Assessment of Variations in Sphenoid Sinus Pneumatization in South Indian Population

Abstract

Introduction Morphometric study of sphenoid sinus shows various degrees of pneumatization. Knowledge of such variability is extremely important to guide the surgeon in predicting what type of surgical approach will be safer for the pathologies involving skull base region. Considering recent advances in trans-nasal trans-sphenoidal endoscopic interventions and improved visualization, it has become imperative to become familiar with the anatomical variations which are likely to be encountered during surgical procedures. Materials and Methods A retrospective study was conducted on the basis of CT scan records of 120 patients to evaluate variability in pneumatization of sphenoid bone and its extensions in South Indian population. Results The study revealed the prevalence of conchal, pre-sellar, incomplete sellar and complete sellar types of sphenoid pneumatization in 02%, 08%, 28% and 62% cases respectively. Posterior or clival extension was the commonest type seen in 80% cases which included sub-dorsal (50%), dorsal(15%) and occipital(15%) types of clival variants. In lateral extensions, pterygoid sub-type was observed in 37% of patients whereas lesser wing, greater wing and full lateral sub-types were present in 20%, 14% and 09% cases respectively. Various combinations of lateral sub-types were seen in 15% of study population. Conclusion In our study higher percentage of pneumatization of sphenoid sinus and its extensions was observed when compared to Egyptian and Chinese populations. High prevalence in South Indian population also provides an additional armament in the hands of surgeon to reach the otherwise unreachable lesions involving middle and posterior cranial fossae through trans-sphenoidal approach.