Cobra-head and other shape-memory abnormalities of nitinol atrial septal occluders: incidence, predisposing factors, and outcomes.

BACKGROUND: Shape-memory abnormalities are seen in some nitinol atrial septal occluders. Variably described as cobra-head, tulip, and others, their incidence, mechanisms, clinical impact, and outcome have not been systematically analysed. METHODS: We retrospectively reviewed all consecutive device closures in the last 6 years for deformations. Type and size of the occluder, deployment technique, size, and angulation/kinking of the delivery sheath were analysed. Procedural success, duration, and other complications were studied. RESULTS: A total of 112 devices (11.8%) among 950 occluders used in 936 patients showed deformities. Fourteen of 936 received 2 devices. Deformities were transient and self-correcting in 40%. Multivariate analysis showed significant associations with oversized sheaths (p = 0.004), kinked/angulated sheaths (p < 0.001), special deployment techniques (p < 0.001), and twist in the device waist (p = 0.011). Despite more frequent deformities with Figulla (15.6%) and Amplatzer (13.9%) occluders than Cera occluders (6.6%) and larger devices (>24 mm - 14.6%) than smaller devices (less than or equal to 24 mm - 9.7%), they were not significant on multivariate analysis. In vivo manipulations corrected most deformities; nineteen needed in vitro reformations and four needed a change of device. Despite prolongation of the procedure, repeated attempts (mean 2.76 ± 1.7 attempts, with a range from 1 to 9 attempts), and supraventricular tachycardia in two patients, there were no serious adverse effects. CONCLUSIONS: Deformations were frequent in 11.8% of atrial septal occluders on a targeted search. Oversized and angulated/kinked sheaths, special techniques like pulmonary vein deployment and twist in device waist during procedure predisposed to deformities. While most deformities were corrected with manipulations, removal of the device was infrequently needed and change of device was rarely required. Long procedural time and multiple attempts for deployment did not affect procedural success.

Successful percutaneous retrieval of unusually knotted temporary pacemaker lead.

Implantation of temporary pacemaker lead is commonly performed procedure and is usually safe, but can sometimes develop rare and serious complication like intracardiac lead knotting which may require challenging retrieval techniques. We report a case of successful percutaneous retrieval of unusually knotted right internal jugular venous temporary pacing lead via left femoral transvenous approach using snare over a long sheath after cutting the electrode proximally and thus avoiding any surgical intervention.

Endovascular Treatment of Acquired Atheromatous Postsubclavian Aortic Coarctation.

Coral reef aorta is a rare calcifying obstructive disease that involves the thoracoabdominal aorta. Similar presentations in the postsubclavian aorta may result in acquired atheromatous aortic coarctation leading to systemic hypertension and heart failure. The associated calcification makes surgical anatomic or extraanatomic bypass and thromboendarterectomy challenging. Extensive circumferential calcification often precludes endovascular intervention. We present the case of a 25-year-old man with an acquired atheromatous coarctation of the postsubclavian aorta who underwent successful endovascular treatment with use of a balloon-expandable covered stent.