Congenital Heart Interventions

Risk factors associated with device embolisation or malposition during transcatheter closure of patent ductus arteriosus. Mumtaz ZA, Sagar P, Sivakumar K, Mohakud AR, Rajendran M, Pavithran S.Cardiol Young. 2023 Oct;33(10):2041-2048. doi: 10.1017/S1047951122003973. Epub 2022 Dec 14.PMID: 36515000 Take home points: Device embolization occurs in 4% of transcatheter patent ductus arteriosus closures and may lead to significant morbidity. Significant risk factors for device embolization are age ≤ 6 months, large tubular duct, and closure with vascular plugs or undersized devices. rptnb Commentary from Dr. Milan Prsa (Switzerland, Europe), section editor of Congenital Heart Disease Interventions Journal Watch: Transcatheter patent ductus arteriosus (PDA) closure is currently routinely performed across the globe. Device embolization, however, remains a major and occasional complication. The authors of this retrospective study sought to identify risk factors for device embolization and report its intermediate term outcomes. They analyzed data from 376 procedures performed at a tertiary center over an 8-year period. Notably, they used almost exclusively a venous approach and chose the device solely based on an echocardiographic evaluation of the PDA. An undersized device was clearly defined as a conical occluder <2 mm larger than narrowest duct diameter or a vascular plug <150% of the duct diameter. Outcomes were detailed according to the various types of ductal occluders. The results mirror what has been previously reported in the literature. The incidence of embolization was relatively low at 4% but had significant implications for those affected, including the necessity of surgical intervention in 20% of embolization cases. Most embolizations occurred in infants ≤ 6 months (73%), weighing < 6 kg (87%), with tubular ducts (80%) and higher pulmonary artery pressures (93%). The use of vascular plugs and the intentional undersizing of devices to avoid vascular obstruction were also identified as significant risk factors (Table 1). Most devices embolized to the branch pulmonary arteries, including two into distal lobar branches that could not be retrieved and were left in place. The PDA was ultimately successfully closed in 60% of embolization cases. Despite its retrospective design and being limited to a single center's experience, the study provides a meaningful contribution to the existing literature by clarifying risk factors associated with device embolization during transcatheter PDA closure. It offers actionable insights for clinicians to refine their procedural strategies, particularly in high-risk groups, thereby potentially reducing the incidence of these serious complications. The detailed discussion of device types and their specific risks provides a useful guide for device selection in clinical practice. Table 1. Risk factors predisposing to embolization. ParameterP valueOdds ratio95% Confidence Interval for Odds ratioLower  Upper  Morphology of duct Conical Tubular Others    0.003 0.264  Reference 13.9 4.5    2.4 0.3    81.0 64.1Pulmonary arterial hypertension0.069.30.996.5Undersizing of the device0.00124.63.8160Device type Duct occluder Vascular plugs others    0.05 0.6  Reference 4.0 0.4    0.96 0.02    16.8 11.5Body surface area0.20.20.022.6Age group(months) >12 6-12 0-6    0.2 0.002  Reference 4.67 27.7    0.42 3.55    52.3 216.6

Risk Factors and Outcome of Pulmonary Artery Stenting After Bidirectional Cavopulmonary Connection (BDCPC) in Single Ventricle Circulation. Callegari A, Logoteta J, Knirsch W, Cesnjevar R, Dave H, Kretschmar O, Quandt D.Pediatr Cardiol. 2023 Oct;44(7):1495-1505. doi: 10.1007/s00246-023-03229-3. Epub 2023 Jul 15.PMID: 37453932  Take Home Points PA stent implantation early after BDCPC is safe and feasible Single RV, larger neo-ascending aorta, and small LPA at the pre-BDCPC cath are independent risk factors for PA-stent implantation post-BDCPC PA diameters after PA-stent implantation and stent dilation show symmetric growth compared to the contralateral side Commentary from Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan) Branch pulmonary artery (PA) stenosis in the single ventricle population remains a common post operative problem that is often addressed in the cath lab. The authors sought to identify patients at risk of PA-stent implantation after bidirectional cavopulmonary connection (BDCPC) surgery. They secondarily sought to determine if PA growth would be similar in a PA-stented group compared to a group that did not require PA-stent implantation at the time of the pre-TCPC (total cavopulmonary connection) surgery. A single center, retrospective, longitudinal analysis of all patients who underwent single ventricle palliation with pre-BDCPC and pre-TCPC catheterizations were included in this study. From 2006 to 2021, 136 patients met the inclusion criteria of which 56 (41%) were female and single right ventricle (RV) physiology was present in 69 (51%). PA-stent implantation was performed in 40 (29%) patients and of these 37 (92.5%) required LPA stent implantation. LPA compression from the neo-ascending aorta was present in 16/40 (40%) of cases and was the most common etiology necessitating stent implantation. On logistic regression analysis, single RV patients were more likely (OR 0.41, p=0.05) to need PA-stent implantation compared to single LV patients. Smaller LPA diameter (OR 0.89, p=0.03) and larger diameter of the neo-ascending aorta pre-BDCPC (OR 1.05, p=0.001) were associated with an increased likelihood of PA-stent implantation post-BDCPC. Overall, PA diameters were smaller in the PA-stent group but when comparing the pre-BDCPC and pre-TCPC absolute PA diameters among both groups, there was no difference in PA growth. The authors conclude that PA-stent implantation early after the BDCPC surgery is safe and ensures symmetrical pulmonary flow and growth of the hilar intrapulmonary vessels. They further extrapolate that based on their findings, patients at higher risk of needing PA-stent implantation i.e. single RV, smaller LPA at pre-BDCPC cath, and dilated neo-ascending aorta, may be good candidates for exit angiography after the BDCPC surgery. The authors acknowledge that flow differential was not quantitatively assessed by cardiac MRI or lung perfusion scan and such flows may have a greater impact on the growth of PAs. Lastly, as this is a single institution study, frequency and timing of intervention may represent an institutional approach to care making generalizability limited to other surgical or interventional approaches.

