USE OF TRANSCRANIAL DOPPLER SONOGRAPHY AND ACETAZOALMIDE TEST TO DEMONSTRATE CHANGES IN CEREBROVASCULAR RESERVE CAPACITY FOLLOWING CAROTID ENDARTERECTOMY

Objectives: To assess the effect of carotid endarterectomy on cerebrov ascular reserve capacity. Methods: Cerebral blood flow velocity (CBFV) and cerebrovascular reserve capacity (CVRC) were measured by transcra nial Doppler sonography (TCD) and acetazolamide test in 40 patients wh o underwent uncomplicated unilateral carotid endarterectomy (CEA). Ind ication for operation was limited to stenoses > 70% as documented by a ngiography and/or Duplex scanning. The TCD studies were carried out 6 days (range 1-14 days) before and 8 days (range 5-12 days) after endar terectomy. Results: Before endarterectomy, resting CBFV values and CVR C in the 40 patients were significantly different between the operated (51 +/- 19 cm/s; 20 +/- 16%) and the non-operated (60 +/- 19 cm/s; 34 +/- 24%) hemisphere (p < 0.05; p < 0.01). After CEA the overall incre ase of resting CBFV of the operated side was highly significant with p reoperative CBFV values of 51 +/- 19 cm/s and postoperative values of 62 +/- 15 cm/s (p < 0.01). Cerebrovascular reserve capacity after oper ation was increased on both sides significantly (non-operated side: fr om 34 +/- 24% to 43 +/- 19%, p < 0.05; operated side: from 20 +/- 16% to 51 +/- 18%, p < 0.001), and the preoperative asymmetry was no longe r present. Conclusions: CEA has a beneficial effect on the cerebral ci rculation in most patients, even those who presented with asymptomatic carotid artery stenosis. Since CVRC has been assessed in the early po stoperative period, our findings also suggest that cerebral vascular a daption occurs within 2 weeks after CEA.