Persistent primitive hypoglossal artery: a classification-based approach to understanding and managing a rare vascular anomaly.

Abstract

Persistent primitive hypoglossal artery (PPHA) is a rare embryological variant of the cerebral circulation in which the posterior circulation is supplied through a persistent embryonic carotid-basilar anastomosis. While often discovered incidentally, PPHA may have important clinical consequences when associated with atherosclerotic disease, aneurysms, or other cerebrovascular abnormalities. To introduce a structured clinical classification system for PPHA that captures its anatomical spectrum, pathological associations, and symptomatic presentations, with the aim of improving diagnostic precision and procedural planning. A six-category framework was developed to stratify PPHA according to its clinical and radiological features. This classification emphasizes anatomical distinctiveness and pathological relevance to facilitate risk stratification and therapeutic decision-making. The proposed classification defines six categories: (1) isolated asymptomatic PPHA, (2) PPHA with stenosis, (3) aneurysmal PPHA, (4) PPHA with carotid artery stenosis, (5) PPHA with cranial nerve compression, and (6) PPHA associated with other vascular anomalies. Organizing PPHA into these categories provides a practical system for clinical assessment and intervention planning. This novel classification addresses the current absence of a standardized clinical framework for PPHA. Its adoption may enhance physician awareness, improve patient safety during cerebrovascular interventions, and aid multidisciplinary decision-making in complex neurovascular cases. Validation in clinical practice is warranted to establish its utility.