The War Against Error: A 15 Year Experience of Completion Angioscopy Following Carotid Endarterectomy

Management of postoperative internal carotid artery intimal flap after carotid endarterectomy: a cohort study and systematic review

OBJECTIVE

Postoperative internal carotid artery (ICA) intimal flap (IF) is a potential complication after carotid endarterectomy (CEA) for carotid artery stenosis. There are no clear recommendations in the current literature on the management of this condition due to sparse evidence. Some authors advocate carotid stent placement or reoperation, while others suggest watchful waiting. The aim of this study was to analyze incidence and management strategies of postoperative ICA-IF, and moreover, to put these findings into context with a systematic literature review.

METHODS

The authors retrospectively reviewed all consecutive CEA cases performed at the University Hospital of Bern over a decade (January 2008 to December 2018). The incidence of postoperative ICA-IF, risk factors, management strategies, and outcomes were analyzed. These results were put into context with a systematic review following the PRISMA guidelines.

RESULTS

A total of 725 CEAs were performed between January 2008 and December 2018. Postoperative ICA-IF was detected by routine duplex neurovascular ultrasound (NVUS) in 13 patients, corresponding to an incidence rate of 1.8% (95% CI 1.0%-3.1%). There were no associated intraluminal thrombi on the detected IF. Intraoperative shunt placement was used in 5.6% and one or more intima tack sutures were performed in 42.5% of the 725 cases. There was no significant association between intraoperative shunt placement and the occurrence of an IF (p > 0.99). Two patients (15.4%) with IF experienced a transient postoperative neurological deficit (transient ischemic attack). In these cases, the symptoms resolved spontaneously without any interventions or change in the antiplatelet regimen. All other cases (84.6%) with IF were asymptomatic. In 1 patient (7.7%) with IF, the antiplatelet treatment was switched from a mono- to a dual-antiaggregating regimen because the IF led to a stenosis > 70%; this patient remained asymptomatic. All cases of IFs were managed conservatively with close radiological follow-up evaluations, without reoperation or stenting of the ICA. All 13 IFs vanished spontaneously after a mean duration of 6.9 months (median 1.5 months, range 0.5-48 months). A systematic literature review revealed a postoperative ICA-IF incidence of 3.0% (95% CI 2.1%-4.1%) with relatively heterogenous management strategies.

CONCLUSIONS

Postoperative ICA-IF is a rare finding after CEA. Conservative therapy with close NVUS follow-up evaluations appears to be an acceptable and safe management strategy for asymptomatic IFs without associated intraluminal thrombi.

Intraoperative completion studies in carotid endarterectomy: systematic review and meta-analysis of techniques and outcomes

BACKGROUND

Declining perioperative stroke and death rates over the past 3 decades have been paralleled by an increasing use of intraoperative completion studies (ICS) following carotid endarterectomy (CEA). Techniques applied include angiography, intraoperative duplex ultrasound (IDUS), flowmetry, and angioscopy. This systematic review and meta-analysis is aiming on providing an overview of techniques and corresponding outcomes.

METHODS

A PubMed based systematic literature review comprising the years 1980 through 2020 was performed using predefined keywords to identify articles on different ICS techniques. Pooled analyses and meta-analyses estimating risk ratios (RR) and 95% confidence intervals (CI) were performed to compare outcomes of different ICS modes to nonapplication of any ICS. I2 values were assessed to quantify study heterogeneities.

