Sphenopalatine Artery Pseudoaneurysm as a Rare Complication of Le Fort III Advancement in Apert Syndrome.

This report describes an especially rare postoperative pseudoaneurysm of the sphenopalatine artery following midface advancement using Le Fort III in an Apert syndrome patient. The Apert patient referenced in this report was a 13-year-old boy with severe midface hypoplasia, significant obstructive sleep apnea, and Angle Class III malocclusion. The patient underwent a low Le Fort III osteotomy, subsequently followed by gradual anterior distraction with an external halo distractor. One month postoperatively, the patient experienced recurrent, massive blood loss due to unilateral epistaxis. In order to immediately address life-threatening hemorrhaging and maintain advanced segment stability, the external distractors were removed, and a custom protraction face mask was applied for retention. A computerized tomography angiography showed a 4×3 mm saccular pseudoaneurysm from a branch of the left sphenopalatine artery in the pterygopalatine fossa near the posterior maxillary sinus wall. Careful microcatheterization and embolization achieved complete occlusion with preservation of adjacent collateral flow, resulting in immediate and sustained cessation of epistaxis, hemoglobin stabilization, and recovery without further complication. After 12 weeks of protraction face mask retention, achieved midface advancement remained stable; there was no recurrent bleeding over the next 6 months, and the patient's occlusion was classified as Angle Class II. This case underscores that recurrent severe postoperative epistaxis occurring after Le Fort III distraction requires immediate computerized tomography angiography to detect pseudoaneurysm and supports endovascular embolization as a safe, minimally invasive, highly effective first-line therapy within a multidisciplinary care model.