Figure 1
Pseudoaneurysm on CT
Contrast-enhanced CT scan showing a 3-cm pseudoaneurysm (arrow heads), filled in part by an eccentric thrombus (arrows) and situated at the posterior of the left ascending ramus.
Clinical History
A vascular lesion complicated a BSSO procedure with active oral bleeding and unstable vital signs.
Imaging Findings
The patient had a cosmetic problem of mandibular prognathism. She underwent bilateral sagittal split osteotomies (BSSO) for correction. Three weeks later, she suffered from left facial asymmetry with frequent oral bleeding and eventually fainted with shock status. Enhanced CT showed an oval enhanced nodule located just posterior and medial to the left ascending ramus. An emergent operation was arranged to stop the bleeding, but in vain. Angiography showed that the proximal internal maxillary artery fed a lobulated pouch with contrast pooling and extravasation.
Discussion
Pseudoaneurysm of the internal maxillary artery (IMA) is usually the result of complications from trauma, maxillomandibular osteotomy, arthroscopy of the temporomandibular joint, or computed tomography-guided fine needle aspiration (1,2). Pseudoaneurysms following mandibular orthognathic surgery, especially vertical or oblique mandibular ramus osteotomies, are most likely to involve the internal maxillary artery, which is usually lacerated when the osteotomy cut is made near the sigmoid notch (3). The incidence is rare. Only five cases of pseudoaneurysm were reported out of 800 complications in orthognathic surgery (3).
The treatment options for postosteotomy bleeding include nasal packing, compression, arterial ligation and selective embolisation. Compression or nasal packing can only stop simple bleeding. For pseudoaneurysm, arterial ligation or selective arterial embolisation is necessary. However, the effect of arterial ligation is variable because of collateral circulation from the contralateral side and artery communication with the internal carotid artery (4). Therefore, arterial embolisation plays an important role in the treatment of intractable haemorrhage in the head and neck regions.
Arterial embolisation can be performed with agents such as gelfoam , metallic coil, polyvinyl alcohol sponge particles or liquid adhesive suspension (2,4). Since dangerous anastomoses may exist with the internal carotid artery or the vertebral artery, superselective cannulation should be performed to reduce the risk of misplaced embolic materials (4). A cannula was introduced superselectively into the orifice of the pseudoaneurysm and a small bolus of liquid adhesive suspension (a mixture of ethiodised oil and N-butyl cyanoacrylate) was delivered into the neck of the pseudoaneurysm. Complete obliteration of the pseudoaneurysm with preservation of the parent artery was achieved after embolisation. The patient's vital signs soon stablised with no haemorrhage following embolisation. No problems were seen over a two-year follow-up.
Differential Diagnosis List
Pseudoaneurysm of the internal maxillary artery
Final Diagnosis
Pseudoaneurysm of the internal maxillary artery
References
[1]
1. Gerbino G, Roccia F, Grosso M, Regge D.
Pseudoaneurysm of the internal maxillary artery and Frey's syndrome after blunt facial trauma.
J Oral Maxillofac Surg. 1997 Dec;55(12):1485-90. (PMID: 9393413)
[2] 2. Walker AT, Chaloupka JC, Putman CM, Abrahams JJ, Ross DA. Sentinel transoral hemorrhage from a pseudoaneurysm of the internal maxillary artery: A complication of CT-guide biopsy of the masticator space. AJNR 1996;17:77-81. (PMID: 8938314)
[3] Lanigan DT, Hey JH, West RA. Major vascular complication of orthognathic surgery: False aneurysms and arteriovenous fistulas following orthognathic surgery. J Oral Maxillofac Surg 1991;49:571-7. (PMID: 2037912)
[4] Rogers SN, Patel M, Beirne JC, Nixon TE. Traumatic pseudoaneurysm of the maxillary artery: The role of interventional radiology. Int J Oral Maxillofax Surg 1995;24:336-9. (PMID: 8627096)
Case information
| URL: | https://www.eurorad.org/case/1627 |
| DOI: | 10.1594/EURORAD/CASE.1627 |
| ISSN: | 1563-4086 |
Figure 2
Psudoaneurysm on angiography
Lateral view of selective left external carotid artery shows the pseudoaneurym (arrow heads) of the internal maxillary artery.
Figure 3
Superselective cannulation by microcatheter
Digital subtraction angiography of the pseudoaneurysm is performed by injection of contrast medium from the microcatheter tip at the neck of the pseudoaneurysm. This shows the sac of the pseudoaneurym (arrow heads) with abnormal contrast medium extravasation from its anterior wall (arrows).
Figure 4
Angiography of postembolisation
Post-embolisation angiogram from left common carotid injection shows complete obliteration of the pseudoaneurysm with preservation of the parent artery.
Pseudoaneurysm on CT
Contrast-enhanced CT scan showing a 3-cm pseudoaneurysm (arrow heads), filled in part by an eccentric thrombus (arrows) and situated at the posterior of the left ascending ramus.
Psudoaneurysm on angiography
Lateral view of selective left external carotid artery shows the pseudoaneurym (arrow heads) of the internal maxillary artery.
Superselective cannulation by microcatheter
Digital subtraction angiography of the pseudoaneurysm is performed by injection of contrast medium from the microcatheter tip at the neck of the pseudoaneurysm. This shows the sac of the pseudoaneurym (arrow heads) with abnormal contrast medium extravasation from its anterior wall (arrows).
Angiography of postembolisation
Post-embolisation angiogram from left common carotid injection shows complete obliteration of the pseudoaneurysm with preservation of the parent artery.