Superficial Temporal Artery-Sparing Mini-Pterional Approach for Cerebral Aneurysm Surgery

Abstract

Objective: The purposes of this study were to introduce a superficial temporal artery (STA)-sparing mini-pterional approach for the treatment of cerebral aneurysms and review the surgical results of this approach.

Methods: Between June 2010 and December 2015, we performed the STA-sparing mini-pterional approach for 117 patients with 141 unruptured intracranial aneurysms. We analyzed demographic, radiologic, and clinical variables including age, sex, craniotomy size, aneurysm location, height of STA bifurcation, and postoperative complications.

Results: The mean age of patients was 58.4 years. The height of STA bifurcation from the superior border of the zygomatic arch was 20.5 mm±10.0 (standard deviation [SD]). The craniotomy size was 1051.6 mm²±206.5 (SD). Aneurysm neck clipping was possible in all cases. Intradural anterior clinoidectomy was performed in four cases. Contralateral approaches to aneurysms were adopted for four cases. Surgery-related complications occurred in two cases. Permanent morbidity occurred in one case.

Conclusion: Our STA-sparing mini-pterional approach for surgical treatment of cerebral aneurysms is easy to learn and has the advantages of small incision, STA sparing, and a relatively wide surgical field. It may be a good alternative to the conventional pterional approach for treating cerebral aneurysms.

Keywords: Cerebral aneurysm; Clipping; Pterion; Surgery.

Fig. 1

Schematic drawing of the surgical technique. A: A skin incision is made from the STA bifurcation ~2–3 cm above the zygomatic arch curvilinearly to the medial hairline (black dotted line). The green line indicates the squamous suture. Red halos indicate burr hole sites. The area surrounded by a yellow dotted line is the craniotomy site. B: After craniotomy, sylvian veins are identified on the temporal base of the field. STA: superficial temporal artery.

Fig. 2

Case illustration 1. A: White arrows and white and gray arrowheads indicate three aneurysms that were located in the left middle cerebral artery bifurcation and the dorsal and ventral walls of the paraclinoid ICA, respectively, on a 3D cerebral angiography image. B: The white arrow indicates the bifurcation of the STA frontal and parietal branches. C: A skin incision was made from the STA bifurcation (~3 cm above the zygomatic arch) to the medial hairline curvilinearly. D: The anterior and superior part of the temporal muscle was cut. E: Reflection of the temporal muscle using fishhook and suture ties. F: Mini craniotomy (3×5 cm) was performed using a craniotome. G: The frontal lobe and sylvian fissure as seen under a microscope after dural opening. H: The internal carotid artery dorsal wall aneurysm was clipped after falciform ligament cutting. I: Multiple clips were seen along the sylvian fissure after clipping. J: The mini craniotomy (3×5 cm) extended to the temporal side (the red arrow indicates temporally extended craniotomy). K: Postoperative CT scan showing clips of three aneurysms. ICA: internal carotid artery, STA: superficial temporal artery, CT: computed tomography, FL: frontal lobe, ON: optic nerve, SV: sylvian vein.

Fig. 3

Case Illustration 2. A and B: 3D image of cerebral angiography showing three aneurysms located in the right middle cerebral artery bifurcation, the right internal carotid artery bifurcation, and the left anterior choroidal artery. C: The black arrow indicates the bifurcation of the STA frontal and parietal branches. D: The skin incision was made curvilinearly from the STA bifurcation ~3 cm above zygomatic arch to the medial hairline. E: The anterior and superior part of the temporal muscle was cut. F: A mini craniotomy (3×5 cm) that extended to the frontal side was made (the red arrow indicates frontally extended craniotomy). G: Microscopic view of the frontal lobe and sylvian fissure after dural opening. H: Microscopic contralateral view showing the clip at the left anterior choroidal artery. I: Microscopic view of the internal cerebral and middle cerebral artery aneurysms after arachnoid dissection. J: The lateral end of incision, ~2 cm above the auricle. K: Postoperative CT scan showing clips of three aneurysms. STA: superficial temporal artery, CT: computed tomography, cICA: contralateral internal cerebral artery, cON: contralateral optic nerve, FL: frontal lobe, iICA: ipsilateral internal cerebral artery, iON: ipsilateral optic nerve, M: middle cerebral artery, PCom: posterior communicating artery, SV: sylvian vein.