Prospective Randomized Study of Carotid Endarterectomy with Fluoropassiv™ Thin Wall Carotid Patch versus Venous Patch

Patches of different types for carotid patch angioplasty

BACKGROUND

Extracranial carotid artery stenosis is the major cause of stroke, which can lead to disability and mortality. Carotid endarterectomy (CEA) with carotid patch angioplasty is the most popular technique for reducing the risk of stroke. Patch material may be made from an autologous vein, bovine pericardium, or synthetic material including polytetrafluoroethylene (PTFE), Dacron, polyurethane, and polyester. This is an update of a review that was first published in 1996 and was last updated in 2010.

OBJECTIVES

To assess the safety and efficacy of different types of patch materials used in carotid patch angioplasty. The primary hypothesis was that a synthetic material was associated with lower risk of patch rupture versus venous patches, but that venous patches were associated with lower risk of perioperative stroke and early or late infection, or both.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register (last searched 25 May 2020); the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 4), in the Cochrane Library; MEDLINE (1966 to 25 May 2020); Embase (1980 to 25 May 2020); the Index to Scientific and Technical Proceedings (1980 to 2019); the Web of Science Core Collection; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) portal. We handsearched relevant journals and conference proceedings, checked reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials (RCTs) comparing one type of carotid patch with another for CEA.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, risk of bias, and trial quality; extracted data; and determined the quality of evidence using the GRADE approach. Outcomes, for example, perioperative ipsilateral stroke and long-term ipsilateral stroke (at least one year), were collected and analysed.

MAIN RESULTS

We included 14 trials involving a total of 2278 CEAs with patch closure operations: seven trials compared vein closure with PTFE closure, five compared Dacron grafts with other synthetic materials, and two compared bovine pericardium with other synthetic materials. In most trials, a patient could be randomised twice and could have each carotid artery randomised to different treatment groups. Synthetic patch compared with vein patch angioplasty Vein patch may have little to no difference in effect on perioperative ipsilateral stroke between synthetic versus vein materials, but the evidence is very uncertain (odds ratio (OR) 2.05, 95% confidence interval (CI) 0.66 to 6.38; 5 studies, 797 participants; very low-quality evidence). Vein patch may have little to no difference in effect on long-term ipsilateral stroke between synthetic versus vein materials, but the evidence is very uncertain (OR 1.45, 95% CI 0.69 to 3.07; P = 0.33; 4 studies, 776 participants; very low-quality evidence). Vein patch may increase pseudoaneurysm formation when compared with synthetic patch, but the evidence is very uncertain (OR 0.09, 95% CI 0.02 to 0.49; 4 studies, 776 participants; very low-quality evidence). However, the numbers involved were small. Dacron patch compared with other synthetic patch angioplasty Dacron versus PTFE patch materials  PTFE patch may reduce the risk of perioperative ipsilateral stroke (OR 3.35, 95% CI 0.19 to 59.06; 2 studies, 400 participants; very low-quality evidence). PTFE patch may reduce the risk of long-term ipsilateral stroke (OR 1.52, 95% CI 0.25 to 9.27; 1 study, 200 participants; very low-quality evidence). Dacron may result in an increase in perioperative combined stroke and transient ischaemic attack (TIA) (OR 4.41 95% CI 1.20 to 16.14; 1 study, 200 participants; low-quality evidence) when compared with PTFE. Early arterial re-stenosis or occlusion (within 30 days) was also higher for Dacron patches. During follow-up for longer than one year, more 'any strokes' (OR 10.58, 95% CI 1.34 to 83.43; 2 studies, 304 participants; low-quality evidence) and stroke/death (OR 6.06, 95% CI 1.31 to 28.07; 1 study, 200 participants; low-quality evidence) were reported with Dacron patch closure, although numbers of outcome events were small. Dacron patch may increase the risk of re-stenosis when compared with other synthetic materials (especially with PTFE), but the evidence is very uncertain (OR 3.73, 95% CI 0.71 to 19.65; 3 studies, 490 participants; low-quality evidence). Bovine pericardium patch compared with other synthetic patch angioplasty Bovine pericardium versus PTFE patch materials  Evidence suggests that bovine pericardium patch results in a reduction in long-term ipsilateral stroke (OR 4.17, 95% CI 0.46 to 38.02; 1 study, 195 participants; low-quality evidence). Bovine pericardial patch may reduce the risk of perioperative fatal stroke, death, and infection compared to synthetic material (OR 5.16, 95% CI 0.24 to 108.83; 2 studies, 290 participants; low-quality evidence for PTFE, and low-quality evidence for Dacron; OR 4.39, 95% CI 0.48 to 39.95; 2 studies, 290 participants; low-quality evidence for PTFE, and low-quality evidence for Dacron; OR 7.30, 95% CI 0.37 to 143.16; 1 study, 195 participants; low-quality evidence, respectively), but the numbers of outcomes were small. The evidence is very uncertain about effects of the patch on infection outcomes.

