Emergency endovascular management of oropharyngeal tumor hemorrhage via aberrant vertebral collateral pathways: illustrative case.

BACKGROUND: Acute oropharyngeal hemorrhage in advanced head and neck squamous cell carcinoma (SCC) is a life-threatening oncological emergency. Concomitant cerebrovascular occlusive disease can severely complicate endovascular access. OBSERVATIONS: The authors report the case of a 66-year-old male with a cT4N1M0 p16-positive SCC of the right base of the tongue who presented with massive oropharyngeal hemorrhage during concurrent chemoradiotherapy. Angiography revealed a chronic right common carotid artery occlusion. The right external carotid artery (ECA) was reconstituted via a large hypertrophied collateral originating from the V2 segment of the right vertebral artery (VA). Utilizing a transcollateral approach, the right lingual artery was successfully superselected and embolized using calibrated microspheres and a platinum coil, achieving complete hemostasis without neurological complication. LESSONS: To the authors' knowledge, this case represents the first reported use of a VA-to-ECA collateral pathway for emergency tumor embolization. This report underscores the necessity of detailed angiographic evaluation and advanced microcatheter navigation in managing head and neck hemorrhage in the presence of aberrant collateral anatomy. https://thejns.org/doi/10.3171/CASE26381.