Local anaesthesia in carotid surgery. A prospective study of 111 endarterectomies in 100 patients

The Role of Carotid Stump Pressure in Carotid Endarterectomy: A Systematic Review and Meta-Analysis

This review evaluates the carotid stump pressure (CSP)’s role as a single parameter at any given pressure as an indicator for selective shunting, or vice versa, in carotid endarterectomy (CEA). A systematic review of literature in MEDLINE and the Cochrane Library from 1969 to 2019 was conducted. The primary end point was set at 0 to 30-day mortality, ischemic stroke (IS), transient ischemic attack (TIA), and a secondary point at recognition of an optimal CSP pressure. The data was subjected to meta-analytics. The odds ratio (OR) was reported at 95% confidence interval (CI). This study has been registered with PROSPERO: CRD42019119851. The pooled analysis on the primary endpoint of IS demonstrated higher incidence of stroke in shunted CEAs solely based on CSP measurement alone (OR, 0.14, 95%CI: 0.08–0.24, I²=48%, p<0.001). Sub group analysis demonstrated similar patterns at 25 mmHg (OR, 0.06, 95%CI: 0.01–0.5, p<0.01), 30 mmHg (OR, 0.07, 95%CI: 0.01–0.63, p=0.02) and 40 mmHg (OR, 0.23, 95%CI: 0.09–0.57, p<0.01). This effect on end points of mortality and TIA demonstrated no benefit in either direction. CSP, as a single criterion, is not a reliable parameter in reduction of TIA, mortality, and IS at any given pressure range.

Carotid endarterectomy and local anaesthesia: reducing the disasters

PURPOSE

The study was designed to assess one surgeon's operative mortality and morbidity for carotid endarterectomy using local anaesthetic (LA) compared to general anaesthetic (GA) techniques.

METHOD

Data were collected prospectively from 200 patients undergoing LA carotid surgery compared with 243 patients undergoing carotid surgery using GA technique. Indication for surgical, pathology, postoperative morbidity and mortality was assessed.

RESULTS

No major strokes or deaths occurred in the LA group (0/200). Significantly more major strokes and/or deaths occurred in the GA group (11/243, 4.5%; P=0.016). Significant less shunt usage was associated with LA (LA 18/200, 9% versus 94/243, 39%; P=0.001). The absence of a shunt was associated with more major events in the GA group (5/143, P=0.001. Age greater than 74 yr was associated with greater major events (4/31, P=0.002). No significant difference in the frequency of cardiovascular complications was observed (LA, 15/200 (7.5%) vs GA, 19/243(7.8%); P=0.924).

CONCLUSION

Local anaesthesia enables the surgeon to assess the level of cerebral perfusion with an awake patient, gives greater assurances of cerebral protection during arterial clamping and a provides for a more relaxed and cautious endarterectomy and repair. This study demonstrates reduction in mortality and major stroke events in patients operated on with these conditions.

Carotid endarterectomy: a comparison of regional versus general anesthesia in 500 operations

The outcomes of 489 patients undergoing 500 carotid endarterectomies were reviewed to compare results from using general anesthesia with those from using regional (cervical block) anesthesia. From September 1982 to May 1998, 228 procedures (221 patients) were performed under general anesthesia and 272 procedures (268 patients) were performed under local anesthesia. A detailed comparison of the two groups revealed close similarity in age, sex, presenting symptoms, and associated risk factors. Overall, perioperative mortality was 0.8%. In comparison to regional anesthesia, the general anesthesia group had greater overall morbidity (23.3 vs. 13. 6%, p < 0.008) and more frequent use of postoperative vasoactive drugs to control blood pressure (40.4 vs. 26.1%, p < 0.001). Furthermore, anesthesia time, operative time, and frequency of shunt use were significantly greater in the general anesthesia group (p < 0.03).

