Patch angioplasty versus primary closure for carotid endarterectomy

Patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Carotid patch angioplasty may reduce the risk of acute occlusion or long-term restenosis of the carotid artery and subsequent ischaemic stroke in people undergoing carotid endarterectomy (CEA). This is an update of a Cochrane Review originally published in 1995 and updated in 2008.

OBJECTIVES

To assess the safety and efficacy of routine or selective carotid patch angioplasty with either a venous patch or a synthetic patch compared with primary closure in people undergoing CEA. We wished to test the primary hypothesis that carotid patch angioplasty results in a lower rate of severe arterial restenosis and therefore fewer recurrent strokes and stroke-related deaths, without a considerable increase in perioperative complications.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, two other databases, and two trial registries in September 2021.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised trials comparing carotid patch angioplasty with primary closure in people undergoing CEA.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and risk of bias; extracted data; and determined the certainty of evidence using the GRADE approach. Outcomes of interest included stroke, death, significant complications related to surgery, and artery restenosis or occlusion during the perioperative period (within 30 days of the operation) or during long-term follow-up.

MAIN RESULTS

We included 11 trials involving 2100 participants undergoing 2304 CEA operations. The quality of trials was generally poor. Follow-up varied from hospital discharge to five years. Compared with primary closure, carotid patch angioplasty may make little or no difference to reduction in risk of any stroke during the perioperative period (odds ratio (OR) 0.57, 95% confidence interval (CI) 0.31 to 1.03; P = 0.063; 8 studies, 1769 participants; very low-certainty evidence), but may lower the risk of any stroke during long-term follow-up (OR 0.49, 95% CI 0.27 to 0.90; P = 0.022; 7 studies, 1332 participants; very low-certainty evidence). In the included studies, carotid patch angioplasty resulted in a lower risk of ipsilateral stroke during the perioperative period (OR 0.31, 95% CI 0.15 to 0.63; P = 0.001; 7 studies, 1201 participants; very low-certainty evidence), and during long-term follow-up (OR 0.32, 95% CI 0.16 to 0.63; P = 0.001; 6 studies, 1141 participants; very low-certainty evidence). The intervention was associated with a reduction in the risk of any stroke or death during long-term follow-up (OR 0.59, 95% CI 0.42 to 0.84; P = 0.003; 6 studies, 1019 participants; very low-certainty evidence). In addition, the included studies suggest that carotid patch angioplasty may reduce the risk of perioperative arterial occlusion (OR 0.18, 95% CI 0.08 to 0.41; P < 0.0001; 7 studies, 1435 participants; low-certainty evidence), and may reduce the risk of restenosis during long-term follow-up (OR 0.24, 95% CI 0.17 to 0.34; P < 0.00001; 8 studies, 1719 participants; low-certainty evidence). The studies recorded very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation, with either patch or primary closure. We found no correlation between the use of patch angioplasty and the risk of either perioperative or long-term stroke-related death or all-cause death rates.

AUTHORS' CONCLUSIONS

Compared with primary closure, carotid patch angioplasty may reduce the risk of perioperative arterial occlusion and long-term restenosis of the operated artery. It would appear to reduce the risk of ipsilateral stroke during the perioperative and long-term period and reduce the risk of any stroke in the long-term when compared with primary closure. However, the evidence is uncertain due to the limited quality of included trials.

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.

Radial Recurrent Artery: Autologous Patch Graft for Acute Brachial Artery Laceration

Brachial artery injury is the most common vascular disruption in upper extremity penetrating trauma, usually treated by primary repair or saphenous vein interposition graft. We report the case of a young male who presented after assault with stab wound to the right antecubital fossa, an asymmetric vascular exam, and unknown depth contaminated wound that warranted operative exploration. We performed open exploration through a triangular flap extension of his oblique linear laceration for both exposure and flexor surface scar contracture prophylaxis. Exploration revealed brachial artery laceration with loss of approximately 30% of vessel circumference proximal to the radial and ulnar artery bifurcation. A near-complete transection of the recurrent radial artery was also present, leading to the decision to sacrifice this vessel for use as an autologous patch graft of the injured brachial artery. Distal vascular flow was re-established, and the vessel was slightly ectatic with no evidence of stenosis. Patient suffered no complications and was discharged at post-operative day four after perioperative heparin drip on anti-platelet therapy. Autologous patch grafting in the acute setting is a less-often considered surgical option that is effective for arterial bifurcation reconstruction, which may be employed through the sacrifice of injured and redundant local branch vessels. Patch grafts are commonly utilized in planned vascular surgery, such as carotid endarterectomy, but this is the first report of autologous patch graft to an acute brachial artery injury. By combining knowledge of the lateral arm flap with the plastic surgery principles of "like replaces like", this technique avoids the stenosis associated with primary repair, the multiple anastomoses necessary for interposition grafting, the need for a secondary donor site, and provides a theoretical blood-flow advantage.

