Predictors for Successful Endovascular Intervention in Chronic Carotid Artery Total Occlusion

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.

Feasibility and efficiency of a new classification based on high-resolution MRI for carotid artery pseudo-occlusion and occlusion: Hybrid revascularization pilot study

BACKGROUND AND PURPOSE

Studies on changes in the distal internal carotid artery based on high resolution magnetic resonance imaging (HRMRI) are scarce. Herein, we propose a histological classification system for patients with carotid artery pseudo-occlusion or occlusion based on preoperative HRMRI, for which we evaluated the feasibility and clinical implications.

MATERIALS AND METHODS

From January 2017 to June 2021, 40 patients with Doppler ultrasound, CTA or MRA suggesting carotid artery occlusion were enrolled in this study. A new classification system based on HRMRI was established and subsequently verified by postoperative specimens. We recorded and analyzed patient characteristics, HRMRI data, recanalization rate, requirements of additional endovascular procedures, complications, and outcomes.

RESULTS

Four histological classifications (type Ⅰ-Ⅳ) were identified. According to our classification system, 20 patients (50.00%) were type I, nine (22.50%) were type II, 7 (17.50%) were type III, and four (10.00%) were type Ⅳ. The success rate of recanalization was 88.89% (32/36) in type I-III patients. Four (44.44%) type Ⅱ patients and five (71.43%) type Ⅲ patients suffered from intraoperative dissection.

CONCLUSION

Patients identified as types I (pseudo-occlusion) and II (thrombotic-occlusion) were able to be treated via hybrid revascularization with relatively low risk, while patients identified as type III (fibrous-occlusion) required more careful treatment. Recanalization is not suitable for patients identified as type Ⅳ. Our proposed classification system based on HRMRI data can be used as an adjunctive guide to predict the technical feasibility and success of revascularization via a hybrid technique.

Incidence and predictors of restenosis following successful recanalization of non-acute internal carotid artery occlusion in 252 cases

BACKGROUND

Data concerning restenosis following successful recanalization of non-acute internal carotid artery occlusion (ICAO) are scarce. This study was conducted to identify the incidence and predictors of restenosis following successful recanalization of non-acute ICAO.

METHODS

We reviewed the incidence of restenosis (defined as >70% restenosis or reocclusion) among 252 consecutive patients with successful recanalization of non-acute ICAO. Baseline, imaging, and surgery-related characteristics were analyzed to assess their association with restenosis. A scoring system was developed to identify high-risk patients for restenosis.

RESULTS

During a median follow-up of 12.6 months, restenosis occurred in 56 patients (22.2%), including 39 with reocclusion and 17 with >70% restenosis. The cumulative restenosis rate was 18.0% at 12 months and 24.1% at 24 months. The incidence of stroke was higher in patients with restenosis (25.0% vs 1.5%, P<0.01). Multivariate analysis showed occlusion length (5-10 cm vs <5 cm (hazard ratio (HR) 3.15, 95% confidence interval (95% CI) 1.07 to 9.29); ≥ 10 cm vs <5 cm (HR 5.01, 95% CI 1.73 to 14.49)), residual stenosis ≥30% (HR 3.08, 95% CI 1.79 to 5.30), and internal carotid artery (ICA) wall collapse (HR 1.96, 95% CI 1.12 to 3.44) as independent predictors of restenosis. Point scores proportional to model coefficients were assigned, with scores ranging from 0 to 6. Patients scoring 3-6 had a 4.00 times higher chance of developing restenosis (95% CI 2.35 to 6.79) compared with those scoring 0-2.

CONCLUSIONS

Nearly one in five patients experienced restenosis following successful recanalization of non-acute ICAO. Occlusion length, residual stenosis ≥30%, and ICA wall collapse were independently associated with restenosis.

Management of intervenable factors to reduce vascular complications in patients with internal carotid artery occlusion treated by non-emergency endovascular treatment

Objective

This study aims to identify risk factors for vascular complications during non-emergency endovascular treatment in patients with internal carotid artery occlusion (ICAO) and to propose potential interventions.

Method

A retrospective analysis of 92 patients with ICAO who received non-emergency endovascular treatment in our center from 1 January 2018 to 31 June 2023, was conducted. The correlation between intraoperative vascular complications and potential risk factors was studied, and interaction analysis was performed.

Results

Our findings revealed that the use of non-neurology guide wires to open vessels (adjusted OR: 4.1, 95%CI: 1.3-12.8; p = 0.014) and glycosylated hemoglobin (HbA1c) ≥ 6.5 mmol/L (adjusted OR: 3.2, 95%CI: 1.2-8.9; p = 0.023) was significantly associated with vascular complications in non-emergency endovascular treatment of ICAO patients. The restricted cubic spline (RCS) showed that the higher the HbA1c level, the higher the risk of vascular complications.

Conclusion

The use of non-neurology guide wires for vessel opening during non-emergency endovascular treatment in patients with ICAO increases the risk of vascular complications. Preoperative assessment and management of HbA1c levels can reduce the incidence of intraoperative vascular complications.

A nomogram predicting the relationship between recanalization time and successful endovascular recanalization of non-acute internal carotid artery occlusion in a Chinese population

Different recanalization times for endovascular interventions may affect the success of non-acute internal carotid artery occlusion procedures. Nomograms can provide personalized and more accurate risk estimates based on predictive values. Therefore, we developed a nomogram to predict the probability of success of endovascular recanalization procedures for non-acute internal carotid artery occlusion. We performed a single-center retrospective analysis of data collected from patients who underwent endovascular treatment for non-acute internal carotid artery occlusion between January 2015 and December 2022. Multifactorial logistic regression analyses were performed to identify independent predictors affecting the success rate of non-acute internal carotid artery occlusion procedures and to create nomograms. The model was differentiated and calibrated using the area under the ROC curve (AUC-ROC) and calibration plots. Internal validation of the model was performed by using resampling (1000 replications). In total, 46 patients were identified and a total of 39 patients met the study criteria. Predictors in the nomogram included vascular occlusion proximal morphology, reversed flow of the ophthalmic artery, and recanalization time. The model showed good resolution with an ROC area of 0.917 (95% CI: 0.814-0.967). The nomogram can be used to personalize, visualize, and accurately predict the surgical success of endovascular treatment of non-acute internal carotid artery occlusion.

A proposed modern standardized technical approach for symptomatic chronic carotid total occlusion management

Chronic carotid total occlusion (CCTO) is a known cause of ischemic stroke and transient ischemic attack. Symptomatic CCTO is associated with up to 30% risk of recurrent ischemic stroke, despite optimal medical treatment. Notably, a randomized controlled trial reported that previous surgical management did not improve the overall prognosis of these patients. Endovascular treatment of CCTO has been proposed as a feasible strategy to re-establish cerebral perfusion in symptomatic patients. However, its use is controversial and not supported by evidence from randomized clinical trials. Recently, a meta-analysis reported a reasonably high procedural success without an excess periprocedural complication rate, but several steps are needed before the procedure is mature enough to be tested in randomized controlled trials. This review highlights the developments in the endovascular recanalization of CCTO and emphasizes key steps towards standardizing the procedure.

Hybrid Surgery for Revascularization of Chronic Occlusion of Internal Carotid Artery

OBJECTIVE

The aim of this study was to conclude the safety and effectiveness of hybrid surgery for revascularization of chronic occlusion of internal carotid artery (COICA).

METHODS

A total of 56 COCIA patients underwent hybrid surgery (carotid endarterectomy+carotid artery stenting) from September 2017 to September 2021 in our department. The clinical material and radiology data (preoperation and postoperation) were retrospectively analyzed to conclude the safety and effectiveness of hybrid surgery for revascularization of COICA.

RESULTS

All 56 patients underwent hybrid surgery got revascularization successfully (with a successful rate of 100%) and improved intracranial blood flow. The computed tomography perfusion results indicate that the postoperative cerebral blood flow perfusion of the patient is significantly improved compared with before surgery. In 1 patient, postoperative brain magnetic resonance imaging within 24 hours showed spotted fresh infarction with head magnetic resonance imaging, without any clinical symptoms; 3 patients developing symptoms of ipsilateral neural-functional defect (hypoglossal nerve, superior laryngeal nerve, and mandibular branch of facial nerve, respectively), 2 weeks later the symptoms were disappeared. Imaging study at 3 and 6 months during the follow-up showed no abnormalities.

CONCLUSION

Hybrid surgery is safe and effective for revascularization of COICA.

Predictors of successful endovascular recanalization in patients with symptomatic nonacute intracranial large artery occlusion

BACKGROUND

Endovascular recanalization in patients with symptomatic nonacute intracranial large artery occlusion (ILAO) has been reported to be feasible, but technically challenging. This study aimed to determine the predictors of successful endovascular recanalization in patients with symptomatic nonacute ILAO.

METHODS

The outcomes of endovascular recanalization attempts performed in 70 consecutive patients showing symptomatic nonacute ILAO with hemodynamic cerebral ischemia between January 2016 to December 2022 were reviewed. Potential variables, including clinical and radiological characteristics related to technical success, were collected. Univariate analysis and multivariate logistic regression were performed to identify predictors of successful recanalization for nonacute ILAO.

