Hypotensive Endovascular Test Occlusion of the Carotid Artery
Object: To evaluate the reliability of balloon test occlusion with hypotensive challenge (BTO and HC) as a predictor of neurological complications before internal carotid artery (ICA) sacrifice in patients with advanced head and neck cancer, the authors retrospectively reviewed the medical records of patients presenting to their institutions between 1992 and 1997 in whom this preoperative assessment was performed.
Methods: Eleven patents who were candidates for extended comprehensive neck dissection (ECND) and potential ICA sacrifice were included in the study. Eight patients tolerated the test and underwent endovascular occlusion or surgical ligation of the ICA before ECND (four patients), preservation of the ICA at the time of surgery (three patients), or palliative therapy (one patient). Of three patients in whom BTO and HC failed, one patient received palliative treatment only; the other two underwent ECND with preservation of the ICA. In the group of patients who passed the test and underwent ICA occlusion or ligation before ECND, fatal thromboembolic stroke occurred within 24 hours of permanent balloon occlusion in one patient, resulting in a combined neurological morbidity/mortality rate of 25% in this subset of patients and an overall complication rate of 9% in this series.
Conclusions: The authors found that BTO and HC offers a simple and reliable method of preoperative risk assessment when ICA resection is planned for regional control of disease in advanced head and neck cancer. This management option, however, is associated with a potential for neurological complication that must be weighed against the natural course of the disease and the risks and benefits of other treatment modalities.

Nonsurgical management (chemo- and radiation therapy) of head and neck cancer is a promising clinical option. Tumor, however, may involve the ICA, threatening spontaneous CA rupture in patients with AHNC. In those patients for whom resection is indicated after nonsurgical management fails to control the disease or for those who choose surgery as the primary treatment of the disease, elective resection of the ICA may be necessary. Because of the potential for significant associated neurological complications, resection of the ICA is controversial. Current management options include the following: 1) ICA preservation with "peeling" of tumor from the vessel; 2) ICA resection after revascularization; 3) ICA occlusion and resection after an asymptomatic temporary test occlusion; and 4) palliative therapy.

With the advent of endovascular techniques, BTO and HC has been performed at our institutions to assess tolerance to ICA occlusion in patients with AHNC in whom there is imaging-based evidence of ICA involvement. After hypotensive endovascular test occlusion, permanent balloon occlusion or sacrifice of the ICA was performed when indicated, often as a separate procedure, before ECND and resection of the ICA. The objective of this study was to review our experience and evaluate the reliability of BTO and HC as a predictor of neurological outcome after CA sacrifice in AHNC.