The effect of carotid revascularization on the ophthalmic artery flow: systematic review and meta-analysis

Ocular Ischemic Syndrome and the Role of Carotid Artery Revascularization

BACKGROUND

Ocular ischemic syndrome (OIS) is a rare presentation of atherosclerotic carotid artery stenosis that can result in permanent visual loss. This severely disabling syndrome remains under diagnosed and undertreated due to lack of awareness; especially since it requires expedited multidisciplinary care. The relevance of early diagnosis and treatment is increasing due to an increasing prevalence of cerebrovascular disease.

METHODS

The long-term visual and cerebrovascular outcomes following intervention for nonarteritic OIS, remain poorly described and were the objective of this concise review. We conducted a PubMed search to include all English language publications (cohort studies and case reports) between 2002 and 2023.

RESULTS

A total of 33 studies (479 patients) report the outcomes of treatment of OIS with carotid endarterectomy (CEA, 304 patients, 19 studies), and carotid artery stenting (CAS, 175 patients, 14 studies). Visual outcomes were improved or did not worsen in 447 patients (93.3%). No periprocedural stroke was reported. Worsening visual symptoms were rare (35 patients, 7.3%); they occurred in the immediate postoperative period secondary to ocular hypoperfusion (3 patients) and in the late postoperative period due to progression of systemic atherosclerotic disease. Symptomatic recurrence due to recurrent stenosis after CEA was reported in 1 patient (0.21%); this was managed successfully with CAS. None of these studies report the results of transcarotid artery revascularization, the long-term operative outcome or stroke rate.

CONCLUSIONS

OIS remains to be an underdiagnosed condition. Early diagnosis and prompt treatment are crucial in reversal or stabilization of OIS symptoms. An expedited multidisciplinary approach between vascular surgery and ophthalmology services is necessary to facilitate timely treatment and optimize outcome. If diagnosed early, both CEA and CAS have been associated with visual improvement and prevention of progressive visual loss.

Influence of Carotid Endarterectomy on Choroidal Perfusion: The INFLATE Study

PURPOSE

Patients with clinically significant carotid artery stenosis (CAS) undergoing carotid artery endarterectomy (CEA) were imaged with swept-source OCT angiography (SS-OCTA) imaging protocol to determine if there were changes in choroidal blood flow after surgery.

DESIGN

Prospective observational study.

PARTICIPANTS

Patients with clinically significant CAS undergoing unilateral CEA.

METHODS

All participants underwent SS-OCTA imaging using a 6 × 6-mm scan pattern on both eyes before CEA and within 1 week after CEA. Previously validated automated algorithms were used to measure the mean choroidal thickness (MCT) and choroidal vascular index (CVI) within 2.5-mm and 5-mm circles centered on the fovea. Multivariable regression analysis was conducted to evaluate the impact of various baseline factors including age, mean arterial blood pressure, and degree of stenosis, on both baseline of MCT and CVI, and the changes in MCT and CVI.

MAIN OUTCOME MEASURES

Changes in MCT and CVI.

RESULTS

One hundred sixteen eyes from 60 patients with a mean age of 71.57 ± 7.37 years were involved in the study. At baseline, MCT in both the 2.5-mm and 5-mm circles was significantly thinner on the surgical side compared with the nonsurgical side (P = 0.03), while no significant differences were seen in the CVI at baseline between the 2 sides (2.5-mm circle: P = 0.24; 5-mm circle: P = 0.09). Within 1 week after CEA, there were significant increases in the MCT on the surgical side, as compared with the nonsurgical side, in both the 2.5-mm (P < 0.001) and the 5-mm (P < 0.001) circles. No significant change in mean CVI was noted before and after CEA on the surgical side versus the nonsurgical side (2.5-mm circle: P = 0.30; 5-mm circle: P = 0.97). Multivariable regression analysis revealed that baseline MCT before CEA significantly decreased with age on both the surgical (P < 0.001) and nonsurgical sides (P = 0.003) while the changes in MCT and CVI after CEA were not associated with age, mean arterial blood pressure, or degree of stenosis.

