Keywords : Transverse- sigmoid junction
MORPHOMETRIC STUDY OF ASTERION AND ITS RELATION TO TRANSVERSE SIGMOID JUNCTION FOR POSTEROLATERAL CRANIAL SURGERIES
European Journal of Molecular & Clinical Medicine,
2022, Volume 9, Issue 7, Pages 1994-1999
Asterion is the craniometric point at the junction of the lambdoid suture, occipitomastoid suture and the parietomastoid suture, it is closely related to the junction of transverse and sigmoid sinus.
Aim of the present study was to identify the safe zone in relation to asterion for initial burr hole placed before craniotomy in posterolateral cranial surgeries in order to prevent larger craniotomies and sinus injuries. As the position of asterion displays population specific variability its anatomic location was studied in adult human dry skulls of Telangana region.
Material and methods: 100 Sides of 50 human adult dry skulls of unknown sex and age from bone banks of medical colleges of Telangana region were studied. Measurements of the asterion from tip of the mastoid, root of zygoma and external occipital protuberance on both right and left sides were taken using digital vernier calipers. Surface projection of transverse sigmoid junction in relation to asterion was noted using transillumination.
Result: The mean distance between the tip of mastoid process and asterion was 49.87±2.09 mm on right side and 51.02 ± 2.01 mm on left side and P value was found to be significant. The mean distance from root of zygoma to asterion was 55.8 ± 1.91 mm on right side and 56.5 ± 1.89 mm on left side. The mean distance between external occipital protuberance and asterion was 62.4 ± 2.23 mm on right side and 62.9 ± 2.02 mm on left side. In majority of skulls (84%) transverse sigmoid junction was at the asterion, in 14% the transverse sigmoid junction was above the asterion and in 2% cases it was below the asterion.
Conclusion: Knowledge of the anatomical position of asterion using palpable bony landmarks, and its relation to the underlying venous sinuses plays an important role in performing safer posterolateral cranial surgeries