Accordion effect during carotid artery stenting. Report of two cases and review of the literature

The term ''accordion effect'' is used to describe a mechanical distortion of tortuous arteries mimicking spasm or dissection. This phenomenon has been reported in patients undergoing percutaneous coronary intervention. To our knowledge, this is the first documentation of the accordion effect during carotid artery intervention. Two patients who developed the accordion effect during carotid artery stenting (CAS) are described. Angiograms obtained just after CAS showed a stenosing lesion with wall irregularity at the distal part of the stent. This lesion disappeared and tortuosity of the internal carotid artery developed after withdrawing the guidewire until its floppy segment rested equally on the lesion. In another patient, the lesion did not disappear completely until the guiding catheter had been withdrawn to the proximal portion of the common carotid artery. We conclude that these stenosing lesions reflected the accordion effect. It is essential to differentiate the accordion effect from dissection, spasm, and thrombosis because the management is importantly different. We report our findings and present a review of the literature. (orig.)