Combined Balloon Test Occlusion and SPECT Analysis for Carotid Sacrifice: Angiographic Predictors for Success or Failure?

Objectives To evaluate angiographic patterns that may predict the success or failure of carotid artery balloon test occlusion (BTO) and single-photon emission computed tomography (SPECT) analysis for carotid sacrifice. Study Design This is a retrospective nonrandomized study. Study Setting Conducted at the University of California Davis Medical Center, Sacramento, California. Patients A total of 31 patients, ranging from 24 to 83 years of age, with a mean age of 61 years (22 men, 9 women) with head and neck cancer (26 patients), malignant glomus tumor (1 patient) or giant carotid aneurysms (4 patients) as possible candidates for surgical carotid artery sacrifice were evaluated from September 2005 to September 2012. Methods All patients underwent unilateral internal carotid artery balloon test occlusion with SPECT analysis (20 mCi technetium 99m-hexamethyl propyleneamine oxime [HMPAO]) imaging before and during carotid occlusion. Carotid angiography with carotid cross-compression (manual compression of the cervical artery contralateral to the side of contrast injection) was used to analyze filling through the anterior communicating artery to the contralateral hemisphere. Intervention The balloon occlusion was terminated in two patients because of deterioration of the neurologic exam. Main Outcome Measures All patients who passed the neurologic examination during BTO and also passed the SPECT occlusive study underwent successful carotid sacrifice without neurologic sequelae. Patients failing the occlusive neurologic examination and/or the SPECT study elected chemoradiation, with the exception of one patient who underwent a successful carotid bypass graft and carotid resection. Results The success of carotid sacrifice in patients passing both the occlusive test and the SPECT analysis for carotid sacrifice was 100%. Three patients failed both the BTO and the SPECT, with two demonstrating no anterior circulation cross-fill, but one showed some cross-fill. Six additional patients passed the BTO but failed the SPECT, with poor cross-fill in five patients. In addition, three patients who had excellent cross-fill through the anterior communicating artery to the contralateral hemisphere failed the SPECT examination in two cases and failed both tests in another case.