Pseudo-occlusions of the internal carotid artery

The pseudo-occlusion (P.O.) of the internal carotid artery is defined as an atheromatous lesion causing a high-grade stenosis, which describes a peculiar angiographic finding ("string sing" or "slim sign"). The authors report their experience with 6 P.O. (angiographically diagnosed) that had been found in 16 months. In all these cases, whenever there was a clinical e/or B-scan ultrasound suspect, angiographic recommendations for the detection of that lesion have been applied. One of these 6 patients, clinically asymptomatic, refused surgery, remaining asymptomatic for cerebral ischemia during the successive 16 months; angiographic control evidenced an unmodified P.O. The other 5 patients, clinically symptomatic, underwent surgical correction: in one, intraoperative finding was a total carotid occlusion. In the other 4 patients the P.O. was confirmed and an endoarterectomy has been done. No immediate or later complications have been noted (clinical and ultrasonographic average follow-up time was 12 months). The experience described by the authors leeds to some considerations: a) the carotid P.O. is not so rare; specially if adequate angiographic technique has been employed; b) the non-invasive studies could not reliably distinguish a P.O; c) intraoperative findings do not confirm, always, angiographic ones but a fibrous, chronic and totally occluded internal carotid artery; d) the evolution of P.O. in a complete carotid occlusion is very probable but not obligatory, and if this happens it needs long period of time; consequently the surgical correction of P.O. could be justified but not urgently; e) the surgical correction of the P.O. can be done without particular difficulty and its outcome is so similar to those obtained from the routine carotid surgery.