Surgical removal using V3-radial artery graft-V4 bypass and occipital artery-posterior inferior cerebellar artery bypass for a giant thrombosed aneurysm of vertebral artery compressing brain stem: Case report

Abstract

Background:Giant thrombosed vertebral artery aneurysms (GTVAs) are difficult disease to treat. Here, we are reporting a case of GTVA successfully treated with excluding the pathological segment and restoring the anterograde blood flow of the parent artery, highlighting the reliable surgical procedure.Case Description:A 55-year-old man with a left GTVA complained of right hemiparesis (manual muscle testing 4/5) represented by hand clumsiness and gait disturbance, in addition to severe left-sided dysesthesia, was referred to our hospital. The posterior inferior cerebellar artery (PICA) was incorporated into the GTVA segment, and the contralateral vertebral artery showed atherosclerotic change. Thus, we decided to treat the aneurysm with aneurysm trapping and thrombectomy, in conjunction with V3-radial artery graft (RAG)-V4 bypass and occipital artery (OA)-PICA bypass through a suboccipital transcondylar approach. The distal end of the dilated segment was meandering and deflecting outwardly to the vicinity of the internal auditory canal and was stretched in an axial direction. Thus, the V4 stump can be transposed to the triangle space made by the medulla, lower cranial nerves, and sigmoid sinus, and we could perform a safe and reliable anastomosis through the corridor. After the surgery, the compression of the brain stem was released, and right hemiparesis was improved completely after rehabilitation. The patient was discharged with a modified Rankin Scale score of 1.Conclusion:Trapping of the aneurysm and thrombectomy are the most radical treatment for GTVA, and if possible, reconstruction of anterograde blood flow with V3-RAG-V4 bypass and OA-PICA bypass is desirable.

Microsurgical Treatment Strategy of Vertebral Artery Fusiform Aneurysm—From the Standpoint of Hemodynamic Integrity and Perforator Preservation

“…As we previously reported ( 39 ), the V3-RAG-V4 anastomosis procedure can be safely performed in shallow surgical fields if the distal V4 segment can be pulled down to the triangular space below the LCNs. In particular, in the case of giant VA aneurysms the distal V4 segment is often meandering and deflects outwardly to the vicinity of the internal auditory canal, while the distal V4 and branches of the VA are often stretched in an axial direction.…”

“…In particular, in the case of giant VA aneurysms the distal V4 segment is often meandering and deflects outwardly to the vicinity of the internal auditory canal, while the distal V4 and branches of the VA are often stretched in an axial direction. Thus, the V4 stump can be easily transposed to the triangle corridor beneath LCNs without perforator injury ( 37 , 39 , 60 , 61 ). If reconstructive clipping is impossible and a V3-RAG-V4 bypass is difficult, then VA occlusion alone is insufficient.…”

“…Prior to this procedure, we perform a layer-by-layer dissection of the suboccipital muscles, which allows us to systematically identify the occipital artery (OA), extracranial VA (V3 portion) in the suboccipital triangle, and the posterior condylar canal. These steps enable the OA-PICA bypass, proximal control by temporary clamping of the V3, and high-flow bypass using the V3 as a blood source (38)(39)(40). The actual procedural steps are shown in Supplementary Video 1.…”

Therapeutic dilemmas regarding giant aneurysms of the intracranial vertebral artery causing medulla oblongata compression

“…Giant aneurysms of the intracranial VA are rare intracranial lesions, and only 53 reported cases were identified in this review. 3–47 The intracranial segment of the VA runs along the anterolateral aspect of the medulla oblongata. Aneurysms originating from the intracranial segment of VA are rare and often dissecting aneurysms, 48 and most of them are stable and do not rupture.…”

“…Hence, surgical procedures aimed at removing the giant aneurysm have a high risk. 12,21 Previously, for treating giant VA aneurysms with aneurysm reserving, balloons or clips were usually used to occlude or reduce blood flow to the aneurysm. 22,23 In recent years, many EVT materials have been developed, making it possible to trap aneurysms both at the proximal and distal ends.…”