Randomized trial of vein versus Dacron patching during carotid endarterectomy: influence of patch type on postoperative embolization

An international, multispecialty, expert-based Delphi Consensus document on controversial issues in the management of patients with asymptomatic and symptomatic carotid stenosis

OBJECTIVE

Despite the publication of various national/international guidelines, several questions concerning the management of patients with asymptomatic (AsxCS) and symptomatic (SxCS) carotid stenosis remain unanswered. The aim of this international, multi-specialty, expert-based Delphi Consensus document was to address these issues to help clinicians make decisions when guidelines are unclear.

METHODS

Fourteen controversial topics were identified. A three-round Delphi Consensus process was performed including 61 experts. The aim of Round 1 was to investigate the differing views and opinions regarding these unresolved topics. In Round 2, clarifications were asked from each participant. In Round 3, the questionnaire was resent to all participants for their final vote. Consensus was reached when ≥75% of experts agreed on a specific response.

RESULTS

Most experts agreed that: (1) the current periprocedural/in-hospital stroke/death thresholds for performing a carotid intervention should be lowered from 6% to 4% in patients with SxCS and from 3% to 2% in patients with AsxCS; (2) the time threshold for a patient being considered "recently symptomatic" should be reduced from the current definition of "6 months" to 3 months or less; (3) 80% to 99% AsxCS carries a higher risk of stroke compared with 60% to 79% AsxCS; (4) factors beyond the grade of stenosis and symptoms should be added to the indications for revascularization in AsxCS patients (eg, plaque features of vulnerability and silent infarctions on brain computed tomography scans); and (5) shunting should be used selectively, rather than always or never. Consensus could not be reached on the remaining topics due to conflicting, inadequate, or controversial evidence.

CONCLUSIONS

The present international, multi-specialty expert-based Delphi Consensus document attempted to provide responses to several unanswered/unresolved issues. However, consensus could not be achieved on some topics, highlighting areas requiring future research.

Literature review of primary versus patching versus eversion as carotid endarterectomy closure

BACKGROUND

Which type of closure after carotid endarterectomy (CEA), whether primary, patching, or eversion, will provide the optimal results has remained controversial. In the present study, we compared the results of randomized controlled trials (RCTs) and systematic meta-analyses of the various types of closure.

METHODS

We conducted a PubMed literature review search to find studies that had compared CEA with primary closure, CEA with patching, and/or eversion CEA (ECEA) during the previous three decades with an emphasis on RCTs, previously reported systematic meta-analyses, large multicenter observational studies (Vascular Quality Initiative data), and recent single-center large studies.

RESULTS

The results from RCTs comparing primary patching vs primary closure were as follows. Most of the randomized trials showed CEA with patching was superior to CEA with primary closure in lowering the perioperative stroke rates, stroke and death rates, carotid thrombosis rates, and late restenosis rates. These studies also showed no significant differences between the preferential use of several patch materials, including synthetic patches (polyethylene terephthalate [Dacron; DuPont, Wilmington, Del], Acuseal [Gore Medical, Flagstaff, Ariz], polytetrafluoroethylene, or pericardial patches) and vein patches (saphenous or jugular). The results from observational studies comparing patching vs primary closure were as follows. The Vascular Study Group of New England data showed that the use of patching increased from 71% to 91% (P < .001). Also, the 1-year restenosis and occlusion (P < .01) and 1-year stroke and transient ischemic attack (P < .03) rates were significantly lower statistically with patch closure. The results from the RCTs comparing ECEA vs conventional CEA (CCEA) were as follows. Several RCTs that had compared ECEA with CCEA showed equivalency of CCEA vs ECEA (level 1 evidence) with patching in the perioperative carotid thrombosis and stroke rates. At 4 years after treatment, the incidence of carotid stenosis was lower for ECEA than for primary closure (3.6% vs 9.2%; P = .01) but was comparable between patching and eversion (1.5% for patching vs 2.8% for eversion).

CONCLUSIONS

Routine carotid patching or ECEA was superior to primary closure (level 1 evidence). We found no significant differences between the preferential use of several patch materials. The rates of significant post-CEA stenosis for CEA with patching was similar to that with ECEA, and both were superior to primary closure.

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.

Registry report on prediction by Pocock cardiovascular score of cerebral microemboli acutely following carotid endarterectomy

Background

Cerebral microemboli may lead to ischaemic neurological complications after carotid endarterectomy (CEA). The association between classical cardiovascular risk factors and acute cerebral microemboli following carotid surgery has not been studied. The aim of this study was to explore whether an established cardiovascular risk score (Pocock score) predicts the presence of cerebral microemboli acutely after CEA.

Subjects and methods

Pocock scores were assessed for the 670 patients from the Carotid Surgery Registry (age 71±1 (SEM) years, 474 (71%) male, 652 (97%) Caucasian) managed from January 2002 to December 2012 in the Regional Vascular Centre at University Hospitals Coventry and Warwickshire NHS Trust, which serves a population of 950 000. CEA was undertaken in 474 (71%) patients for symptomatic carotid stenosis and in 196 (25%) asymptomatic patients during the same period. 74% of patients were hypertensive, 71% were smokers and 49% had hypercholesterolaemia.

