Downward Migration of Carotid Stent on 8 Months Follow-Up Imaging: Possible Stent “Watermelon- Seeding” Effect

Abstract

Interventionalists should be aware of the rare possibility of migrating downward "watermelon-seeding" of carotid stents. This report may generate the hypothesis that the stent watermelon-seeding effect may be related to proximal placement of a short stent below the ICA angulation and at the carotid bulb in severely stenotic lesion.

Bilateral Migration of Open-Cell Design Carotid Stents in the Early Post-Procedure Period: A Rare Complication

“…During left ICA stenting, we incidentally noted migration of the recently placed stents in the right carotid artery. Angiography of the right carotid artery showed caudal migration of 4,5 . In both of the cases reported previously, stent migration was identified on imaging performed several months after placement.…”

“…gration has rarely been described. Two previously published cases include a report of proximal migration of a carotid artery stent identified at eight-month follow-up and a case of distal migration of a stent placed in the CCA identified at 15-month follow-up 4,5 .…”

“…The precise cause of stent migration is not known although several hypotheses have been postulated, including the "watermelon seeding" effect described by Badruddin et al 4 . They described stent migration after deployment of a 2 cm long closed-cell design stent across a short segment of ICA stenosis with angulation close to the stenotic site.…”

“…Long-term complications include in-stent re-stenosis or stent occlusion. Stent migration is a rare occurrence, and has only been reported with closedcell design stents 4,5 .…”

Delayed Proximal Flow Diverting Stent Migration in a Ruptured Intracranial Aneurysm: A Case Report

“…Regarding lesion factors, when the distal vessel diameter is too small compared with the proximal vessel diameter, the distal end of the stent cannot be fully flared to enhance the apposition of the stent, and a squeezing force can occur. This phenomenon is called the “watermelon seed effect” [ 6 , 7 , 9 ].…”