Preoperative Evaluation

The successful evaluation of patients with arterial occlusive disease must address the systemic and progressive nature of atherosclerosis (see Chapter 25 ). CAD is common in patients presenting for carotid endarterectomy^[574] and is the leading cause of early and late mortality.^{[575] [576] [577]} Hertzer and coworkers^[574] performed coronary angiograms in 506 patients presenting for carotid endarterectomy and found severe correctable CAD in 28%. Despite the known high incidence of CAD in patients presenting for carotid endarterectomy, I rarely request preoperative studies (i.e., DTI or DSE) aimed at the evaluation of myocardial function or ischemic potential. Exceptions to this practice are patients with unstable angina, recent MI with evidence of ongoing ischemia, decompensated congestive heart failure, and significant valvular disease. Unless the surgical plan can be altered, the perioperative management improved, or the mortality reduced, specialized studies are not appropriate for most patients presenting for carotid endarterectomy. My approach is based on the following rationale. First, randomized trials have definitively established that carotid endarterectomy can prevent stroke in appropriately selected patients. Second, an alternative or less stressful procedure is not an option at this time. Percutaneous angioplasty and stenting of the carotid artery may evolve into an appropriate alternative for some high-risk patients,^[578] but it is still investigational. ^[579] Third, based on the previous two reasons, it would be unlikely that the results of specialized testing would result in the procedure being canceled. Fourth, because careful intraoperative and postoperative monitoring and medical management is standard for all patients undergoing carotid endarterectomy, specialized testing has little potential to alter perioperative management. Lastly, I do not believe that preoperative strategies leading to coronary angiography and ultimately coronary revascularization are appropriate in patients undergoing carotid endarterectomy, given the low overall rates of perioperative cardiac morbidity and mortality. Reduction in short-term mortality has not been shown with prophylactic coronary revascularization before noncardiac surgery. For patients with asymptomatic or stable CAD, I believe that the best strategy is to proceed with carotid endarterectomy without additional studies. This approach does not take into consideration the potential long-term benefits from aggressive preoperative cardiac assessment and ultimate coronary revascularization. However, there is no convincing evidence that such benefit exists.

Patients with severe CAD and severe carotid artery occlusive disease represent somewhat of a management dilemma^[580] because it is often unclear which disease should be treated first.^[581] The severity of cerebrovascular and coronary disease must be evaluated in terms of clinical symptoms and anatomic lesions, and a decision must be made for a combined or a staged procedure. A meta-analysis of 16 studies with 844 combined patients and 920 staged patients reported that the combined approach may be associated with a higher risk of stroke or death than a staged approach.^[582] A staged approach with carotid endarterectomy as the first procedure may result in significant morbidity from cardiac causes.^[583] Conversely, coronary revascularization first may result in a high incidence of stroke. ^[584] For patients with unstable CAD and symptomatic carotid artery disease, a combined procedure has been advocated.^[585] Numerous reports from centers of excellence support a combined approach, demonstrating low morbidity and low mortality.^{[580] [586] [587] [588]} However, these reports may not reflect community-wide outcomes of the combined approach.^[589] No randomized trials have been performed to assess the benefit of combined verses staged procedures. Given this lack of objective data, management of the individual patient should be guided by a careful assessment of the relative severity of their coronary and carotid disease with particular emphasis on surgeon- and institution-specific results in these patient populations.