RESULTS

Technically successful recanalization was achieved in 57 patients (81.4%). The periprocedural complication rate was 21.4% (15 of 70), and the overall 30-day morbidity and mortality rates were 7.1% (5 of 70) and 2.9% (2 of 70), respectively. Univariate analysis showed that successful recanalization was associated with occlusion duration, stump morphology, occlusion length, slow distal antegrade flow sign, and the presence of bridging collateral vessels. Multivariate analysis showed that occlusion duration ≤ 3 months (odds ratio [OR]: 22.529; 95% confidence interval [CI]: 1.636-310.141), tapered stump (OR: 7.498; 95% CI: 1.533-36.671), and occlusion length < 10 mm (OR: 7.049; 95% CI: 1.402-35.441) were independent predictive factors for technical success of recanalization.

CONCLUSIONS

Occlusion duration ≤ 3 months, tapered stump, and occlusion length < 10 mm were independent positive predictors of technical success of endovascular recanalization for symptomatic nonacute ILAO. These findings may help predict the likelihood of successful recanalization in patients with symptomatic nonacute ILAO and also provide a reference for the selection of appropriate patients. Further prospective and multicenter studies are required to validate our findings.

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.

Endovascular recanalization for symptomatic chronic internal carotid artery occlusion: proposal of a modified angiographic classification and clinical outcomes

PURPOSE

To stratify angiographic images of chronic internal carotid artery occlusion (CICAO) into a newly modified angiographic classification, and identify suitable candidates for endovascular recanalization.

METHODS

This study included 51 consecutive patients with symptomatic CICAO who underwent endovascular recanalization at our institution. Patients' clinical information, angiographic findings, procedural results, and outcomes were recorded. We attempted to stratify all angiographic images into categories based on morphological occlusive patterns and distal internal carotid artery (ICA) lumen reconstitution on digital subtraction angiography (DSA).

RESULTS

Four types (I-IV) of CICAO were identified based on angiographic characteristics. We defined type I as having a tapered (IA) or blunt stump (IB) and distal ICA lumen reconstitution with collateral filling; type II as having no stump but with distal ICA lumen reconstitution; type III as having a tapered (IIIA) or blunt stump (IIIB) but no distal ICA lumen reconstitution; type IV as having no stump and no distal ICA lumen reconstitution. The rate of successful recanalization was 90.3 % for type I, 60.0 % for type II, 50.0 % for type III, 0 % for type IV, respectively (P = 0.002). The overall intraoperative complication rate was 11.8 %, and none of them led to severe neurological damage or death. The follow-up modified Rankin Scale (mRS) scores were significantly decreased in successfully revascularized patients, whilst there were no significant changes in the other failed patients.

CONCLUSION

For symptomatic CICAO, our newly modified angiographic classification may be comprehensive and useful in selecting suitable patients for recanalization and grading the difficulty of the procedures.

The efficacy of STA-MCA double anastomosis comparing to single anastomosis in chronic internal carotid artery occlusion patients

OBJECTIVE

To investigate the efficacy of STA-MCA double-anastomosis and single-anastomosis in patients with cerebral hypoperfusion caused by chronic internal carotid artery occlusion(CICAO).

METHODS

In this retrospective study, data were collected from 19 patients with CICAO who underwent STA-MCA anastomosis at our hospital between January 2016 and January 2022, and they were divided into single anastomosis group and double anastomosis group according to the surgical method. The study collected general clinical data from both groups, including age, sex, lipid levels, blood pressure, glucose levels, smoking and alcohol consumption. Additionally, pre- and postoperative neurological function, cerebral hemodynamic parameters, and postoperative ischemic events were also recorded. By combining our study findings with the existing literature, a comparative analysis of the efficacy of single- and double-anastomosis in patients with CICAO was conducted.

RESULTS

Prior to surgical treatment，there were no statistically significant differences in cerebral hemodynamic parameters, including rob (0.65 ± 0.09 VS. 0.62 ± 0.04), rut (1.73 ± 0.40 VS. 1.99 ± 0.53), and rTMax (2.02 ± 0.49 VS. 1.72 ± 0.46), as well as neurofunctional scores, including modified Rankin Scale (MRS) (2.8 ± 1.03 VS. 2.4 ± 0.88) and National Institutes of Health Stroke Scale (NIHSS) (9.1 ± 5.08 VS. 8.3 ± 4.09) between the two groups. After operation, rCBF (single: 0.65 ± 0.09 VS.0.84 ± 0.08, p = 0.007; double: 0.62 ± 0.04 VS.1.08 ± 0.20, p = 0.001) were significantly increased in both groups, but the rMTT (1.99 ± 0.53 VS.1.27 ± 0.42, p = 0.0447) and rTMax (1.72 ± 0.46 VS.1.16 ± 0.16, p = 0.038) showed significant differences postoperatively only in the double-anastomosis group. The MRS (single: 1.8 ± 1.23, double: 1.7 ± 0.9) in both groups and the NIHSS (7.2 ± 5.11) in single-anastomosis group were not improved after surgery, while the NIHSS (8.3 ± 4.09 VS.4.4 ± 3.08, p = 0.037) in double-anastomosis group was improve significantly. In summary, the double-anastomosis group showed better improvement in rCBF and NIHSS scores compared to the single-anastomosis group.(ΔrCBF: 0.19±0.09 VS. 0.45±0.18, p=0.02, ΔNIHSS: 1.9±0.56 VS. 4±1.73, p=0.002). The cases were followed up for 20.3 ± 18.6 months, and there were no ischemic events in either group during the follow-up period.

CONCLUSION

STA-MCA revascularization can improve CBF in patients with hypoperfusion caused by CICAO, and prevent the reoccurrence of ischemic stroke effectively. Compared with single-anastomosis, double-anastomosis can provide more CBF and improve neurologic dysfunction.

Subintimal recanalization for non-acute occlusion of intracranial vertebral artery in an emergency endovascular procedure: A case report

BACKGROUND

Endovascular recanalization of non-acute intracranial artery occlusion is technically difficult, particularly when the microwire enters the subintima. Although the subintimal tracking and re-entry technique has been well established in the endovascular treatment of coronary artery occlusion, there is limited experience with its use in intracranial occlusion due to anatomical variations and a lack of dedicated devices.

CASE SUMMARY

A 74-year-old man was admitted to the hospital two days after experiencing acute weakness in both lower extremities, poor speech, and dizziness. After admission, imaging revealed acute ischemic stroke and non-acute occlusion of bilateral intracranial vertebral arteries (ICVAs). On the fourth day of admission, the patient's condition deteriorated and an emergency endovascular recanalization of the left ICVA was performed. During this procedure, a microwire was advanced in the subintima of the vessel wall and successfully reentered the distal true lumen. Two stents were implanted in the subintima. The patient's Modified Rankin Scale was 1 at three months postoperatively.

CONCLUSION

We present a technical case of subintimal recanalization for non-acute ICVA occlusion in an emergency endovascular procedure. However, we emphasize the necessity for caution when applying the subintimal tracking approach in intracranial occlusion due to the significant dangers involved.

A single-center retrospective study of the COCO technique in the treatment of chronic internal carotid artery occlusion

OBJECTIVE

To introduce a novel endovascular recanalization method and to investigate its success rate, periprocedural complications, and early outcomes in patients with chronic internal carotid artery occlusion (CICAO). As this novel technique was designed to treat CICAO with a full coaxial system, we named it the COCO technique.

METHODS

Data from consecutive patients with symptomatic CICAO who underwent endovascular recanalization in our institution were retrospectively reviewed. The COCO technique allows extracranial angioplasty and stenting with occasional intracranial angioplasty and stenting as needed to be performed in a coaxial fashion. Patients' demographic and clinical information, morphologic characteristics, procedural results, complications, and follow-up outcomes were recorded.

RESULTS

Forty-nine patients were enrolled in this study. The technical success rate was 89.8% (44/49). Four patients experienced intraoperative complications, two patients had a slight subarachnoid hemorrhage, and two patients had asymptomatic dissection. Distal embolization or carotid-cavernous arteriovenous fistula was not detected. In addition, three patients developed hemorrhagic complications and three developed postoperative ischemic complications. All these patients improved after conservative treatment and subsequent rehabilitation. During the median 6 (3-6) months of follow-up, one patient died of severe pneumonia and two patients experienced recurrent ischemic events. In patients with successful recanalization, modified Rankin Scale scores were lower at the 3-month follow-up than at baseline (1 (0-2) vs 2 (1-2), P=0.04). Restenosis was observed in six (15.8%) patients.

CONCLUSIONS

Our study showed that the COCO technique is effective and safe for endovascular recanalization in patients with CICAO and has low periprocedural complications and favorable functional outcomes.

Combined Endovascular Antegrade and Direct Retrograde Carotid Artery Stenting for Chronic and Long Segment Common Carotid Artery Occlusion: Technical Note and Review of Literature

Common carotid artery (CCA) occlusion (CCAO) is a rare cause of ischemic stroke and bypass surgery is the common treatment approach. However, safer alternatives should be developed to treat CCAO. A 68-year-old male was diagnosed with left-sided CCAO with decreased left visual acuity due to neck radiation therapy for laryngeal cancer. Recanalization therapy using a pull-through technique was initiated because cerebral blood flow progressively decreased during the follow-up period. First, after a short sheath was inserted into the CCA, the occluded CCA was retrogradely penetrated through the sheath. Second, a micro-guidewire was guided to the aorta from the femoral sheath where it was caught using a snare wire guided from the cervical sheath. Subsequently, the micro-guidewire was gently pulled out from the cervical sheath, penetrated the occluded lesion, and was secured to the femoral and cervical sheaths. Finally, the occluded lesion was dilated using a balloon, and the stent was placed. Five days postprocedure, the patient was discharged uneventfully and exhibited improved left visual acuity. In terms of reliable penetration of obstructive lesions and reduction of embolic and hemorrhagic complications, combined endovascular antegrade and direct retrograde carotid artery stenting is a versatile and minimally invasive treatment option for CCAO.

