Durability of surgery for restenosis after carotid endarterectomy

Analysis of Recurrent Stenosis After Carotid Endarterectomy Featuring Primary Plaque Calcification

BACKGROUND

The relationship between calcification in primary plaque and restenosis after carotid endarterectomy (CEA) has been seldom investigated.

OBJECTIVE

To clarify the relationship between characteristics of calcified carotid plaque and recurrent stenosis after CEA, as well as the disease's natural course.

METHODS

Ninety-four plaques out of 107 consecutive CEAs were retrospectively analyzed with regard to calcification, employing calcium score as well as shape, location, and other characteristics of original plaques. CEA was performed in a standard fashion with primary closure using an internal shunt. Restenosis was assessed by direct measurement of stenosis mainly using multidetector row computed tomography (CT) angiography.

RESULTS

Univariate analysis revealed that calcium score and calcification circularity score were significantly lower in more than moderate restenosis (≥50%; 422.1 ± 551.6 vs 84.2 ± 92.0, P < .001; 1.8 ± 1.3 vs 1.1 ± 0.3, P < .001, respectively). Receiver operating characteristic analysis demonstrated a calcium score of 80, which was the optimal cutoff value for restenosis over 50% (sensitivity 0.70, specificity 0.68, pseudopositive ratio 0.32, area under curve 0.71, Youden's index 0.38). Low calcium score (OR 2.88, CI 1.06-7.79, P = .04) and low calcification circularity (OR 5.72, CI 1.42-23.1, P = .01) were independent predictors for more than moderate recurrent carotid stenosis 1 year postoperatively. Cases with decreasing tendency of restenosis showed higher calcium scores than those with increasing or unchanged tendency (217.2 ± 245.3 vs 164.5 ± 155.5, P < .001). Lower calcium score cases showed lower restenosis-free survival.

CONCLUSION

Carotid plaque calcification may be inversely associated with recurrent stenosis 1 year after CEA or later. Preoperative CT assessment for less calcification will benefit restenosis patients by early prediction and close follow-up.

Anatomical and Technical Factors Influence the Rate of In-Stent Restenosis following Carotid Artery Stenting for the Treatment of Post-Carotid Endarterectomy Stenosis

Background

Carotid artery stenting (CAS) has been advocated as an alternative to redo surgery for the treatment of post-carotid endarterectomy (CEA) stenosis. This study analyzed the efficacy of CAS for post-CEA restenosis, focusing on an analysis of technical and anatomical predictive factors for in-stent restenosis.

Methods

We performed a retrospective monocentric study. We included all patients who underwent CAS for post-CEA restenosis at our institution from July 1997 to November 2013. The primary endpoints were the technical success, the presence of in-stent restenosis >50% or occlusion, either symptomatic or asymptomatic, during the follow-up period, and risk factors for restenosis. The secondary endpoints were early and late morbidity and mortality (TIA, stroke, myocardial infarction, or death).

Results

A total of 153 CAS procedures were performed for post-CEA restenosis, primarily because of asymptomatic lesions (137/153). The technical success rate was 98%. The 30-day perioperative stroke and death rate was 2.6% (two TIAs and two minor strokes), and rates of 2.2% (3/137) and 6.2% (1/16) were recorded for asymptomatic and symptomatic patients, respectively. The average follow-up time was 36 months (range, 6–171 months). In-stent restenosis or occlusion was observed in 16 patients (10.6%). Symptomatic restenosis was observed in only one patient. We found that young age (P = 0.002), stenosis > 85% (P = 0.018), and a lack of stent coverage of the common carotid artery (P = 0.006) were independent predictors of in-stent restenosis.

Conclusion

We identified new risk factors for in-stent restenosis that were specific to this population, and we propose a technical approach that may reduce this risk.

Stenting versus endarterectomy for restenosis following prior ipsilateral carotid endarterectomy: an individual patient data meta-analysis

OBJECTIVE

To study perioperative results and restenosis during follow-up of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) for restenosis after prior ipsilateral CEA in an individual patient data (IPD) meta-analysis.

BACKGROUND

The optimal treatment strategy for patients with restenosis after CEA remains unknown.

