Carotid endarterectomy in the awake patient.

The advantages of performing carotid endarterectomy in the awake patient have been presented based on a 13 year experience. Anesthesia consisted of either local infiltration of local lidocaine or regional neck block supplemented by intravenous sedation. The principal advantages of the technique are that it is the only exact method of assessing the need for an intraluminal shunt by neurologic assessment of the awake patient during trial carotid cross-clamping, and the elimination of general anesthesia allows carotid endarterectomy to be safely performed on patients with advanced inoperable coronary artery disease and in those with chronic obstructive pulmonary disease. One hundred consecutive carotid endarterectomies have been reported with one late death and one mild, permanent neurologic deficit. These results support the belief that carotid endarterectomy can be performed with very low morbidity and mortality rates by operating on the awake patient.

Newer developments of extra-anatomic bypass.

We have analyzed our eight year experience with more than 200 instances of extra-anatomic bypass and have made certain observations. Extra-anatomic bypass provides an acceptable alternative to extensive direct intra-abdominal and intrathoracic vascular reconstructive procedures. This is particularly true in high risk patients and in the presence of infection. While axillobifemoral bypass is widely known and used, other types of extra-anatomic bypass are emphasized. These are axillary-axillary, axillopopliteal, axillotibial and axillofemoral bypass under local anesthesia. Technical factors, such as the type of graft, the course of the bypass and ancillary techniques to improve the long term patency, are also discussed herein.

Successful management of prosthetic graft infection with continuous povidone-iodine irrigation.

In ten consecutive patients, prosthetic graft infections were managed by a continuous povidone-iodine irrigation technique supplemented by intravenous administration of an appropriate antibiotic. A colostomy bag apparatus was used to ensure constant soaking and immersion of the infected wound. Wound healing occurred in all patients either by secondary intention, direct suturing, or rotation graft technique, and all grafts except one have remained patent and functional over a follow-up period of one to four years. The effectiveness of this management modality permits control of infection without the necessity of prosthetic graft removal and eliminates the need for other intricate bypass operations in these patients with sepsis who are often critically ill.

Stump pressure: an unreliable guide for shunting during carotid endarterectomy.

A correlative analysis was made between the neurological status of the awake patient and the internal carotid artery stump pressure in 125 consecutive patients undergoing carotid endarterectomy. There was no mortality in this series. Twenty-four patients lost consciousness immediately after carotid cross-clamping, even though stump pressures were above 50 mm Hg in more than one third of the cases. The majority (80.8%) of the patients tolerated cross-clamping (stump pressures were between 20 and 90 mm Hg). This study demonstrated the variability of cerebral tolerance relative to absolute stump pressure guidelines, such as 25 or 50 mm Hg; reliance on these values to determine the need for intraoperative shunting could lead to stroke at operation. Our experience also showed that assessment of the awake but tranquil patient continues to be the safest and most reliable guide to selective shunting during carotid endarterectomy.

Improved results with carotid endarterectomy.

Two hundred ninety patients undergoing carotid endarterectomy were reviewed. From 1968 to 1972, 188 patients had carotid endarterectomy under general anesthesia with use of a shunt and hypercarbia. Stump pressures were not recorded in this group. There were three deaths, three postoperative hemiplegias and two complications of transient limb weakness. From 1973 to 1975, 102 patients were operated on under local anesthesia with systemic Innovar and Sublimaze, normocarbia and intra-operative assessment of stump pressure. In this group there was one death, no hemiplegia, and no complications of transient limb weakness. Twenty of the 102 were shunted either on the basis of stump pressure or the loss of motor ability or consciousness on carotid clamping. Those shunted had stump pressures ranging from 10 to 70 mm Hg with a mean of 20 while those not shunted had stump pressures ranging from 20 to 85 mm Hg with a mean of 53 mm Hg. Five patients lapsed into unconsciousness despite internal carotid stump pressures of 30, 30, 34, 36 and 70 mm Hg respectively, thus requiring intraoperative shunting. This experience seriously questions the reliability of carotid stump pressure as the sole determinant to identify those patients who require intraoperative shunting. We have come full circle, back to operation under local anesthesia, since intraoperative assessment of the patient's motor ability and consciousness alone provide the only absolute criteria for assessing the need for intraoperative shunting. Since the operation can be performed with greater technical efficiency without a shunt and without the potential complications of shunting itself, it behooves the surgeon to have a reliable method of knowing when it is not required.