A Systematic Review of Randomized Controlled Trials of Different Types of Patch Materials During Carotid Endarterectomy
An Updated Systematic Review
Graeme J. Hankey, MD, FRCP, FRACP Section Editor:
Patch angioplasty performed during carotid endarterectomy may reduce the risk of restenosis and, hence, the long-term risk of recurrent stroke. However, there is uncertainty regarding the optimal patch material.1 We sought to determine whether any particular patch material was associated with a lower risk of perioperative or long-term complications.
Materials and Methods
Two reviewers independently searched MEDLINE (1996–November 2008), EMBASE (1980–November 2008), and Index to Scientific and Technical Proceedings (1980–2008).2 We also searched the Stroke Group trials register (August 2009) and hand-searched relevant journals, conference proceedings, and reference lists, and contacted experts in the field.
We sought to identify all randomized trials in which 1 type of carotid patch was compared with another. Thirty-day and long-term risks of stroke, death, restenosis (>50%), and wound complications were extracted. Proportional odds reductions were calculated using the Peto method and the I2 test for heterogeneity.
Thirteen trials (2083 operations) were included. Nine compared vein to synthetic patch closure and 4 compared Dacron to other synthetic materials. Allocation was not adequately concealed in 2 trials, and 1 only followed-up patients to the time of hospital discharge. Intention-to-treat analysis was possible for 6 trials.
The Table summarizes the results. The absolute risks of perioperative stroke (1.8%; 25/1369), death (1.0%; 14/1369), and combined stroke and death (2.4%; 27/1122) were all very low; consequently, it was not possible to determine reliably whether there was any difference between vein and synthetic patches for perioperative stroke, death, and arterial complications. During follow-up of >1 year, there was also no difference in risks of stroke, death, or arterial restenosis. However, there were significantly fewer pseudoaneurysms associated with synthetic patches than vein (OR, 0.09; 95% CI, 0.02–0.49). However, the clinical significance of this finding is uncertain because of small numbers and poor definitions of pseudoaneurysm. Meta-analysis of the 4 trials that compared Dacron and other synthetic patches showed that Dacron was associated with a higher risk of perioperative combined stroke and transient ischemic attack (OR, 4.41; 95% CI, 1.2–16.1; P=0.03) and restenosis at 30 days (OR, 7.26; 95% CI, 1.9–28.0; P=0.004), a borderline significant excess risk of perioperative stroke (OR, 4.34; 95% CI, 0.9–20.9; P=0.07), and a nonsignificant increased risk of perioperative carotid thrombosis (OR, 11.6; 95% CI, 0.6–212.2; P=0.1). During subsequent follow-up of >1 year, there were significantly more strokes (OR, 10.6; 95% CI, 1.3–83.4; P=0.03), stroke/death (OR, 6.1; 95% CI, 1.3–28.1; P=0.02) and arterial restenoses (OR, 8.3; 95% CI, 3.0–22.5; P<0.0001) with Dacron compared with other synthetic materials, but the numbers of outcomes were small.
Implication for Practice
These results do not support the use of vein over synthetic patch material in carotid endarterectomy; therefore, the choice remains a matter of individual preference. However, if synthetic material is used, then the currently available (limited) evidence from small trials appears to suggest a better outcome with polytetrafluoroethylene vs Dacron.
Further trials comparing one type of patch with another are required, but they will need large numbers of patients.
Sources of Funding
The authors thank Faculty of Medicine, Chiang Mai University, for travel grants for the presentation of this research at the 2010 Annual Meeting of Society of Vascular Surgery, USA.
- Received March 22, 2010.
- Accepted March 24, 2010.
Bond R, Rerkasem K, Naylor AR, Rothwell PM. A systematic review of randomized controlled trials of different types of patch materials during carotid endarterectomy. Stroke. 2005; 36: 1350–1351.
Rerkasem K, Rothwell PM. Patches of different types for carotid patch angioplasty. Cochrane Database Syst Rev. 2010; (1): CD000071.