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The occipital-vertebral anastomosis revisited.

BACKGROUND
The goal of the study was to provide relevant data about the location and prevalence of the OA-VA anastomosis in patients without visible occlusive disease, as well as to thoroughly discuss the clinical significance of these anastomotic channels. Furthermore, the morphometric properties of the OA and its branches were also analyzed.


MATERIALS AND METHODS
A retrospective study was carried out to indicate anatomical variations, their prevalence, and morphometrical data on the OA and its branches. The study was performed on 55 randomly selected computed tomography angiographies (CTA) of the head and neck region. Each CTA result was analyzed bilaterally. Thus, 110 results were originally assessed.


RESULTS
The OA median maximal diameter was demonstrated at 4.85 mm (LQ: 4.11; UQ: 5.53) and the median maximal diameter of VA at 3.60 mm (LQ: 2.79; UQ: 4.38). The distances between OA and its branches were also measured giving a median result of 21.73, 30.29, 60.84, 34.88, 18.02, 55.16 mm for the LSCMB, USCMB, MeB, MaB, and DB respectively. The median distance between OA and its first anastomosis was set to be 51.15 mm (LQ: 37.20; UQ: 60.10). Moreover, a set of additional measurements was carried out in order to create a 3-dimensional anatomical heat-map of the occurrence of the OA-VA anastomosis.


CONCLUSIONS
Knowledge about the anatomy of the OA-VA anastomosis might be of immense importance to avoid potentially fatal complications during embolization of the OA and its branches.