An Unusual Result from Cross‐Compression in Carotid Angiography

SummaryWhen an aneurysm of the intracranial portion of the internal carotid artery is demonstrated at common carotid angiography performed by needle puncture, it may not be possible to produce satisfactory cross‐circulation by needling the opposite carotid, and yet there may be adequate clinical indication for common carotid ligation. If the age of the patient contra‐indicates a selective transfemoral approach, the desired result is sometimes achieved at a further cross‐compression study after catheterization of the common carotid contralateral to the aneurysm. A case is reported of an unusual complication of this latter procedure, involving transient syncope, bradycardia and hypotension, with a brief generalized epileptiform seizure. The angiogram made showed not only excellent cross‐circulation, but also reflux of contrast into the basilar and both vertebral arteries, an unexpected finding in the sexagenarian patient concerned. The possible mechanism is discussed, with particular reference to the role of the contrast medium and untoward effects of carotid palpation and compression.