Effect of patching on reducing restenosis in the carotid revascularization endarterectomy versus stenting trial

BACKGROUND AND PURPOSE

The purpose is to determine whether patching during carotid endarterectomy (CEA) affects the perioperative and long-term risks of restenosis, stroke, death, and myocardial infarction as compared with primary closure.

METHODS

We identified all patients who were randomized and underwent CEA in Carotid Revascularization Endarterectomy versus Stenting Trial. CEA patients who received a patch were compared with patients who underwent CEA with primary closure without a patch. We compared periprocedural and 4-year event rates, 2-year restenosis rates, and rates of reoperation between the 2 groups. We further analyzed results by surgeon specialty.

RESULTS

There were 1151 patients who underwent CEA (753 [65%] with patch and 329 [29%] with primary closure). We excluded 44 patients who underwent eversion CEA and 25 patients missing CEA data (5%). Patch use differed by surgeon specialty: 89% of vascular surgeons, 6% of neurosurgeons, and 76% of thoracic surgeons patched. Comparing patients who received a patch versus those who did not, there was a significant reduction in the 2-year risk of restenosis, and this persisted after adjustment by surgeon specialty (hazard ratio, 0.35; 95% confidence interval, 0.16-0.74; P=0.006). There were no significant differences in the rates of periprocedural stroke and death (hazard ratio, 1.58; 95% confidence interval, 0.33-7.58; P=0.57), in immediate reoperation (hazard ratio, 0.6; 95% confidence interval, 0.16-2.27; P=0.45), or in the 4-year risk of ipsilateral stroke (hazard ratio, 1.23; 95% confidence interval, 0.42-3.63; P=0.71).

CONCLUSIONS

Patch closure in CEA is associated with reduction in restenosis although it is not associated with improved clinical outcomes. Thus, more widespread use of patching should be considered to improve long-term durability.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

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.

A regional quality improvement effort to increase beta blocker administration before vascular surgery

OBJECTIVE

To determine if a regional quality improvement effort can increase beta-blocker utilization prior to vascular surgery and decrease the incidence of postoperative myocardial infarction (POMI).

METHODS

A quality improvement effort to increase perioperative beta blocker utilization was implemented in 2003 at centers participating in the Vascular Study Group of New England (VSGNE). A 90% target was set and feedback given at biannual meetings. Beta blocker utilization (<1 month preoperative versus chronic) and POMI rates were prospectively collected for patients undergoing open abdominal aortic aneurysm (AAA) repair (n = 926) and lower extremity bypass (LEB; n = 2,123) from 2003 through 2008. Predictors of POMI were determined using multivariate logistic regression. Rates of beta blocker administration and POMI were analyzed over time, and across strata of patient risk based on a multivariate model.

RESULTS

Perioperative beta blocker treatment increased from 68% of patients in the first 3 months of 2005 to 88% by the last 3 months of 2008 (P < .001). In 2003, 44% of patients not on chronic beta blockers were treated with preoperative beta blockers; by 2008, 78% of patients not on chronic beta blockers were started perioperatively on these medications (P < .001). Beta blocker utilization increased across all centers and surgeons participating during the study period, and increased in patients of low, medium, and high cardiac risk. However, the rate of POMI did not change over time (5.2% in 2003, 5.5% in 2008; P = .876), although a trend towards lower POMI rate was seen in patients on preoperative beta blockers (4.4% in 2003-2005, 2.6% in 2006-2008; P = .43). In multivariable modeling we found that age >70 (odds ratio [OR], 2.1), positive stress test (OR, 2.2), congestive heart failure (CHF; OR, 1.7), chronic beta blocker administration (OR, 1.7), resting heart rate <70 (OR, 1.8), and diabetes (OR, 1.6) were associated with POMI. Resting heart rate was similar for patients on chronic (67), preoperative (70), and no beta blockers (70; P = .521).

CONCLUSIONS

Our regional quality improvement effort successfully increased perioperative beta blocker utilization. However, this was not associated with reduced rates of POMI or resting heart rate. While this demonstrates the effectiveness of regional quality improvement efforts in changing practice patterns, further work is necessary to more precisely identify those patients who will benefit from beta blockade at the time of vascular surgery.

Patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Carotid patch angioplasty (with either a venous or a synthetic patch) may reduce the risk of carotid artery restenosis and subsequent ischaemic stroke. This is an update of a Cochrane Review originally published in 1995 and previously updated in 2004.