METHODS

A comprehensive search of electronic databases (Medline, Embase) until July 1, 2013, was performed, supplemented by a review of references. Studies were considered for inclusion if they reported procedural outcome of CAS or CEA after prior ipsilateral CEA of a minimum of 5 patients. IPD were combined into 1 data set and an IPD meta-analysis was performed. The primary endpoint was perioperative stroke or death and the secondary endpoint was restenosis greater than 50% during follow-up, comparing CAS and CEA.

RESULTS

In total, 13 studies were included, contributing to 1132 unique patients treated by CAS (10 studies, n = 653) or CEA (7 studies; n = 479). Among CAS and CEA patients, 30% versus 40% were symptomatic, respectively (P < 0.01). After adjusting for potential confounders, the primary endpoint did not differ between CAS and CEA groups (2.3% vs 2.7%, adjusted odds ratio 0.8, 95% confidence interval (CI): 0.4-1.8). Also, the risk of restenosis during a median follow-up of 13 months was similar for both groups (hazard ratio 1.4, 95% (CI): 0.9-2.2). Cranial nerve injury (CNI) was 5.5% in the CEA group, while CAS was in 5% associated with other procedural related complications.

CONCLUSIONS

In patients with restenosis after CEA, CAS and CEA showed similar low rates of stroke, death, and restenosis at short-term follow-up. Still, the risk of CNI and other procedure-related complications should be taken into account.

Repeated carotid endarterectomy versus carotid artery stenting for patients with carotid restenosis after carotid endarterectomy: Systematic review and meta-analysis

PURPOSE

Carotid restenosis (CRS) after carotid endarterectomy (CEA) is an issue that cannot be ignored. This study was undertaken to compare the outcomes of repeated CEA (redo CEA) and carotid artery stenting (CAS) for CRS after CEA.

METHODS

We performed a systematic analysis using the search terms "CEA restenosis," "carotid restenosis," or "CEA recurrent stenosis" in the MEDLINE, EMBASE, PubMed, and Cochrane Library databases. After applying the inclusion criteria, all available data were summarized to evaluate the effects of redo CEA and CAS for patients with CRS after prior CEA.

RESULTS

Fifty articles (9 comparative studies and 41 noncomparative studies) involving 4,399 patients were included. No differences were observed in the 30-day perioperative mortality, stroke and transient ischemic attack rates in the comparative studies (P > .05) and the noncomparative studies (P > .05). Patients undergoing redo CEA suffered more cranial nerve injuries (CNIs) than those undergoing CAS (P < .05), but most of these cases recovered within 3 months. Patients treated with redo CEA exhibited similar myocardial infarction (MI) rates to those treated with CAS in the comparative studies (P = .53), but the rate was higher in the noncomparative studies (P < .01). However, a nonsignificant difference was noted in freedom from stroke at 36 months in the comparative studies (P = .47) and at 12 months in the noncomparative studies (P = .89). The risk of restenosis was greater in the CAS patients than in the redo CEA patients (P < .05 for comparative and noncomparative studies).

CONCLUSION

Both redo CEA and CAS are safe and feasible for CRS after CEA. Although the incidences of CNI and MI were increased in the redo CEA group, most of the CNI cases were reversible. Patients treated with CAS were more likely to develop restenosis than those treated with redo CEA over long-term follow-up.

Spontaneous echo contrast and thrombus formation at the carotid bifurcation after carotid endarterectomy

Spontaneous echo contrast (SEC) consists of numerous microechoes swirling in the cardiovascular lumen and is usually seen during blood stasis in dysfunctional left atrium. However, SEC and consecutive local thrombus formation at the carotid artery early after carotid endarterectomy (CEA) have not been reported. This study retrospectively investigated the clinical importance and therapeutic strategy of postoperative SEC and thrombus formation in 113 consecutive patients who underwent CEA between 2001 and 2009. Ultrasonography was routinely performed preoperatively, intraoperatively, and 1 day and 1 week after the operation. If SEC and/or thrombus was detected at any time after the operation, follow-up ultrasonography was performed at short intervals, once a week for inpatients and once every 1-2 months for outpatients. Eight of the 113 patients (7%) had SEC after the operation from Day 1 to 12 (mean 7.2 days), and 6 of these 8 patients developed local de novo thrombus formation at the site of SEC from Day 6 to 33 (mean 14.7 days). The maximum luminal narrowing by the thrombi were 26-62% (mean 37%). After administering anticoagulant therapy, all thrombi disappeared from Day 13 to 190 (mean 57 days) from CEA. SEC seen after CEA is highly associated with consecutive local thrombus formation. Postoperative geometric blood stasis with the absence of intima may be the causative factor for its development.

