Transcranial Doppler directed Dextran therapy in the prevention of carotidthrombosis: Three hour monitoring is as effective as six hours

Background: six hours' monitoring by transcranial Doppler (TCD) has been su ccessful in directing Dextran therapy in patients at high risk of thromboti c stroke after carotid endarterectomy (CEA). Objectives: is 3 h of routine monitoring as effective as 6 h in the prevent ion of early postoperative thrombotic stroke? Design: prospective, consecut ive study in all patients with an accessible cranial window. Methods: one hundred and sixty-six patients undergoing CEA underwent 3 h of postoperative monitoring by TCD. Any patient with >25 emboli detected in a ny 10 min period or those with emboli that distorted the arterial waveform were commenced on an incremental infusion of dextran 40. Results: the majority of patients destined to embolise will do so within th e first 2 postoperative hours. Dextran therapy was instituted in nine patie nts (5%) and rapidly controlled this phase of embolisation although the dos e had to be increased in three (33%). No patient suffered a postoperative c arotid thrombosis but one suffered a minor stroke on day 5 and was found to have profuse embolisation on TCD; high dose dextran therapy was again inst ituted, the embolus count rate fell rapidly and he made a good recovery the reafter. Overall, the death and disabling stroke rate was 1.2% and the deat h/any stroke rate was 2.4%. Conclusion: three hours of postoperative TCD monitoring is as effective as 6 h in the prevention of postoperative carotid thrombosis.