To Patch or not to Patch?
Malas M, Glebova NO, HughesSE, Voeks JH, Qazi U, Moore WS, et al. Effect of Patching on Reducing Restenosis in the Carotid Revascularization Endarterectomy Versus Stenting Trial. Stroke. 2015
It is known from NASCET that CEA’s prevent stroke in symptomatic carotid stenosis. Prior literature has pointed to a restenosis rate however of 5-15%. Many have argued that lack of using a patch during the CEA increases the rate of restenosis. The idea is that closure of an arteriotomy with a patch minimizes the effect of neointimal hyperplasia and scarring, maintaining arterial lumen diameter after the procedure. A handful of retrospective studies, a meta-analysis and one small randomized trial have contributed to answering this question. While some data points to improvement of stenosis rate with application of the patch and improvement in recurrent stroke prevention as well; the data is still a mixed bag with both positive and negative results. Malas et al evaluate whether patching in carotid revascularization reduces restenosis and provides the benefit of preventing further strokes.
This study’s strength lies in the number of patients it has to evaluate. Using the CREST results, 1082 patients were included. As a reminder, CREST randomly assigned patients with symptomatic or asymptomatic carotid stenosis to undergo carotid-artery stenting or carotid endarterectomy. For this study, only the CEA patients were evaluated. Duplex ultrasounds were performed at baseline, 1,6,12,24 and 48 months. Restenosis rates at two years were assessed, defined as 70% or greater diameter reducing stenosis based on elevated peak systolic velocity of 3.0 m/s or higher.
With regards to results: 753 (65%) underwent CEA with patch and 329 (29%) underwent primary closure. 44 patients were excluded due to undergoing eversion CEA and 25 patients had missing data. By specialty, 89% of vascular surgeons, 6% of neurosurgeons and 76% of thoracic surgeons patched. There was significant reduction in the 2-year risk of restenosis, even when adjusted by surgeon specialty (HR = 0.35, p=.006). There was however no significant difference in the rates of periprocedural stroke and death (HR 1.58, P=.57) or 4-year risk of ipsilateral stroke (HR=1.23, P=0.71).
The results that Malas et al generate in terms of restenosis reduction at 2 years are quite convincing. Prior studies may have shown mixed results due to the small sample size which may not have adequately powered for a difference. In this sense, one could argue that patching should be routine for CEA patients. The study however, does not evaluate for complications of patching such as infection which is a function of the CREST data set. Curiously, even though there is improvement of the 2 year restenosis rates, there is no clear effect on the 4 year risk of ipsilateral stroke. While prior smaller studies have shown this benefit (a recent CREST analysis showed that patients with restenosis had significantly higher risk of stroke), one could argue that at 4 years, evaluating a stroke as a function of that restenosis may be not long enough of a time span to see that benefit. It is unclear what the average duration of restenosis is in these patients, but if restenosis develops at 2 years post CEA, we know that the benefits of CEA aren’t potentially seen until 5 years in moderate stenosis as per NASCET2. Thus evaluation of a stroke at 4 years (which is only 2 years after the cut off for evaluation of restenosis) may be too short of a time window to actually capture strokes which are a function of that particular stenosis.
By in large, there is likely something beneficial to patching in CEA. Multiple studies have found similar findings, although at times, the data are not completely in harmony. Although this study only hit home on one of its’ two endpoints, it still lends support to “PRO Patch,” and, in my opinion, there is enough data out there otherwise to suggest a benefit.