RESULTS

Identification of 34 studies including patients undergoing CEA with angiography (n=53,218), IDUS (n=20,030), flowmetry (n=16,812), and angioscopy (n=2,291). Corresponding rates of perioperative stroke were 1.5%, 1.8%, 3.6%, and 1.5%, perioperative stroke or death occurred in 1.7%, 1.9%, 2.2%, and 2.0%. Intraoperative surgical revision rates were 6.2%, 5.9%, and 7.9% after CEA with angiography, IDUS, and angioscopy, respectively. Compared to nonapplication of any ICS, the pooled analysis revealed angiography to be significantly associated with lower rates of stroke (RR 0.47; 95% CI, 0.36-0.62; P<0.0001) and stroke or death (RR 0.76; 95% CI, 0.70-0.83; P<0.0001). IDUS was significantly associated with lower rates of stroke (RR 0.56; 95% CI, 0.43-0.73; P<0.0001) and stroke or death (RR 0.83; 95% CI, 0.74-0.93; P=0.0018), whereas angioscopy showed a significant association with a lower stroke rate (RR 0.48; 95% CI, 0.033-0.68; P=0.0001), but no effect on the combined stroke or death rate. Angioscopy was associated with a higher intraoperative revision rate compared to angiography (RR 1.29; 95% CI, 1.07-1.54; P=0.006). The meta-analyses confirmed lower perioperative stroke or death rates for angiography (RR 0.83; 95% CI, 0.76-0.91) and IDUS (RR 0.86; 95% CI, 0.76-0.98) compared to non-application of any ICS, whereas flowmetry showed no significant association.

CONCLUSIONS

This study represents the first systematic literature review and meta-analysis on usage of ICSs in CEA. Data strongly indicate a significant beneficial effect of angiography, IDUS, and angioscopy on perioperative CEA outcomes. Any carotid surgeon should consider implementation of ICSs in his routine armamentarium.

Procedural Stroke after Carotid Revascularization - Critical Analysis of the Literature and Standards of Reporting

OBJECTIVE

Mechanisms of procedural stroke after carotid endarterectomy (CEA) or stenting (CAS) are surprisingly underresearched. However, understanding the underlying mechanism could: (1) assist in balancing the choice for revascularization versus conservative therapy; (2) assist in choosing either open or endo techniques; and (3) assist in taking appropriate periprocedural measures to further reduce procedural stroke rate. The purpose of this study was to overview mechanisms of procedural stroke after carotid revascularization and establish reporting standards to facilitate more granular investigation and individual patient data meta-analysis in the future.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) statement.

RESULTS

The limited evidence in literature was heterogeneous and of low quality and hence no formal data meta-analysis could be performed. Procedural stroke was classified as haemorrhagic or ischemic; the latter was subclassified as haemodynamic, embolic (carotid- or cardio-embolic) or carotid occlusion-derived, using a combination of clinical inference and imaging data. Most events occurred in the first 24h after the procedure and were related to hypoperfusion (pooled incidence 10.2% (95% c.i. 3.0-17.5) versus 13.9% (95% c.i. 0.0-60.9) post-CEA vs CAS events, respectively) or atheroembolism (28.9% (95% c.i. 10.9-47.0) versus 34.3 (95% c.i. 0.0-91.5)) After the first 24 hours, haemorrhagic stroke (11.6 (95% c.i. 5.7-17.4) versus 9.0 (95% c.i. 1.3-16.7)) or thrombotic occlusion (18.4 (95% c.i. 0.9-35.8) versus 14.8 (95% c.i. 0.0-30.5)) became more likely.

CONCLUSIONS

Although procedural stroke incidence and aetiology may have changed over the last decades due to technical improvements and improvement in perioperative monitoring and quality control, the lack of literature data limits further statements. To simplify and enhance future reporting, procedural stroke analysis and classification should be documented pre-emptively in research settings. We propose a standardized form enclosing reporting standards for procedural stroke with a systematic approach to inference of the most likely aetiology, for prospective use in registries and RCTs on carotid revascularization.

Completion imaging techniques and their clinical role after carotid endarterectomy: Systematic review of the literature

BACKGROUND

Completion imaging has been suggested for the intraoperative quality control assessment of the carotid endarterectomy technical success, in order to immediately resolve pathologic findings and accordingly improve patients' outcome. The aim of this study was to present existing evidence of different completion imaging techniques after carotid endarterectomy and their role on clinical outcome.

MATERIAL AND METHODS

A systematic review was performed searching in MEDLINE, CENTRAL, and Cochrane databases including studies reporting on completion imaging techniques after carotid endarterectomy.