Results

A high Pocock score (≥2.3%) was significantly associated with evidence of cerebral microemboli acutely following CEA (P=0.039, Mann-Whitney (MW) test). A Pocock score (≥2.3%) did not predict patients who required additional antiplatelet therapy (microemboli signal (MES) rate >50 hour^-1: P=0.164, MW test). Receiver operating characteristic analysis also showed that the Pocock score predicts acute postoperative microemboli (area under the curve (AUC) 0.546, 95% CI 0.502 to 0.590, P=0.039) but not a high rate of postoperative microemboli (MES >50 hour⁻¹: AUC 0.546, 95% CI 0.482 to 0.610, P=0.164). A Pocock score ≥2.3% showed a sensitivity of 74% for the presence of acute postoperative cerebral microemboli. A Pocock score ≥2.3% also showed a sensitivity of 77% and a negative predictive value of 90% for patients who developed a high microembolic rate >50 hour⁻¹ after carotid surgery.

Conclusion

These findings demonstrate that the Pocock score could be used as a clinical tool to identify patients at high risk of developing acute postoperative microemboli.

Right carotid-cutaneous fistula and right carotid pseudoaneurysm formation secondary to a chronically infected polyethylene terephthalate patch

Carotid endarterectomy (CEA) remains the treatment for significant carotid stenosis and stroke prevention. Approximately 100,000 CEAs are performed in the United States every year. Randomized trials have demonstrated an advantage of patch carotid angioplasty over primary closure. Complications from patches include thrombosis, transient ischemic attack, stroke, restenosis, pseudoaneurysm (PA), and infection. PA after CEA is rare, with a reported average of 0.37% of cases. We describe an unusual case of PA after polyethylene terephthalate (PTFE) patching for CEA. An 88-year-old female with Alzheimer's disease living in a nursing facility with a history of skin cancer on her right chest developed a new area of intermittent brisk bleeding on her right neck which was initially believed to be related to her skin cancer. She had a remote history of right CEA with a PTFE patch approximately a decade ago. A computed tomography angiograph-head-and-neck with showed a partially thrombosed PA in the region of her right common carotid artery bifurcation with a tract containing gas and fluid extending to the skin surface suspicious for a partially thrombosed, leaking PA. She was taken urgently to the operating room on broad-spectrum antibiotics where we performed a right neck exploration, ligation of a bleeding carotid PA by ligation of the right common, internal, and external carotid arteries, explantation of a chronically infected polyethylene terephthalate patch, and closure with a sternocleidomastoid advanced flap with multilayered closure. She was discharged to her nursing facility with 6 weeks of ceftriaxone intravenous (IV) and metronidazole IV through a peripherally inserted central catheter (PICC) line with no neurological sequelae.

Late Dacron Patch Inflammatory Reaction after Carotid Endarterectomy

OBJECTIVE

The aim was to analyse the incidence and presentation of carotid patch inflammatory reactions following carotid endarterectomy (CEA).

METHODS

This was a cohort study using a prospectively maintained database. All patients who underwent elective CEA at a tertiary vascular centre between 2002 and 2016 were included. Computed tomography scan angiogram, duplex scan, and leucocyte scintigraphy were used to assess patients with suspected inflammatory patch complications. Re-intervention procedures and outcomes were noted. Histopathology and organisms cultured from the harvested material during re-intervention were assessed.

RESULTS

During the study period, 633 patients underwent elective CEA. Fifty-one underwent eversion endarterectomy: 111 did not require a patch, whereas 471 patients had a patch repair. Four hundred and twenty eight had a Dacron patch repair and 43 a biological patch. Eight patients returned with late Dacron patch inflammatory complications (1.3% of all CEA and 1.9% of Dacron patch closures) after a period ranging from 18 months to 7 years (mean 4.1 ± 2.1 years). Seven of the eight patients underwent surgical re-intervention, and the eighth patient was deemed high surgical risk. One patient underwent a vein bypass, three had vein patch repair, one required internal carotid artery (ICA) ligation after patch excision, and two were managed by debridement, with omohyoid and sternomastoid muscle covering of the patch. The patient who required ICA ligation suffered a fatal stroke. The remaining patients had a satisfactory outcome. All patients showed evidence of foreign body reaction in pathological examination with no pathological organism cultured from swabs or tissue harvested during surgery.

CONCLUSION

Late wound complications after CEA may be related to inflammatory reaction of the Dacron patch rather than infection. Infection should be excluded first. Reconstruction with vein is effective. However, debridement with sternomastoid and omohyoid muscle covering of the patch may be considered in high risk patients after exclusion of infection with regular follow-up.

Carotid Endarterectomy: A Review

Background:

Since the validation of carotid endarterectomy (CEA) as an effective means of stroke prevention, there has been renewed interest in its best indications and methods, as well as in how it compares to carotid angioplasty and stenting (CAS). This review examines these topics, as well as the investigation of carotid stenosis and the role of auditing and reporting CEAresults.

Investigation:

Brain imaging with CTor MRI should be obtained in patients considered for CEA, in order to document infarction and rule out mass lesions. Carotid investigation begins with ultrasound and, if results agree with subsequent, good-quality MRAor CTangiography, treatment can be planned and catheter angiography avoided. An equally acceptable approach is to proceed directly from ultrasound to catheter angiography, which is still the gold-standard in carotid artery assessment.

