Posterior Condylar and Mastoid Emissary Canals, Radiologic Evaluation of Morphological and Morphometric Characteristics

Abstract

INTRODUCTION: Emissary veins pass through the skull holes and connect the dural venous sinuses and extracranial venous system. Preoperatively, it is crucial to identify the posterior fossa emissary veins because these veins may cause complications during surgery. In this study, we investigated rate of insidance mastoid emissary and posterior condylar channels and whether there is a statistical correlation between these canal diameters. METHODS: In our study, the temporal CT scan of 100 patients in our hospital PACS archive was evaluated retrospectively. Presence of mastoid emissary canal and accessory mastoid emissary canal were examined. Widths of mastoid foramen and mastoid canal were evaluated, and presence of posterior condylar canal and its width were evaluated. RESULTS: Right mastoid canal was absent in 16 individuals, while left mastoid canal was absent in 13, right posterior condylar canal in 19 and left condylar canal in 17. The mean diameter of mastoid canal was 1.3+-0.8 mm on the right side and 1.3+-07 mm on the left side, the mean posterior condylar canal diameter was 3+-1.5 mm on the right side and 2.9+-1.3 mm on the left side. Mastoid accessory canal was present in 24 patients on the right and 25 on the left. There was no significant correlation between the diameter of the mastoid canal and the diameter of the posterior condylar canal in cases with and without accessory mastoid canal. DISCUSSION AND CONCLUSION: It is important to understand anatomy and cranial venous drainage physiology to avoid surgical complications. Temporal computed tomography is very successful in detecting and visualizing these channels.

Keywords

• computed tomography
• emissary vein
• mastoid emissary canal
• posterior condylar canal
• posterior condylar vein.