Carotid stenting versus endarterectomy in patients undergoing reintervention after prior carotid endarterectomy

BACKGROUND

Outcomes for patients undergoing intervention for restenosis after prior ipsilateral carotid endarterectomy (CEA) in the era of carotid angioplasty and stenting (CAS) are unclear. We compared perioperative results and durability of CAS vs CEA in patients with symptomatic or asymptomatic restenosis after prior CEA and investigated the risk of reintervention compared with primary procedures.

METHODS

Patients undergoing CAS and CEA for restenosis between January 2003 and March 2012 were identified within the Vascular Study Group of New England (VSGNE) database. End points included any stroke, death or myocardial infarction (MI) within 30 days, cranial nerve injury at discharge, and restenosis ≥ 70% at 1-year follow-up. Multivariable logistic regression was done to identify whether prior ipsilateral CEA was an independent predictor for adverse outcome.

RESULTS

Out of 9305 CEA procedures, 212 patients (2.3%) underwent redo CEA (36% symptomatic). Of 663 CAS procedures, 220 patients (33%) underwent CAS after prior ipsilateral CEA (31% symptomatic). Demographics of patients undergoing redo CEA were comparable to patients undergoing CAS after prior CEA. Stroke/death/MI rates were statistically similar between redo CEA vs CAS after prior CEA in both asymptomatic (4.4% vs 3.3%; P = .8) and symptomatic patients (6.6% vs 5.8%; P = 1.0). No significant difference in restenosis ≥ 70% was identified between redo CEA and CAS after prior CEA (5.2% vs 3.0%; P = .5). Redo CEA vs primary CEA had increased stroke/death/MI rate in both symptomatic (6.6% vs 2.3%; P = .05) and asymptomatic patients 4.4% vs 1.7%; P = .03). Prior ipsilateral CEA was an independent predictor for stroke/death/MI among all patients undergoing CEA (odds ratio, 2.1; 95% confidence interval, 1.3-3.5). No difference in cranial nerve injury was identified between redo CEA and primary CEA (5.2% vs 4.7%; P = .8).

CONCLUSIONS

In the VSGNE, CEA and CAS showed statistically equivalent outcomes in asymptomatic and symptomatic patients treated for restenosis after prior ipsilateral CEA. However, regardless of symptom status, the risk of reintervention was increased compared with patients undergoing primary CEA.

In-hospital versus postdischarge adverse events following carotid endarterectomy

OBJECTIVE

Most studies based on state and nationwide registries evaluating perioperative outcome after carotid endarterectomy (CEA) rely on hospital discharge data only. Therefore, the true 30-day complication risk after carotid revascularization may be underestimated.

METHODS

We used the National Surgical Quality Improvement Program database 2005-2010 to assess the in-hospital and postdischarge rate of any stroke, death, cardiac event (new Q-wave myocardial infarction or cardiac arrest), and combined stroke/death and combined adverse outcome (S/D/CE) at 30 days following CEA. Multivariable analyses were used to identify predictors for in-hospital and postdischarge events separately, and in particular, those that predict postdischarge events distinctly.

RESULTS

A total of 35,916 patients who underwent CEA during 2005-2010 were identified in the National Surgical Quality Improvement Program database; 59% were male, median age was 72 years, and 44% had a previous neurologic event. Thirty-day stroke rate was 1.6% (n = 591), death rate was 0.8% (n = 272), cardiac event rate was 1.0% (n = 350), stroke or death rate was 2.2% (n = 794), and combined S/D/CE rate was 2.9% (n = 1043); 33% of strokes, 53% of deaths, 32% of cardiac events, 40% of combined stroke/death, and 38% of combined S/D/CE took place after hospital discharge. Patients with a prior stroke or transient ischemic attack had similar proportions of postdischarge events compared with patients without prior symptoms. Independent predictors for postdischarge events, but not for in-hospital events were female sex (stroke [odds ratio (OR), 1.6; 95% confidence interval (CI), 1.2-2.1] and stroke/death [OR, 1.4; 95% CI, 1.1-1.7]), renal failure (stroke [OR, 3.0; 95% CI, 1.4-6.2]) and chronic obstructive pulmonary disease (death [OR, 2.5; 95% CI, 1.6-3.7], stroke/death [OR, 1.8; 95% CI, 1.4-2.4], and S/D/CE [OR 1.8, 95% CI 1.4-2.3]).