Indications:

Appropriate patients for CEA are those symptomatic with transient ischemic attacks or nondisabling stroke due to 70-99% carotid stenosis; the maximum allowable stroke and death rate being 6%. Uncertain candidates for CEA are those with 50 - 69% symptomatic stenosis, and those with asymptomatic stenosis ≥ 60% but, if selected carefully on the basis of additional risk factors (related to both the carotid plaque and certain patient characteristics), some will benefit from surgery. Asymptomatic patients will only benefit if surgery can be provided with exceptionally low major complication rates (3% or less). Inappropriate patients are those with less than 50% symptomatic or 60% asymptomatic stenosis, and those with unstable medical or neurological conditions.

Techniques:

Carotid endarterectomy can be performed with either regional or general anaesthesia and, for the latter, there are a number of monitoring techniques available to assess cerebral perfusion during carotid cross-clamping. While monitoring cannot be considered mandatory and no single monitoring technique has emerged as being clearly superior, EEG is most commonly used. “Eversion” endarterectomy is a variation in surgical technique, and there is some evidence that more widely practiced patch closure may reduce the acute risk of operative stroke and the longer-term risk of recurrent stenosis.

Carotid angioplasty and stenting:

Experience with this endovascular and less invasive procedure grows, and its technology continues to evolve. Some experienced therapists have reported excellent results in case series and a number of randomized trials are now underway comparing CAS to CEA. However, at this time it is premature to incorporate CAS into routine practice replacing CEA.

Auditing:

It has been shown that auditing of CEA indications and results with regular feed-back to the operating surgeons can significantly improve the performance of this operation. Carotid endarterectomy auditing is recommended on both local and regional levels.

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.

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.

Prospective randomized trial of ACUSEAL (Gore-Tex) vs Finesse (Hemashield) patching during carotid endarterectomy: long-term outcome

BACKGROUND

Several studies have reported that carotid endarterectomy with patch angioplasty is superior to primary closure. Conventional polytetrafluoroethylene (Gore-Tex, W. L. Gore & Associates, Flagstaff, Ariz) patching has been shown to have results similar to autogenous saphenous vein patching; however, it requires a longer hemostasis time. This study examined the long-term clinical outcome and incidence of restenosis after carotid endarterectomy using the new ACUSEAL (Gore-Tex) patching vs Hemashield Finesse (Boston Scientific Corp, Natick, Mass) patching.

METHODS

The study randomized 200 patients (1:1) undergoing carotid endarterectomy to 100 with ACUSEAL patching and 100 with Hemashield-Finesse patching. All patients underwent immediate and 1-month postoperative duplex ultrasound studies, which were repeated at 6-month intervals. Kaplan-Meier analysis was used to estimate the freedom from stroke, stroke-free survival, and the risk of restenosis for both groups.

RESULTS

The demographic and clinical characteristics, the mean operative diameter of the internal carotid artery, and the length of the arteriotomy were similar in both groups. The mean hemostasis time was 5.1 for the ACUSEAL patching vs 3.7 minutes for Finesse patching (P = .01); however, the mean operative times were similar for both groups (P = .61). The incidence of ipsilateral stroke was 2% for ACUSEAL patching (both early perioperative strokes) vs 3% for Finesse patching (2 early and 1 late stroke) at a mean follow-up of 21 months. The respective cumulative stroke-free rates at 1, 2, and 3 years were 98%, 98%, and 98% for ACUSEAL patching vs 97%, 97%, and 97% for Finesse patching (P = .7). The respective cumulative stroke-free survival rates at 1, 2, and 3 years were 97%, 92%, and 88% for ACUSEAL patching vs 96%, 96%, and 91% for Finesse patching (P = .6). The respective freedom from > or =70% carotid restenosis at 1, 2, and 3 years was 98%, 96%, and 89% for ACUSEAL patching vs 92%, 85%, and 79% for Finesse patching (P = .04).

CONCLUSIONS

Carotid endarterectomy with ACUSEAL patching and Finesse patching had similar stroke-free rates and stroke-free survival rates. The mean hemostasis time for the ACUSEAL patch was 1.4 minutes longer than that for the Finesse patch; however, the Finesse patch had higher restenosis rates than the ACUSEAL patch.

Primary closure, routine patching, and eversion endarterectomy: what is the current state of the literature supporting use of these techniques?

Our objective in this article was to review the most recent literature on the status of carotid patching or primary carotid closure following carotid endarterectomy; to determine the best patch material if needed; and to clarify the place of eversion carotid endarterectomy in management of carotid artery atherosclerosis. In order to accomplish this, a literature review was performed of the Ovid, PubMed and MedLine databases using appropriate search terms. An evidence-based approach was taken; with all articles graded using the Scottish Intercollegiate Guidelines Network system (levels of evidence 1 to 5) and recommendations were made using an A to D system. Most weight was given to well-conducted, adequately powered, randomized control trials. After review of the literature, we were able to make the following Grade A recommendation: carotid patching is superior to primary closure, resulting in fewer postoperative strokes and a lower incidence of restenosis in most surgeons' hands. However, it was also concluded that, based on review of the literature, that the choice of patch material in 2007 has little impact; eversion carotid endarterectomy (CEA) and conventional patch CEA have equivalent postoperative morbidity and similar incidences of long-term restenosis. In conclusion, the technique of CEA continues to evolve, but in most reported series, immediate and long-term outcomes are excellent. A variety of technical approaches are acceptable, but it appears that carotid patching remains superior to primary closure.

