Side effects due to high dose irradiation of normal tissue may appear immediately or a few months after completion of the treatment. The most common vascular lesions related to radiation therapy are stenosis of the carotid artery, which may later progress to unilateral or bilateral occlusion. Occasionally, transmural necrosis of the vessel wall may also result in formation of a false aneurysm. Exceptionally, the pseudoaneurysm may be related to invasion of the arterial wall by the neoplasm itself [1]. A few cases of maxillary artery FA have been reported in the literature, but all without exception follow trauma or a surgical procedure. Such abnormalities have been described in cases of blunt facial trauma, jaw fracture, maxillary gunshot injury, mandibulary and maxillary Lefort I and Lefort III osteotomy, transsphenoidal surgery, or after functional endoscopic sinus surgery [2]. In the series reported by Mak et al., three out of eight nasopharyngeal carcinoma patients presenting with intractable epistaxis had an internal carotid artery aneurysm detected at angiography that was likely to be a result of irradiation [3].
Among all the cases of FA and haemorrhage caused by carcinomas of the head and neck, different embolisation materials were used such as gelfoam, polyvinyl alcohol, isobutyl-2 cyano-acrylate, detachable and non-detachable coils, detachable balloons, and more recently covered stents, in order to exclude the FA. The results of these techniques varied from a complete resolution of the symptoms to rebleeding in up to 37% of the cases [1,3].
We did not try to place another coil at the distal neck of the FA because the IMA blood flow stopped immediately after placement at its proximal neck, and further microcatheterisation through the initially implanted coil was supposed to be hasardous in this patient in poor conditions.
In this case, the high irradiation dose received (greater than 60Gy), the necrosis of the lateral pharyngeal mucosa and masticatory muscles (Fig. 4) and the presence of diffuse and multiple arterial stenoses (Figs 1a,2b) in a young adult within the field of previous radiotherapy treatment, are positive arguments towards the diagnosis of post-radiation FA [4]. Subacute arterial rupture of the maxillary artery with life-threatening bleeding may have been precipitated by wound complications after performance of the careful "blind" biopsies by the surgeon.
Internal maxillary artery ligation has proved to be not so effective as percutaneous embolisation in treating epistaxis and was not appropriate in this case. Many contributing factors may explain this difference such as incomplete ligation of vessels, alternative dominance of vessels, or reconstruction of flow through collaterals.
The optimal treatment should have preserved the IMA blood flow by restoring the arterial patency and altering the flow dynamics in the pseudoaneurysm, resulting in thrombosis and thus reducing the risk of worsening of the pharyngeal radionecrosis. That was not feasible because of the shape and location of the FA, and the technical difficulty and inherent danger of angioplasty (covered stent) in an already structurally compromised maxillary artery. Yuen et al. stressed the importance of collateral revascularisation from the peripheral tissue bed after percutaneous embolisation in order to prevent necrosis [5].
The radiation-induced tissue fibrosis, the poor collateral network and the percutaneous permanent occlusion of the pterygoid, masseteric and buccal arterial branches (second portion of the IMA) may explain the worsening of the pharyngeal tissue necrosis and the absence of healing during follow-up, that led the patient to lethal septic meningitis.
