Superficial temporal artery–superior cerebellar artery bypass and trapping of a fusiform aneurysm using intradural anterior petrosectomy: technical case report and anatomical study

Abstract

<jats:p>Aneurysms at the distal portion of the superior cerebellar artery (SCA) are very rare. Because of the deep location and a propensity for nonsaccular morphology, aneurysm trapping or endovascular occlusion of the parent artery are the usual treatment options, which are associated with varying risks of ischemic complications. The authors report on a 60-year-old woman who had a 3.5-mm unruptured aneurysm in the lateral pontomesencephalic segment of the SCA with a significant interval growth to 8 mm. Direct surgical intervention comprising trapping of the aneurysm through a subtemporal approach and intradural anterior petrosectomy combined with revascularization of the distal SCA using the superficial temporal artery (STA) was performed. This approach provided sufficient space for the bypass instruments to be introduced into the deep surgical field at a more favorable angle to enhance microscopic visualization of the anastomosis with minimal retraction of the temporal lobe. The patient was discharged with no neurological deficit. Preservation of the blood flow in the distal SCA should be attempted to minimize the risk of ischemic injury, particularly when the aneurysms arise in the anterior or lateral segment of the SCA. The authors demonstrate the safety and effectiveness of the intradural anterior petrosectomy for STA-SCA bypass along with a relevant anatomical study.</jats:p>

Advantages of petrosectomy for superficial temporal artery to superior cerebellar artery bypass based on three-dimensional distance measurements using cadaver heads

“…Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is known to be effective for revascularization in steno-occlusive disease of the posterior circulation [ 2 , 3 , 5 , 8 , 10 , 11 , 16 , 22 , 27 ]. This procedure is also required when an aneurysm in the posterior circulation is treated using a flow alteration technique that requires trapping [ 13 , 14 , 18 , 23 ]. However, cases that actually require STA-SCA bypass are rare, at 3.6% of all total bypass surgery cases [ 29 ].…”

“…On the other hand, this approach has the disadvantages that it provides a deep and narrow operative field that makes the bypass difficult to perform and can cause serious intraoperative complications due to cerebral retraction [ 9 , 10 ]. A few case reports have described the anterior transpetrosal approach (ApA) [ 8 , 12 , 23 ] or the combined petrosal approach (CpA) [ 7 , 16 ] as helpful in expanding the operative field for STA–SCA bypass. These approaches require anatomical knowledge of the skull base.…”