Endovascular Recanalization of Symptomatic Chronic ICA Occlusion: Procedural Outcomes and Radiologic Predictors

BACKGROUND AND PURPOSE

Endovascular recanalization has been attempted in patients with symptomatic chronic ICA occlusion, however, the heterogeneity of recanalization outcomes and the perioperative complications present challenges for the clinical application. Our aim was to evaluate the safety and efficacy of endovascular recanalization for symptomatic chronic ICA occlusion and identify potential predictors for successful recanalization.

MATERIALS AND METHODS

This study included 47 consecutive patients with symptomatic chronic ICA occlusion who underwent endovascular recanalization at our institution. Patients' clinical information, radiologic characteristics, procedural results, and outcomes were recorded. Factors related to technical success were analyzed by univariate and multivariate analyses.

RESULTS

The technical success rate was 74.5% (35/47); 12.8% of patients (6/47) experienced intraoperative complications, but none had permanent neurologic deficits. Three months after recanalization, 21 of the 29 recanalized patients (72.4%) and 3 of the 10 failed patients (30.0%) demonstrated improved mRS scores. Restenosis or re-occlusion occurred in 12.9% of patients (4/31) with successful recanalization. Multivariate analysis showed that tapered or blunt stump (P  = .016), distal ICA occlusion segment (below the cavernous segment versus at or above the ophthalmic segment, P  = .003; at the cavernous or clinoid segment versus at or above the ophthalmic segment, P  = .027), and radiologic occlusion to recanalization of ≤3 months (P  = .044) were significantly associated with successful recanalization. Patients were assigned points according to the coefficients of the prediction model, and the technical success rates were 0%, 46.2%, 90.5%, and 100% in patients with 1, 2, 3, and 4 points, respectively.

CONCLUSIONS

Endovascular recanalization is a safe and effective treatment for symptomatic chronic ICA occlusion in selected patients. A residual stump, low levels of the distal ICA occlusion segment, and a short radiologic occlusion time were identified as positive predictors of technical success.

Clinical study on endovascular recanalization of non-acute symptomatic middle cerebral artery occlusion

Objective

Endovascular recanalization in patients with non-acute symptomatic middle cerebral artery occlusion remains clinically challenging. Here, we aimed to evaluate the feasibility and safety of endovascular recanalization for non-acute symptomatic middle cerebral artery occlusion and propose a new patient classification.

Methods

Between January 2019 and December 2021, 88 patients with non-acute symptomatic middle cerebral artery occlusion underwent prospective endovascular recanalization at our hospital. All patients were divided into three groups according to occlusion length, occlusion duration, occlusion nature, calcification of the occlusion site, and occlusion angulation. The indicators of each group were analyzed, including general baseline data, imaging data, surgical conditions, and follow-up results.

Results

Of the 88 patients, 73 were successfully recanalized and 15 were abandoned because the instruments either could not reach the distal true lumen of the occlusion or broke through the blood vessels. The overall technical success rate was 83.0% (73/88), and perioperative complications occurred in 15 patients. Preoperatively, all patients were divided into three risk groups: low, medium, and high. From the low- to high-risk groups, the recanalization rate gradually decreased (100.0, 91.7, and 16.7%, respectively, P = 0.020), the perioperative complication rate gradually increased (0, 13.9, and 83.3%, respectively, P < 0.001), the proportion of the modified Rankin scale scores >2 at 90 days increased (0, 11.7, and 50.0%, P < 0.001), and the restenosis/reocclusion rates in the 73 cases of successful recanalization increased (0, 16.1, and 100%, P = 0.012) during follow-up.

Conclusion

Endovascular recanalization may be feasible and safe in well-selected patients with non-acute symptomatic middle cerebral artery occlusion, especially in the low- and medium-risk groups.

Morphological and Compositional Features of Chronic Internal Carotid Artery Occlusion in MR Vessel Wall Imaging Predict Successful Endovascular Recanalization

Background: We sought to determine if the morphological and compositional features of chronic internal carotid artery occlusion (CICAO), as assessed by MR vessel wall imaging (MR-VWI), initially predict successful endovascular recanalization. Methods: Consecutive patients with CICAO scheduled for endovascular recanalization were recruited. MR-VWI was performed within 1 week prior to surgery for evaluating the following features: proximal stump morphology, extent of occlusion, occlusion with collapse, arterial tortuosity, the presence of hyperintense signals (HIS) and calcification in the occluded C1 segment. Multivariate logistic regression was used to identify features associated with technical success and construct a prediction model. Results: Eighty-three patients were recruited, of which fifty-seven (68.7%) were recanalized successfully. The morphological and compositional characteristics of CICAO were associated with successful recanalization, including occlusions limited to C1 and extensive HIS, as well as the absence of extensive calcification, absence of high tortuosity, and absence of artery collapse. The MR CICAO score that comprised the five predictors showed a high predictive ability (area under the curve: 0.888, p < 0.001). Conclusion: the MR-VWI characteristics of CICAO predicted the technical success of endovascular recanalization and may be leveraged for identifying patients with a high probability of successful recanalization.

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

Chronic internal carotid artery occlusion (CICAO) has high prevalence and incidence rates, and patients with CICAO can be completely asymptomatic, experience a devastating stroke or die. It is important to note that CICAO causes cerebrovascular accidents. Currently, the external carotid-internal carotid (EC-IC) bypass technique is used to treat CICAO. However, many clinical studies showed that EC-IC bypass was not beneficial for many patients with CICAO. Meanwhile, endovascular intervention treatment options for CICAO are evolving, and an increasing number of patients are undergoing endovascular intervention therapy. Accordingly, a review comparing both techniques is warranted. For this review, we searched PubMed and collected relevant case study reports comparing endovascular interventional therapy and internal and external cervical bypass surgeries to provide strategies for clinical treatment.

Primary balloon angioplasty for chronic occlusion of intracranial internal carotid artery: A case report

Chronic occlusion of large intracranial arteries is the main cause of ischemic stroke in China. Patients with symptomatic intracranial artery occlusion and hemodynamic impairment are at high risk of recurrent stroke. Chronic occlusion of the intracranial segment of the internal carotid artery is a common type of intracranial artery occlusion. Medical management is regarded as the standard treatment for this disease. With the development of endovascular treatment, some patients with chronic cerebral artery occlusion have achieved satisfactory results with endovascular therapy. We reported a patient with symptomatic chronic occlusion of the ophthalmic segment of the internal carotid artery. Simple balloon angioplasty was performed, and the occluded ophthalmic segment of the internal carotid artery was successfully recanalized without perioperative complications. At 4 months follow-up, the internal carotid artery remained patent and perfusion of the right cerebral hemisphere improved dramatically. In addition, we briefly reviewed the relevant literature.

Case of effective suction to secure the true lumen for acute occlusion after carotid endarterectomy

During or following carotid endarterectomy, dissection and occlusion of the internal carotid artery can occur. In cases of stenosis or almost complete occlusion, recanalization is relatively easy; however, in cases of complete occlusion, advancing a guidewire into the true lumen may be challenging. Few reports on how to address this problem have been published. Here, we report a case of suction-enabled advancement of the wire into the true lumen during endovascular treatment of an acute occlusion of the internal carotid artery after carotid endarterectomy. An 80-year-old man underwent carotid endarterectomy; the next morning, he exhibited aphasia and right-sided paralysis, and magnetic resonance images showed left cerebral infarction and left internal carotid artery occlusion. The patient was transferred to our hospital for recanalization. Imaging with contrast material showed that the left internal carotid artery was completely occluded. During recanalization, futile attempts were made to advance the wire into the true lumen. The occlusion was aspirated, and angiography then showed an inflow of contrast material into the vessel, which indicated slight distal widening; this widening allowed the wire to move into the true lumen. The occlusion extended distally, and 2 stents were placed over the entire lesion. Good recanalization was eventually achieved.

Association of occlusion time with successful endovascular recanalization in patients with symptomatic chronic intracranial total occlusion

OBJECTIVE

Endovascular treatment is one of the choices for symptomatic chronic intracranial total occlusion (CITO); however, its safety and efficacy remain unclear. The present study was performed to evaluate the safety and long-term outcome of endovascular treatment for CITO at a high-volume stroke center.

METHODS

Data about patients with symptomatic CITO who received endovascular treatment were retrospectively collected. Technique success was regarded as ≤ 30% residual stenosis. Periprocedural complications within 30 days were used to evaluate safety. Baseline characteristics and lesion features were compared between patients with successful recanalization and those with recanalization failure. Stroke recurrence and in-stent restenosis (ISR) of the culprit arteries during follow-up were used to evaluate long-term efficacy.

RESULTS

From June 2012 to September 2019, 117 patients (mean ± SD age 55.8 ± 9.6 years) were included. The successful recanalization rate was 82.9% (97/117 patients). The combined rate of periprocedural stroke, myocardial infarction, and death was 8.5% (10/117). Compared with patients with successful recanalization, patients with recanalization failure had longer occlusion time and longer lesion length (27.0 mm vs 15.4 mm, p = 0.001). In the median 23.0-month clinical follow-up period, recurrent stroke occurred in 12.6% (11/87) of patients with successful recanalization. In the median 5-month imaging follow-up period, ISR was detected in 26.6% (21/79) of patients.

CONCLUSIONS

Endovascular treatment was relatively safe for patients with symptomatic CITO. Shorter occlusion time and shorter lesion length may be associated with higher recanalization rate. The rates of stroke recurrence and symptomatic ISR were acceptable but need to be confirmed in future studies.