CONCLUSIONS

With 38% of perioperative adverse events after CEA happening posthospitalization, regardless of symptoms status, we need to be alert to the ongoing risks after discharge particularly in women, patients with renal failure, or chronic obstructive pulmonary disease. This emphasizes the need for reporting and comparing 30-day adverse event rates when evaluating outcomes for CEA, or comparing carotid stenting to CEA.

Indications for treatment of recurrent carotid stenosis

Background

There is significant variation in the indications for intervention in patients with recurrent carotid artery stenosis. The aim of the present study was to describe these indications in a contemporary cohort of patients.

Methods

This was a systematic review of all peer-reviewed studies reporting on the indications for carotid intervention in patients with recurrent stenosis after carotid endarterectomy (CEA) or carotid artery stenting (CAS) that were published between 1990 and 2012.

Results

There were 50 studies reporting on a total of 3524 patients undergoing a carotid procedure; of these, 3478 underwent CEA as the initial intervention. Reintervention was by CEA in 2403 patients and by CAS in 1121. Only 54·7 per cent of the patients were treated for any symptoms and, importantly, just 444 (23·1 per cent of 1926 symptomatic patients) underwent intervention for documented ipsilateral symptoms. None of the studies reported whether the patients were evaluated for other sources of emboli. The remaining 45·3 per cent of patients had asymptomatic restenosis and in the majority of the studies were treated when the degree of stenosis exceeded 80 per cent. The time to repeat intervention was significantly longer in patients with recurrent atherosclerosis, in asymptomatic patients and in patients undergoing CEA.

Conclusion

The reported criteria for retreatment of carotid stenosis were not rigorous and there is still significant ambiguity surrounding the indications for intervention.

Article Commentary: Late Outcomes of Carotid Artery Stenting: A Critical Review

The role of carotid artery stenting (CAS) as an alternative to carotid endarterectomy for the treatment of extracranial carotid occlusive disease for stroke prevention continues to evolve. Although technical and device refinements aimed at making CAS safer continue to this day, safety as measured by 30-day and 1-year outcomes has been the primary recipient of regulatory and practice attention. Relatively less emphasis has been placed on the incidence of recurrent stenosis after CAS and the efficacy of CAS in late stroke prevention. Data on late outcomes of CAS, including factors of potential influence, have been emerging and are addressed in this review.

Open surgery remains a valid option for the treatment of recurrent carotid stenosis

OBJECTIVE

The choice between open surgery (OS) and transluminal carotid angioplasty with stenting (CAS) for the treatment of primary carotid stenosis remains controversial. However, CAS is considered a valid option for selected cases, such as recurrent carotid stenosis (RCS). Tertiary RCS seems to be a concerning issue after CAS but few large reports focused on the durability of CAS and OS. We report our early and long-term results with OS for RCS.

METHODS

From 1989 to 2006, perioperative data regarding 4245 consecutive surgical carotid reconstructions was prospectively collected. Patients whose indication was RCS were subjected to further analysis. Indications for surgery were symptomatic RCS >50% or asymptomatic RCS >80%. Freedom from neurologic event was defined as the absence of any ipsilateral symptom at any time after the procedure. Kaplan-Meier analysis was used to estimate freedom from reintervention, freedom from restenosis >50% and occlusion, freedom from neurologic event and survival.

RESULTS

A total of 119 patients (2.8%) with RCS underwent OS. The average time from the primary OS was 59.4 +/- 54.5 months (range, 2-204). Forty-nine patients (41%) were symptomatic. In 103 patients (87%), the technique did not differ from a primary approach. Postoperative (<30 days) combined stroke and death rate was 3.3%. Cranial nerve injury occurred in 5 cases (4.2%). With a mean follow-up of 53 +/- 48 months (range, 1-204), 3 patients had an ipsilateral stroke (including one hemorrhagic stroke) and 7 were diagnosed with a tertiary RCS >50%. At 5 years, Kaplan-Meier estimates of freedom from reintervention, freedom from restenosis and occlusion, freedom from neurologic event, and survival were 99%, 91%, 89%, and 91%, respectively.

