[Attempt of intracranial IC bypass for giant aneurysm in the cavernous portion of the carotid artery].

We report here, a novel method for internal carotid (IC) bypass between C2 and C5, by using the autologous saphenous vein. The patient was a 58 year-old female, complaining of pain and motor disturbance in her right ocular region. She suddenly developed left-sided hemiparesis during her stay in our hospital. The following CT examination demonstrated a high density homogenous round mass, which occupied the right side of the parasellar region with no perifocal edema. The contrast enhancement CT, however, suggested there was still a certain degree of blood flow in the mass. On the other hand, carotid angiography showed an occlusion of blood flow at the C5 level (interosseous portion), which seemed to indicate either giant aneurysm or cavernous angioma. The mass was identified as a giant aneurysm during surgery, and the decompression procedure by removing the intra-aneurysmal blood clot was attempted first. However, this trial failed due to an accidental severe bleeding. Because of this, we then decided to perform the grafting of autologous saphenous for a length of 10 cm between C2 and C5. Intraoperative heavy bleeding mentioned above seemed to have occurred due to release of compression by the aneurysm against the internal carotid artery through which there was restricted blood flow. Postoperative angiography demonstrated that the graft remained patent enough to be approximately equal in size to the original artery. From our experiences in this case, two important points are, we suggest, to be kept in mind while applying this method; (1) to carefully expose the C5 segment, (2) to avoid damage of the surrounding structures such as the Eustachian tube, facial nerve and cochlear nerves, and so forth. In conclusion, we strongly recommend this IC bypass technique for other types of tumors in the cavernous portion as well.