The additional value of high-resolution vessel wall imaging in screening suitable chronic internal carotid artery occlusion candidates for endovascular recanalization: comparison with digital subtraction angiography

BACKGROUND

High-resolution vessel wall imaging (HR-VWI) can provide information about exact occluded length, etiology, and the presence of intraluminal thrombus or residual cavity.

PURPOSE

To investigate the extra value of HR-VWI in screening patients with chronic internal carotid artery occlusion (CICAO) for recanalization suitability in comparison with digital subtraction angiography (DSA).

MATERIAL AND METHODS

We retrospectively reviewed patients who underwent endovascular recanalization with no internal carotid artery signal on magnetic resonance angiography (MRA) and whose both preoperative DSA and HR-VWI data were available. Patients were classified into type I (focal occlusion distal to ophthalmic artery), type II or III (occlusion proximal or at/distal to clinoid segment), and near-occlusion. Occlusion etiology and suitability for recanalization were analyzed both on preoperative DSA and HR-VWI. Accuracy of occlusion classification and differences in the modified Rankin scale scores between the baseline and follow-up were estimated.

RESULTS

A total of 20 patients were included. With intraoperative DSA as the gold standard, we found HR-VWI could additionally show intraluminal thrombi. Preoperative DSA misclassified one near-occlusion, one type I occlusion, and one type II occlusion as type III occlusions, and one near-occlusion as a type II occlusion. Therefore, compared with the preoperative DSA, three additional cases were successfully recanalized based on HR-VWI. The accuracy of HR-VWI was higher than preoperative DSA (100% vs. 80%). Prognosis improvement of type I was significantly better than type II and near-occlusion (P<0.05).

CONCLUSION

HR-VWI can identify occluded etiology, extent, and classification of CICAO. This information is potentially useful in screening candidates for endovascular recanalization and helpful to indicate prognosis.

Hybrid surgery versus endovascular intervention for patients with chronic internal carotid artery occlusion: A single-center retrospective study

Objective

Chronic internal carotid artery occlusion (CICAO) can cause transient ischemic attack (TIA) and ischemic stroke. Carotid artery stenting (CAS) with embolic protection devices and hybrid surgery combining carotid endarterectomy and endovascular treatment are effective methods for carotid revascularization. The objective of this study was to evaluate and compare the effect and safety of the two surgical procedures.

Methods

This was a single-center retrospective study. In this study, 44 patients who underwent hybrid surgery and 35 who underwent endovascular intervention (EI) at our center were enrolled consecutively between May 2016 and March 2022. All patients were classified into four groups (A-D), as described by Hasan et al. We recorded and analyzed clinical data, angiographic characteristics, technical success rate, perioperative complications, and follow-up data.

Results

There was no significant difference in baseline characteristics between hybrid surgery group and EI group, except for plasma high density lipoproteins (HDL) levels (median [interquartile range]: hybrid surgery, 0.99 [0.88–1.18] vs. EI, 0.85 [0.78–0.98] mmol/L, P = 0.001). The technical success rate of hybrid surgery was higher than that of EI (37/44 [84.1%] vs. 18/35 [51.4%], P = 0.002; type A: 15/16 [93.8%] vs. 10/11 [90.9%], P = 1.000; type B: 9/10 [90.0%] vs. 5/7 [71.4%], P = 0.537; type C: 12/15 [80.0%] vs. 3/12 [25.0%], P = 0.004; type D: 1/3 [33.3%] vs. 0/5 [0%], P = 0.375). No significant difference was observed in the incidence of perioperative complications between the two procedures (hybrid surgery: 7/44 [15.9%] vs. EI: 6/35 [17.1%], P = 0.883). In addition, there were no significant differences in the rates of stroke and restenosis during follow-up.

Conclusions

For patients with symptomatic CICAO, hybrid surgery may have an advantage over EI in successfully recanalizing occluded segments. There was no significant difference in safety and restenosis between hybrid surgery and EI.

High-resolution magnetic resonance imaging for predicting successful recanalization in patients with chronic internal carotid artery occlusion

Objective

The main aim of the study was to investigate the predictive factors of high-resolution magnetic resonance imaging (HR-MRI) for successful recanalization in patients with chronic internal carotid artery occlusion (CICAO).

Methods

We included 41 consecutive patients who had CICAO and underwent recanalization attempts. The demographics, clinical data, and HR-MRI features in relation to the technique success were collected and analyzed using univariate and multivariate analyses. A score-based prediction model was constructed using a regression coefficient-based scoring method.

Results

Technical success was achieved in 26 (63.4%) patients, with a complication rate of 12.2% (5/41). Based on multivariate analysis, occlusions involving ophthalmic artery segment (C6) or above (OR: 0.036; 95% confidence interval [CI]: 0.004–0.336) and nontapered stump (OR: 0.064; 95% CI: 0.007–0.591) were identified as independent negative predictors of successful recanalization in patients with CICAO. Point scores were assigned according to the model coefficients, and the patients who scored 0, 1, or 2 points had success rates of 93.33% (14/15), 66.67% (12/18), or 0% (0/8), respectively.

Conclusion

HR-MRI characteristics may be valuable in identifying candidates for endovascular recanalization in patients with CICAO. Occlusions involving the C6 segment or higher, as well as nontapered stumps, were independent negative predictors of technical success.

High-resolution magnetic resonance vessel wall imaging-guided endovascular recanalization for nonacute intracranial artery occlusion

OBJECTIVE

On the basis of the characteristics of occluded segments on high-resolution magnetic resonance vessel wall imaging (MR-VWI), the authors evaluated the role of high-resolution MR-VWI-guided endovascular recanalization for patients with symptomatic nonacute intracranial artery occlusion (ICAO).

METHODS

Consecutive patients with symptomatic nonacute ICAO that was refractory to aggressive medical treatment were prospectively enrolled and underwent endovascular recanalization. High-resolution MR-VWI was performed before the recanalization intervention. The characteristics of the occluded segments on MR-VWI, including signal intensity, occlusion morphology, occlusion angle, and occlusion length, were evaluated. Technical success was defined as arterial recanalization with modified Thrombolysis in Cerebral Infarction grade 2b or 3 and residual stenosis < 50%. Perioperative complications were recorded. The characteristics of the occluded segments on MR-VWI were compared between the recanalized group and the failure group.

RESULTS

Twenty-five patients with symptomatic nonacute ICAO that was refractory to aggressive medical treatment were consecutively enrolled from April 2020 to February 2021. Technical success was achieved in 19 patients (76.0%). One patient (4.0%) had a nondisabling ischemic stroke during the perioperative period. Multivariable logistic analysis showed that successful recanalization of nonacute ICAO was associated with occlusion with residual lumen (OR 0.057, 95% CI 0.004-0.735, p = 0.028) and shorter occlusion length (OR 0.853, 95% CI 0.737-0.989, p = 0.035).

CONCLUSIONS

The high-resolution MR-VWI modality could be used to guide endovascular recanalization for nonacute ICAO. Occlusion with residual lumen and shorter occlusion length on high-resolution MR-VWI were identified as predictors of technical success of endovascular recanalization for nonacute ICAO.

High-Resolution MRI for Evaluation of the Possibility of Successful Recanalization in Symptomatic Chronic ICA Occlusion: A Retrospective Study

BACKGROUND AND PURPOSE

Accurate radiologic evaluation of the possibility of successful recanalization in symptomatic chronic ICA occlusion remains challenging. This study aimed to investigate the high-resolution MR imaging characteristics of symptomatic chronic ICA occlusion and their association with successful recanalization.

MATERIALS AND METHODS

Consecutive patients with symptomatic chronic ICA occlusion who underwent balloon dilation plus stent implantation were identified retrospectively and divided into 2 groups: a successful recanalization group and an unsuccessful recanalization group. Clinical and high-resolution MR imaging characteristics were compared between the groups. Univariate and multivariate analyses were used to identify the characteristics associated with successful recanalization.

RESULTS

A total of 114 patients were included in the study. High-resolution MR imaging characteristics independently associated with unsuccessful recanalization were longer lesion length (OR, 0.41; 95% CI, 0.36-0.55; P = .009) and larger calcification volume (OR, 0.56; 95% CI, 0.37-0.68; P = .002) for proximal occlusion and reversed distal ICA flow at the level of ophthalmic segment or above (OR, 0.14; 95% CI, 0.08-0.48; P = .001). Reversed distal ICA flow at the level of the petrous segment or below (OR, 4.07; 95% CI, 1.65-8.38; P = .001) and lumen area (OR, 1.13; 95% CI, 1.04-1.61; P = .002) for distal occlusion were risk factors of successful recanalization.

CONCLUSIONS

In symptomatic chronic ICA occlusion, lesion length and calcification volume (for proximal occlusion), the level of reversed distal ICA flow, and the lumen area (for distal occlusion) appear to be predictors of successful recanalization. High-resolution MR imaging can evaluate chronic ICA occlusion and help in clinical decision-making.

Retrograde endovascular revascularization for chronic total occlusion of the internal carotid artery: a case report

Endovascular revascularization of a chronically occluded internal carotid artery (ICA) is challenging because the occlusive segment can be long and tortuous. A case is presented of a successful recanalization of a chronically occluded ICA by retrograde passing of a guidewire from the intracranial ICA to the cervical ICA via the posterior communicating artery. This case suggests that a retrograde approach for reopening an occluded artery may be useful during neurovascular interventions, similar to percutaneous coronary interventions. In this patient, daily transient ischemic attacks disappeared after successful recanalization of the ICA.

