Patient selection for carotid endarterectomy: how far is risk modeling applicable to the individual?

Risk-factor modeling has been proposed to identify patients with carotid stenosis who will most benefit from surgery. Validation by independent institutions performing carotid endarterectomy is necessary to determine the applicability of such models to the individual patient.

A series of patients with a recently symptomatic high-grade carotid stenosis were selected for surgery according to current guidelines and were consecutively operated on in a single institution. In addition, a prognostic model was applied to the patients to analyze the concordance of both selection methods.

The study included 134 patients operated on between 1999 and 2001. The risk model predicted that 49% of the patients should have been excluded from surgery because the operation was found to be possibly harmful in 1 patient (1%) and not significantly beneficial in 65 patients (48%). This resulted from the predominant negative weight of the surgical risk factors in the model. However, this predominance was negated in our series by the fact that only 1 major complication (0.75%) occurred during follow-up.

Exclusion of single patients on the basis of risk modeling may be problematic when the rate of perioperative complications is very low.