Angiography and Cerebral Perfusion Scintigraphy in Balloon Test Occlusion of Carotid Artery in Head and Neck Tumors

Validity of venous phase delay assessment in balloon occlusion test of internal carotid artery

The aim of the present study was to investigate the utility of venous phase delay assessment to evaluate the balloon occlusion test (BOT) of the internal carotid artery (ICA). A total of 38 patients who received BOT of the ICA were included in this retrospective study. Clinical examination and venous phase assessment were performed in all patients to evaluate their suitability for the evaluation of the BOT of the ICA. The venous phase delay assessment compared the venous phase of supratentorial and infratentorial structures between hemispheres. Venous phase delay was defined as the time lag for opacification of the first cortical vein between the occluded hemisphere and the hemisphere examined. The results of the clinical examination and the venous phase delay assessment were compared. In most patients negative on clinical examination, the venous phase delay was no more than 2 sec, while for most patients positive on clinical examination, the delay was >2 sec. All patients with a venous phase delay of >4 sec had a positive clinical result. The present results indicated that venous phase delay assessment is a reliable method for evaluating BOT of the ICA, and in those with a delay of <2 sec, parent vessel occlusion of the ICA, which may be used as a pre-operative procedure prior to tumor resection for patients suffering from neck or skull-base tumors, was considered safe.

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.