AUTHORS' CONCLUSIONS

The number of outcome events is too small to allow conclusions, and more trial data are required to establish whether any differences do exist. Nevertheless, there is little to no difference in effect on perioperative and long-term ipsilateral stroke between vein and any synthetic patch material. Some evidence indicates that other synthetic patches (e.g. PTFE) may be superior to Dacron grafts in terms of perioperative stroke and TIA rates, and both early and late arterial re-stenosis and occlusion. Pseudoaneurysm formation may be more common after use of a vein patch than after use of a synthetic patch. Bovine pericardial patch, which is an acellular xenograft material, may reduce the risk of perioperative fatal stroke, death, and infection compared to other synthetic patches. Further large RCTs are required before definitive conclusions can be reached.

A meta-analysis of randomized trials comparing bovine pericardium and other patch materials for carotid endarterectomy

OBJECTIVE

Patch angioplasty during carotid endarterectomy is commonly used to treat symptomatic and asymptomatic carotid artery stenosis. The objective of the present study was to compare the different patch materials that are currently available (synthetic vs venous vs bovine pericardium) in terms of short- and long-term outcomes.

METHODS

This study was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines and eligible randomized control trials were identified through a comprehensive search of PubMed, Scopus, and Cochrane Central published until September 2017. A meta-analysis was conducted with the use of a random effects model. The I² statistic was used to assess for heterogeneity. The primary study end point was the incidence of long-term restenosis. Secondary study end points were 30-day stroke, transient ischemic attack (TIA), myocardial infarction, neck wound infection, local hematoma, carotid artery thrombosis, cranial nerve injury, long-term stroke incidence, and death.

RESULTS

Eighteen studies and 3234 patients were included. The risk of 30-day stroke (relative risk [RR], 1.00; 95% confidence interval [CI], 0.45-2.19; I² = 0%), TIA (RR, 1.14; 95% CI, 0.41-3.19; I² = 0%), myocardial infarction (odds ratio, 0.75; 95% CI, 0.14-3.97; I² = 0%), death (RR, 0.53; 95% CI, 0.21-1.34; I² = 0%), wound infection (RR, 1.84; 95% CI, 0.43-7.81; I² = 0%), carotid artery thrombosis (RR, 1.47; 95% CI, 0.44-4.97; I² = 0%), cranial nerve palsy (RR, 1.21; 95% CI, 0.53-2.77; I² = 0%), and long-term stroke (RR, 2.33; 95% CI, 0.76-7.10; I² = 0%), death (RR, 1.09; 95% CI, 0.65-1.83; I² = 0%) and restenosis of greater than 50% (RR, 0.48; 95% CI, 0.19-1.20; I² = 0%) were similar between the synthetic vs venous patch groups. Also, no differences in terms of 30-day stroke (RR, 0.31; 95% CI, 0.02-5.16; I² = 63.1%), TIA (RR, 0.49; 95% CI, 0.14-1.76; I² = 0%), death (RR, 0.74; 95% CI, 0.05-10.51; I² = 31.7%), carotid artery thrombosis (RR, 0.13; 95% CI, 0.02-1.07; I² = 0%), and long-term restenosis of greater than 70% (RR, 0.15; 95% CI, 0.01-2.29; I² = 70.9%) were detected between the synthetic polytetrafluoroethylene and Dacron patch groups. The comparison between the bovine pericardium vs synthetic patch did not yield any statistically significant results in terms of 30-day stroke (RR, 1.44; 95% CI, 0.19-10.79; I² = 12.7%), TIA (RR, 1.05; 95% CI, 0.11-10.27; I² = 0%), local neck hematoma (RR, 4.01; 95% CI, 0.46-34.85; I² = 0%), and death (RR, 4.01; 95% CI, 0.46-34.85; I² = 0%).

