Proximal superficial temporal artery to proximal middle cerebral artery bypass using a radial artery graft: an anatomic approach

Clinical importance of the superficial temporal artery in neurovascular diseases: A PRISMA-compliant systematic review

The superficial temporal artery (STA) plays a very important role in neurovascular diseases and procedures. However, until now, no comprehensive review of the role of STA in neurovascular diseases from a neurosurgical perspective has ever been published. To review research on the clinical importance of STA in neurovascular diseases, a literature search was performed using the PubMed database. Articles were screened for suitability and data relevance. This paper was organized following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. According to the literature, STA is one of the terminal branches of the external carotid artery and can give off scalp, muscle, and transosseous branches. STA-middle cerebral artery (MCA) bypass is very useful for intracranial ischemic diseases, including moyamoya disease, chronic ICA and MCA insufficiency, and even acute ischemic stroke. For intracranial complex aneurysms, STA bypass remains a major option that can serve as flow replacement bypass during aneurysmal trapping or insurance bypass during temporary parent artery occlusion. Occasionally, the STA can also be involved in dural AVFs (DAVFs) via to its transosseous branches. In addition, the STA can be used as an intraoperative angiography path and the path to provide endovascular treatments. Therefore, STA is a very important artery in neurovascular diseases.

Surgical Technique for High-Flow Internal Maxillary Artery to Middle Cerebral Artery Bypass Using a Superficial Temporal Artery Interposition Graft

BACKGROUND: Extracranial-to-intracranial high-flow bypass often requires cranial, cervical, and graft site incisions. The internal maxillary artery (IMA) has been proposed as a donor to decrease invasiveness, but its length is insufficient for direct intracranial bypass. We report interposition of a superficial temporal artery (STA) graft for high-flow IMA to middle cerebral artery (MCA) bypass using a middle fossa approach.

OBJECTIVE: To assess the feasibility of an IMA–STA graft-MCA bypass using a new middle fossa approach.

METHODS: Twelve specimens were studied. A 7.5-cm STA graft was obtained starting 1.5 cm below the zygomatic arch. The calibers of STA were measured. After a pterional craniotomy, the IMA was isolated inside the infratemporal fossa through a craniectomy within the lateral triangle (lateral to the posterolateral triangle) in the middle fossa and transposed for proximal end-to-end anastomosis to the STA. The Sylvian fissure was split exposing the insular segment of the MCA, and an STA-M2 end-to-side anastomosis was completed. Finally, the length of graft vessel was measured.

RESULTS: Average diameters of the proximal and distal STA ends were 2.3 ± 0.2 and 2.0 ± 0.1 mm, respectively. At the anastomosis site, the diameter of the IMA was 2.4 ± 0.6 mm, and the MCA diameter was 2.3 ± 0.3 mm. The length of STA graft required was 56.0 ± 5.9 mm.

CONCLUSION: The STA can be used as an interposition graft for high-flow IMA–MCA bypass if the STA is obtained 1.5 cm below the zygomatic arch and the IMA is harvested through the proposed approach. This procedure may provide an efficient and less invasive alternative for high-flow EC–IC bypass.

Posterior auricular artery-middle cerebral artery bypass: a rare superficial temporal artery variant with well-developed posterior auricular artery-case report

The posterior auricular artery (PAA) is one of the branches of the external carotid artery, but is usually too small for use as a donor artery for middle cerebral artery (MCA) territory revascularization. An extremely unusual case of PAA-MCA anastomosis was performed in a patient requiring MCA territory revascularization because the superficial temporal artery (STA) parietal branch was absent and the PAA was large enough. A 65-year-old man developed mild motor weakness in the right extremities caused by multiple small infarctions. Single photon emission computed tomography (CT) revealed deterioration of the vascular reserve capacity in the left MCA area. Cerebral angiography showed severe stenosis in the C2 portion of the left internal carotid artery, absence of the parietal branch of the left STA, and a well-developed PAA extending to the parietal area. The patient underwent STA (frontal branch)-MCA and PAA-MCA double anastomosis, and has suffered no stroke or transient ischemic attack. The STA with no bifurcation is known as a rare variation. The PAA also occurs with size variations but well-developed PAA is thought to be extremely rare. PAA can be used as a donor artery for MCA territory revascularization if the vessel size is suitable. Preoperative evaluation of the anatomy is mandatory for harvesting the arteries.

Direct, High-flow Bypass for a Pediatric Giant, Fusiform Aneurysm of the Inferior Division of M2: Case Report and Review of Literature

In this case report, we describe the first reported case of treating a 7-year-old male patient who has a giant, fusiform aneurysm confined to the inferior M2 segment by means of a saphenous vein graft. Given the lack of good endovascular management options for this particular scenario, craniotomy was recommended and an end-to-side ECA-ICA anastomosis was carried out with technical details of the surgery outlined in the manuscript. The patient did not sustain any major postoperative complications. The graft remained patent upon completion of the surgery and at the time of last follow-up, 9 months post-surgery. This case serves as an illustrative example of the need for high-flow bypass for a select few patients even as endovascular technology continues to improve.

Anatomy of the superficial temporal artery and its branches: its importance for surgery

The temporoparietal, parieto-occipital flaps or the forehead flaps that are used in reconstructive surgery are prepared on the superficial temporal artery (STA) and its branches. For a successful surgery and a suitable flap design, adequate anatomical knowledge is needed. In our study, the red colored latex solution was injected into the external carotid artery; the STA and its branches were dissected in 27 specimens. The mean diameter of the STA at the zygomatic arch was determined as 2.73+/-0.51 mm. The diameters of the frontal branch were bigger than those of the parietal branch in 15 samples out of 27. The diameters of both the frontal and parietal branches were equal in four samples. The diameter of the parietal branch was bigger than that of the frontal branch in eight samples. In 20 samples out of 27 (74.07%), the bifurcation point of the STA was above the arch. In six samples (22.22%), the STA bifurcated directly over the arch. In only one sample (3.70%), bifurcation was not observed and the STA continued only as a frontal branch (absence of the parietal branch). The absence of the frontal branch was not encountered. In one sample (3.70%), double parietal branches were observed. In six samples out of 27 (22.22%), zygomatico-orbital artery was not encountered. In 21 samples (77.77%), zygomatico-orbital arteries ran towards the face, parallel to zygomatic arch and distributed in the orbicularis oculi muscle. The transverse facial artery existed in all samples. The auricular branches running to the helix and tragus were observed in all samples. The STA was 16.68+/-0.35 mm at the front of the tragus. Some landmarks were chosen on the head and then the STA was observed where it crossed all of these landmarks. This paper confirms the well-known variability of the superficial temporal arterial branches and their relation to the pericranial region. Knowledge concerning the arterial features of the lateral forehead region is important for the aesthetic surgeon. STA and its branches have been found to be suitable for use in microvascular anastomoses. A better understanding of the midline forehead vascularity should allow modification of reconstructive techniques and reduce postoperative complications.