Multimodal recanalization for subacute symptomatic internal carotid artery occlusion due to atherosclerosis: Outcomes and notes on hybrid techniques

OBJECTIVES

Subacute internal carotid artery occlusion (ICAO) is associated with ipsilateral recurrent stroke, and successful recanalization of ICAO can improve cerebral blood perfusion (CBP) and prevent stroke. However, the optimal treatment remains controversial.

METHODS

We conducted a retrospective analysis of patients with subacute symptomatic ICAO due to atherosclerosis treated at our center. The hybrid surgical procedures included carotid endarterectomy, Fogarty balloon catheter embolectomy, aspiration thrombectomy and percutaneous transluminal angioplasty/stenting. Recanalization rates, CBP improvement, stroke recurrence and restenosis/reocclusion were investigated.

RESULTS

Fourteen symptomatic atherosclerotic ICAO patients (type A, 4; type C, 10; men, 11; women, 3; average age, 68.1 ± 7.9 years) in the subacute phase were treated with a multimodal recanalization technique. Symptoms included mild cerebral infarction, transient ischemic attack (TIA) and amaurosis fugax. The average onset-to-treatment time was 18.1 ± 4.8 days. The successful recanalization (thrombolysis in cerebral ischemia grade 2 or 3) rate was 100%. The ipsilateral-to-contralateral mean transit time ratio was significantly lower at the 1-year follow-up than preoperatively (1.01 ± 0.05 vs. 1.26 ± 0.09, P < 0.0001). There was one case of restenosis detected 1 year after surgery and no cases of reocclusion. During the 28.3 ± 10.0 months of follow-up, only 2 cases of TIA occurred. The average modified Rankin Scale score and National Institute of Health Stroke Scale score were significantly lower at themost recent follow-up than before recanalization (1.21 ± 0.89 vs. 1.86 ± 0.66, P = 0.0003; 1.36 ± 1.55 vs. 2.00 ± 1.88, P = 0.0066).

CONCLUSION

Multimodal recanalization techniques performed in a hybrid operation theater can safely achieve high recanalization rates in atherosclerotic ICAO patients in the subacute phase, which can be beneficial for recovering CBP and preventing stroke.

Drug-Coated Balloon for the Treatment of Nonacute Symptomatic Intracranial Carotid Artery Terminus Occlusion: Initial Experience and Follow-Up Outcome

Background

Studies on the recanalization for occlusion of the internal carotid artery terminus are scattered. Recently, drug-coated balloon (DCB) has been increasingly applied in the intracranial artery occlusion and achieved encouraging results. However, there seems no convincing data for the nonacute symptomatic internal carotid artery terminus occlusion (sICATO).

Objective

To assess the feasibility and effectiveness (safety) of DCB for patients with nonacute sICATO refractory to medical therapy.

Approach

This study included 30 patients with nonacute sICATO treated with DCBs and/or remedial stenting. The rate of successful recanalization, periprocedural complications, and clinical and vascular imaging follow-up outcomes were retrospectively analyzed.

Results

Drug-coated balloon (DCB) dilatation of nonacute sICATO gives a 100% rate of successful recanalization, with a low complication rate (10.00%), good clinical outcomes (86.20%), low restenosis/reocclusion rate (3.45%), and one asymptomatic ipsilateral infarction (3.45%).

Conclusion

Drug-coated balloon dilation seems to be the promising treatment option for nonacute sICATO considering its safety and feasibility.

Symptomatic and Asymptomatic Chronic Carotid Artery Occlusion on High-Resolution MR Vessel Wall Imaging

BACKGROUND AND PURPOSE

Chronic carotid artery occlusion remains a poorly understood risk factor for subsequent stroke, and potential revascularization is dependent on understanding the anatomy and nature of the occlusion. Luminal imaging cannot assess the nature of an occlusion, so the internal structure of the occlusion must be inferred. The present study examines the signal characteristics of symptomatic and asymptomatic carotid occlusion that may point to management differentiation.

MATERIALS AND METHODS

We prospectively recruited patients who were diagnosed with chronic carotid artery occlusion defined as longer than 4 weeks and confirmed by DSA. All patients underwent high-resolution MR vessel wall imaging examinations after enrollment. Baseline characteristics, vessel wall imaging features, and DSA features were collected and evaluated. The vessel wall imaging features included segment involvement, signal intensity, contrast enhancement, and vessel wall thickness. The symptomatic and asymptomatic chronic carotid artery occlusions were compared.

RESULTS

A total of 44 patients with 48 lesions were included in this study from February 2020 to December 2020. Of the 48 lesions, 35 (72.9%) were symptomatic and 13 (27.1%) were asymptomatic. There was no difference in baseline and DSA features. On vessel wall imaging, C1 and C2 were the most commonly involved segments (91.7% and 68.8%, respectively). Compared with symptomatic lesions, asymptomatic lesions were more often isointense (69.2%) in the distal segment (P = .03). Both groups had diffuse wall thickening (80% and 100%).

CONCLUSIONS

Signal characteristics between those with symptomatic and asymptomatic carotid artery occlusions differ in a statistically significant fashion, indicating a different structure of the occlusion.

[A comparative analysis of the clinical and anamnestic status of patients with chronic occlusion of the carotid arteries based on the data of observational registries]

OBJECTIVE

To study the clinical and anamnestic status of patients with chronic carotid artery occlusion (CCAO) based on the analysis of risk factors, demographic and clinical and anatomical characteristics, the dynamics of the disease; to evaluate ongoing drug therapy, the incidence of strokes (MI) and deaths (according to the local registry compared with the results of other observational studies).

MATERIAL AND METHODS

PubMed and eLibrary searches for a systematic review were performed from October 24 to December 10, 2021 independently by two investigators. Out of 870 articles, based on inclusion/exclusion criteria, 8 studies were selected and included in the systematic review.

RESULTS

A comparative analysis of the clinical and anamnestic status of patients with CCAO according to the present review showed the following data on the prevalence of the main risk factors/diseases: hypertension - 79.1%; male gender - 83.7%; smoking - 46%; diabetes mellitus - 30.5%. Of the entire of own Duplex registry group (n=2548), 7 patients were identified with CCAO (0.27%). All patients were male (mean age 71.3±9.4 years). Endpoints were recorded in 5 of 7 participants during the follow-up period (8.9 years): 5 deaths, 2 fatal MI, 1 non-fatal MI, 1 myocardial infarction. A significant impact of the fact of MI on the survival of patients was confirmed using the standard log-rank test (p=0.02 and the Cox-Mendel test (p=0.04). The incidence of MI during the prospective follow-up according to the analyzed studies ranged from 4.3% (within a month of follow-up) to 42.8% (with a follow-up of 8.9 years), and averaged 12%.

CONCLUSIONS

A comparative analysis of the clinical and anamnestic status of patients with CCAO based on data from observational registers showed that the probability of detecting this pathology is associated with age and male gender. Data obtained from prospective observation of patients with CCAO in our own study show that the development of MI is one of the main factors affecting the survival of this category of patients.

Imaging Predictors for Endovascular Recanalization of Non-acute Occlusion of Internal Carotid Artery Based on 3D T1-SPACE MRI and DSA

Objectives: To investigate the predictive factors for successful recanalization based on digital subtraction angiography and three-dimensional T1W sampling perfection with application-optimized contrasts using different flip angle evolutions (3D T1-SPACE) high-resolution magnetic resonance imaging (MRI) signal features.

Methods: Consecutive internal carotid artery occlusion cases with ipsilateral ischemic stroke refractory to therapy who visited our institution between February 2017 and August 2020 were retrospectively analyzed. Epidemiology, symptomatology, imaging morphology on angiography and MRI, peri-procedural complications, technical success rate, and follow-up results were summarized. Factors related to technical success were analyzed using univariate and multivariate analyses.

Results: In total, 75 cases (53 men, mean age 57.51 ± 9.71 years) were included. The total successful recanalization rate was 72.00% (54/75), with a complication rate of 13.33% (9/75). Through multivariate analysis, first ischemic stroke in <3 months (OR: 2.57; 95% CI: 1.13–4.58), tapered stump (OR: 4.31; 95% CI: 1.37–13.55), reversed flow of the ophthalmic artery (OR: 2.99; 95% CI: 1.06–8.49), high intraluminal signal on unenhanced T1-SPACE sequence (OR: 16.15; 95% CI: 3.40–76.72), no vessel wall collapse (OR: 17.00; 95% CI: 3.57–81.02), short occlusion length (OR: 9.87; 95% CI: 2.09–46.64), and primary occlusion site at the cervical internal carotid artery (OR: 8.42; 95% CI: 1.04–68.19) were associated with successful recanalization.

Conclusion: Besides traditional features such as short ischemic event time, tapered stump, and distal ICA reconstitution by the ophthalmic artery, our study demonstrates that luminal and mural changes determined by 3D SPACE high-resolution MRI could also predict successful endovascular recanalization. Endovascular recanalization for non-acute internal carotid artery occlusion is feasible, but prudent case selection is mandatory considering the high periprocedural complication rate.

Vascular Diameters as Predictive Factors of Recanalization Surgery Outcomes in Internal Carotid Artery Occlusion

Background: Revascularization surgery sometimes can achieve recanalization in patients with internal carotid artery occlusion (ICAO). High-resolution vessel wall magnetic resonance imaging (HRVWI) is a feasible technique to give detailed characteristics of the vessel wall, which may help to identify patients that carry higher success rates and more suitable for revascularization surgery.

