Pannus formation and iatrogenic ventricular septal defect after transcatheter aortic valve implantation

A 72-year-old female with progressive dyspnoea for 3 months underwent transcatheter aortic valve implantation (TAVI) with a 24 mm self-expanding valve (VitaFlow Liberty, China) 2 years ago. During regular follow-up, echocardiography and computed tomography revealed subaortic pannus encroaching from below the frame and causing left ventricular outflow tract (LVOT) obstruction (Figure 1A-xD, Video 1) without ventricular dilatation. The evaluated mean transvalvular pressure gradient was 52 mmHg (Figure 1E). A 4.4 mm perimembranous ventricular septal defect (VSD) was found (Figure 1F), which was absent previously (Supplementarymaterial online, Video S1). The peak systolic pressure gradient of subaortic pannus was 84 mmHg measured by cardiac catheterization, Qp/Qs ratio was 1.7 and mean pulmonary artery pressure (PAP) was 35 mmHg. An interventional procedure was performed with fluoroscopy and transesophageal echocardiography guidance under general anaesthesia. Left ventricle angiography demonstrated obstruction of LVOT and left-to-right shunt (Figure 1G, Video 2). A new 24 mm self-expandable valve (VitaFlow, China) was positioned lower than usual to completely cover the pannus and partially seal the aneurysm of membranous ventricular septum without affecting neighbour structures. After the transfemoral valve-in-valve TAVI, the peak transvalvular pressure gradient declined to 0 and mean PAP was 26 mmHg. Ventriculography showed relief of subvalvular obstruction and remarkable reduction of shunt (Figure 1H, Video 3), which were confirmed by follow-up imaging examination (Figure 1I-K). The patient recovered and was discharged with anticoagulation agent. Pannus formation, iatrogenic ventricular septal defect, and valve-in-valve TAVI. (A–C) Subaortic pannus formation in transesophageal echocardiography, computed tomography angiogram, and three-dimensional reconstruction (red arrow). (D) Subaortic obstruction caused by pannus in transthoracic echocardiography (red arrow). (E) The evaluated transvalvular pressure gradient. (F) Perimembranous ventricular septal defect (red arrow). (G) Partial subaortic obstruction (red arrow) and left-to-right shunt (white arrow). (H) Disappeared subaortic obstruction (red arrow) and small residual shunt (white arrow). (I–K) The pannus covered by stent frame without subaortic obstruction after procedure (red arrow). Pannus overgrowth is a rare but serious complication of surgical aortic valve replacement, which is not yet fully evaluated in TAVI. Our case is the first report of subaortic pannus and secondary spontaneous rupture of membranous aneurysm after TAVI. Valve-in-valve TAVI may be a feasible bail-out for sealing pannus and iatrogenic VSD located near annulus. Supplementary material is available at the European Heart Journal – Case Reports online. Consent: The authors confirm that written consent for submission and publication of this case report including images and associated text has been obtained from the patient in line with COPE guidance. Conflict of interest: None declared. Funding: This work was supported by grants from the Shanghai Committee of Science and Technology (grant numbers 17411970900 and 22YF1443000) and the Clinical Research Plan of SHDC (grant number SHDC2020CR1039B), China.