Perioperative stroke. Part I: General surgery, carotid artery disease, and carotid endarterectomy

Although stroke, defined as a focal neurological deficit lasting more than 24 hr, is uncommon in the perioperative period, its associated mortality and long-term disability are high. No large-scale data are available to identify the importance of recognized risk factors for stroke in the perioperative period. A review of the literature shows that the incidence and mechanism of its occurrence are influenced by the presence of cardiovascular disease and the type of surgery. The most common cause of perioperative stroke is embolism. In non-cardiac surgery, the incidence of perioperative stroke is higher among the elderly. Properly administered, controlled hypotension is associated with minimal risk of stroke. Cerebral vasospasm may be the cause of focal cerebral ischaemia in eclamptic patients, and the aggressive treatment of hypertension may exacerbate the neurological damage. The risk of stroke associated with carotid endarterectomy is closely related to the preoperative neurological presentation, and the experience of the surgical/anaesthetic team. Symptomatic cerebrovascular disease, acute stroke, asymptomatic carotid lesions, preoperative assessment of risk, local and general anaesthesia, cerebral protection and monitoring during carotid endarterectomy are discussed with reference to reducing the risk of perioperative stroke. Adequate monitoring and protection have minimized the risk of ischaemia from carotid clamping, and the major mechanism of stroke is embolization.

Pressure measurements as predictors for peroperative neurologic deficits in carotid surgery

Forty-eight carotid endarterectomies were performed using local anaesthesia. The need for an intra-operative shunt was estimated from the development of neurological symptoms during a test clamping period of 1 min. Two patients developed symptoms during test clamping but four others developed symptoms after 11 to 20 min of clamping. The internal carotid back pressure was 30 to 40 mmHg in all these cases and significantly lower than among patients not developing symptoms. A better prediction of the need for a shunt was developed from a combination of the stump index (SI = internal carotid artery stump pressure/systemic pressure x 100) and the carotid index (CI = carotid pressure before clamping/systemic pressure x 100). The combination of SI less than 30 and CI greater than 85 predicted in a highly significant way the need for a shunt during operation. With this method a group of patients with a higher risk of postoperative stroke may also be detected.

Local versus general anaesthesia in carotid surgery. A prospective, randomised study

A randomised, prospective study was performed to compare local (LA) and general anaesthesia (GA) in carotid surgery with special emphasis on complications and the need for intra-operative shunting. Fifty-six patients were randomised to LA and 55 to GA. Eight patients in the LA group required a GA for various reasons. During the same period 14 patients were not randomised. Seven perioperative neurological deficits occurred (5.6%), four in the LA group, two in the GA group, and one in the non-randomised group (NS). Selective shunting was used, in the Ga group according to stump pressure or in cases with a previous stroke and in the LA group according to the appearance of neurological symptoms. In the GA group 25 patients were shunted and in the LA group five patients (P less than 0.001) needed a shunt. If strict pressure criteria for shunting had been used in the LA patients, ten would have been shunted and three of the patients who developed symptoms during clamping would not have been shunted. During surgery the highest recorded systolic pressure was significantly higher in the LA group (210 mmHg versus 173 mmHg, P less than 0.001). LA for carotid endarterectomy is comparable with general anaesthesia regarding peroperative complications but produces significantly higher blood pressures than general anaesthesia. On the other hand it allows the possibility of neurologic monitoring of the patient and leads to significantly less use of an intra-operative shunt.

Detailed comparison of regional and general anesthesia for carotid endarterectomy

Forty-one variables were examined in 75 patients who underwent carotid endarterectomy to determine if significant differences were present between 45 patients who had general anesthesia and 30 patients who had regional anesthesia. The two groups were similar in terms of age, existing medical illnesses, neurologic presentation, and angiographic severity of the carotid lesions. There were no differences between the two groups for operative time, anesthesia time, blood loss, maximum or minimum blood pressures, postoperative hemodynamic data, or the requirement for or duration of intravenous pressor or antihypertensive medications. One patient in the regional group had a postoperative neurologic deficit which resolved in 1 month. Three patients in the general group had cardiovascular complications. Postoperative hospital stay was significantly longer in the general anesthesia group (5.6 to 3.2 days, p = 0.003). Regional and general anesthesia produce similar perioperative hemodynamic and surgical outcomes, but regional anesthesia results in a shorter hospital stay and less cardiovascular morbidity in this high risk population.