Abstract
A 66-year-old woman was referred for occlusion of a hemodialysis AV shunt in the right upper arm. Because the patient had an allergy to iodine contrast, carbon dioxide (CO2) gas was used for contrast during balloon angioplasty after a surgical thrombectomy. The patient developed seizures and impaired consciousness postoperatively, and MRI showed a right cerebellar infarction.
With CO2 angiography for dialysis shunt problems, retrograde flow of CO2 contrast from the brachial artery to the cerebral vasculature resulting in loss of consciousness and hemiplegia has been reported, but these symptoms have been transient. However, our patient developed cerebellar infarction due to CO2 angiography after thrombectomy of the AV shunt.
Because CO2 gas does not mix with liquids, a faster injection rate compared to liquid contrast agents is necessary for imaging. Therefore, retrograde flow towards the CNS can occur, and residual microthrombi in an AV graft after thrombectomy may be propelled retrograde by the gas, thus possibly causing cerebral infarction. For this reason, extreme caution is required when CO2 arteriography is performed after a thrombectomy.
