ORIGINAL ARTICLES   

International Angiology 1998 September;17(3):168-70

Copyright © 2000 EDIZIONI MINERVA MEDICA

lingua: Inglese

Is transcranial Doppler a worthwhile examination for preoperative evaluation of the Circle of Willis? Evaluation of 137 carotid endarterectomies performed under regional anesthesia

Lagneau P., Baujat B., Anidjar S., Borie H., Kovarsky S., Decamps Le Chevoir J., Coppe G.

From the Department of Vascular Surgery, Hopital Saint Michel, Paris, France

Background. Transcranial Doppler is often pro­posed for eval­u­a­tion of the Circle of Willis prior to carot­id endar­te­rec­to­my. The pur­pose of this study was to eval­u­ate pre­op­er­a­tive TCD ­before carot­id sur­gery.
Methods. This is a ret­ro­spec­tive ­report of 137 carot­id endar­te­rec­to­mies per­formed under region­al anes­the­sia oper­at­ed ­between January 1992 on June 1996. All ­patients have a ­thight sten­o­sis ­between 70% on 99%, and 49% were symp­to­mat­ic. Forty-three ­patients of the 132 had a con­tro­lat­er­al hemo­dy­nam­i­cal­ly sig­nif­i­cant carot­id sten­o­sis with none occlu­sion. The TCD exam­ina­tions were all per­formed with ADMS Doppler Spectradop with 3-MHz and 2-MHz ­probes. Clinical eval­u­a­tion dur­ing cross-clamp­ing was com­pared to the pre­op­er­a­tive TCD. In 14% of the ­patients, the TCD could not be per­formed ­because there are not tem­po­ral bone win­dows.
Results. When the ­patients could be test­ed the pos­i­tive pre­dic­tive value of the TCD was 18% and the sen­si­tiv­ity was 33%. The neg­a­tive pre­dic­tive value was 94%. 8% of the ­patients were shunt­ed. TCD had numer­ous dif­fi­cul­ties. The most com­mon is the lack of the tem­po­ral bone win­dow (40% of the ­patients). The com­pres­sion test is often dif­fi­cult when the ­lesion is cal­car­e­ous. Preoperative TCD is not accord­ing to our ­results, a reli­able ­enough exam­ina­tion to mod­i­fy oper­a­tive strat­e­gy dur­ing carot­id sur­gery. When cou­pled with arter­i­og­ra­phy it is a good way to study cere­bral hemo­ynam­ics.
Conclusions. Regional anes­the­sia with local sup­pli­ca­tion ­remains the meth­od of ­choice to ­select those ­patients who ­require a shunt dur­ing carot­id sur­gery. It can be used rou­tine­ly and it is less com­plex than the var­i­ous meth­ods.