Discretionary carotid patch angioplasty leads to good results

BACKGROUND

This study evaluated the type and need for angioplasty in 253 consecutive carotid endarterectomies.

METHODS

Polyester knitted gelatin sealed patch (DP) and polytetrafluoroethylene (PTFE) patches were used in, respectively, 159 and 29 patients, with 65 vessels closed primarily (no patch [NP]).

RESULTS

Surgical results, estimated blood loss, and surgical time were similar in each group. Postoperative hematomas occurred in 6 DP and 3 NP patients. There were 3 strokes in the DP group. Long-term duplex evaluation was possible in 201 patients. The number of patients who had less than 15%, 15% to 50%, 50% to 79%, 80% to 99%, 100%, or an ungraded degree of narrowing were as follows for each group: DP, 117, 2, 5, 0, 1, and 2; PTFE, 18, 1, 1, 0, 0; and NP, 53, 0, 0, 0, 1. Statistical analysis failed to show any difference between groups postoperatively or in long-term follow-up evaluation.

CONCLUSIONS

It appears that selective patching is safe and effective in male patients who undergo carotid endarterectomy. The type of patch material also is inconsequential. Patch type and its use should be at the surgeon's discretion.

Closure of the arteriotomy after carotid endarterectomy: Patch type is related to intraoperative microemboli and restenosis rate

OBJECTIVE

Patch closure after carotid endarterectomy (CEA) improves clinical outcome compared with primary closure. Whether there are differences in outcome between various patch materials is still not clear. The objective of this retrospective study was to investigate whether a relationship exists between the patch type and the number of microemboli as registered during CEA by transcranial Doppler imaging, the clinical outcome (transient ischemic attack and cerebrovascular accident), and the occurrence of restenosis.

METHODS

We included 319 patients who underwent CEA. Intraoperative microembolus registration was performed in 205 procedures. Microembolization was recorded during four different periods: dissection, shunting, clamp release, and wound closure. The decision to perform primary closure or to use a patch for the closure of the arteriotomy was made by the surgeon, and Dacron patches were used when venous material was insufficient. Cerebral events were recorded within the first month after CEA, and duplex scanning was performed at 3 months (n = 319) and 1 year (n = 166) after CEA. A diameter reduction of more than 70% was defined as restenosis.

RESULTS

Primary, venous, and Dacron patch closures were performed in 83 (26.0%), 171 (53.6%), and 65 (20.4%) patients, respectively. Primary closure was significantly related to sex (Dacron patch, 35 men and 30 women; venous patch, 108 men and 63 women; primary closure, 72 men and 11 women; P < .001). The occurrence of microemboli during wound closure was also related to sex (women, 2.5 +/- 0.6; men, 1.0 +/- 0.2; P = .01). Additionally, during clamp release, Dacron patches were associated with significantly more microemboli than venous patches (11.1 +/- 3.4 vs 4.0 +/- 0.9; P < .01), and this difference was also noted during wound closure (3.1 +/- 0.9 vs 1.4 +/- 0.4; P < .05). Transient ischemic attacks and minor strokes after CEA occurred in 5 (2.4%) of 205 and 6 (2.9%) of 205 procedures, respectively, and the degree of microembolization during dissection was related to adverse cerebral events (P = .003). In contrast, the type of closure was not related to immediate clinical adverse events. However, primary closure and Dacron patches were associated with an increase in the restenosis rate compared with venous patches: after 400 days, the restenosis rate for Primary closure was 11%, Dacron patch 16%, and venous patch 7% (P = .05; Kaplan-Meier estimates).

CONCLUSIONS

Microemboli are more prevalent during clamp releases and wound closure when Dacron patches are used. Additionally, the observed differences in embolization noted by patch type were mainly evident in women. However, the use of Dacron patches was not related to immediate ischemic cerebral events but was associated with a higher restenosis rate compared with venous patch closure. This suggests that venous patch closure may be preferred for CEA.

Primary closure of the carotid artery is associated with poorer outcomes during carotid endarterectomy

INTRODUCTION

Arterial endarterectomy and reconstruction during carotid endarterectomy (CEA) can be performed in a variety of ways, including standard endarterectomy with primary closure, standard endarterectomy with patch angioplasty, and eversion endarterectomy. The optimal method of arterial reconstruction remains a matter of controversy. The objective of this study was to determine the effect of the method of arterial reconstruction during CEA on perioperative outcome.

METHODS

A retrospective cohort study of consecutive CEAs performed by 81 surgeons during 1997 and 1998 in six regional hospitals was performed. Detailed clinical data regarding each case and all deaths and nonfatal strokes within 30 days of surgery were ascertained by an independent review of the inpatient chart, outpatient surgeon record, and the hospitals' administrative databases. Two physician investigators--one neurologist and one internist--confirmed each adverse event by independently reviewing patients' medical records.

