Purpose: The aim of this study was to evaluate the relationship between the rate of emboli (ER), as detected with transcranial Doppler scan (TCD) monitoring during and shortly after carotid endarterectomy (CEA), and early cerebrovascular complications (CVC).
Materials and methods: One-hunderd eighty-five consecutive patients underwent 203 CEAs with general anesthesia at the Sint Lucas Andreas Hospital. Inclusion criteria included adequate TCD monitoring during the operation and for at least 10 minutes in the recovery room. Fifteen patients were excluded because of inadequate TCD monitoring. To prevent statistical bias, only data from the first operation of those patients who underwent bilateral CEA were included. The study group thus consisted of 170 patients (113 men, 57 women) with a mean age of 67 years (range, 45 to 83 years). The monitored TCD signals were stored on tape for offline analysis. ERs during dissection, wound closure, and the postoperative period shortly after arrival in the recovery room were studied. Preoperative and early postoperative neurologic examination, including grading with the modified Rankin scale, was performed by the same board-certified neurologist.
Results: A CVC occurred in 10 patients (5.9%). Five minor strokes (2.9%) and three major strokes (1.8%) occurred, one with a fatal outcome (0.6%). Two patients (1.2%) had transient ischemic attacks. Median ERs for the three periods studied were significantly different (postoperative period, 0.3/min; dissection, 0.03/min; wound closure: 0/min; Friedman, P <.005). ERs were significantly higher in the CVC group but only during wound closure (P =.0003) and the postoperative period (P <.0001). Women had significantly more CVCs than men (14% versus 2.7%; P <.02) and, during the postoperative period, had a significantly higher median ER (0.70/min) than men (0.25/min) (P <.002). High ERs during dissection in two men were associated with CVC. An ER of 0.9/min or more during the postoperative period was significantly correlated with CVC (P <.0001; odds ratio, 64.6; 95% CI, 3.7 to 1128).
Conclusion: Especially during the postoperative period, high ER is associated with early CVC. Women have a higher ER than men in this period. If the ER is 0.9/min or more during the postoperative period, there appears to be at least a nearly four-fold increased risk of CVC.