OBJECTIVES

To assess the safety and efficacy of routine or selective carotid patch angioplasty compared to carotid endarterectomy with primary closure.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched 5 May 2009), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2009), MEDLINE (1966 to November 2008), EMBASE (1980 to November 2008) and Index to Scientific and Technical Proceedings (1980 to November 2008). We handsearched journals and conference proceedings, checked reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing carotid patch angioplasty with primary closure in any patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We included 10 trials involving 1967 patients undergoing 2157 operations. The quality of trials was generally poor. Follow up varied from hospital discharge to five years. Carotid patch angioplasty was associated with a reduction in the risk of ipsilateral stroke during the perioperative period (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.15 to 0.63, P = 0.001) and long-term follow up (OR 0.32, 95%CI 0.16 to 0.63, P = 0.001). It was also associated with a reduced risk of perioperative arterial occlusion (OR 0.18, 95% CI 0.08 to 0.41, P < 0.0001), and decreased restenosis during long-term follow up in eight trials (OR 0.24, 95% CI 0.17 to 0.34, P < 0.00001). These results are more certain than those of the previous review since the number of operations and events have increased. However, the sample sizes are still relatively small, data were not available from all trials, and there was significant loss to follow up. Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure. No significant correlation was found between use of patch angioplasty and the risk of either perioperative or long-term all-cause death rates.

AUTHORS' CONCLUSIONS

Limited evidence suggests that carotid patch angioplasty may reduce the risk of perioperative arterial occlusion and restenosis. It would appear to reduce the risk of ipsilateral stroke and there is a non significant trend towards a reduction in perioperative any stroke rate and all-cause case fatality.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting)

BACKGROUND

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. This may improve outcome. This is an update of a Cochrane Review originally published in 1996 and previously updated in 2001.

OBJECTIVES

To assess the effect of routine versus selective, or never, shunting during carotid endarterectomy, and to assess the best method for selecting patients for shunting.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched September 2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2009), MEDLINE (1966 to November 2008), EMBASE (1980 to November 2008) and Index to Scientific and Technical Proceedings (1980 to November 2008). We handsearched journals and conference proceedings, checked reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the searches and applied the inclusion criteria. We identified one new relevant randomised controlled trial.

MAIN RESULTS

We included four trials in the review: three trials involving 686 patients compared routine shunting with no shunting; the other trial involving 131 patients compared shunting with a combination of electroencephalographic and carotid pressure measurement with shunting by carotid pressure measurement alone. Allocation was adequately concealed in one trial, and one trial was quasi-randomised. Analysis was by intention-to-treat where possible. For routine versus no shunting, there was no significant difference in the rate of all stroke, ipsilateral stroke or death up to 30 days after surgery, although data were limited. There was no significant difference between the risk of ipsilateral stroke in patients selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared to pressure assessment alone, although again the data were limited.

AUTHORS' CONCLUSIONS

This review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy. It was suggested that large scale randomised trials between routine shunting versus selective shunting were required. No one method of monitoring in selective shunting has been shown to produce better outcomes.

Patches for carotid artery endarterectomy: current materials and prospects

Patch angioplasty is commonly performed after carotid endarterectomy. Randomized prospective trials and meta-analyses have documented improved rates of perioperative and long-term stroke prevention as well as reduced rates of restenosis for patches compared with primary closure of the arteriotomy. Although use of vein patches is considered to be the gold standard for patch closure, newer generations of synthetic and biologic materials rival outcomes associated with vein patches. Future bioengineered patches are likely to optimize patch performance, both by achieving minimal stroke risk and long-term rates of restenosis as well as by minimizing the risk of unusual complications of prosthetic patches such as infection and pseudoaneurysm formation. In addition, lessons from bioengineered patches will likely enable construction of bioengineered and tissue-engineered bypass grafts.

Early Carotid Surgery in Acute Stroke: A Multicentre Randomised Pilot Study

BACKGROUND

Standard practice has been to delay carotid endarterectomy (CEA) for 2 months following acute stroke to avoid a perceived risk of cerebral haemorrhage. We investigated whether early CEA reduces early recurrent stroke and improves outcome in partial anterior circulation infarction (PACI).

METHODS

Patients with PACI and a Barthel score of >18 before stroke underwent carotid duplex and CT imaging within 7 days of stroke. Forty consenting patients fit for surgery with greater than 70% ipsilateral carotid stenosis were randomised, 19 to 'early' (within 24 h) and 21 to 'delayed' surgery (at 8 weeks). Modified Rankin and Barthel scores were recorded at 1 week, 2 months, 6 and 12 months.

RESULTS

Rankin scores improved more rapidly following 'early' surgery to a score of 1 (0-4) at 2 and 6 months compared with 2.5 and 2 (1-4), respectively, for delayed surgery (p < 0.05). Barthel scores were also significantly improved following 'early' CEA at 7 days but both groups reached a median score of 20 by 2 months. Four 'delayed' and 3 'early' patients suffered extension or recurrence of neurological deficits with 1 death in each group.