RESULTS

A total of 1972 CEAs were performed. The mean age of the patients was 72.3 years, and 57.2% were male. Preoperative neurologic symptoms occurred in 28.7% of cases (n = 566), and the remaining 71.3% were asymptomatic before surgery (n = 1406). The method of arterial reconstruction was chosen by the surgeon. Primary closure was performed in 11.8% (n = 233), patch angioplasty in 69.8% (n = 1377), and eversion endarterectomy in 18.4% (n = 362). There was no significant difference in the preoperative symptom status of patients who underwent primary closure compared with the other methods of reconstruction (72.5% asymptomatic vs 71.1%, p = NS). Primary closure cases were significantly more likely to experience perioperative stroke compared with the other closure techniques (5.6% vs 2.2%, P = .006). Primary closure cases also had a higher incidence of perioperative stroke or death compared with the other closure techniques (6.0% vs 2.5%, P = .006). There were no significant differences with regard to either perioperative stroke, or perioperative stroke/death noted when comparing patch angioplasty with eversion endarterectomy: stroke, 2.2% vs 2.5% (P = NS) and stroke/death, 2.5% vs 2.5% (P = NS) respectively.

CONCLUSION

It appears that primary closure is associated with significantly worse perioperative outcomes compared with endarterectomy with patch angioplasty and eversion endarterectomy, even when the preoperative symptom status of the patient cohorts is equivalent. Although some of its advocates have reported that they can properly select appropriate patients for primary closure based on the size of the artery and other factors, the data demonstrate that these patients have poorer outcomes nonetheless. Primary closure during carotid endarterectomy should predominantly be abandoned in favor of either standard endarterectomy with patch angioplasty or eversion endarterectomy.

Cost-effectiveness of Intraoperative Imaging in Carotid Endarterectomy

OBJECTIVE:

There has never been a large, randomized controlled trial to assess the impact of intraoperative imaging on the success of carotid endarterectomy (CEA). This comparison involves cost-effectiveness analysis.

METHODS:

We constructed a decision-analytic model to compare effectiveness and costs of intraoperative ultrasound (IUS) and completion angiography as adjuncts to CEA. Data on procedural mortality, morbidity, and costs were obtained from the English-language literature. The review included a total of 52 reports, encompassing more than 22,000 patients. The main components of costs were those of the monitoring interventions and the care of perioperative stroke.

RESULTS:

Mean perioperative outcome without completion imaging is approximately 96.7% of what it would be in the absence of perioperative stroke or death. IUS and completion angiography each result in approximately 2% improvement in expected outcome. Mean perioperative costs are $396.50 for IUS, $721.30 for no monitoring, and $840.90 for completion angiography. Because IUS is significantly more effective at detecting technical errors that would likely result in perioperative stroke than no imaging and is significantly less costly than angiography, this strategy dominates the other two (i.e., it provides greater effectiveness at lower cost).

CONCLUSION:

Although surgical complications are uncommon, IUS substantially lowers the rate of perioperative stroke and mortality and thus is significantly more cost-effective than either completion angiography or no operative imaging.

Identification of Patients at Risk for Ischaemic Cerebral Complications After Carotid Endarterectomy with TCD Monitoring

OBJECTIVES

Transcranial Doppler (TCD) monitoring for micro embolic signals (MES), directly after carotid endarterectomy (CEA) may identify patients at risk of developing ischaemic complications. In this retrospective multicentre study, this hypothesis was investigated.

METHODS

Centres that monitored for MES after CEA were identified by searching Medline. Individual patient data were obtained from centres willing to collaborate. The number of emboli in 1h was computed. Uni- and multivariate logistic regression analyses were performed for the variables gender, age and number of MES. Discriminative ability of MES monitoring was investigated in a ROC curve.

RESULTS

Nine hundred and ninety-one patients were monitored in the first 3h after CEA. Two percent developed ischaemic cerebral complications. Univariate analysis revealed statistically significant associations between ischaemic cerebral complications and both gender and MES, but not age. In a multivariate analysis, > or =8 MES/h showed a statistically significant relationship with cerebral complications (OR 8.1, 95% CI 1.8-36), in contrast to gender (OR 2.2, 95% CI 0.9-5.5). The ROC curve yielded an AUC of 0.83 for monitoring of MES.

CONCLUSIONS

These results support the use of TCD monitoring for MES shortly after CEA in order to identify patients at risk of developing ischaemic cerebral complications.

Prospective study of carotid endarterectomy with modified polytetrafluoroethylene (ACUSEAL) patching: Early and late results

OBJECTIVE

Carotid endarterectomies (CEAs) with standard polytetrafluoroethylene (PTFE) patching have been shown to have results comparable with those of autogenous vein patching; however, prolonged bleeding through needle holes in PTFE is a commonly recognized problem. This is the first study of CEA using a new hemostatic modified PTFE patch (GORE-TEX) analyzing the early and late outcomes.

METHODS

Two hundred consecutive CEAs were entered into this protocol. All patients had an immediate postoperative carotid duplex ultrasound scan that was repeated at 1 month and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate the stroke-free survival and the risk of restenosis. The mean follow-up was 21 months (range, 1 to 48 months).

