch after coarctation repair in neonates weighing less than 2.5 kg. J Thorac Cardiovasc Surg 2009; 137:1163.), with smaller size at time of repair a known risk factor. Alternatively, transcatheter balloon angioplasty and/or stent implantation have also been shown to achieve good short-term outcomes. In many centers, transcatheter treatments have been used in infants to delay surgery until patients are larger and in critically ill children with high surgical risk (such as impaired left ventricular function with relief of obstruction allowing for recovery of function). Aortic angioplasty has limited long term effectiveness and stent implantation mandates repeat procedures to enlarge the stent or surgery to remove the stent. Additionally, currently available stents that are implanted into infants cannot be made to adult size and need to be surgically excised or fractured with additional stent placement. No data exist on long term outcomes in infants treated with stenting.   A retrospective review was performed on all patients with biventricular circulation who underwent transcatheter intervention for CoA (native and recurrent) at Seattle Children’s Hospital from 2004-2020. There were 34 infants who were included in the analysis; 16 underwent stent implantation (angioplasty was attempted in 8 of these 16 with inadequate results). 31/34 procedures were performed via a femoral arterial approach. There were no baseline differences between the angioplasty and stent groups in patient demographics, procedure indication (LV dysfunction or gradient), whether the CoA was native or recurrent, or baseline peak-to-peak systolic gradient. Stent implantation led to a greater reduction in the gradient than angioplasty (27.6 ± 16.8 mmHg vs. 19.1 ± 10.4 mmHg) and lower residual gradient (5.6 ± 6.6 mmHg versus 11.9 ± 9.5 mmHg). The minimal luminal diameter was smaller in the stent group (2.0 ± 0.9 mm) than the angioplasty group (2.7 ±1.1 mm). The post-intervention to pre-intervention minimum aortic diameter ratio was larger in the stent group (2.8 ± 1.1 mm) than the angioplasty group (1.7 ± 0.6 mm). There were four (12%) vascular complications; 3 were loss of lower extremity pulse that were medically treated, and the other was an aortic wall injury requiring covered stent placement. The mean follow-up time was 8.1 ± 5.2 years for the stent group and 3.0 ± 3.6 years for the angioplasty group. Need for reintervention was earlier in the stent group (1.7 ± 3.1 years) than for the angioplasty group (2.7 ± 3.9 years), though this did not quite meet statistical significance. 12 patients ultimately required surgical reintervention (3/18 angioplasty, 9/16 stent).   This study shows that transcatheter intervention for CoA is safe and achieves accept relief of the obstruction in infants. This date is valuable as a previous study looking at outcomes of surgical repair of recurrent CoA in biventricular hearts had a serious adverse event rate of 28%. While angioplasty can achieve acceptable results in many patients, previous studies have shown a re-intervention rate of 17.9%. Stent implantation achieves superior immediate results but as previously discussed poses problems in getting the stented aorta to adult sized dimensions. In this cohort, more than 50% of patients who underwent stent implantation ultimately required surgical revision. While this is not ideal, it does allow for the surgical intervention to be delayed until the patient is older and larger or more medically stable (i.e., improved LV function). Advances in stent technology (bioresorbable stents, stents that can be implanted in infant sized aortas and expanded to adult size) could allow for a further shift in treatment of CoA away from surgery and towards less invasive transcatheter intervention.   Recurrent CoA in 3-month-old Stent imnplantation after failed angioplasty.