Perfusion Study for Internal Carotid Artery Trapping of a Traumatic Pseudoaneurysm in an Unconscious Patient

Perfusion study should be preoperatively required for the trapping of an internal carotid artery (ICA) in the traumatic pseudoaneurysm in the petrous ICA. A 23-year-old man was admitted with a semicomatose consciousness after a passenger traffic accident. A fracture on the right petrous apex and a pseudoaneurysm in the right petrous ICA was found in the brain computed tomography (CT) angiogram. The size of aneurysm grew in the catheter angiogram at the 3rd day of trauma. One-day protocol of brain single photon emission CT (SPECT), which the first scan with 20 mCi of technetium-99m-ethyl cysteinate diethylester ((99m)Tc-ECD) and the second scan with 40 mCi in double dose at 15 minutes during the balloon test occlusion (BTO) at the same day, was done for the perfusion evaluation before trapping the right ICA. Perfusion asymmetry was aggravated of 21% at the post-occlusion scan in the right frontal cortex. So, he got a superficial temporal artery-middle cerebral artery anastomosis and then ICA trapping. After the surgery, he recovered consciousness and went back to his normal life. He has not developed new neurologic symptom for 8 years. Brain SPECT with double-dose injection of (99m)Tc-ECD may be a useful tool to be performed with BTO.