Objective: To examine the association between HRVWI characteristics of ICAO and the success rate of revascularization surgery in ICAO patients.

Methods: We conducted a retrospective analysis of 31 ICAO recanalization patients enrolled from October 2017 to May 2019. The clinical data of patients and lesions were collected and analyzed.

Results: A total of 31 ICAO patients were enrolled in this study. No significant differences were found between recanalization success and recanalization failure groups with regard to occlusion length, distal end of the occluded segment, and the treatment applied. The ipsilateral-to-contralateral diameter ratios (I/C ratios) of C1 or C2 and the diameter of C7 were positively related to recanalization success. A two-factor predictive model was constructed, and the I/C ratio of C2 < 0.86 and the diameter of C7 < 1.75mm were separately assigned 1 point. The ICAO patients who scored 0, 1, or 2 points had a risk of 5.6% (1/18), 55.6% (5/9), or 100% (4/4) to fail in the recanalization.

Conclusions: The I/C ratios of C1 or C2 and the diameter of C7 are predictive factors of a revascularization surgery success in ICAO patients. A risk stratification model involving C2 and C7 was constructed for future clinical applications.

Carotid artery stenting in patients with chronic internal carotid artery occlusion

BACKGROUND

The risk of ischemic stroke in patients with chronic total occlusion (CTO) of the internal carotid artery (ICA) on best medical treatment has been estimated to be 5.5% per year. The purpose of this study was to assess early and mid-term outcome of patients who underwent an attempt at transfemoral carotid artery stenting (CAS) for CTO of the ICA.

METHODS

Clinical data of symptomatic patients who underwent attempt at CAS for CTO of the ICA between January 1, 2010 and July 1, 2020 were retrospectively reviewed. Clinical success, perioperative and mid-term stroke and death rates were recorded. Descriptive statistics were used.

RESULTS

There were 27 patients, 14 females, 13 males, with a mean age of 66.8 years, range: 57 to 79. All patients had symptoms within 6 months prior to the procedure. 16 had ipsilateral stroke at a mean of 2.8 months, ranges: 1.5-4 months, two had transient ischemic attack (TIA), at 1 week and at 6 months, one had amaurosis fugax at one week, two had chronic ocular ischemia and six had chronic cerebral hypoperfusion. Technical success was 52% (14/27). One patient developed a minor reversible stroke (1/27, 3.7%) there was no early death, for an overall 30-day stroke and death rate of 3.7% (1/27). Two patients had perioperative TIAs. Among 14 patients with successful CAS (group A) one had minor, reversible ipsilateral stroke during a follow-up of 29 months (range: 4-112), two had contralateral stroke. There was no death. One patient developed asymptomatic stent occlusion, three had asymptomatic in-stent restenosis >50%, two had reinterventions. Among patients with unsuccessful attempt at CAS (group B), 31% (4/13) had stroke at 4, 10, 14 and 22 months, respectively. One stroke patient died at 10 months.

CONCLUSIONS

Transfemoral CAS of symptomatic patients with CTO of the ICA was feasible in half of the patients, with no mortality or major stroke, for an overall early stroke/death rate of 3.7%. Since one third of the patients with unsuccessful stenting developed stroke during follow-up, further studies to investigate the safety, efficacy and durability of CAS for CTO of the ICA are needed.

A systematic review of endovascular treatment for chronic total occlusion of the internal carotid artery

The management of patients with symptomatic chronic total occlusion (CTO) of the internal carotid artery (ICA) is controversial. The aim of this systematic review was to investigate patient selection, technical success, early and late outcome of endovascular treatment for CTO of the ICA. PubMed/Medline and EMBASE databases were searched until January 2, 2020 for studies on endovascular treatment for CTO of the ICA. A descriptive analysis of demographic, clinical and anatomic data, endovascular technique, perioperative and late outcomes was performed. A total of 1,222 articles were screened, 8 retrospective or prospective cohort studies were reviewed; 276 patients, 18.9% females, mean age: 64.3 years, underwent attempt at endovascular treatment of 278 lesions. Two hundred and thirteen patients (77.2%) had neurological symptoms; the others had evidence of ipsilateral cerebral hypoperfusion. Two hundred and thirty-eight lesions (91.2%) were treated >30 days after diagnosis of occlusion. Technical success was 66.9%. Perioperative mortality was 1.64% (4/243), early stroke rate was 3.3%. Follow-up averaged 23.4 months (range, 0.25–84 months), late mortality was 1.89% (5/265), stroke rate was 3.4% (9/265). Stroke rate was similar after successful stenting (3.57%, 4/112) vs. failed stenting (3.61%, 2/61; P=1.00), stroke/death rates were also similar after successful stenting (5.36%, 6/112) than after failed stenting (3.28%, 2/61; P=0.71). Endovascular treatment of CTO of the ICA in eight cohort studies was safe and feasible with a technical success of 67% and a low rate of early and late neurological complications. Pooled data in this review failed to confirm the benefit of successful stenting on stroke and mortality, but some of the included studies suggest benefit and some also supported improvement in neurocognitive function after successful stenting. Prospective randomized trials to investigate the benefit of endovascular treatment in addition to best medical therapy for symptomatic CTO of the ICA are urgently needed.

Surgical therapy for chronic internal carotid artery occlusion: a systematic review and meta-analysis

Chronic internal carotid artery occlusion (CICAO) significantly increases the risk of recurrent stroke. Given unfavorable outcomes, revascularization procedures are not generally recommended for CICAO. In the last several years, loads of studies reported successful surgical revascularization for CICAO with promising success rate and favorable short-term outcomes. Meanwhile, due to the lack of high-quality evidence, the safety and efficacy of revascularization procedures remain debatable. This systematic review aims to scrutinize current evidence for the applicability of revascularization for CICAO. We also investigated potential predictors of postoperative prognosis. We searched clinical studies on surgical treatment of CICAO on the Medline, Cochrane library, and Embase databases, published from Jan 1990 to Jan 2021. Surgical operation was restricted to bypass surgery, endarterectomy, endovascular therapy, and hybrid surgery. Controlled clinical studies were included for clinical outcomes. Large-sample single-arm studies were supplemented to assess complications and success rate. Co-primary endpoints were technical success rate and neurological function; secondary endpoints were recurrent stroke/cerebrovascular events, complications, and deaths within follow-up. This systematic review has been registered in PROSPERO (CRD42020181250). One RCT and 5 cohort studies with a total of 465 patients were included in this review. Seven single-arm studies were supplemented for assessing success rate and complications. Bypass surgery presented the highest graft patency of 96% and a low incidence of complications, but no benefits on neurological function, recurrent stroke, or deaths. Endovascular therapy (carotid stenting) was characterized by a relatively lower technical success rate, significant neurological function recovery, and nonsignificant reduction of cerebrovascular events and deaths. Hybrid surgery was considered as a potential treatment for CICAO because of a high technical success rate and significant neurological improvement. Endarterectomy is only suitable for short-segment occlusion. Prospective clinical trials should focus on carotid stenting and hybrid surgery for their significant capacity of improving neurologic function and potential capacity of reducing deaths and cerebrovascular events.

A novel angiographic classification for the endovascular recanalization of symptomatic nonacute extracranial vertebral artery occlusion

BACKGROUND

There remains major uncertainty regarding the optimal therapy for symptomatic nonacute extracranial vertebral artery occlusion (EVAO). Endovascular recanalization for EVAO is technically challenging, and limited data are available. This research aimed to report a multicenter clinical experience of endovascular recanalization for symptomatic nonacute EVAO and establish a novel angiographic classification.

METHODS

From June 2011 to December 2019, 50 symptomatic nonacute EVAO patients treated with endovascular recanalization in three regional referral stroke centers were retrospectively analyzed. All patients were categorized into four groups based on the angiographic classification. The rates of technical success, periprocedural complications, any stroke or death within 1 month, and follow-up data were assessed.

RESULTS

The rates of technical success, periprocedural complications, and any stroke or death within 1 month were 86.0% (43/50), 12.0% (6/50), and 4.0% (2/50), respectively. The recanalization rates gradually decreased from Type A to Type D (100%, 94.7%, 80%, and 63.6%, respectively; P=0.007). The EVAO patients in the Type A group with tapered stump and short-segment occlusions showed excellent recanalization effects, with 100% technical success rates and no complications. Conversely, the lowest recanalization rate of 63.6% (7/11) and the highest periprocedural complication rate of 27.3% (3/11) were observed for the Type D group.

CONCLUSIONS

Endovascular recanalization for symptomatic nonacute EVAO is technically feasible, especially Type A EVAO patients, which can provide an alternative treatment option for recurrent vertebrobasilar ischemia despite optimal medical therapy. The angiographic categorization established in this study is conducive to the selection of suitable patients prior to treatment decision.

Imaging Identification and Prognosis of the Distal Internal Carotid Artery With Near and Complete Occlusion After Recanalization

Background and Purpose: Previous studies have mainly focused on treatment strategies and clinical outcomes for internal carotid artery near occlusion (ICANO) and internal carotid artery complete occlusion (ICACO). However, reports on the morphological changes of distal internal carotid artery (ICA) after recanalization are scarce. This study aimed at illustrating identifying features, assessing prognosis of the distal ICA after recanalization, and exploring best practices for treatment for ICANO and ICACO.

Materials and Methods: We retrospectively studied the clinical characteristics of 57 patients with ICANO or ICACO who underwent surgical recanalization. The clinical data, angiographic morphology, technical successful rate, perioperative complications, and the lumen changes of distal ICA before and after successful recanalization were analyzed.

