89 - Unilateral Variation of the Left Ascending Pharyngeal Artery

Poster Board Number: 89
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Co-authors:

Madison Guell - New York Institute of Technology College of Osteopathic Medicine; Lokesh Coomar - Saint Louis University School of Medicine; Meadow Campbell - Saint Louis University School of Medicine

Abstract Body : Introduction:




The ascending pharyngeal artery (APA) is the smallest branch of the external carotid artery (ECA). Despite its size, it provides blood supply to vital structures within the head and neck. Knowledge of APA variations are essential for clinical procedures, surgeries, and diagnostic interpretations, as well as in medical education and research. Therefore, our main objective is to report a novel case of unilateral APA variation.









Methods:




A 77-year-old male donor was received through the Saint Louis University Gift of Body Program of the Center for Anatomical Science and Education (CASE) with signed informed consent from the donor. The CASE gift body program abides by all the rules set forth by the Uniform Anatomical Gift Act. During routine dissection, the bisected head of the donor was disarticulated from the first cervical vertebrae and reflected anteriorly to separate the neck viscera from the prevertebral region of the neck. The carotid sheaths were cleared bilaterally to examine their contents.









Results:




The anticipated carotid branching pattern was observed on the right side. The right common carotid artery (CCA) bifurcated into an ECA and internal carotid artery (ICA) at the level between the third and fourth cervical vertebrae. Both the right ECA and ICA presented normal branching patterns extracranially. The left side demonstrated atypical vascular branching. The left CCA bifurcated into the ECA and ICA at roughly the same level as its right counterpart. An additional artery arose from the CCA between the ECA and ICA with no observable branching on it. We concluded that it was most likely the left APA due to its antero-superior course towards the sphenopalatine region and that the left APA was absent from the left ECA. Additional branching was observed arising from the left ICA. A common trunk emerged from the posterior surface of the left ICA, approximately 27 mm above the left CCA bifurcation. This common trunk then divided into two branches: accessory artery A (AA) and accessory artery B (AB). Accessory artery A terminated as multiple muscular branches for the salpingopharyngeus muscle, while AB continued as a single branch, terminating within the jugular foramen.









Conclusion:




The current case presents a unique set of arterial variations within the anterior cervical region consisting of two APAs with different origins unilaterally, a pattern not previously described in the literature.









Significance:




Documentation of unique APA variations such as this is critical due to APA’s extensive intracranial and extracranial anastomoses which can have implications in oncology, surgery, and many more.









Funding Sources:




This study was supported by the Center for Anatomical Science and Education, Saint Louis University School of Medicine, St. Louis, MO, United States.