Morphological Variation of Subarcuate Artery and Canal in Atresia.

OBJECTIVES: An aberrant subarcuate artery (SAA) and its related canal are infrequent and asymptomatic. The presence of this variation may cause untoward hemorrhages, if accidentally nicked. Therefore, it is important for otologists to be aware of this entity, and its relative anatomy, to avoid any unexpected complication. We present a case of a 7-year-old girl who presented with right-sided microtia with membranous atresia.

METHODS: High-resolution computed tomographic scan and three-dimensional reconstruction of the temporal bone showed bilateral enlarged SAA.

RESULTS: The width of the right-sided bone canal was between 0.76 and 1.33 mm. The left temporal bone showed the same variation, with the width of the canal consistently greater than 1.0 mm, ranging from 1.07 to 1.23 mm in greatest transverse dimension.

CONCLUSIONS: The variation proposed in microtia was not previously reported in the literature, which may have important implications for the canal reconstruction.