Cerebral Revascularization After the Carotid Occlusion Surgery Study

What Candidates Remain, and Can We Do Better?

Timothy G. White, MD; Hussam Abou-Al-Shaar, MD; Jung Park, MD, PhD; Jeffrey Katz, MD; David J. Langer, MD; Amir R. Dehdashti, MD

Disclosures

Neurosurg Focus. 2019;46(2) 

In This Article

Methods

A retrospective chart review of all patients who underwent cerebral revascularization for symptomatic cerebral atherosclerotic stenosis and occlusion between January 2011 and August 2018 was done. All patients who underwent cerebral revascularization for nonmoyamoya vasculopathy were included in the study. This study was approved by the IRB at the Feinstein Institute under the Northwell Health System. Clinical and demographic data were collected for each patient. Variables studied included patient age, sex, diagnosis, medical history, clinical course, medical therapy, preoperative imaging, postoperative imaging, and postoperative clinical outcomes. Independent radiologists determined bypass patency. Clinical outcomes were gathered from date of last patient follow-up in the medical record. Of particular concern was the perioperative morbidity associated with individual cases; therefore, 30-day outcomes were collected as the primary surgical outcome in these patients.

Patient Choice and Surgical Technique

Patients were identified as possible candidates for cerebral revascularization if they showed evidence of atherosclerotic carotid or middle cerebral artery (MCA) steno-occlusive disease and optimal medical therapy had failed, or if they had perfusion-dependent neurological examinations. Optimal medical therapy including dual-antiplatelet therapy (DAPT), tight blood pressure control, glycemic control, and statin use was determined by the stroke neurologist taking care of the individual patients and was documented as part of the data that were collected. Once identified as possible candidates, the patients underwent conventional cerebral angiography for diagnostic purposes, to determine the site of disease, and for presurgical planning. All patients also underwent some form of hemodynamic imaging, including either SPECT with and without Diamox, quantitative MRA (QMRA) noninvasive optimal vessel analysis (NOVA), MR perfusion, or CT perfusion. SPECT was done to determine those patients with impaired cerebrovascular reserve (CVR), and QMRA NOVA was used as an adjunct demonstrating decreased flow in the vascular territory in question.

Surgery was subsequently performed teamed with a trained neuroanesthesiologist and with strict blood pressure control. Direct superficial temporal artery (STA)-MCA bypass was preferred in all cases because the goal in each procedure was flow augmentation. Postoperatively, patients were followed after 30 days had passed postdischarge in order to accurately assess perioperative morbidity. Postprocedure bypass patency was assessed using digital subtraction angiography, CT angiography (CTA), or QMRA NOVA.

Perioperative management focused on tight blood pressure controls and adherence to an aspirin regimen as well as patient positioning. During the case, systolic blood pressure was maintained above 120 mm Hg during the procedure, especially for induction. Postoperative blood pressure goals depended on graft flow but generally were from 120 to 140 mm Hg. Patients were placed on aspirin (81 mg) prior to the procedure, given aspirin (325 mg) on the night of the procedure, and then continued on 81 mg daily. CTA was done on postoperative day 1. If any patient developed a new deficit on examination, MRI and QMRA NOVA studies were done to assess for hyperperfusion versus new stroke.

Statistical Analysis

All data were collected and stored via a REDcap (Research Electronic Data Capture) database, and statistics were analyzed using SPSS and Excel. All variables are expressed as the average ± SD, and where appropriate p = 0.05 was used for statistical significance. For descriptive statistics the average was calculated. Univariate (Student t-test and chi-square analysis for continuous variable) and multivariate regression were used to predict factors associated with bypass patency and clinical outcome.

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