RESULTS

The perioperative stroke rate was 1.5% (1% ipsilateral and 0.5% contralateral, two minor strokes and one major stroke) with no perioperative mortality or perioperative carotid thrombosis. The incidence of perioperative transient ischemic attacks was 3.5% (2.5% ipsilateral and 1% contralateral). The mean hemostasis time after completion of the patching was 3 minutes, in contrast to 14 minutes for conventional PTFE (in a previous study). The rates of freedom from ipsilateral strokes at 1, 2, 3, and 4 years were 99%, 99%, 99%, and 99%, respectively. The cumulative stroke-free survival rates at 1, 2, 3, and 4 years were 98%, 96%, 93%, and 93%, respectively. The rates of freedom from > or =70% restenosis at 1, 2, 3, and 4 years were 97%, 97%, 94%, and 94%, respectively.

CONCLUSIONS

CEAs with a new modified PTFE patch are safe, have low perioperative stroke rates, are durable, and have an acceptable hemostasis time.

Transcranial Doppler Monitoring after Carotid Endarterectomy

The objectives of this study were to evaluate the feasibility of transcranial Doppler (TCD) monitoring after carotid endarterectomy (CEA) and to investigate whether 1 hr of monitoring is sufficient to detect a clinically relevant change in the number of postoperative microemboli. We also evaluated the association of patient characteristics and procedure-related variables with the number of postoperative microemboli. One hundred and two patients were monitored during the second hour after CEA. The main outcome measure was the number of TCD-detected microemboli. The secondary outcome measure was a procedure-related cerebral complication graded according to the modified Rankin scale. The median number of microemboli during the second postoperative hour was two (interquartile ranges, 0.75-11) and decreased in most the patients during this time. Two patients had a relatively high and increasing number of microemboli and developed a minor stroke after a symptom-free interval. One patient developed a TIA intraoperatively. There was no significant association between patient characteristics and the use of a venous patch and the number of postoperative microemboli. Conversely, a statistically significant negative association was found between shunt use and the number of microemboli (p = 0.02). The majority of patients had no or a small and decreasing number of microemboli. One hour of monitoring appeared to be effective to select those patients in whom the number of microemboli did not spontaneously decrease and who may need additional medical treatment or surgical reexploration. The role of TCD-detected microemboli as a surrogate measure for the risk of stroke after CEA remains to be validated.

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

BACKGROUND

Patch angioplasty during carotid endarterectomy (CEA) may reduce the risk for perioperative or late carotid artery recurrent stenosis and subsequent ischemic stroke. We performed a systematic review of randomized controlled trials to assess the effect of routine or selective carotid patch angioplasty compared with CEA with primary closure, and the effect of different materials used for carotid patch angioplasty.

METHODS

Randomized trials were included if they compared carotid patch angioplasty with primary closure in any patients undergoing CEA or use of one type of carotid patch with another.

RESULTS

Thirteen eligible randomized trials were identified. Seven trials involving 1281 operations compared primary closure with routine patch closure, and 8 trials with 1480 operations compared different patch materials (2 studies compared both). Patch angioplasty was associated with a reduction in risk for stroke of any type (P = .004), ipsilateral stroke (P = .001), and stroke or death during both the perioperative period (P = .007) and long-term follow-up (P = .004). Patching was also associated with reduced risk for perioperative arterial occlusion (P = .0001) and decreased recurrent stenosis during long-term follow-up (P < .0001). Seven trials that compared different patch types showed no difference in the risk for stroke, death, or arterial recurrent stenosis either perioperatively or at 1-year follow-up. One study of 180 patients (200 arteries) compared collagen-impregnated Dacron (Hemashield) patches with polytetrafluoroethylene patches. There was a significant increase in risk for stroke (P = .02), combined stroke and transient ischemic attack (P = .03), and recurrent stenosis (P = .01) at 30 days, and an increased risk for late recurrent stenosis greater than 50% (P < .001) associated with Dacron compared with polytetrafluoroethylene.

CONCLUSIONS

Carotid patch angioplasty decreases the risk for perioperative death or stroke, and long-term risk for ipsilateral ischemic stroke. More data are required to establish differences between various patch materials.

Randomized trial of vein versus dacron patching during carotid endarterectomy: Long-term results

BACKGROUND AND PURPOSE

Overviews of randomized patch trials by the Cochrane Collaboration suggest that a policy of routine patching is preferable to routine primary closure. However, there is no systematic evidence that patch type, whether prosthetic or vein, influences outcome after carotid endarterectomy (CEA).

METHODS

Two hundred seventy-three patients were randomized to vein or thin-walled Dacron patch (Hemashield Finesse) closure of the arteriotomy after 276 CEA procedures. Patients were reviewed clinically and with duplex ultrasound scanning at 1, 6, 12, 24, and 36 months or until death. No patients were lost to follow-up. Cumulative statistical analyses are presented for the 264 patients (269 CEAs) who actually received a randomized treatment allocation.

RESULTS

Cumulative freedom from death or ipsilateral stroke at 3 years (including operative events) was 93.0% in the Dacron patch group and 95.5% in the vein group P =.42). Cumulative freedom from death or any stroke was 91.5% after Dacron patch closure and 93.9% after vein closure (P =.46). Cumulative freedom from recurrent stenosis greater than 70% or occlusion at 3 years was 92.9% for patients randomized to the Dacron patch group and 98.4% for patients randomized to the vein group (P =.03). At 3 years the incidence of stroke in the carotid territory not operated on was 1.0% in 93 patients with no contralateral internal carotid artery disease at randomization, and increased to 1.3% in 78 patients with 1% to 69% stenosis, and 2.0% in 51 patients with contralateral 70% to 99% stenosis. No late strokes occurred distal to 42 occluded contralateral internal carotid arteries.