Results: Fifty-two patients who achieved successfully recanalization were studied. Based on the postoperative lumen diameter changes in the distal ICA, 19 cases were classified as distal-dilatation and the remaining 33 as distal-narrowness. Patients in the distal-narrowness group mostly had ICACO (21.1 vs. 54.5%) and were men (68.4 vs. 93.9%). In the distal-narrowness group, the lumen of the distal ICA recovered to normal in 32 of the 33 patients during the follow-up period. Of the 32 patients reviewed, the ICA of 28 patients dilated back to normal after 1 week of surgery; the ICA of remaining patients 4 dilated 2 weeks postoperatively.

Conclusions: Narrowness of the distal ICA after hybrid recanalization was more prevalent in male patients with ICACO. Homogeneous stenosis of the whole course of the distal ICA is a low-perfusion narrowness which does not require intervention and will spontaneously recover after successful recanalization with an increase in the forward flow.

Endovascular revascularization of symptomatic chronic total occlusions of the internal carotid artery using a proximal balloon protection device

To investigate the feasibility, efficacy, and safety of endovascular recanalization for symptomatic chronic internal carotid artery occlusions (ICAO). Thirty patients with symptomatic chronic ICAO were treated using the endovascular recanalization method. Proximal balloon protection devices were used to prevent embolic migration by completely blocking the blood flow. The morphology of the internal carotid artery (ICA) at the occluded segment based on catheter angiography was analyzed. Recanalization of symptomatic chronic internal carotid artery occlusion (CICAO) was successful in 20 of the 30 patients (66.7%). The time required for successful revascularization ranged from 120 to 180 min (mean, 150 min). Of the 20 successful patients, 14 were at the cervical ICAs, and six were at the intracranial ICAs. No permanent complications occurred in our study. Ischemic symptoms related to chronic ICAO did not occur during the 18.3 month follow-up period (range, 12-24 months) in the 20 successful patients. Endovascular revascularization can improve hemodynamic compromise. The treated sites of all 20 successfully recanalized patients were patent on computed tomographic angiography or carotid duplex sonography, and no case with >50% restenosis was observed during the follow-up period. Three patients with failed recanalization had a stroke during the follow-up period. Endovascular revascularization of symptomatic CICAO using a proximal balloon protection device is technically feasible in selected patients, and the outcomes are favorable for patients who benefit from revascularization.

Chronic total occlusion and spontaneous recanalization of the internal carotid artery: Natural history and management strategy

OBJECTIVES

Spontaneous recanalization of a chronic total occlusion of the extra-cranial internal carotid artery is an under-reported clinical entity. This paper reviews the different etiologies of internal carotid artery occlusion, its natural course, as well as the significance and our recommendations for the management of spontaneous internal carotid artery recanalization.

METHODS

A review of literature on etiology, diagnosis, and treatment of internal carotid artery occlusion and recanalization was conducted. PubMed database was searched using the terms "internal carotid occlusion" and "recanalization". Articles were reviewed and studies involving the management of internal carotid artery occlusion and spontaneous recanalization were included. We subsequently developed a management algorithm for chronic total occlusion of the internal carotid artery and spontaneous recanalization of such lesions based on the available evidence.

RESULTS

Common etiologies of chronic total occlusion of the internal carotid artery include carotid atherosclerotic disease, cardioembolic, and carotid dissection. Progression of an asymptomatic to symptomatic occlusion is estimated at 2-8% annually. Well-compensated patients can be asymptomatic. In others, clinical symptoms range from ipsilateral or global hypoperfusion to embolic stroke in some cases of spontaneous recanalization. Spontaneous recanalization occurs in 2.3-10.3% of patients but rarely results in a cerebrovascular event.

CONCLUSIONS

Progression of an asymptomatic chronic total occlusion of the internal carotid artery to symptomatic is infrequent. The management algorithm of chronic total occlusion of the internal carotid artery and spontaneous recanalization of the internal carotid artery must be tailored to the patient based on symptoms, etiology of the lesion, imaging findings, surgical risk, and reliability for follow-up.

Mid-/Long-Term Outcome of Neuroendovascular Treatment for Chronic Carotid Artery Total Occlusion

Objective

The natural course of chronic carotid artery total occlusion (CTO) is poor. Previous reports suggested that carotid artery stenting (CAS) improves the clinical outcome of CTO. However, its long-term efficacy has not been established. This study assessed the mid- and long-term clinical outcome of CAS for CTO.

Methods

We evaluated the clinical outcome of 15 patients who underwent CAS for CTO between September 2010 and October 2019.

Results

The technical success rate of recanalization was 93.3% (14 of 15 patients). Eight patients were treated using self-expanding stents, and six were treated using self-expanding coronary stents. Symptomatic procedure-related complications developed in two patients (13.3%). During the follow-up period (mean 34.9 months), symptomatic ipsilateral stroke was not noted. One patient (7.1%) developed asymptomatic re-occlusion, but stent patency was preserved in 13 patients (92.9%).

Conclusion

CAS for CTO may be safe and feasible based on the mid- and long-term outcome.

Combined Endovascular and Surgical Treatment of Chronic Carotid Artery Occlusion: Hybrid Operation

Objectives

The optimal treatment choice of chronic carotid artery occlusion (CAO) remains inconclusive. This study was aimed at exploring the safety and effectiveness of hybrid surgery in the treatment of CAO and at determining predictors for successful recanalization.

Methods

In this study, we enrolled 37 patients with CAO who underwent hybrid surgical treatment during the period 2016–2018. We extracted and analyzed patients' demographic data, disease characteristics, surgical success rates, perioperative complications, and prognosis.

Results

A total of 37 patients with symptomatic CAO underwent hybrid surgical treatment. Thirty cases (81.1%) were successfully recanalized, while seven were not. Blood reflux after carotid endarterectomy occurred in 18 patients (60%) of the success group and 1 (14.3%) of the failure group (OR, 9.0; 95% CI, 0.95-54.5; P = 0.042). The rate of distal ICA reconstruction below the clinoid segment was 20 (66.7%) in the success group and 1 (14.3%) in the failure group (OR, 12.0; 95% CI, 1.3-113.7; P = 0.029). In patients with successful recanalization, no ischemic events occurred after surgery and during follow-up, but restenosis of >50% was found in one case. In the failure group, two patients experienced recurrent ischemic events during follow-up. Perfusion imaging in successful recanalization cases is significantly improved, preoperative I/C ratio was 1.44 (IQR 1.27-1.55), and postoperative 1.12 (IQR 1.05-1.23). National Institutes of Health Stroke Scale (NIHSS) score of successful recanalization cases was 5.35 (2.26) before surgery and 2.03 (1.40) at 6 months (P < 0.01).

Conclusion

Hybrid surgery might be a safe and effective way to treat CAO. Distal internal carotid artery reconstruction to below the clinoid segment and blood reflux after carotid endarterectomy are predictors of successful recanalization.

Remodeling of occluded internal carotid artery in vessel wall magnetic resonance imaging

OBJECTIVE

The purpose of the present study was to investigate the remodeling pattern of the extracranial occluded internal carotid artery (OICA) by vessel wall magnetic resonance imaging (VWI).

METHODS

Thirty-nine atherosclerotic OICAs from 32 consecutive cases underwent 3-Tesla VWI to acquire pre- and post-contrast T1-weighted two-dimensional fluid-attenuated inversion recovery fast spin echo sequences. 25 symptomatic CAs exhibited ipsilateral downstream cerebral ischemia or ophthalmic artery embolism within last three months. The 14 remaining CAs were asymptomatic. Twenty-four CAs from 22 patients with atherosclerosis but no stenosis were recruited as control group. The outer wall area (OWA) was calculated based on the outer contour of the carotid artery drawn on the pre-contrast VWI. Negative remodeling was defined as a lower OWA compared to that of control group.

RESULTS

Clinical characteristics including age, sex and vascular risk factors showed no significant difference between the occluded and control group. However, the OWA was lower in the occluded group than in the control group (0.63 versus 0.90 cm², p = 0.004). For all OICAs, the OWA was larger in symptomatic cases than asymptomatic cases (0.71 versus 0.49cm², p = 0.025). Using a cutoff value of 0.44, the sensitivity and specificity of OWA for detecting symptomatic OICA were 0.88 and 0.57, respectively. Heterogeneous signal intensity and enhancement were more often observed at the proximal than the distal segment of occlusion (p < 0.001). The inter-observer agreement regarding the evaluation of VWI characteristics was desirable (κ = 0.805 ∼ 0.847).

CONCLUSIONS

Negative remodeling is prevalent in OICA, especially in asymptomatic cases.

A Novel Endovascular Technique for Recanalization of Carotid Artery Chronic Total Occlusion: Staged Carotid Angioplasty and Stenting

AIM

Symptomatic carotid artery chronic total occlusion (SCACTO) can lead to neurocognitive function decline and carries a high risk or recurrent stroke. The treatment option is limited, endovascular intervention may be an alternative treatment but still controversial. To our knowledge, the staged carotid angioplasty and stenting (SCAS) did not previously reported. The purpose of this study was to report our experiences in this novel technique.

METHODS

In 2017-2018, we attempted the staged carotid angioplasty and stenting (SCAS) approach in 13 patients who received SCACTO treatment. The SCAS approach involves two stages of intervention. The first stage involves initial recanalization and initial small-sized balloon angioplasty. The second stage, which is performed 4-6 weeks later, involves angioplasty and carotid stent placement.

