The Localization of the Asterion According to the Anatomical Landmarks of Posterior Cranial Fossa in Newborns: Clinical Implications

Abstract

SUMMARY:The purpose of this study was to determine the localization of the asterion according to the anatomical landmarks of posterior cranial fossa and its relation with sinuses for posterolateral surgical approaches in newborns. On 70 head-halves, a needle about 2 mm with diameter was placed on the centre point of asterion (posterolateral fontanel) by inserting into the whole cranial bony tissue by forming an right angle with the bony surface. Various localizations of asterion and its measurements from the internal and external anatomical landmarks were investigated on term neonatal cadavers. The localization of asterion was found as on the sigmoidtransverse sinus junction (STJ) (5., 6., 7., 8. squares) in 40% of cases on right side and in 34%, on left side. Additionally, it was located below the STJ (9., 10., 11., 12. squares) in 60% of cases, on right side and in 63% of cases on left side. We determined that the most frequent localization of asterion as the 11. square both for the right and left sides 12 (34%) cases for the right side and 11 (31,4%) cases for the left side. The asterion was not located on 1., 2., 3., 4., 5. and 12. squares on right side and 1., 3., 4., 8. and 9. squares on left side. It has been found that the region of asterion has an average distance value of 19.9 mm to internal acoustic meatus (MI), 31.7 mm to posterior clinoid process (PC), 34.4 to dorsum sellae (DS), 19.2 mm to jugular foramen (FJ), 23.0 mm to hypoglossal canal (HC), internally. The distance of asterion as 28.8 mm to zygoma root (ZR) and 22.3 mm to Henle's spine (HS) and 15.8 mm to mastoid tip (MT) and 35.9 mm to external occipital protuberance (PE) were observed. By the guide of point asterion on newborns the area of 1cm2 on this point which was placed on superior 4 squares of our scale diagram is suggested as a safe area of placement of first burr hole to avoid from the risk of bleeding of sigmoid and transverse sinuses on craniotomies of posterior fossa.

Evaluation of the inion and asterion as neurosurgical landmarks for dural venous sinuses: osteological study on a sample of South African skull specimens

“…7,16 Therefore, the right asterion is more likely to be either directly, or superiorly related to the right transverse-sigmoid sinus junction, in comparison to the left side (Table III). Similar results were reported by Demir and et al (2015), mentioning that their sample consisted of neonatal cadavers aged between 38-40 gestational weeks. 19 This study confirms that variations in the relation of the inion to the confluence of sinuses, as well as the relation of the asterion to the transverse-sigmoid sinus junction, do exist, especially when compared with other studies, as previously reported.…”

“…Similar results were reported by Demir and et al (2015), mentioning that their sample consisted of neonatal cadavers aged between 38-40 gestational weeks. 19 This study confirms that variations in the relation of the inion to the confluence of sinuses, as well as the relation of the asterion to the transverse-sigmoid sinus junction, do exist, especially when compared with other studies, as previously reported. Variations found in the location of the asterion might be ascribed to population-specific locations or sexual dimorphism.…”

“…Examples of such procedures include the surgical treatment of cerebrovascular diseases, 16 midline suboccipital craniotomy 17 and retrosigmoid craniotomy. 18,19 Certain superficial landmarks have been established to assist the neurosurgeon in placing the initial burr hole to limit injury to the venous sinuses, 4,20 particularly in key-hole methods during microvascular decompression 5 and surgical approaches to the posterior cranial fossa. 15 Landmarks include the inion, asterion, superior nuchal line, sutures of the skull and the apex of the mastoid process.…”

Anatomic Study of Localization of Foramen Ovale, Carotid Canal, Jugular Foramen Using Henle’s Spine as Surface Landmark in South Indian Adult Skulls

“…It represents one of the latest surgical frontiers and poses surgical challenges for the otolaryngologists and the neurosurgeons. (1,2) Otologic and neurotologic skull base surgery requires a thorough knowledge of the temporal bone anatomy, as the temporal bone is one of the great gateways of the skull. (3) Its petrous portion gives the passage for the internal carotid artery, vestibulocochlear nerve and facial nerve.…”

“…(3) Its petrous portion gives the passage for the internal carotid artery, vestibulocochlear nerve and facial nerve. (4) Therefore, in order to identify and safely approach the vital structures in the skull base during surgeries, many accessible anatomical surface landmarks like the mastoid tip, the digastric muscle, the spine of Henle, the cribriform area, the temporal line, the external auditory canal and the root of the zygomae (2) are used to relate and access the underlying anatomical structures. The Henle's Spine (HS)/spina suprameatica/spina suprameatalis/meatal spine or spina meatus, is a small bony prominence anterior to the supramastoid pit at the posterosuperior margin of the bony external acoustic meatus ( Figure 1).…”