CONCLUSIONS

Patch type has no influence on early operative risk, no association with enhanced patterns of thrombogenicity in the early postoperative period, and no influence on risk for ipsilateral or any stroke at 3 years. Dacron patches were, however, associated with a significantly higher incidence of recurrent stenosis at 3 years, with most occurring within 6 to 12 months of surgery. However, the higher incidence of recurrent stenosis was not associated with a parallel increase in late stroke, and in this study a program of serial ultrasound surveillance could not have prevented one ipsilateral stroke.

Patients' thromboembolic potential after carotid endarterectomy is related to the platelets' sensitivity to adenosine diphosphate

Background and purpose Postoperative microemboli in patients undergoing carotid endarterectomy are a significant risk factor for stroke. These emboli can be detected by intraoperative transcranial Doppler monitoring. They are not linked to technical error and are variable between patients. As it is known that platelets play a key role in arterial thrombosis, it was hypothesized that a patient's risk of postoperative carotid thrombosis was linked to the individual's platelet response to physiologic agonists.

METHODS

Blood samples from 120 patients undergoing carotid endarterectomy were analyzed before surgery. Platelet aggregation was measured in response to adenosine diphosphate (ADP) (0.5 to 4 micromol/L), collagen (10 to 50 mg/mL), and arachidonic acid (3 or 6 micromol/L), and fibrinogen binding to GPIIb-IIIa was measured by whole blood flow cytometry in response to ADP (0.1 to 10 micromol/L) and thrombin (0.02 to 0.16 micro/mL). Patients underwent intraoperative transcranial Doppler monitoring for 3 hours after surgery, and platelet functional data of those who had >25 emboli in this period (n = 22) were compared with the data of those with <25 emboli (n = 88).

RESULTS

The platelet response to ADP was significantly higher in the patients with >25 emboli, as measured both by aggregometry (P =.0012) and by flow cytometry (P <.0001). Platelet aggregation with collagen was also significantly higher in this group (P =.0018), but the response to thrombin was not statistically different in the two groups. In addition, there was no difference in the response to arachidonic acid between the groups.

CONCLUSION

The platelet response to ADP may be linked to clinical outcome, and thus, specific ADP receptor inhibitors may be appropriate for this group of patients.

Patches of different types for carotid patch angioplasty

BACKGROUND

Some surgeons who use carotid patching favour using a patch made from an autologous vein, whilst others prefer to use synthetic materials.

OBJECTIVES

The objective of this review was 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 November 2002). In addition, we searched the Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2001), MEDLINE (1966 to December 2001), EMBASE (1980 to December 2001) and Index to Scientific and Technical Proceedings (1980 to 2001). We also handsearched eight journals and five conference proceedings. Reference lists were checked and we contacted experts in the field to identify further published and unpublished studies.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility, trial quality, and extracted the data

MAIN RESULTS

The previous version of this review included three trials involving 326 operations. Since then a further five trials have been reported, increasing the number of operations to 1480. Prior to 1995, all studies had compared vein closure with PTFE closure, but three of the later studies compared vein to Dacron grafts instead and one compared Dacron with PTFE. Allocation was not adequately concealed in two trials, and one only followed up patients to the time of hospital discharge. Intention to treat analysis was possible for six trials. In all but two trials a patient could be randomised twice and have each carotid artery randomised to different treatment groups. There were too few operative events to determine whether there was any difference between the vein and Dacron patches for perioperative stroke, death and arterial complications. The one study that compared Dacron and PTFE patches found a significant risk of combined stroke and transient ischaemic attack (p = 0.03) and restenosis at 30 days (p = 0.01), a borderline significant risk of perioperative stroke (p = 0.06), and a non significant increased risk of perioperative carotid thrombosis (p = 0.1) with dacron compared with PTFE. Five trials followed up patients for longer than 30 days. During follow-up for more than one year, no difference was shown between the two types of patch for the risk of stroke, death, or arterial restenosis. However, the number of events was small. Based on 15 events in 776 patients in four trials, there were significantly fewer pseudoaneurysms associated with synthetic patches than vein (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.02 to 0.49) but the numbers involved were small and the clinical significance of this finding is uncertain.

REVIEWERS' CONCLUSIONS

It is likely that the differences between different types of patch material are very small. Consequently, many more data than are currently available will be required to establish whether any differences do exist. Some evidence exists that PTFE patches may be superior to Colagen impregnated Dacron grafts in terms of perioperative stroke rates and restenosis. However the evidence is based upon data from a single, small trial and more studies that compare different types of synthetic graft are required to make firm conclusions. Psuedo aneurysm formation may be more common after use of a vein patch compared with a synthetic patch.

Prospective randomized trial of carotid endarterectomy with polytetrafluoroethylene versus collagen-impregnated dacron (Hemashield) patching: late follow-up

OBJECTIVE

To compare the late clinical outcome and incidence of recurrent stenosis after carotid endarterectomy (CEA) with polytetrafluoroethylene (PTFE) versus Hemashield patching.

SUMMARY BACKGROUND DATA

Several randomized trials have confirmed the advantages of patching over primary closure when performing CEA.

