Transnasal X-Ray–Guided Biopsy for a Clival Lesion

ABSTRACT Skull base biopsies are technically challenging due to complex anatomy and proximity to vital structures. Traditional transcervical and transoral approaches offer limited access to the clivus and risk poor depth perception and complications. Although transnasal techniques have improved access, X-ray–guided methods are rarely reported. We describe the first transnasal X-ray–guided clival biopsy in a middle-aged patient with suspected skull base osteomyelitis. Preoperative CT, MRI, and PET-CT enabled precise targeting and safe trajectory planning. In a biplane angiographic suite, a guidewire was advanced transnasally, and a 9F introducer sheath was positioned against the anterior clivus. An 11G bone needle was then advanced under fluoroscopy and cone-beam CT into the lesion. Tissue sampling was successful and complication-free, confirming Staphylococcus haemolyticus osteomyelitis, which resolved with targeted antibiotics. This minimally invasive technique offers accurate access to superior clival lesions and may broaden options for selected skull base biopsy cases.