Topographic and morphometric anatomy of the superficial temporal artery for STA-MCA bypass in Vietnamese adults.

PURPOSE: The superficial temporal artery (STA) is the principal donor vessel for extracranial-intracranial bypass, particularly the STA-middle cerebral artery (MCA) bypass. The present study aimed to characterise the topographic and morphometric anatomy of the STA common trunk and terminal branches, to establish surface mapping data for pre-operative planning, and to evaluate the suitability of terminal branches as bypass conduits in Vietnamese adults. METHODS: Fifty hemi-head specimens from 25 embalmed Vietnamese adult cadavers were dissected. Topographic relationships between the STA, adjacent neurovascular structures (superficial temporal vein [STV] and auriculotemporal nerve [ATN]), and craniofacial landmarks were documented. Terminal branching patterns, outer diameters at defined levels, branch lengths to the 1-mm diameter threshold, branch angulations, and the parietal axis angle were measured. RESULTS: All STAs arose posterior to the mandibular neck. Terminal bifurcation was present in 90% of specimens; the remaining 10% exhibited an anaplastic pattern. Among bifurcating specimens, the branching point was located above, at, and below the zygomatic arch (ZA) in 93.33%, 4.44%, and 2.22%, respectively. The common trunk lay 10.92 ± 4.14 mm anterior to the tragus along the lateral canthus-tragus line and 12.85 ± 6.26 mm anterior to the superior helix attachment. Mean outer diameters at the ZA level and immediately before bifurcation were 1.88 ± 0.40 mm and 1.76 ± 0.36 mm, respectively. At 70 mm from the ZA (working length), mean diameters of the frontal and parietal branches were 1.26 ± 0.25 mm and 1.11 ± 0.22 mm. Bypass suitability rates were 88% for the frontal branch, 68% for the parietal branch, and 62% when both branches were required. CONCLUSION: The STA anatomy in Vietnamese adults is highly compatible with its use in STA-MCA bypass surgery. The topographic and morphometric data presented provide a practical basis for pre-operative surface mapping and intra-operative vessel preservation.