RESULTS

A total of 12,378 patients in 35 studies (20 retrospective and 15 prospective) underwent a completion imaging technique after carotid endarterectomy: in 19 studies, 5340 patients underwent arteriography; in 5 studies, 2095 angioscopy; in 21 studies, 5722 DUS; and in 2 studies, 150 patients underwent transcranial Doppler. Ten studies assessed > 1 imaging technique. The mean age was 67 ± 7 years old (69% males) with common co-morbidities to be hypertension (74%), smoking (64%), and hyperlipidemia (54%). Almost half of the patients (4949; 44%) were treated for symptomatic disease. In 1104 (9.7%) patients, a major defect was identified intra-operatively, while in 329 patients (2.9%), a minor defect. Common pathological findings were the presence of mural thrombus, carotid dissection, residual stenosis, and intimal flaps. An immediate re-intervention was undertaken in 75% (790/1053) of the patients to treat a major intra-operative imaging finding. In patients with re-intervention, only 2.3% (14/609) had an intra-operative stroke and 0.8% (5/609), a transient ischemic attack, while only 1.4% (8/575) had a stroke and 0.2% a transient ischemic attack (1/575) during 30-day post-operative period. No intra-operative death was reported. In the same period, the restenosis rate of internal and common carotid artery was 0.5% (3/575) and 0.2% (1/575), respectively.

CONCLUSION

Completion imaging techniques can detect defects in almost 10% of patients that may lead to immediate intra-operative surgical revision with low intra-operative stroke/transient ischemic attack rate and low early carotid restenosis. During the 30-day follow-up period, in those patients, the incidence of stroke/transient ischemic attack may be low but present. This review cannot provide any evidence on which completion imaging technique is better, and the clinical impact conferred by each technique in the absence of a randomized control studies.

[Intraoperative completion diagnostics in open vascular surgery]

Intraoperative imaging diagnostics during open vascular surgical procedures aim to enhance diagnostic certainty during the operation, ensure quality control documentation and reduce avoidable complications; however, the evidence for the various diagnostic imaging procedures with respect to improvement of perioperative outcome is not confirmed for carotid endarterectomy or for infrainguinal bypass surgery. Nevertheless, an intraoperative diagnostic control is principally recommended. The advantage of intraoperative imaging is confirmed and essential for the surgical reconstruction of bypass occlusions and acute thromboembolic occlusions.

Asymptomatic dissecting intimal lesions of common carotid arteries after carotid endarterectomy

PURPOSE

Carotid endarterectomy is a standard treatment for symptomatic high-degree internal carotid artery stenosis. The aim of this article is to present possible intimal lesions after carotid endarterectomy. These lesions could be manifested as intimal flaps, intimal steps or dissections with or without occlusion or stenosis of the artery.

METHODS

The evaluation of the frequency and characteristics of the asymptomatic dissecting intimal lesions of the common carotid arteries was performed in a sample of 100 patients who underwent endarterectomy for symptomatic high-grade stenosis of the internal carotid artery.

RESULTS

We found five patients with asymptomatic dissecting intimal lesions of the common carotid arteries.

CONCLUSION

The most common causes of these intimal lesions were shunting and prolongation of the clamping time. Routine carotid ultrasound follow-up exams are necessary because of the potential need for a change in the antithrombotic therapy or due to a need to perform an endovascular treatment.

Observation of vertebral artery damage using angioscopy in autopsy cases

The vertebral arteries are important blood vessels that supply the cerebral circulation in conjunction with the internal carotid arteries. In cases of subarachnoid hemorrhage, it is necessary to examine the vertebral arteries as potential sources of bleeding due to blunt trauma (head and neck) or of cerebral embolism that originated on the surface of the damaged intima as a result of hyperflexion or hyperextension. However, a considerable part of the vertebral arterial surface is surrounded by bone, resulting in challenges during examination in a routine autopsy. In this study, angioscopy was used to inspect the vertebral artery intima for damage in cases of neck injury, head injury, or neck strangulation. Intimal damage was detected in 34 out of the total 75 cases. Of the 28 cases with cervical discopathy or fracture, 61% had intimal damage. In addition, postmortem application of computed tomography angiography was performed to identify the injured vessel in a case with traumatic subarachnoid hemorrhage, and a perforated hole was detected using angioscopy, which did not introduce autopsy-related artifacts. Therefore, angioscopy may be a useful and nondestructive method to identify intimal damage in the vertebral arteries during an autopsy.