Poster 182: AV Fistulas and False Aneurysms Following Orthognathic Surgery

Abstract

False aneurysms (FAs) and arterio-venous fistulas (AVFs) have been described in the literature following maxillofacial trauma, and after a wide range of head and neck procedures including orthognathic surgery. There have been several case reports and a few review articles describing the pathophysiology and anatomy of these vascular complications. This study is a review and analysis of all the reported cases in the literature. A thorough literature review was performed which included Medline search from 1950 to date. All the case reports with AVFs and/ or FAs following orthognathic surgery were selected. Data that was reviewed included the procedure, report of intra-operative complications, presenting symptoms, diagnosis, treatment modalities, and outcome. One recent unreported case from our institution was included in the data. Subjective data analysis was performed. 12 cases of FA, and 10 cases of AVF have been reported. The FAs involved the maxillary artery (MA) in eight cases, the sphenopalatine artery in three cases, and the infraorbital artery in one case. The AVFs were noted between intracavernous portion of the internal carotid artery (ICA) and the cavernous sinus in four cases, ICA and internal jugular vein in one case, and the MA in remaining four cases. Procedures performed included 12 Le Fort I osteotomies, nine Le Fort I osteotomies combined with bilateral saggital split osteotomies, and one bilateral mandibular subcondylar osteotomy. Initial symptoms presented as early as few hours post surgery to almost one year after the surgery. Nine cases reported intra-operative events ranging from difficult downfractures to excessive bleeding. In the FA group, nine patients presented initially with epistaxis of varying severity, one had acute swelling of the cheek, and two presented with pulsating noise and dizziness. In the AVF group the initial signs and symptoms included pulsating noise in six patients, chemosis and periorbital edema in four patients, extraoccular paresis in three patients, ptosis in two patients, and profuse bleeding in one patient. The FA cases were treated with embolization in eight patients and with surgery in four. Two of the four surgical cases failed one or two embolizations. All the AVFs were treated with embolization except for one that was treated surgically. Overall, all signs and symptoms resolved in all patients except in three AVF cases. The residual signs and symptoms included left hemiparesis in one individual, chronic bilateral maxillary pain in another individual, and persistent ophthalmoplegia in the third patient. Surgical trauma of orthognathic procedures may result in a variety of complications including hemorrhage and formation of vascular malformations such as FAs and AVFs. Although many procedures have been linked to formation of these vascular complications, review of the cases in this study shows an association with Lefort I osteotomies in all but one of the cases. Majority of the FAs in this series involve the MA and less frequently its smaller terminal branches. The AVFs seem to be associated with the larger ICA and MA with the same frequency. The most common signs and symptoms include epistaxis refractory to conventional treatment, and pulsatile noises heard by the patient. When cavernous sinus is involved, the sequelae are ophthalmoplegia, proptosis and chemosis that result from increased pressure in the sinus. There may be no intraoperative indications of a vascular injury associated with formation of AVFs and FAs. Based on this series, embolization is an effective and predictable modality of treatment in both AVFs and FAs resulting in very few permanent complications. Surgical management although effective has few obvious disadvantages including compromising the blood supply to the osteotomized segments, acute hemorrhage of the vascular anomaly and other co-morbidities associated with surgical exploration.