Recanalization of the Chronically Occluded Internal Carotid Artery: Review of the Literature

INTRODUCTION: We reviewed the literature on interventions for patients with medically refractory chronically occluded internal carotid artery (COICA) to assess the risks and/or benefits after recanalization via an endovascular technique (ET) or hybrid surgery (HS, i.e., ET plus carotid endarterectomy). METHODS: A systematic search of the electronic databases was performed. Patients with COICA were classified into 4 different categories according to Hasan et al classification. RESULTS: Eighteen studies satisfied the inclusion criteria. Only 6 studies involved an HS procedure. We identified 389 patients with COICA who underwent ET or HS; 91% were males. The overall perioperative complication rate was 10.1% (95% confidence interval [CI]: 7.4%–13.1%). For types A and B, the successful recanalization rate was 95.4% (95% CI: 86.5%–100%), with a 13.7% (95% CI: 2.3%–27.4%) complication rate. For type C, the success rate for ET was 45.7% (95% CI: 17.8%–70.7%), with a complication rate of 46.0% (95% CI: 20.0%–71.4%) for ET and for the HS technique 87.6% (95% CI: 80.9%–94.4%), with a complication rate of 14.0% (95% CI: 7.0%–21.8%). For type D, the success rate of recanalization was 29.8% (95% CI: 7.8%–52.8%), with a 29.8% (95% CI: 6.1%–56.3%) complication rate. Successful recanalization resulted in a symmetrical perfusion between both cerebral hemispheres, resolution of penumbra, normalization of the mean transit time, and improvement in Montreal Cognitive Assessment (MoCA) score (ΔMoCA = 9.80 points; P = 0.004). CONCLUSIONS: Type A and B occlusions benefit from ET, especially in the presence of a large penumbra. Type C occlusions can benefit from HS. Unfortunately, we did not identify an intervention to help patients with type D occlusions. A phase 2b randomized controlled trial is needed to confirm these findings.