Background and Purpose-Acute disruption of atherosclerotic plaques precedes the onset of clinical syndromes, and studies have implicated a role for matrix metalloproteinases (MMPs) in this process. The aim of this study was to establish the character, level, and expression of MMPs in carotid plaques and to correlate this with clinical status, cerebral embolization, and histology. Methods-Plaques were obtained from 75 consecutive patients undergoing carotid endarterectomy and divided into 4 groups according to symptomatology (group 1, asymptomatic; group 2, symptomatic Ͼ6 months before surgery; group 3, symptomatic within 1 to 6 months; group 4, symptomatic within 1 month). All patients underwent preoperative and intraoperative transcranial Doppler monitoring. Plaques were subjected to histological examination and quantification of MMPs by zymography and ELISA. Results-The level of MMP-9 was significantly higher in group 4 (median 125.7 ng/mL for group 4, median Ͻ32 ng/mL for all other groups; Pϭ0.003), with no difference in the levels of MMPs 1, 2, or 3. Furthermore, the MMP-9 concentration was significantly higher in plaques undergoing spontaneous embolization (Pϭ0.019) and those with histological evidence of plaque instability (PϽ0.03). In situ hybridization demonstrated increased MMP-9 expression in highly symptomatic plaques in areas of intense inflammatory infiltrate. Conclusions-The concentration, production, and expression of MMP-9 is significantly higher in unstable carotid plaques.If this proves to be a causal relationship, MMP-9 may be a strong candidate for pharmacotherapy aimed at stabilizing plaques and preventing stroke. (Stroke. 2000;31:40-47.)

2), the 2017 writing group had to adhere to guidance regarding the overall word count. Shortly after deciding on the titles of the various carotid chapters, we were then asked to include the investigation and management of atherosclerotic vertebral artery disease, thereby significantly increasing the overall burden of the project. As was stated in the introduction to the guidelines, the writing group did not include nonatherosclerotic conditions that affect the carotid and vertebral arteries, not least because of the very extensive number of conditions that would have had to be included (fibromuscular dysplasia, carotid body tumours, paragangliomas, acute dissection, radiation arteritis, giant cell arteritis, Takayasu's arteritis, carotid aneurysms, and trauma, etc.). This was partly because of the constraints applied (regarding word count), but mainly because many non-atherosclerotic conditions also affect other vascular territories within the body, and it was felt that these would be best considered as a separate guideline. This suggestion has already been passed to the ESVS Guidelines Committee for future consideration. The co-chairmen do, however, apologise for not referencing the 2009 ESVS guidelines on carotid disease 2 within the introduction to the 2017 guidelines. This was an oversight and we would like to place on record how influential the 2009 carotid guidelines became after their publication.

At present in the United Kingdom a number of different criteria are used to grade disease in carotid ultrasound investigations. One main cause of this has been the difference in the method of grading angiograms used in the NASCET and ECST large carotid surgery trials. It is desirable that all centres reporting carotid ultrasound investigations report to the same standard. This paper presents recommendations for the reporting of ultrasound investigations of the extra cranial arteries produced by a Joint Working Group formed between the Vascular Society of Great Britain and Ireland, and the Society for Vascular Technology of Great Britain and Ireland. The recommended criteria are based on the NASCET method of grading carotid bulb disease. Key recommendations include recording peak systolic velocity (PSV) and end-diastolic velocity (EDV) in both internal and distal common carotid arteries; measuring all velocities at a Doppler angle of 45-60 degrees; the use of internal carotid PSV of >1.25 ms(-1) and >2.3 ms(-1) and a Peak Systolic Velocity Ratio of >2 and >4 to indicate >50% and >70% stenosis respectively; and the use of the St Mary's Ratio to grade >50% stenoses in deciles. General recommendations are also given for the acquisition, interpretation and reporting of the data.

10-12% of patients undergoing staged or synchronous procedures suffered death or major cardiovascular morbidity (stroke, MI) within 30 days of surgery. Overall, there was no significant difference in outcomes for staged and synchronous procedures and no comparable data for patients with combined cardiac and carotid disease not undergoing staged or synchronous surgery.

Carotid disease is an important aetiological factor in the pathophysiology of post-CABG stroke. However, even assuming that prophylactic carotid endarterectomy carried no additional risk, it could only ever prevent about 40-50% of procedural strokes.