RESULTS

The success rate of SCAS was 76.9%. At the second stage, the lumen remained patent in all the patients. The mean spontaneous increase in lumen diameter after 4-6 weeks was 51.7%. The median length of the stent was 4.0 cm, and the median number of stents used was 1. One patient had a complication of dissection, with a complication rate of 7.6%.

CONCLUSIONS

SCAS is a novel technique in the endovascular treatment of SCACTO. It is a feasible and safe approach that could reduce the complication rate and number of carotid stents needed.

Evaluation of chronic carotid artery occlusion by non-contrast 3D-MERGE MR vessel wall imaging: comparison with 3D-TOF-MRA, contrast-enhanced MRA, and DSA

OBJECTIVES

To analyze the accuracy of a non-contrast MR vessel wall imaging technique, three-dimensional motion-sensitized driven equilibrium prepared rapid gradient echo (3D-MERGE) for diagnosing chronic carotid artery occlusion (CCAO) characteristics compared with 3D time-of-flight (TOF) MRA, and contrast-enhanced MRA (CE-MRA), using digital subtraction angiography (DSA) as a reference standard.

METHODS

Subjects diagnosed with possible CCAO by ultrasound were retrospectively analyzed. Patients underwent 3.0-T MR imaging with 3D-MERGE, 3D-TOF-MRA, and CE-MRA followed by DSA within 1 week. Diagnostic accuracy of occlusion, occlusion site, and proximal stump condition were assessed independently on 3 MRI sequences and DSA. Agreement of the above indicators was evaluated in reference to DSA.

RESULTS

One hundred twenty-four patients with 129 suspected CCAO (5 with bilateral occlusions) met the inclusion criteria for our study. 3D-MERGE demonstrated a sensitivity, specificity, and accuracy of 97.0%, 86.7%, and 94.6%, respectively, with excellent agreement (Cohen's κ = 0.85; 95% CI, 0.71, 0.94) for diagnosing CCAO in reference to DSA. 3D-MERGE was superior in diagnosing CCAO compared with 3D-TOF-MRA (Cohen's κ = 0.61; 95% CI, 0.42, 0.77) and similar to CE-MRA (Cohen's κ = 0.93; 95% CI, 0.86, 1.00). 3D-MERGE also had excellent agreement compared with DSA for assessing occlusion sites (Cohen's κ = 0.85; 95% CI, 0.71, 0.97) and stump condition (Cohen's κ = 0.83; 95% CI, 0.71, 0.94). Moreover, 3D-MERGE provided additional information regarding the occluded segment, such as distal lumen collapse and vessel wall lesion components.

CONCLUSION

3D-MERGE can reliably assess chronic carotid occlusive characteristics and has the ability to identify other vessel wall features of the occluded segment. This non-contrast MR vessel wall imaging technique is promising for assessment of CCAO.

KEY POINTS

• Excellent agreement was found between 3D-MERGE and DSA for assessing chronic carotid artery occlusion, occlusion site, and proximal stump condition. • 3D-MERGE was shown to be a more accurate and efficient tool than 3D-TOF-MRA to detect the characteristics of the occluded segment. • 3D-MERGE provides not only luminal images for characterizing the proximal characteristics of occlusion but also vessel wall images for assessing the distal lumen and morphology of occlusion segment, which might help clinicians to optimize the treatment strategy for patients with chronic carotid artery occlusion.

A Treatment Option for Symptomatic Chronic Complete Internal Carotid Artery Occlusion: Hybrid Surgery

Background

Internal carotid artery occlusion (ICAO) is a relatively uncommon but important cause of transient ischemic attack and cerebral infarction. The majority of cases of symptomatic ICAO requires surgical treatment. In this study we performed an investigation of the efficacy and safety of hybrid surgery which is a surgical method for symptomatic chronic complete ICAO.

Methods

Fifty-five patients with symptomatic chronic ICAO treated by hybrid surgery from 2016 to 2019 were included. We recorded and analyzed the patients’ clinical characteristics, angiographic data, recanalization rate, complications, and outcomes. Catheter angiography or computed tomography angiography was used to assess the patency of the recanalized ICA during follow-up.

Results

The total success rate of recanalization was 78.2% (43/55). The occlusions were significantly shorter in the success than failure group (5.40 ± 1.50 vs. 7.56 ± 0.99 cm, respectively; P < 0.001). The median duration of ICA occlusion was significantly shorter in the success than failure group (90 vs. 200 days, respectively). The success rates of distal ICA recanalization at the petrous segment or below, cavernous segment, and clinoid segment or above were 100, 33.3, and 14.3%, respectively (P < 0.001). Multivariate analysis showed that the level of distal ICA reconstitution was the only factor affecting the recanalization success rate. Periprocedural complications included hyperperfusion syndrome (n = 1) and laryngeal nerve injury (n = 1). ICA reocclusion occurred in one patient (2.3%). Significant postoperative improvement in symptoms was observed in the success group, with a median modified Rankin scale score of 0 at the 3-month follow-up compared with before recanalization (median, 1) (P<0.001).

Conclusion

Hybrid surgery might be safe and effective for patients with symptomatic chronic complete ICAO. The level of distal ICA reconstitution is a predictor of successful recanalization in hybrid operations.

Assessment of Apparent Internal Carotid Tandem Occlusion on High-Resolution Vessel Wall Imaging: Comparison with Digital Subtraction Angiography

BACKGROUND AND PURPOSE

Not all tandem occlusions diagnosed on traditional vascular imaging modalities, such as MRA, represent actual complete ICA occlusion. This study aimed to explore the utility of high-resolution vessel wall imaging in identifying true ICA tandem occlusions and screening patients for their suitability for endovascular recanalization.

MATERIALS AND METHODS

Patients with no signal in the ICA on MRA were retrospectively reviewed. Two neuroradiologists independently reviewed their high-resolution vessel wall images to assess whether there were true tandem occlusions and categorized all cases into intracranial ICA occlusion, extracranial ICA occlusion, tandem occlusion, or near-occlusion. DSA classified patient images into the same 4 categories, which were used as the comparison with high-resolution vessel wall imaging. The suitability for recanalization of occluded vessels was evaluated on high-resolution vessel wall imaging compared with DSA.

RESULTS

Forty-five patients with no ICA signal on MRA who had available high-resolution vessel wall imaging and DSA images were included. Among the 34 patients (34/45, 75.6%) with tandem occlusions on DSA, 18 cases also showed tandem occlusions on high-resolution vessel wall imaging. The remaining 16 patients, intracranial ICA, extracranial ICA occlusions and near-occlusions were found in 2, 6, and 8 patients, respectively, on the basis of high-resolution vessel wall imaging. A total of 20 cases (20/45, 44.4%) were considered suitable for recanalization on the basis of both DSA and high-resolution vessel wall imaging. Among the 25 patients deemed unsuitable for recanalization by DSA, 11 were deemed suitable for recanalization by high-resolution vessel wall imaging.

CONCLUSIONS

High-resolution vessel wall imaging could allow identification of true ICA tandem occlusion in patients with an absence of signal on MRA. Findings on high-resolution vessel wall imaging can be used to screen more suitable candidates for recanalization therapy.

Endovascular recanalization of chronically occluded internal carotid artery

Background

It is debated whether endovascular treatment is indicated for a symptomatic chronically occluded internal carotid artery (COICA).

Objective

To assess outcomes after endovascular treatment of COICA.

Methods

We performed a systematic search of three databases (PRISMA guidelines), including endovascular series of COICA. Outcomes were analyzed with random-effects models.

Results

We included 13 studies and 528 endovascularly treated patients with COICA. Successful recanalization was 72.6% (347/528, 95% CI 65.4% to 79.9%, I2=68.9%). Complications were 18% (88/516, 95% CI 12.1% to 23.8%, I2=65%), with 5% (25/480, 95% CI 2% to 7%, I2=0%) of permanent events, and 9% (43/516, 95% CI 6% to 13%, I2=34%) of thromboembolisms. Treatment-related mortality was 2% (11/516, 95% CI 0.5% to 2.6%, I2=0%). Shorter duration of the occlusion was associated with higher recanalization: 80% (11/516, 95% CI 54% to 89%, I2=0%), 63% (33/52, 95% CI 49% to 76%, I2=0%), and 51% (18/35, 95% CI to 37% to 88%, I2=40%) recanalization rates for 1, 3, and >3 months occlusions, respectively. Complications were 6% (3/50, 95% CI 3% to 21%, I2=0%), 14% (4/27, 95% CI 5% to 26%, I2=0%), and 25% (13/47, 95% CI 10% to 30%, I2=0%) for 1, 3, and >3 months occlusions, respectively. Patient aged <70 years presented higher revascularization rates (OR=3.1, 95% CI 1.2 to 10, I2=0%, p=0.05). Successful reperfusion was higher (OR=5.7, 95% CI 1.2 to 26, I2=60%, p=0.02) and complications were lower (OR=0.2, 95% CI 0.6 to 0.8, I2=0%, p=0.03) for lesions limited to the cervical internal carotid artery compared with the petrocavernous segment. Successful recanalization significantly lowered the rate of thromboembolisms (OR=0.2, 95% CI 0.8 to 0.6, I2=0%, p=0.01) and mortality (OR=0.5, 95% CI 0.1 to 0.9, I2=0%, p=0.04), compared with conservative treatment.

Conclusions

Endovascular treatment of COICA gives a 70% rate of successful recanalization, with 5% morbidity. Patients aged <70 years, lesions limited to the cervical internal carotid artery, and a shorter duration of the occlusion decreased the risk of complications. Successful recanalization of symptomatic lesions lowered by about 80% the likelihood of thromboembolisms, compared with medical management.