Intraprocedural rupture of an intracranial aneurysm is a potentially catastrophic complication, but can be even more devastating in a heparinized patient in an offsite interventional suite. This chapter presents a case study of a 67-year old woman with hypertension presented to the emergency department with the sudden onset of the worst headache of her life. A noncontrast head computed tomography scan was obtained, which showed expected diffuse subarachnoid hemorrhage (SAH) and a small hypo-attenuating spherical abnormality in the basilar artery tip. The intracranial pressure (ICP) measurement from the ventriculostomy precipitously increased to 40 mm Hg. An injection of contrast dye demonstrated extravasation from the aneurysm. Intraprocedural rupture can occur both in elective procedures, as well as in the treatment of previously-ruptured aneurysms. The anesthesiology team must therefore always be prepared for expeditious transport to the operating room in the event that an endovascular procedure fails.