Technique of Carotid Endarterectomy

Carotid endarterectomy (CEA) can be performed under general or regional anaesthesia and requires full cardiac and blood pressure monitoring. Transcranial Doppler is a major adjuvant for:

• Identifying embolic events (microembolic signals, MES) that may occur during surgical dissection.

• Deciding whether to use shunt when the operation is performed under general anaesthesia.

• Assessing function and cerebral flow post-operatively.

Persistent MES after carotid declamping and/or in the recovery room may represent an increased risk of thrombus formation at the operated carotid and subsequent stroke.

Longitudinal or oblique (skin crease) cervical incision is performed and exposure of the carotid bifurcation obtained by division of the facial vein. Careful dissection is mandatory to avoid iatrogenic lesions of the hypoglossal, vagus and recurrent laryngeal nerve, causing dysphonia and hoarseness; unnecessary manipulation of the arteries should be avoided to prevent cerebral embolization.

Heparin (2500-5000 U) is routinely administered before clamping and a longitudinal arteriotomy is performed from the distal common carotid to the internal carotid as far as the end of the plaque.

Subsequent steps of the operation are shown in Fig. 2.2.8. Insertion of a shunt to preserve flow depends upon the appearance of appropriate neurological symptoms when the operation is performed with the patient awake, or based upon indirect evidence of insufficient collateral flow assessed by:

Carotid Thromboendarterectomy
Fig. 2.2.8 Carotid endarterectomy: plaque removal and final aspect before artery closing

• A carotid stump pressure <50 mmHg

• A 50% reduction in flow velocity detected in the middle cerebral artery by TCD if the operation is performed under general anaesthesia.

To remove the plaque, dissection is initiated in a sub-ad-ventitial plane using the Watson-Cheyne dissector and it is carried out meticulously, separating the lesion from the arterial wall. Complete removal of the lesion should always be attempted; when the dissection is in the correct plane the plaque "feathers out" distally, so tacking sutures of the distal intima are very seldom required. Clearing of the external carotid artery ostium and of its initial segment is performed routinely, and proximally, in the common carotid, the lesion is cut with scissors to avoid fragmentation and irregularities. Extreme care is taken to remove all remaining fragments of plaque and intimal flaps, which may be a source of secondary embolization or lead to secondary thrombosis.

The arteriotomy is routinely closed with a Dacron patch, aiming to enlarge the artery and to prevent early recurrent restenosis secondary to proliferative fibrosis [71], to correct kinking of the artery immediately distal to the endarterectomized segment and to reduce post-operative neurological morbidity [28]. Clamps are released sequentially in order to allow an initial flush through the external carotid and to prevent cerebral embolization. Vein can also be used, but there is no convincing evidence of its additional advantage over the Dacron patch.

Peri-operative completion assessment is routinely performed with colour flow Duplex scan to identify technical defects such as thrombus, floating flaps >2 mm or residual stenosis, which, if present, require prompt correction.

Monitoring with transcranial Doppler is continued in the recovery room to detect brain embolization; if there is evidence of repeated high-intensity transient signals (HITS), this could correspond to thrombus formation at the endarterectomized segment. Administration of 250 ml Dextran 40 is performed intravenously, and usually this is sufficient to ensure its disappearance. However, if there is persistence of HITS despite Dextran administration, immediate cervical re-exploration is carried out, the arteriotomy opened and thrombectomy of the carotid artery performed to prevent a major stroke [43].

Drainage is always applied and routine closure of subcutaneous tissues and skin performed after careful inspection and perfect haemostasis.

Other techniques have been described, such as eversion endarterectomy. Details of this technique can be

Table 2.2.1. Early results of carotid endarterectomy. (TIA Transient ischaemic attack)

Morbidity and mortality

< 30 days

Asymptomatic disease

0.7% (1/129)

TIAs/reversible stroke

1.5% (6/376)

Stroke with partial deficit

4.8% (2/41)

Acute stroke

10% (1/10)

found in this volume in Chapter 2.3, Reversed Carotid Endarterectomy, by D. Kiskinis.

Our preference is for conventional endarterectomy and our personal experience is based upon 556 patients and 610 procedures, two-thirds symptomatic patients, either TIAs or reversible strokes, and the overall morbidity and mortality was 1.7%. Its stratification according to clinical presentation is as in Table 2.2.1.

Complications of CEA in our patients were acute thrombosis in three patients, leading to major stroke and death in two; two patients had haemorrhagic stroke, with full recovery after several weeks and two patients died during the first 30 days postoperatively, one from pulmonary embolus and the second from acute myocardial infarct.

Peripheral nerve injuries have been described in association with CEA; in our patients its incidence was 2.5%, mainly dysphonia due to vocal cord paralysis and reversible in all patients except one, who required transient tracheotomy followed by laser segmental cord resection, because of contralateral cord paralysis following previous stroke. Neck and submandibular paraesthesia are common and transient.

The impact of completion assessment in our practice was analysed in a consecutive group of 114 patients; 4 required immediate re-operation to correct minor defects such as free-floating flaps, thrombi at the endarterectomy area and/or significant residual stenosis. There was no mortality or neurological morbidity in this group of patients.

Long-term results were analysed during a follow-up period, mean 48 months, ranging from 6 to 120 months; restenosis was identified by colour flow Duplex scan and its overall incidence was 7.5%, but for >70% it was only 3.3%, and the majority were asymptomatic. The annual stroke incidence in the operated patients was 0.9% and the major cause of death in this group was myocardial infarct.

2.2.6 Endovascular Treatment

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