A Case of Endovascular Treatment for Followed by Side to Side Bypass for Vertebral Artery Dissecting Aneurysms Involved Posterior Inferior Cerebellar Artery
A 45-year-old woman was admitted to our hospital with a chief complaint headache and dizziness. On initial neurologic examinations, the patient had no neurologic signs. A 3-dimensional computed tomography angiography scan on admission showed left vertebral artery stenosis. On day 5, the patient underwent magnetic resonance angiography at a follow-up, showing no interval change of left vertebral artery stenosis (). On day 10, the patient underwent transfemoral cerebral angiography (TFCA) showing complex vertebral dissecting aneurysm of long segment arising from the PICA (). These findings were suggestive of a sign of impending rupture of left vertebral artery dissecting aneurysm because a short-term follow-up radiography revealed a change in the vessel contour. In this patient, we decided on the segmental occlusion using a coil with stent insertion of contralateral vertebral artery after PICA-to-PICA bypass surgery because of the proximity and parallel course of the distal segments of the PICA (). Because simple stenting method had still risk for rupture of aneurysm after intervention and parent artery occlusion had risk for ipsilateral PICA territory infarction, we decided that.\nAfter a midline suboccipital craniotomy, the cisterna magna was opened. After temporary clipping of proximal and distal PICA and perforating artery, a curved incision rather than a straight one along the PICA was done. To do this, the distal end of both PICA was stay-sutured. This was followed by the continuous suture from outside to inside of inner side of the vessel. Then, the final suture was done from inside to outside of the vessel. Following this, the proximal end was also stay-sutured on the external side and then tied with the final inner suture. Moreover, the continuous suture of outer side from outside to inside of the vessel was done in the same manner. After removal of temporary clips, a good patency was also seen on intraoperative indocyanine green angiography ().\nOn postoperative TFCA, a PICA to PICA anastomosis achieved a good patency of both PICA from the right vertebral artery (VA) (). Then, we performed left VA balloon occlusion test and the both PICA territories showed well. Then, the patient underwent segmental occlusion using a coil with stent insertion of contralateral vertebral artery. The patient finally, achieved a total occlusion of the dissecting aneurysms and a good patency of both PICA territories (). At a 2-year follow-up, the patient underwent uneventful course.