Cerebral embolization in patients undergoing protected carotid-artery stenting and carotid surgery.

AIM: Intraoperative cerebral embolization is a greater concern in patients undergoing carotid-artery stenting (CAS) than in those undergoing the reference standard treatment carotid endarterectomy (CEA). We evaluated cerebral embolism with diffusion-weighted magnetic resonance imaging (DW-MRI) and transcranial Doppler monitoring during CAS and CEA. METHODS: A series of 75 patients with carotid stenosis, 40 undergoing CEA and 35 transfemoral protected CAS, underwent preoperative and postoperative cerebral DW-MRI. Of the 75 patients, 64 (85%) underwent intraoperative transcranial Doppler monitoring to evaluate the mean number of microembolic signals (MES) recorded in each procedure. RESULTS: None of the patients died. No patient in the CEA but two in the CAS group had strokes (5.7%, P=NS). The mean MES count on transcranial Doppler monitoring was higher in the CAS than in the CEA group (330.0 MES, range 2754 vs 13.2, range 0-49 MES; P<0.01). DW-MRI disclosed a significantly larger number of new ischemic lesions in the CAS than in the CEA group (40 lesions in 12/35 patients, 34.3% vs 4 lesions in 3/40 patients, 7.5%; P<0.01). In the CEA group, all patients with ischemic lesions were asymptomatic whereas in the CAS group 5 were symptomatic (14.3%) and 7 asymptomatic (20%). The cerebral distribution also differed in the two groups: no CEA but 20% of CAS lesions were contralateral. CONCLUSION: CAS is associated with a significantly higher rate of cerebral embolization than CEA. Even though the clinical meaning of new postoperative ischemic lesions remains debatable, it seems prudent to reduce the embolic load by improving procedural techniques and cerebral protection devices.

[Carotid-carotid bypass. Indications and results]. / Bypass carotido-carotideo. Indicazioni e risultati.

AIM: The aim of this study is to evaluate the indications for a carotid-carotid bypass and its therapeutic efficacy. METHODS: Between January 1995 and December 2001, 42 out of 782 patients with obstructive lesions of carotid vessels were submitted to carotid-carotid bypass. Preoperative investigations included Duplex scanning, transcranial Doppler and cerebral CT in all the patients, angiography in 24, spiral CT in 8, MR angiography in 6. Carotid bypass was planned pre-operatively in 13 cases due to internal carotid occlusion in 4, to pseudo-occlusion in 8 and to restenosis in 1. In the remaining 29, due to a too thin residual wall or to the lack of a good clivage plane, a carotid bypass was planned intraoperatively. A PTFE graft was employed in 30 cases while the autologous saphenous vein in 12. Four patients were lost in a 12-80-month follow-up. No intra or postoperative mortality was recorded. RESULTS: Three patients died during the follow-up. In 1 patient the death followed an ischemic stroke due to bypass occlusion. Four bypasses became occluded, in 3 cases without clinical signs. Eight patients suffered by transient superior laryngeal nerve iniury. CONCLUSIONS: Carotid bypass, as an alternative to CEA, provides good results in the treatment of the patients with carotid stenosis, pseudo-occlusion or segmental occlusion. In most of the cases the surgical technique is planned intraoperatively but in selected cases angiographic findings, spiral CT and color flow duplex can suggest in the preoperative phase that carotid bypass is the best choice.