Major Vessels of the Interclavicular Suprasternal Space: A Suprasternal Notch-Referenced Topographic Classification with Potential Procedural Relevance

Background/Objectives: The suprasternal notch (SN) is the conventional landmark for front-of-neck airway access and anterior cervical surgery, yet the great vessels may extend to or above it. To our knowledge, no previous study has jointly classified the aortic arch (AA), brachiocephalic trunk (BCT), left brachiocephalic vein (LBCV), and sternoclavicular joint (SCJ) configuration relative to the SN in a single adult cohort. Methods: In this single-centre retrospective study, 100 consecutive adult computed tomography angiography (CTA) studies were reviewed. Using a horizontal SN reference plane, the AA, BCT, and LBCV were each graded as mediastinal, cervicomediastinal, or cervical/high-riding; the bilateral SCJ manubrial joining grade was scored on four levels and integrated into three categories (mild, clear, marked). Two observers independently classified all cases (weighted Cohen kappa = 0.89). Associations were assessed with Spearman correlation and chi-square tests. Results: The BCT was the most variable structure, cervical/high-riding in 49% and reaching or crossing the SN in 64%; the AA and LBCV were cervical/high-riding in 3% and 5%, respectively. Complete SCJ manubrial joining was absent in all cases, and the integrated SN space was marked in 15% of cases. Cervical/high-riding BCT was more frequent in women (63.5% vs. 33.3%; p = 0.005). Five of six pairwise correlations remained significant after Benjamini–Hochberg adjustment, with the strongest association for AA–BCT (rho = 0.406). Conclusions: The BCT was the principal great vessel extending to or above the SN in this cohort, whereas cervical/high-riding AA and LBCV were uncommon. The SN-referenced classification provides a reproducible descriptive framework for this topography. These findings represent cohort frequencies rather than population-based prevalence estimates, and their potential procedural relevance requires prospective validation.