Background: Extensive experience and critical evaluation of the efficacy of a pharmacologic hypotensive challenge during conventional balloon test occlusion (BTO) of the internal carotid artery (ICA) is lacking. This prompted us to review our institution's most recent experience with this adjunctive provocative test before planned therapeutic balloon occlusion of the ICA.
Methods: Twenty consecutive cases of endovascular therapeutic balloon occlusion of the ICA were retrospectively reviewed. Conventional BTO under normotension and with hypotensive challenge were performed within a standardized protocol.
Results: Sixteen patients underwent provocative testing, of which 13 had BTO with hypotensive challenge. All patients in this group tolerated these maneuvers without acute neurologic deficit. Two (15%) of these patients developed delayed permanent neurologic deficits, which seemed to be attributable to hemodynamic ischemia. One of seven patients not undergoing hypotensive challenge also developed transient neurologic deficits after carotid occlusion.
Conclusions: Despite the conceptually attractive and early positive experience of the hypotensive challenge in attempting to increase sensitivity and specificity of risk for developing delayed hemodynamic ischemia, we have found two significant false-negative results. This experience is reviewed in the context of risks of permanent balloon occlusion of the carotid artery after balloon test occlusion.