CONCLUSIONS

Closure of the carotid arteriotomy with any of the studied patch materials seems to be similar in terms of short- and long-term end points. However, additional randomized trials with adequate follow-up periods are needed to compare bovine pericardium patches with other patch materials.

Systematic review of randomized controlled trials of different types of patch materials during carotid endarterectomy

Background and Purpose

Carotid endarterectomy (CEA) with patch angioplasty produces greater results than with primary closure; however, there remains uncertainty on the optimal patch material in CEA. A systematic review of randomized controlled trials (RCTs) was performed to evaluate the effect of angioplasty using venous patch versus synthetic patch material, and Dacron patch versus polytetrafluoroethelene (PTFE) patch material during CEA.

Methods

A multiple electronic health database screening was performed including the Cochrane library, Pubmed, Ovid, EMBASE and Google Scholar on all randomized controlled trials (RCTs) published before November 2012 that compared the outcomes of patients undergoing CEA with venous patch versus synthetic patch. RCTs were included if they compared carotid patch angioplasty with autologus venous patch versus synthetic patch material, or compared one type of synthetic patch with another.

Results

Thirteen RCTs were identified. Ten trials, involving 1946 CEAs, compared venous patch with synthetic patch materials. Two trials, involving 400 CEAs in 380 patients, compared Dacron patch with PTFE patch. The hemostasis time in CEA with PTFE patch was significantly longer than with venous patch (P<0.0001), and longer than with Dacron patch (P<0.0001). There was no significant difference of mortality rate, stroke rate, restenosis, and operative time in CEA with venous patch versus synthetic patch material, or in CEA with Dacron patch versus PTFE patch (all P>0.05). One RCT of 95 CEAs in 92 patients compared bovine pericardium with Dacron patch, and demonstrated a statistically significant decrease in intraoperative suture line bleeding with bovine pericardium compared with Dacron patch (P<0.001).

Conclusions

The hemostasis time in CEA with PTFE patch was longer than with venous patch or Dacron patch. The overall perioperative and long-term mortality rate, stroke rate, restenosis, and operative time were similar when using venous patch versus synthetic patch material or Dacron patch versus PTFE patch material during CEA. More data are required to clarify differences between different patch materials.

Systematic review of randomized controlled trials of patch angioplasty versus primary closure and different types of patch materials during carotid endarterectomy

OBJECTIVE

Patch angioplasty during carotid endarterectomy (CEA) can reduce the risk of perioperative stroke or late carotid artery recurrent stenosis and subsequent ischaemic stroke. We aimed to update our previous systematic review of randomized controlled trials (RCTs) of routine or selective carotid patch angioplasty compared with CEA with primary closure, and of different materials used for carotid patch angioplasty.

METHODS

We identified new RCTs published during 2002-2010 by searching Medline, Embase and the Cochrane Stroke Group Trials Register. We also hand-searched six relevant journals. Pooled estimates of treatment effects combined with our previous review (1966-2001) were calculated on the basis of a weighted estimate of the odds ratio (OR) with the Peto method.

RESULTS

Twenty-three eligible RCTs were identified in both periods. Ten RCTs involving 2,157 operations compared primary closure with routine patch closure. Patch closure significantly reduced the combined risk of perioperative stroke and later stroke during long-term follow-up [OR = 0.49, 95% confidence interval (CI) = 0.27-0.90, p = 0.001; 7 RCTs]. Patching also reduced the risks of perioperative arterial occlusion (OR = 0.18, 95% CI = 0.08-0.41, p < 0.0001; 7 RCTs) and recurrent stenosis during long-term followup (OR = 0.24, 95% CI = 0.17-0.34, p < 0.001; 8 RCTs).

CONCLUSION

Meta-analysis of relatively small RCTs suggests that carotid patch angioplasty reduces the combined perioperative and long-term risk of stroke and the risk of restenosis. More data are needed.

