Haddad RN, Bentham J, Adel Hassan A, Al Soufi M, Jaber O, El Rassi I, Kasem M.Front Cardiovasc Med. 2023 Jul 10;10:1150579. doi: 10.3389/fcvm.2023.1150579. eCollection 2023. PMID: 37492157
Take Home Points:
- Use of modified MVP to decrease pulmonary blood flow is feasible, with the ability to surgically remove the devices up to 6 months post-implant.
- Increasing experience with this technology is allowing for decrease in procedural complications – device migration and over-circulation.
- Devices that are specifically designed as intra-luminal pulmonary flow restrictors are needed to facilitate wider adoption and implementation.
Commentary from Dr. Konstantin Averin (Cohen Children’s Heart Center), catheterization section editor of Pediatric Cardiology Journal Watch:
Surgical pulmonary artery banding is the standard of care for reducing pulmonary blood flow and controlling distal pulmonary artery pressure in patients who are at high risk for definitive biventricular repair or are planned to undergo single ventricle palliation. Recent case reports have suggested that percutaneous “pulmonary artery banding” can be performed using modified microvascular plugs (MVP) (Medtronic Inc, USA) (Figure 1) implanted in each pulmonary artery. The authors sought to expand the published experience by gathering multi-institutional data on all patients who underwent transcatheter implantation of modified MVPs as pulmonary flow regulators (PFRs). This was a descriptive study.
Variable techniques for modification of the MVP have been described. These authors used a carbon steel surgical scalpel blade No. 11 (Swann-Morton®, England). The blade was used to excise ~50% of the diamond (2 diamonds in the MVP-5Q and 1 diamond in 7Q and 9Q) (Figure 2). An MVP-5Q was used for vessels up to 4mm, MVP-7Q for up to 6mm, and MVP-9Q for vessels up to 8mm. From September 2021-September2022 28 pulmonary flow restrictors (PFR) were implanted in 14 patients: median age of 1.6 months (IQR, 0.3-2.3) and weight of 3.1kg (IQR, 2.7-3.6). Most patients were anticipated to have biventricular circulation (9 with large left to right shunt, 2 borderline left ventricles, 2 Taussig Bing anomaly and 1 with hypoplastic left heart syndrome). There was reduction in pulmonary blood flow in all cases.
Fourteen PFRs (7 patients) were surgically explanted at a median of 4.3 months (IQR, 1.2-6) post-implant; 4 are awaiting surgical explant and the remainder (3) were dead or not planned for further repair (palliative). Explants were performed with forceps or via a snare and sometimes required piecemeal removal.
The authors conclude that use of modified MVPs to decrease pulmonary blood flow is feasible. The technique described by the authors seeks to address some challenges of this procedure: distal device migration can be mitigated by oversizing the MVP and their approach to creating stable size fenestration seems to decrease the chance of excessive pulmonary blood flow. Importantly, the MVPs were able to be removed in 50% of patients up to 6 months post-device implant suggesting this approach can be used to bridge patients to a more definitive repair later in life. To facilitate wider adoption and implementation of this technique devices specifically designed as intra-luminal pulmonary flow restrictors are needed.
Figure 1.
Figure 2.