METHODS

Two hundred CEAs (180 patients) were randomized into 100 with PTFE patching and 100 with Hemashield. All patients underwent postoperative color duplex ultrasounds at 1, 6, and 12 months, and every year thereafter. The mean follow-up was 26 months. Kaplan-Meier analysis was used to estimate the risk of re-stenosis, stroke, and stroke-free survival. A multivariate analysis of various risk factors was also done.

RESULTS

Demographic and clinical characteristics were similar in both groups. The incidence of all ipsilateral strokes (early and late) was 8% (7% perioperative) for Hemashield versus 0% for PTFE patching. Both groups had similar mortality rates. The cumulative stroke-free rates at 6, 12, 24, and 36 months were 93%, 93%, 93%, and 89% for Hemashield versus 100%, 100%, 100%, and 100% for PTFE patching. The cumulative stroke-free survival rates at 6, 12, 24, and 36 months were 90%, 89%, 87%, and 79% for Hemashield versus 98%, 98%, 92%, and 92% for PTFE patching. Kaplan-Meier analysis also showed that freedom from 50% or greater re-stenosis at 6, 12, 24, and 36 months was 89%, 81%, 73%, and 66% for Hemashield versus 100%, 100%, 100%, and 92% for PTFE. Similarly, the freedom from 70% or greater re-stenosis at 6, 12, 24, and 36 months was 93%, 91%, 86%, and 78% for Hemashield versus 100%, 100%, 100%, and 100% for PTFE. Univariate and multivariate analyses of demographic and preoperative risk factors showed that only Hemashield was significantly associated with a higher incidence of 70% or greater recurrent stenosis.

CONCLUSIONS

PTFE patching was superior to Hemashield in lowering the incidence of postoperative ipsilateral strokes and late recurrent stenosis.

Scientific surgery

The BJS is committed to the practice of surgery based on scientific evidence. Each month we will publish a list of randomized trials and meta-analyses collated from English-language publications. A collection of all these papers will be available in the Scientific Surgery Archive which will be held on the BJS website together with links to free Medline sites where the full papers can be accessed (see below for details). If you have published a recent randomized trial that has not been featured in Scientific Surgery, the Editors would be pleased to receive a reprint and consider its inclusion.

Chlamydia pneumoniae serology is associated with thrombosis-related but not with plaque-related microembolization during carotid endarterectomy

BACKGROUND AND PURPOSE

Chlamydia pneumoniae has repeatedly been associated with atherosclerotic disease. Our study was designed to clarify whether this association is based on C pneumoniae-induced transformation of a stable into an unstable atherosclerotic plaque or on stimulation of hypercoagulability leading to increased thrombotic arterial occlusions by C pneumoniae infection. Transcranial Doppler ultrasonographic monitoring of the middle cerebral artery during carotid endarterectomy offers the opportunity to study, before removal of the plaque, atherothrombotic emboli dislodging from an unstable carotid plaque (plaque-related emboli) and emboli related to (excessive) thrombus formation at the endarterectomy site after removal of the plaque and restoration of flow (thrombosis-related emboli).

METHODS

C pneumoniae IgA (> or =1/16) and IgG (> or =1/64) seropositivity was assessed in 53 patients with symptomatic carotid artery disease undergoing carotid endarterectomy. The removed carotid plaques were studied histologically to assess plaque instability.

RESULTS

Plaque- and thrombosis-related emboli were registered in 43 patients with an adequate transtemporal window. IgA seropositivity (58%) was associated significantly with thrombosis-related embolization (P=0.030) but not with plaque-related embolization or with histological plaque instability.

CONCLUSIONS

C pneumoniae serology is associated with microembolization after endarterectomy and restoration of flow. Since these microemboli represent platelet aggregations and are related to cerebrovascular complications, our data suggest that C pneumoniae infection contributes to cerebrovascular events in patients with carotid artery disease through stimulation of thrombosis.

Prosthetic patch infection after carotid endarterectomy

OBJECTIVES AND DESIGN

prospective audit of the management and outcome of prosthetic patch infection after carotid endarterectomy (CEA) at Leicester Royal Infirmary plus review of the literature.

RESULTS

8/936 CEA patients (0.85%) developed a prosthetic patch infection. Responsible organisms included MRSA (n=3), Staphylococcus epidermidis(n=2), haemolytic Streptococcus (n=1), Staphylococcus aureus(n=1) and Pseudomonas (n=1). Early wound complications preceded 4/5 infections presenting within 9 weeks of surgery. In addition to systemic antibiotics and debridement, management included patch removal and: (i) carotid ligation (n=3), vein patch repair (n=1), vein bypass (n=3). One patient had antibiotic irrigation of the in-situpatch. No patient died, one suffered a disabling postoperative stroke and two had temporary cranial nerve injuries. Including this series, a literature review identified 43 prosthetic patch infections, 91% culturing Staphylococci or Streptococci. Cumulative freedom from perioperative stroke/death or re-infection was 65% at 2 years. Patients treated by patch excision and autologous venous reconstruction had the best outcome with a cumulative freedom from perioperative stroke/death or re-infection of 91% at 2 years.

CONCLUSION

prosthetic patch infection after CEA is rare. This study emphasises the importance of close surveillance of early wound complications. Surgical decision-making, especially the safety of carotid ligation, was facilitated by access to transcranial Doppler.