Abstract
Background
The timing of surgery for recently symptomatic carotid artery stenosis remains controversial. Early cerebral revascularization may prevent a disabling or fatal ischemic recurrence, but it may also increase the risk of hemorrhagic transformation, or of dislodging a thrombus. This review examined the randomized controlled evidence that addressed whether the increased risk of recurrent events outweighed the increased benefit of an earlier intervention.
Objectives
To assess the risks and benefits of performing very early cerebral revascularization (within two days) compared with delayed treatment (after two days) for people with recently symptomatic carotid artery stenosis.
Search methods
We searched the Cochrane Stroke Group Trials Register in January 2016, the Cochrane Central Register of Controlled Trials (CENTRAL;The Cochrane Library 2016, Issue 1), MEDLINE (1948 to 26 January 2016), EMBASE (1974 to 26 January 2016), LILACS (1982 to 26 January 2016), and trial registers (from inception to 26 January 2016). We also handsearched conference proceedings and journals, and searched reference lists. There were no language restrictions. We contacted colleagues and pharmaceutical companies to identify further studies and unpublished trials.
Selection criteria
All completed, truly randomized trials (RCT) that compared very early cerebral revascularization (within two days) with delayed treatment (after two days) for people with recently symptomatic carotid artery stenosis.
Data collection and analysis
We independently selected trials for inclusion according to the above criteria, assessed risk of bias for each trial, and performed data extraction. We utilized an intention-to-treat analysis strategy.
Main results
We identified one RCT that involved 40 participants, and addressed the timing of surgery for people with recently symptomatic carotid artery stenosis. It compared very early surgery with surgery performed after 14 days of the last symptomatic event. The overall quality of the evidence was very low, due to the small number of participants from only one trial, and missing outcome data. We found no statistically significant difference between the effects of very early or delayed surgery in reducing the combined risk of stroke and death within 30 days of surgery (risk ratio (RR) 3.32; confidence interval (CI) 0.38 to 29.23; very low-quality evidence), or the combined risk of perioperative death and stroke (RR 0.47; CI 0.14 to 1.58; very low-quality evidence). To date, no results are available to confirm the optimal timing for surgery.
Authors’ conclusions
There is currently no high-quality evidence available to support either very early or delayed cerebral revascularization after a recent ischemic stroke. Hence, further randomized trials to identify which patients should undergo very urgent revascularization are needed. Future studies should stratify participants by age group, sex, grade of ischemia, and degree of stenosis. Currently, there is one ongoing RCT that is examining the timing of cerebral revascularization.
Plain language summary
Timing of treatment for people with recent symptoms from neck artery narrowing
Background
Ischemic stroke occurs when blood flow is blocked from part of the brain. This can be caused by a disease in the neck (carotid) artery that can cause a severe narrowing of the artery, leading to blood clot formation and blockage of a smaller blood vessel downstream. Opening up the carotid artery can reestablish adequate blood flow by surgical removal of the diseased area, or by inserting a tube (stent) to open the artery.
There is uncertainty about whether to perform the treatment immediately, or to wait a few days. Early treatment can improve blood flow, and prevent new strokes. However, early treatment may carry a higher risk of causing a stroke or associated bleeding.
Review question
We reviewed the effectiveness of performing very early treatment (within two days) compared with delayed treatment (after two days) for individuals with recent symptoms from neck (carotid) artery narrowing.
Study characteristics
The searches are up-to-date to 26 January 2016. We found only one randomized trial that assessed the effect of the timing of surgery. It included a total of 40 participants, ranging in age from 47 to 84 years.
Key results
From the limited evidence available, we cannot tell if the timing of surgery is an important factor in determining the outcome for individuals with recent symptoms from carotid artery narrowing.
Quality of the evidence
There is not enough evidence on the best time for surgical treatment for people with recent symptoms from carotid artery narrowing. The overall quality of the evidence was very low, due to the small number of participants from only one trial and missing outcome data. Further studies with a larger number of patients are needed.
