Gillespie MJ, Maschietto N, Aboulhosn JA, Balzer DT, Qureshi AM, McElhinney DB. Catheter Cardiovasc Interv. 2024 Aug;104(2):256-263. doi: 10.1002/ccd.31147. Epub 2024 Jul 5.PMID: 38967206
Take Home Points
- Cardiovascular perforation by the Alterra pre-stent is an observed phenomenon that can be detected incidentally on post-procedure CT imaging
- In the patients presented, no clinical complications occurred from the Alterra perforation, though the potential to become clinically significant remains
- The pre-stent perforated the main PA in all 6 patients and in 1 patient there was also perforation of the subvalvar RVOT
Commentary from Dr. Jonathon Hagel (C.S. Mott Children’s Hospital, University of Michigan)
Patients with patched or native right ventricular outflow tracts (RVOTs) that are too large for traditional balloon expandable pulmonary valves are now often treated with a self-expanding platform. The Alterra adaptive pre-stent is a transcatheter self-expanding device that provides a landing zone for a balloon expandable 29 mm Sapien 3 valve implant. The authors of this study reported selected cases of the Alterra-Sapien implant form 6 institutions to document the phenomenon and provide considerations for potential procedural and patient characteristics in such cases.
Each institution provided one patient with a perforation of the Alterra pre-stent that was incidentally discovered on a CT scan performed one day to 21 months after implant. The age range of patients included in this descriptive case series was 16-50 years. Three patients had a history of Tetralogy of Fallot, two had valvar pulmonary stenosis (PS) and one had pulmonary atresia with an intact ventricular septum. One of the valvar PS patients underwent balloon valvuloplasty only and had no history of surgical RVOT intervention. All procedures were acutely successful without significant compilations. In all patients there was perforation of the main pulmonary artery by the distal row of the pre-stent and in one case there was also perforation of the subvalvar RVOT.
The perforations did not cause clinical complications in any of the presented cases, though the authors do note, however, in 4 patients the perforating stent cell was in proximity or even extending into the adjacent vascular structure including the ascending aorta, left pulmonary vein, and left atrial appendage. Procedural considerations noted by the authors include asymmetrical delivery of the pre-stent due to inability to achieve coaxial alignment of the delivery system and difficulty advancing the 29 mm Sapien valve through the newly implanted pre-stent. The authors propose that perforation did not cause clinical compromise with extravasation of blood due to direct occlusion of the perforation with the device itself or scar tissue filling the potential space that could allow for fluid to accumulate. As such, the authors note that those who have only had a balloon valvuloplasty and no surgical history may be at increased risk of extravasation of blood due to the absence of scar tissue. The authors note that this study was designed to explain the phenomenon and ensure implanters are aware of the potential clinical significance. A larger study designed to determine risk factors, incidence, and implications of this phenomenon is needed.
