CHICAGO – Patients undergoing carotid endarterectomy with cervical block anesthesia had fewer hemodynamic fluctuations and required less vasoactive medications than those under general anesthesia in a retrospective evaluation.
"Under cervical block anesthesia, carotid endarterectomy can be performed with a better hemodynamic profile," Dr. Marika Y. Gassner, a resident with Henry Ford Macomb Hospital, Clinton Township, Mich., said at the annual meeting of the Midwestern Vascular Surgical Society*.
The practice switched in 2003 from using general anesthesia for the majority of carotid endarterectomy to performing more than 90% of cases under local cervical block anesthesia (CBA). Exceptions include patients who are extremely nervous, unable to communicate in English, or who have plaque extending above C2.
The investigators organized the retrospective cohort study after initial observations suggested patients under CBA had less intraoperative hypotension or fluctuations in mean arterial pressure below 65 mm Hg. Vasoactive therapy demands were also lower. For example, anesthesia records showed that several doses of beta-blockers and ephedrine were required for a patient under general anesthesia, while a patient under CBA had only a single dose of midazolam (Versed) early in the procedure, she said.
Other advantages of CBA include continuous feedback on neurologic status/cerebral perfusion, endotracheal intubation not required, shorter operative times, and reduced use of shunts, Dr. Gassner said.
The analysis included 651 patients who underwent carotid endarterectomy by a single surgeon at two suburban teaching hospitals, with 397 under general anesthesia (GA) and 254 under CBA.
The CBA and GA groups were similar in age (71.26 vs. 70.97 years) and incidence of coronary artery disease (57% vs. 56%), hypertension (77% vs. 75%), and renal failure (3.5% vs. 4.0%). The GA group, however, had significantly more females (39% vs. 46.6%), and a higher incidence of chronic obstructive pulmonary disease (16% vs. 23%), nicotine abuse, (50% vs. 63%), and symptomatic patients (41.3% vs. 54%).
The incidence of intraoperative hypotension (systolic BP less than 100 mm HG) was 0.52% with CBA and 17.84% with GA (P less than .001), Dr. Gassner said.
Mean arterial pressure changes of 20% or more per patient occurred in 20% and 41%, respectively (P less than .001).
Vasopressors were required during surgery in 51.13% of the GA group and 36.22% of the CBA group (P = .0002), and antihypertensive medications in 64% and 73.6% (P = .0085). Drugs from both categories were required by significantly fewer CBA patients (22.5% vs. 33.75%; P = .045), she said.
There were no deaths in either group. Postoperative complications were higher in the GA than the CBA group including myocardial infarction (4 vs. 0 events), stroke (6 vs. 0 events), hematoma (7 vs. 2 events), and return to the OR (7 vs. 0 events). The difference did not reach statistical significance because of the sample size, Dr. Gassner said.
Earlier in the presentation, she observed that there was no difference in the primary composite endpoint of stroke, myocardial infarction, or death at 30 days in the randomized GALA (general anaesthesia vs. local anaesthesia for carotid surgery) trial conducted at 95 centers in 24 countries (Lancet 2008;372:2132-42).
"If they couldn’t find it [a survival advantage] in GALA with 3,500 patients, we couldn’t find it here," Dr. Gassner said, adding that a randomized trial powered to look at late mortality is needed.
The group has no current plans to conduct such a study or perform a cost analysis, although a subsequent analysis of the GALA data revealed a cost savings of about $283 favoring carotid endarterectomy using local anesthesia (Br. J. Surg. 2010;97:1218-25).
Dr. Gassner and her coauthors reported having no financial disclosures.
*CORRECTION, 10/29/2013: An earlier version of this article misstated the name of the annual meeting of the Midwestern Vascular Surgical Society.