The Dorsal Sagittal Venous Sinus Anatomical Variations in Brachycephalic, Dolichocephalic, and Mesocephalic Dogs and Their Significance for Brain Surgery

Abstract

Dorsal sagittal venous sinus (DSVS) is an encephalic structure located in the midline of brain dorsal surface, starting behind the frontal venous sinus and following the brain falx in its extension. Knowing DSVS morphology and cranial-cerebral relationships it is very important for surgeon when he is planning the placement of craniotomies, in order to prevent the damage of this structure. The main purpose of this study were to establish craniometric points that can be used as key points of neurosurgical importance providing an anatomic framework to brain access regarding the localization of DSVS, and to characterize the morphology of DSVS in the three groups considered in study according their type of skull (brachycephalic-B, dolychocephalic-D and mesocephalic-M). The study was performed on 138 formalin-fixed cerebral hemispheres of 69 adult dog cadavers (23 of each group) which had been removed from the skulls after the introduction of plastic catheters through properly positioned burr holes placed on the five craniometric points considered: asterion(ast), bregma(br), glabella(g), stephanion(st) and pterion(pt). From the three groups, DSVS length and width were different, his geometry in B assumed a triangular appearance and in D, M a ''butterfly'' shape. From all craniometric points considered, only bregma (br) can be useful as a landmark to delimitate DSVS morphology in all three groups. Asterion in M, stephanion in B, glabella and pterion in all three groups, can not be used to compose a framework that help to understand skull surface projection of DSVS morphology, since their measurements were not uniform.

Longitudinal Cerebral Fissure Anatomy Variations in Brachy‐, Dolicho‐ and Mesaticephalic Dogs and Their Importance to Brain Surgery

“…Dorsal to the LCF is the dorsal sagittal venous sinus (DSVS). Carreira et al () reported that, in the D and in M groups, the DSVS presents dilated anterior and posterior regions and a narrow middle region, similar to the LCF morphology. However, in the B group, the DSVS assumes a triangular morphology with a posterior base (Fig.…”

“…Thus, in the B and M groups we should consider the vault anterior area, and in the D group the vault posterior area, respectively. human medicine, there are only a few references to their location and use in veterinary medicine (Onar et al, 2001;De Machado et al, 2007;Schmidt et al, 2011;Carreira et al, 2011;Onar et al, 2012). The five craniometric points selected were quite useful to understand LCF anatomical morphology, its projection over the external skull surface, and to establish cranioencephalic relationships between the LCF and the vault.…”

“…The AR was the most uniform area, and the MR showed more differences between the groups. Dorsal to the LCF runs the dorsal sagittal venous sinus (DSVS), which, according to Carreira et al (2011), presents similar architecture to LCF morphology in the D and M groups. However, in B, the DSVS assumes a triangular morphology instead of dilated anterior and posterior regions and a narrow middle.…”

“…The experimental group was the same utilized for the paper previously published by Carreira et al () in the Anatomical Record (294:1920−1929) that studied 69 adult cadavers dogs ( Canis familliaris ) without any skull and brain injuries; 23 specimens per group were analyzed (i.e., brachy‐B, dolico‐D, and mesaticephalic‐M). The study has been performed after owner consent was obtained and authorized by the Institution's Ethical Committee for Analysis of Research Projects – CEBEA.…”

Sulci of the canine brain: a review of terminology

“…Earlier studies determined that the anatomy of the canine brain varies between breed types [47,48], as for example, in brachycephalic dogs, the rostral cranial fossa is shorter than in dolichocephalic dogs and the ethmoidal fossa is less deep, thus the position of the frontal lobe and the olfactory bulbs in brachycephalic breeds may differ from breeds with other skull types [49]. There is also a difference between the frequency of occurrence of the known shape variations among the sulci [50].…”