Percutaneous Mitral Valve Repair in Pediatric Patients. Haregu F, Wong N, McCulloch M, Lim DS.Pediatr Cardiol. 2023 Dec 27. doi: 10.1007/s00246-023-03387-4. Online ahead of print.PMID: 38150041 Take Home Points:  TEER is feasible in pediatric patients of adequate size with severe MR and high surgical risk. Further studies are needed to understand long-term implications of TEER in the pediatric population. Commentary from Dr. Arash Salavitabar (Ann Arbor, MI, USA), section editor of Congenital Heart Disease Interventions Journal Watch: The authors report on a case series of 4 pediatric patients who underwent transcatheter edge-to-edge repair (TEER) to treat severe mitral regurgitation (MR). The patients were 6-17 years of age and as small as 19 kg, with cardiac diagnoses ranging from heart transplantation following single ventricle palliation, dilated cardiomyopathy and congenital mitral valve dysplasia with degenerative MR. The MitraClip device (Abbott Vascular, Santa Clara, CA) was utilized in all cases. All patients were deemed to be high risk or non-surgical candidates and all cases resulted in a significant improvement in MR. The authors described the MitraClip, which has delivery system that consists of a steerable guide catheter that is 24-French at the skin and 22-French as it crosses the interatrial septum. The large profile was thought to be a likely limitation in its utility in patients under 15-20 kg. The MitraClip device grasps between the anterior and posterior MV leaflets, which brings them together to reduce the regurgitant orifice area. Though there remains a paucity of long-term data on the durability of TEER’s efficacy, particularly when considering younger patients who are surgical candidates, TEER has the potential to reduce heart failure symptoms and degree of MR. Pre-procedural planning is important, with due consideration to patient size and vascular access.

Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement. Boucek DM, Qureshi AM, Aggarwal V, Spigel ZA, Johnson J, Gray RG, Martin MH. Cardiol Young. 2023 Nov;33(11):2282-2290. doi: 10.1017/S104795112200405X. Epub 2023 Jan 27.PMID: 36705001 Take Home Points: Right ventricle to pulmonary artery conduits can be dilated beyond 110% of their implant diameter. Procedural complications were more common in the over-dilation group but these were mostly managed in the catheterization lab without significant morbidity and mortality. The ability to over-dilate small diameter conduits can allow patients with right ventricular outflow tract dysfunction to defer or avoid surgical pulmonary valve replacement. Commentary from Dr. Konstantin Averin (Cohen Children’s Heart Center), catheterization section editor of Pediatric Cardiology Journal Watch: Trans-catheter pulmonary valve replacement (TPVR) with the Medtronic Melody valve is now routinely utilized in treatment of right ventricular outflow tract pathology, especially in dysfunctional right ventricular to pulmonary artery conduits.  The original indication for the Melody valve was for conduits with implant diameters of 16mm or greater, excluding many patients with smaller conduits from this therapy.  There has been increasing experience with overdilation of conduits beyond a theoretical guideline of 110% of their implant diameter.  The authors sought to compare outcomes of conduit dilation to >110% of nominal diameter with a control group of ≤ 100%. From November 2010 to March 2017, 172 patients were included in the study – 51 in the overdilation group and 121 in the control group with the overdilation group being younger (11.2 vs 16.7 years, p < 0.001) and smaller (32.8 vs 57.8 kg, p < 0.001) than the controls.  There were more homograft conduits in the overdilation group (73 vs 44%).  The success rate for TPVR was 98% in both groups with the relationship of original conduit size to average final valve diameter in the overdilation group demonstrated in Figure 1.  Amazingly, even conduits <12mm at implant were usually able to be dilated to an average of approximately 20mm.  Procedural complications were more common in the overdilation group (18% vs 7%, p = 0.046).  In the overdilation group complications included 1 uncontained conduit tear requiring ECMO and emergent surgical pulmonary valve replacement; 7 patients had contained tears and 1 had an MPA pseudoaneurysm treated with a vascular plug.  There were no differences in TVPR durability at a mean follow-up of 3.6 years (overdilation) vs 4.1 years (control) – including a combined freedom from reintervention of 89%.  Endocarditis was more common in the overdilation group (16%) compared to the control group (5%) suggesting that a smaller implant conduit diameter (independent of final TPVR diameter or pressure gradient) could be a risk factor for endocarditis. The authors conclude that right ventricle to pulmonary artery conduits can be dilated beyond 110% of their implant diameter.  While complications were more common in the overdilation group these could safely be managed in the catheterization lab without serious morbidity or mortality.  This study continues to add to the literature supporting the overdilation of small conduits to adult diameters, in fact the authors report dilating 9mm conduits to 20+ mm (>200% of implant diameter).  Diseases of the right ventricular outflow tract requiring conduit implant are life-long conditions that will necessitate multiple surgical and catheter-based interventions.  If small conduits can be dilated to large diameters (as suggested by the authors) with relative safety this will allow providers to minimize the number of lifetime surgical interventions.  Figure 1.