Early neurologic outcome after bovine pericardium versus venous patch angioplasty in 599 patients undergoing carotid endarterectomy

Bovine pericardium was compared to great saphenous vein patch angioplasty regarding the neurologic events after carotid endarterectomy (CEA) with or without concomitant cardiac surgery (CS). From January 1996 to December 2007, 599 patients undergoing CEA (259 with concomitant CS) were enrolled; 456 patients were treated with the great saphenous vein (GSV group) and 143 were treated with bovine pericardium (BP group). Neurologic outcome and Rankin score (RS) were recorded after 24 hours and 30 days. We found comparable rates of neurologic complications (transient ischemic attack, stroke) between the two groups. Thirty-day mortality was 4% (17 of 456 patients) in the GSV group and 0% in the BP group (p = .12). None of the patients died as a consequence of a fatal stroke. Preoperative RS was a prognostic factor for postoperative neurologic deterioration (p = .001). Early neurologic outcome was comparable for the two types of patch material. Preoperative RS predicted postoperative neurologic deterioration.

Fluoropassivation and gelatin sealing of polyester arterial prostheses to skip preclotting and constrain the chronic inflammatory response

Fluoropassivation and gelatin coating have been applied to polyethylene terephthalate (PET) vascular prosthesis to combine the advantages of both polytetrafluoroethylene (PTFE) and PET materials, and to eliminate the preclotting procedure. The morphological, chemical, physical, and mechanical properties of such prostheses were investigated and compared with its original model. Fluoropassivation introduced -OCF(3), -CF(3), and -CFCF(2)- structures onto the surface of the polyester fibers. However, the surface fluorine content was only 28-32% compared to the 66% in expanded PTFE (ePTFE) grafts. The fluoropassivation decreased the hydrophilicity, slightly increased the water permeability, and marginally lowered the melting point and the crystallinity of the PET fibers. After gelatin coating, the fluoropassivated and nonfluoropassivated prostheses showed similar surface morphology and chemistry. While gelatin coating eliminated preclotting, it also renders the prostheses slightly stiffer. The original prosthesis had the highest bursting strength (275 N), with the fluoropassivated and gelatin-sealed devices showing similar bursting strength between 210 and 230 N. Fluoropassivation and gelatin coating lowered the retention strength by 23 and 30% on average, respectively. In vitro enzymatic incubation had only marginal effect on the surface fluorine content of the nongelatin-sealed prostheses. However, the gelatin-sealed ones significantly lost their surface fluorine after in vitro enzymatic incubation (by 69-85%) or in vivo 6-month implantation (by 51-60%), showing the lability of the fluoropolymer layer under the hostile biological environment.

Patches of different types for carotid patch angioplasty

BACKGROUND

Carotid patches for carotid endarterectomy may be made from an autologous vein or synthetic material.

OBJECTIVES

To assess the safety and efficacy of different materials for carotid patch angioplasty.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched 3 August 2009), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2009), MEDLINE (1966 to November 2008), EMBASE (1980 to November 2008) and Index to Scientific and Technical Proceedings (1980 to 2008). We handsearched relevant journals and conference proceedings, checked reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing one type of carotid patch with another for carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, trial quality, and extracted data.

MAIN RESULTS

We included 13 trials involving a total of 2083 operations; seven trials compared vein closure with PTFE closure, and six compared Dacron grafts with other synthetic materials. In most trials a patient could be randomised twice and have each carotid artery randomised to different treatment groups. There were no significant differences in the outcomes between vein patches and synthetic materials apart from pseudoaneurysms where there were fewer associated with synthetic patches than vein patches (odds ratio (OR) 0.09, 95% confidence interval (CI) 0.02 to 0.49). However, the numbers involved were small and the clinical significance of this finding is uncertain. Compared to other synthetic patches, Dacron was associated with a higher risk of: perioperative combined stroke and transient ischaemic attack (P = 0.03); restenosis at 30 days (P = 0.004); perioperative stroke (P = 0.07) and perioperative carotid thrombosis (P = 0.1). During follow-up for more than one year, there were also significantly more strokes (P = 0.03), stroke/death (P = 0.02) and arterial restenoses (P < 0.0001) with Dacron but the numbers of outcomes were small and the significance of this finding is uncertain.

AUTHORS' CONCLUSIONS

The number of outcome events is too small to allow reliable conclusions to be drawn and more trial data are required to establish whether any differences do exist. Nevertheless, there is some evidence that other synthetic (e.g. PTFE) patches may be superior to collagen impregnated Dacron grafts in terms of perioperative stroke rates and restenosis. Pseudoaneurysm formation may be more common after use of a vein patch compared with a synthetic patch.