CONCLUSIONS

Early CEA within 7 days of ischaemic stroke improved functional outcome with earlier hospital discharge. A large multicentre study is needed to exclude the possibility that 'early' CEA increases the risk of cerebral haemorrhage or death.

Patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Carotid patch angioplasty (with either a venous or a synthetic patch) may reduce the risk of carotid artery restenosis and subsequent ischaemic stroke.

OBJECTIVES

The objective of this review was to assess the safety and efficacy of routine or selective carotid patch angioplasty compared to carotid endarterectomy with primary closure.

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 carotid patch angioplasty with primary closure in any patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

The previous review included six trials involving 794 patients undergoing 882 operations. Since the last review only one study of adequate quality to be included has been reported. This added 399 operations randomised to either primary closure, vein patch or synthetic patch groups resulting in 1127 patients undergoing 1307 operations being available for analysis. The quality of trials was generally poor. Follow-up varied from hospital discharge to five years. Carotid patch angioplasty was associated with a reduction in the risk of stroke of any type (OR = 0.33, p = 0.004), ipsilateral stroke (OR = 0.31, p = 0.0008), and stroke or death, during the perioperative period (OR = 0.39, p = 0.007) and long term follow-up (OR = 0.59, p = 0.004). It was also associated with a reduced risk of perioperative arterial occlusion (odds ratio 0.15, 95% confidence interval 0.06 to 0.37 p = 0.00004), and decreased restenosis during long-term follow-up in five trials, (odds ratio 0.20, 95% confidence interval 0.13 to 0.29 p < 0.00001). These results are more certain than those of the previous review since the number of operations and events have increased. However, the sample sizes are still relatively small, data were not available from all trials, and there was significant loss to follow-up. Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure. No significant correlation was found between use of patch angioplasty and the risk of either perioperative or long-term all-cause death rates

REVIEWERS' CONCLUSIONS

Limited evidence suggests that carotid patch angioplasty may reduce the risk of perioperative arterial occlusion and restenosis. It would appear to reduce the risk of combined death or stroke and there is a non significant trend towards a reduction in all-cause mortality.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting)

BACKGROUND

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. This may improve outcome.

OBJECTIVES

The objective of this review was to assess the effect of routine versus selective, or never, shunting during carotid endarterectomy, and to assess the best method for selecting patients for shunting.

SEARCH STRATEGY

For the original review the authors searched the Cochrane Stroke Group trials register, Medline (1966 to 1994), Embase (1980 to 1995) and Index to Scientific and Technical Proceedings (1980 to 1994). They also hand searched Annals of Surgery (1981 to 1995), British Journal of Surgery (1985 to 1995), European Journal of Vascular Surgery (1988 to 1995) and World Journal of Surgery (1978 to 1995). For the updated review, for the dates January 1994 - December 2000 we: 1. Repeated all these searches performed for the original review and developed more comprehensive search strategies for Medline and Embase. The Cochrane Stroke Group Trials Register was last searched in May 2001. 2. Hand searched the Journal of Vascular Surgery, Stroke, Annals of Vascular Surgery, American Journal of Surgery and Cardiovascular Surgery. 3. Hand searched the abstracts from the International Stroke Conference, AGM of the Vascular Surgical Society (UK), AGM of the Association of Surgeons of Great Britain and Ireland and the Annual Meeting of the Society for Vascular Surgery (USA). 4. Searched reference lists from all relevant trials All the authors of studies included in the initial review, and other authors known to have published relevant work, were contacted requesting information about further published or unpublished data.

SELECTION CRITERIA

Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

For the original review two reviewers independently performed the searches and applied the inclusion criteria. The data were extracted by one reviewer and double-checked. Trial quality was assessed. During the update, two reviewers independently performed the searches and applied the inclusion criteria. No new relevant randomised controlled trials were found.

MAIN RESULTS

Despite recommendation from the original review that further studies were required, no new trials of adequate quality and fitting the inclusion criteria were found. The initial review included three trials. Two trials involving 590 patients compared routine shunting with no shunting. The other trial involving 131 patients compared shunting with a combination of electroencephalographic and carotid pressure measurement, with shunting by carotid pressure measurement alone. Allocation was adequately concealed in one trial, and one trial was quasi-randomised. Analysis was by intention-to-treat where possible. For routine versus no shunting, there was no significant difference in the rate of all stroke, ipsilateral stroke or death up to 30 days after surgery, although data were limited. There was no significant difference between the risk of ipsilateral stroke in patients selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared to pressure assessment alone, although again the data were limited.

REVIEWER'S CONCLUSIONS

When first published in 1995, this review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy. It was suggested that large scale randomised trials using no shunting as the control group were required. No one method of monitoring in selective shunting has been shown to produce better outcomes. No further prospective randomised or quasi-randomised trials have been performed since then and the conclusions therefore remain unchanged.