Spotlight on clinical strategies of Chronic Internal Carotid Artery Occlusion: Endovascular interventions and external-intracarotid bypasses compared to conservative treatment

Comparison of the treatment strategies for symptomatic chronic internal carotid artery occlusion

OBJECTIVE

The best management of symptomatic chronic internal carotid artery occlusion (CICAO) has been controversial. This systematic review and meta-analysis were to compare the outcomes of different treatment strategies for symptomatic CICAO.

METHODS

Two independent researchers conducted a search of articles on the treatment of CICAO published between January 2000 and October 2023 in PubMed, Web of Science, Embase, and The Cochrane Library. Twenty-two articles were eligible for meta-analysis using a random effects model to combine and analyze the data for the pooled rates of stroke and death, and the rates of procedural success and significant restenosis/occlusion.

RESULTS

A total of 1193 patients from 22 publications were included in this study. Six of them had bilateral internal carotid artery occlusion. The 30-day stroke and death rates were 1.1% (95% confidence interval [CI], 0%-4.4%) in the best medical treatment (BMT) group, 4.1% (95% CI, 0.7%-9.3%; I2 = 71.4%) in the extracranial-intracranial (EC-IC) bypass group, 4.4% (95% CI, 2.4%-6.8%; I2 = 0%) in the carotid artery stenting (CAS) group, and 1.2% (95% CI, 0%-3.4%; I2 = 0%) in the combined carotid endarterectomy (CEA) and stenting (CEA + CAS) group. During follow-up of 16.5 (±16.3) months, the stroke and death rates were 19.5%, 1.2%, 6.6%, and 2.4% in the BMT, EC-IC, CAS, and CEA + CAS groups respectively. The surgical success rate was 99.7% (95% CI, 98.5%-100%; I2 = 0%) in the EC-IC group, 70.1% (95% CI, 62.3%-77.5%; I2 = 64%) in the CAS group, and 86.4% (95% CI, 78.8%-92.7%; I2 = 60%) in the CEA + CAS group. The rate of post-procedural significant restenosis or occlusion was 3.6% in the EC-IC group, 18.7% in the CAS group, and 5.7% in the CEA + CSA group. The surgical success rate was negatively associated by the length of internal carotid artery (ICA) occlusion. Surgical success rate was significantly higher in the patients with occlusive lesion within C1 to C4 segments, compared with those with occlusion distal to C4 segment (odds ratio, 11.3; 95% CI, 5.0-25.53; P < .001). A proximal stump of ICA is a favorable sign for CAS. The success rate of CAS was significantly higher in the patients with an ICA stump than that in the patients without (odds ratio, 11.36; 95% CI, 4.84-26.64; P < .01). However, the success rate of CEA + CAS was not affected by the proximal ICA stump.

CONCLUSIONS

For the management of symptomatic CICAO, BMT alone is associated with the highest risk of mid- and long-term stroke and death. EC-IC bypass surgery and CEA + CAS should be considered as the choice of treatment based on operator's expertise and patient's anatomy. CAS may be employed as an alternative option in high surgical risk patients, especially when proximal ICA stump exists.

Significance of atherosclerotic plaque location in recanalizing non-acute long-segment occlusion of the internal carotid artery

To investigate the significance of atherosclerotic plaque location in hybrid surgery comprising both endovascular recanalization approaches and carotid endarterectomy for symptomatic atherosclerotic non-acute long-segment occlusion of the internal carotid artery (ICA), 162 patients were enrolled, including 120 (74.1%) patients in the proximal plaque group and 42 (25.9%) in the distal plaque group. Surgical recanalization was performed in all patients, with successful recanalization in 119 (99.2%) patients in the proximal and 39 (92.9%) in the distal plaque group. The total successful recanalization rate was 97.5% (158/162) with a failure rate of 2.5% (4/162). Periprocedural complications occurred in 5 (4.2% or 5/120) patients in the proximal plaque group, including neck infection in two (1.7%), recurrent nerve injury in 1 (0.8%), and laryngeal edema in 2 (1.7%), and 2 (4.8%) in the distal plaque group, including femoral puncture infection in 2 (4.8%). No severe complications occurred in either group. Univariate analysis showed plaque location was a significant (P = 0.018) risk factor for successful recanalization, and multivariate analysis indicated that the plaque location remained a significant independent risk factor for recanalization success (P = 0.017). In follow-up 6-48 months after the recanalization surgery, reocclusion occurred in two (2.8%) patients in the proximal plaque group and 4 (13.3%) in the distal plaque group. In conclusion, although hybrid surgery achieves similar outcomes in patients with ICA occlusion caused by either proximal or distal atherosclerotic plaques, plaque location may be a significant risk factor for successful recanalization of symptomatic non-acute long-segment ICA occlusion.

Recanalization of chronic long-segment occlusion of the internal carotid artery with endovascular and hybrid surgery

To investigate the effect of endovascular and/or hybrid surgical recanalization on chronic long-segment occlusion of the internal carotid artery (ICA) and the effect of occlusion location on the recanalization rate and prognosis, 87 patients with chronic ICA occlusion treated with endovascular approach only or hybrid surgery were retrospectively enrolled. The duration of ICA occlusion ranged from 21 to 360 days (median 30). Type I occlusion (from the neck to below the cavernous segment) consisted of 46 (52.8%) patients while type II (from the neck to above the clinoid segment) of 41 (47.1%). Hybrid surgery was performed in 44 (50.6%) patients while endovascular recanalization only was conducted in the other 43 (49.4%). In all patients, the success rate of recanalization was 93.0% (40/43) for the endovascular approach and 95.5% for the hybrid surgical approach. In patients with type I occlusion, endovascular recanalization only was performed in 22 (47.8%) patients and hybrid surgery in 24 (52.2%), resulting in successful recanalization in all patients (100%). In patients with type II occlusion, the success rate of recanalization was 85.7% (18/21) for the endovascular approach only but 90% (18/20) for the hybrid surgery. The total success rate of recanalization was 94.3% (82/87) for all patients, 100% for type I occlusion, and 87.8% for type II occlusion. No significant (P = 0.12) differences existed in the recanalization rate between groups I and II. Clinical follow-up was performed in 82 (94.3%) patients 6-39 months (mean 16) after the surgery. Re-occlusion occurred in 0 in group I but in four (9.8%) in group II. The mRS was good with 0-2 in 38 (82.6%) patients in group I and in 27 (75%) patients in group II, with no significant (P = 0.78) difference. In conclusion, chronic long-segment ICA occlusion can be safely and efficiently recanalized with the endovascular and hybrid surgery. The location of ICA occlusion may have a critical role in determining the recanalization rate, and careful evaluation of the occlusion location may be helpful in increasing the prognosis of recanalization.