Coexistence of a retroesophageal right subclavian artery with a left maxillary artery medial to the mandibular nerve.

This case report describes the coexistence of a retroesophageal right subclavian artery and left maxillary artery which passed deep to the mandibular nerve. An 88-year-old woman died of acute heart failure, and the postmortem revealed that the right subclavian artery originated from the aortic arch as the last branch at the level of the fourth thoracic vertebra, then passed between the esophagus and the vertebral column. The artery then ascended right superiorly and passed behind the anterior scalene muscle. The right vertebral artery arose from the retroesophageal right subclavian artery and entered the transverse foramen of the sixth cervical vertebra. The left maxillary artery branched at the common trunk of the posterior deep temporal and the inferior alveolar arteries. The maxillary artery then turned anteromedially and branched to give the middle meningeal artery. The mandibular nerve gave off the buccal nerve, deep temporal nerve and a thick nerve just below the foramen ovale. The auriculotemporal nerve that branched from the thick nerve ran deep to the maxillary artery. The maxillary artery turned anteriorly, passing deep to the branches. The artery then split to give the buccal artery and the anterior deep temporal artery. In the pterygopalatine section, the maxillary artery branched off to form the common trunk of the infraorbital and sphenopalatine arteries and the posterior superior alveolar artery. It may be necessary to pay attention to the course of the maxillary artery and its relationship to the mandibular nerve branches, when a retroesophageal right subclavian artery is seen.