Pseudoaneurysm is a rare occurrence mainly affecting vessels in the head and neck region, especially the superficial temporal artery, which is a branch of the internal maxillary artery. Most of the time, these aneurysms are secondary to trauma to the face, surgical procedures, or infections. The best imaging modality is angiography; however, alternative less-invasive imaging such as CT angiogram is also helpful in establishing the diagnosis and treatment. Most patients are asymptomatic; however, few patients will need surgical intervention and/or embolization to prevent bleeding as a complication.
Pseudoaneurysm is a rare occurrence and usually results from blunt trauma to the vessel wall with resultant laceration. This leads to extravasation of blood to the surrounding tissue which is followed by a tamponade and clot formation. Incidence of pseudoaneurysm of extracranial carotid artery is rare because the trauma usually results in total transection rather than partial laceration of the vessel. Superficial temporal artery, internal maxillary artery and distal facial artery are commonly affected arteries because of their location, which are near the mandible and zygomatic bone [1]. Most aneurysms (~85%) are found extracranially in the head and neck region and the artery that is commonly involved is the superficial temporal artery followed by internal maxillary artery and facial artery [2]. Internal maxillary artery (IMA) pseudoaneurysm is rare and most lesions are associated with fracture of the neck of the mandible [3, 4]. Here we present a case of a pseudoaneurysm of the right sphenopalatine artery after endoscopic turbinoplasty. To the authors’ knowledge, this is a rarely reported incident.
A 33-year-old male presented to the otorhinolaryngology clinic in Hospital Sultanah Bahiyah with complaints of occasional nasal blockage associated with rhinorrhea and difficulty in sleeping. His medical history was significant for a motor vehicle accident one year ago in which he sustained facial trauma with bilateral Le Fort II fracture and left Le Fort III fracture and nasal bone fractures (Figure 1).
He later underwent embolization at a referral center by an interventional radiologist. At present, patient is doing well at three monthly follow-ups at our rhinology clinic. During his last follow-up, a routine zero degree rigid nasoendoscopy showed synechiae formation in the right nasal cavity between the posterior part of right inferior turbinates and the septum. However, patient was asymptomatic and not keen for a synechiae release.
Aneurysm consists of two types, a true aneurysm and a pseudoaneurysm. In true aneurysm, the aneurysmal wall contains all the vessel wall layers. Pseudoaneurysm is formed when the wall of an artery is partially transected causing blood to fill in the cavities with subsequent pseudocapsule formation around the vessel. This pseudocapsule surrounds the hematoma and is fibrous in nature. Cavitations that occur inside a hematoma form the pseudoaneurysm [2, 4]. Pseudoaneurysms involving branches of external carotid artery are rare and are usually caused by penetrating or blunt trauma, partially transecting the vessel wall [1]. Rogers et al reported two cases of Le Fort III fractures and Le Fort I osteotomy with subsequent development of pseudoaneurysm in internal maxillary artery; patients presented with epistaxis weeks after surgery [5].
Gerbino et al reported a case of IMA psedoaneurysm in a patient six months after Le Fort I fracture [4]. Facial fractures are also found to have late vascular complications and warrant frequent follow-ups [6, 7]. In our case, even though the cause of epistaxis was iatrogenic in nature, we believe that the initial facial trauma was the likely cause of pseudoaneurysm. Another explanation is the manipulation of facial bones during facial reconstruction surgery which might injure the right sphenopalatine artery causing pseudoaneurysm formation. Imaging must be done to investigate the cause of bleeding especially in a postoperative patient. According to Procopio et al, while investigating the cause of major bleeding after Le Fort osteotomy, angiography is the diagnostic examination of choice [8]. They also described plain CT without contrast to be useful in defining the bone anatomical change, side of pathology and vessel relationship. A CT scan with contrast will be able to give detailed information on the pathological anatomy [8]. In this case, after the second episode of bleeding, we decided to proceed with CT angiogram as the history of trauma and previous operation were significant enough to suggest a bleeding pseudoaneurysm. Some authors reported that although the diagnosis of IMA pseudoaneurysm is best obtained with angiography, contrast enhanced CT is useful enough to establish the site of pseudoaneurysm if it is more than 1 cm in size [9]. This will help to guide the interventional
radiologist or vascular surgeon to selectively embolize the affected vessel. The objective in treating pseudoaneurysm is to obtain proximal and distal control before the aneurysm is excised [4]. However, currently the pseudoaneurysm is better treated by endovascular embolization using a catheter, which is most of the time performed by an interventional radiologist [2]. Few agents can be used to embolize the involved vessels such as polyvinyl alcohol foam, gel foam, steel coils, methyl methacrylate and silicone spheres [5]. Embolization does require an experienced interventional radiologist. It may also cause serious neurological complications such as ophthalmoplegia, facial paralysis and hemiplegia at rates of 0–8% [10]. Rodesch et al encountered complications of 0.4% and 1% permanent and transient complications secondary to chemoembolization for epistaxis. About 0.4% of his cases developed nasal septum necrosis [11]. Ntomouchtsis et al reported a complicated and unfortunate case of right IMA post-embolization for epistaxis of a patient that developed left-sided hemiparesis and right-sided facial nerve paresis, followed by ulceration and necrosis of the soft palate, nasal septum, and right nasal ala [12]. This shows that although complications of selective embolizations are rare, there is potential for extensive and debilitating complications. In our case, there was no incidence of complications or rebleeding after the embolization and initial embolization was successful. In summary, we present a case of pseudoaneurysm which was diagnosed postoperatively and the etiology of pseudoaneurysm could have been an operative complication or previous history of facial fracture. Pseudoaneurysm was diagnosed with CT angiography and was treated with chemoembolization of the involved artery with good results.