CONCLUSION

A rapid and significant increase in MCT was observed on the ipsilateral side of CEA, suggesting an improvement in choroidal perfusion within 1 week after surgery.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The Impact of Carotid Endarterectomy on Choriocapillaris Perfusion

Purpose

The impact of carotid endarterectomy (CEA) on choriocapillaris (CC) perfusion was investigated using swept-source optical coherence tomography angiography (SS-OCTA) imaging before and after surgery in patients with clinically significant carotid artery stenosis (CAS).

Methods

In this prospective observational study, patients with clinically significant CAS undergoing unilateral CEA had SS-OCTA imaging performed in both eyes before and within 1 week after surgery. The percent CC flow deficits (CC FD%) and CC thickness were assessed using previously validated algorithms. Multivariable regression analysis was conducted to evaluate the impact of variables on the change in CC measurements.

Results

A total of 112 eyes from 56 patients with an average age of 72.6 ± 6.9 years were enrolled. At baseline, significantly higher CC FD% and thinner CC thickness were observed on the surgical side (eyes ipsilateral to the side of CEA) versus the nonsurgical side (eyes contralateral to the side of CEA) (P = 0.001 and P = 0.03, respectively). Following CEA, a significant reduction in CC FD% and a significant increase in CC thickness were detected on the surgical as compared with the nonsurgical side (P = 0.008 and P = 0.01, respectively). Smoking status positively affected CC FD% change (coefficient of variation [CV] = 0.84, P = 0.01) on the surgical side and negatively affected CC thickness change on both the surgical side (CV = -0.382, P = 0.009) and the nonsurgical side (CV = -0.321, P = 0.04). The degree of stenosis demonstrated a positive influence on CC FD% change (CV = 0.040, P = 0.02) on the surgical side.

Conclusions

Unilateral CEA on the side of clinically significant CAS increases carotid blood flow, which further results in improved CC perfusion.

Long-Term Functionality Prediction for First Time Ischemic Middle Cerebral Artery Stroke Patients Receiving Conventional Medical Treatment

BACKGROUND

Middle cerebral artery (MCA) ischemic stroke poses a major threat to human beings and prompts intravenous thrombolytic and/or thrombectomy management remains the gold standard treatment. However, not all MCA stroke patients fit in the inclusion and exclusion criteria that many patients only receive conventional medical therapy. We attempt to seek the baseline parameters that can effectively predict patients' long-term functionality, as well as hypothesizing that the carotid duplex derived resistance/pulsatility index might be capable of fulfilling this purpose.

METHODS

The 741 MCA ischemic stroke patients have been retrospectively recruited for the project. Under the initial screening, matching the inclusion and exclusion criteria, there are 471 participants to be enrolled in the study. The patients' basic information, along with outcome assessments, pre-admission Barthel index and NIHSS score, and pre- and post-treatment mRS are recorded. All statistical analyses were performed using R for Windows (version 3.6.3). The significance level was set at P < 0.05 for all analyses.

RESULTS

Of the 471 patients, 239 participants show a net mRS improvement, whereas the other 232 show deterioration. Hyperlipidaemia, chronic kidney disease, and dementia are related to long-term functionality improvement. The multivariate logistic regression analysis shows that right common carotid artery (CCA) resistance index (RI) and ischemic heart disease play a significant role in favourable outcome functionality. The ROC and Youden Index models are formulated, and it shows that Barthel Index and the NIHSS are most significant in the outcome measurement group (AUC: 0.675, 0.653; cut-off point: 57.5, 3.5, respectively). The right-side CCA RI is the solely important outcome predictor for the baseline carotid duplex study (AUC: 0.5; cut-off point: 0.785).

CONCLUSION

The favourable long-term functionality of MCA ischemic stroke patients receiving conventional medical treatment seems to correlate fairly with pre-admission NIHSS and Barthel index scores. Underlying hyperlipidaemia, chronic kidney disease, and dementia are conversely associated with favourable long-term capability. Moreover, the value of CCA RI appears to significantly alter the long-term outcomes in this group of patients.