CONCLUSION

OS for RCS is not a high-risk procedure and provides excellent long-term results, with low rates of tertiary RCS and reinterventions. The comparison between OS and CAS in this indication suffers from the absence of standardized follow-up paradigms after primary OS and the lack of prospective randomized trial comparing the two techniques. Despite these limitations in the available data, we conclude that OS should remain the first line therapy when treatment of RCS is indicated.

MMP and TIMP alterations in asymptomatic and symptomatic severe recurrent carotid artery stenosis

OBJECTIVES

This study aimed to determine whether the plasma levels of matrix metalloproteinases (MMPs)-2 and -9 and their specific inhibitors (tissue inhibitors of metalloproteinases (TIMPs-1 and -2)) were altered in patients with symptomatic and asymptomatic, severe, recurrent carotid artery stenosis.

PATIENTS

Fifty-two patients (out of a total of 621) who had undergone successful carotid artery endarterectomy (CEA) between 1999 and 2003 and developed recurrent carotid artery stenosis (>/=70%) were included in the study. Restenosis was symptomatic in 23 patients and asymptomatic in 29 patients.

METHODS

Recurrent carotid artery stenosis was classified based on presentation, and as early-intermediate (6 months to 3 years) or late (>3 years). A detailed clinical history was taken and two blood samples were drawn from each patient to determine plasma levels of MMPs and TIMPs along with other biological parameters. Recurrent stenosis was confirmed with computed tomographic angiography.

RESULTS

Patients with symptomatic restenosis had significantly (p<0.001) higher active MMP-2 and -9 plasma values and significantly (p<0.001) lower TIMP-1 and -2 plasma values when compared to patients with asymptomatic restenosis. Plasma concentrations of active MMPs were higher and TIMPs lower in patients affected with late recurrent stenosis as compared to early-intermediate restenosis (p<0.001). No differences were recorded in latent MMP plasma values. Multivariate analysis showed that active MMP-2 and -9 were independent predictors of late recurrent carotid artery stenosis (p<0.03 and p<0.001, respectively).

CONCLUSIONS

Higher plasma concentrations of active MMP-2 and -9 were associated with an increased risk of carotid restenosis with plaque recurrence.

Prosthetic carotid bypass grafts for atherosclerotic lesions: a prospective study of 198 consecutive cases

OBJECTIVES

Carotid endarterectomy (CEA) is the standard treatment for atherosclerotic lesions involving the carotid bifurcation. However, CEA can be challenging under some conditions. The goal of this study was to determine the outcome and durability of prosthetic carotid bypass grafting (PCB) with polytetrafluoroethylene (PTFE) grafts as an alternative to CEA.

METHODS

This is a prospective series of 198 consecutive patients with PCB, representing 12.4% of 1595 patients with a carotid reconstruction procedure performed in our department between September 1986 and December 2006. Qualifying event was stroke in 67 patients (34%) and transient ischaemic attack (TIA) in 45 (23%), and 86 patients (43%) were asymptomatic. Primary indications for PCB were extensive atherosclerotic lesions (n=71; 36%), carotid stenosis associated with kinking (n=49; 25%), recurrent stenosis (n=47; 23%), stenosis after radiation therapy (n=18; 9%) and technical failure of CEA (n=13; 7%), with excessive arterial wall thinning and perforation after endarterectomy (n=10) or intimal flap on completion digital angiography (n=3).

RESULTS

The combined stroke and death rate at 30 days were 0.5% (one stroke). Median follow-up was 9.5 years (interquartile range (IQR): 6.2-18.3 years). At 10 years, primary patency was 97.9+/-3.4%. Six PCBs (3.0%) became occluded during follow-up; one patient had a restenosis greater than 50% and 18 patients (9.1%) had a restenosis of less than 50%. Five patients had an ipsilateral stroke (one postoperative stroke, one at 103 days with a patent PCB and three related to occlusion of the PCB at 4, 13 and 15 years after the procedure). At 10 years, cumulative stroke-free survival was 98.4+/-3.2%, and cumulative survival was 78.8+/-7.0%.

CONCLUSIONS

PCB is a safe surgical alternative and is durable, with a low incidence of graft restenosis, when CEA seems hazardous.