This is cross-sectional analytic study, enrolled 32 adult male and female Egyptian patients, presented to the stroke unit(s) of Kasr Al-Ainy (Cairo University) and Al-Demerdash (Ain Shams University) hospitals, both located in Cairo, Egypt, with cerebrovascular stroke or transient ischemic attacks. The enrolment period extended from December 2014 to February 2016, and the follow-up period extended to September 2016.
Inclusion criteria were based on the presence of significant (more than 70%) carotid artery stenosis ipsilateral to the symptomatic side of the brain. Exclusion criteria were less than 70% stenosis, intracranial pathologies other than stroke, and severe concurrent illness (renal, hepatic, heart failure, etc.).
Carotid stenosis was detected by screening all stroke patients with color-coded duplex ultrasound. Patients with > 70% symptomatic carotid stenosis were enrolled and then subdivided into two groups: 70–90% stenosis and > 90 stenosis. They, then, underwent transcranial Doppler (TCD) assessment of cerebrovascular reactivity (CVR) by breath holding index (BHI). They were, then, sent for angioplasty and stenting (CAS). One week following the procedure, TCD for BHI was repeated to assess CVR.
Ultrasound examination
TCCD was done in the neurovascular lab of the Cairo University Neurosonology Unit (CUNU). Carotid stenosis was assessed according to NASCET and flow analysis [10] using Philips iU22 machine (22100 Bothel Evrett Highway, Bothel, WA. 98021 USA).
Breath holding index was assessed by Doppler “Multidop” T device (Compumedics GmbH, Josef-Schuttler str. 2 D-78224 Singen, Deutschland/Germany). It was performed using headset to fix the probe (2 MHz) during the test. Patients were instructed to breathe quietly for 3 min during which the mean flow velocity in the MCA proximal segment was measured. Then, the patient was asked to hold his breath for at least 24 s. The maximum increase in mean flow velocity following regaining of breathing was recorded for 3 s regardless of the time of onset of changes (as the time of onset varies between patients). BHI was calculated according to the following formula [11]:
$$ \frac{\mathrm{MFV}30\mathrm{s}-\mathrm{MFVb}}{\mathrm{MFV}\mathrm{b}-\mathrm{BHT}}- 100=\mathrm{BHI}\% $$
Angiography and assessment of collateral circulation
Using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral scale, based on DSA, it classifies the cerebral collateral status to grades from 0 to 4. When there is a dichotomized score, “inadequate collaterals” (score of 0, 1, or 2) versus “adequate collaterals” (score of 3 or 4) was used [12].
Carotid angiography, angioplasty, and stenting
All patients underwent the same procedure:
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1.
Eight French guiding catheter MAC 40 degree [Boston Scientific] in the access phase
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2.
Transend soft tip 0.014 in. [Stryker] microwire to bypass the lesion
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3.
Spider filter [ev3-Medtronic] as a distal protection device
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4.
Carotid wall stent [Boston Scientific] closed-cell design
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5.
All patients had post-dilatation balloon angioplasty with Sterling balloons [Boston Scientific], while only patients with severe stenosis more than 90% had pre-dilatation with Maverick balloons [Boston Scientific].
Written consent was obtained either from the patient or from a close relative. The study protocol was approved by the ethical committee of the Faculty of Medicine, Cairo University.