INTRODUCTION
Fracture of the zygomaticomaxillary complex (ZMC) is a common injury observed in maxillofacial units with documented well management [
1]. Pseudoaneurysms can occur following partial disruption in the wall of blood vessel, causing hematoma that is either contained by vessel adventitia or perivascular soft tissue [
2]. Intracranial pseudoaneurysm is a rare complication of blunt cerebrovascular injury. Its incidence is less than 1% [
3]. Specifically, there are only a few reports of pseudoaneurysm in facial bone fracture [
1,
4-
8]. Despite a low incidence, due to reduced support from the vessel wall, the risk of pseudoaneurysm rupture is much higher than that of true aneurysm [
9]. This can cause secondary hemorrhage from the vessel at any time which may lead to life-threatening situation [
2].
Herein, we report two cases of locally uncontrollable hemorrhage after ZMC fracture. The hemorrhage was treated by embolization of the maxillary artery branch. Our patients presented persistent nasal bleeding and malar swelling that might be overlooked by surgeons. Under suspicion of intracranial vessel injury, we performed angiograms and made diagnosis of pseudoaneurysm.
DISCUSSION
Management of blunt facial trauma and hemorrhage is well-established. The first step should be airway management to ensure breathing and circulation. Nasal packing, correction of coagulopathy, reduction of fractures, and arterial ligation remain standard treatments. However, in unstable patients or patients with persistent bleeding, angiographic embolization should be considered [
10,
11]. We followed this protocol. Based on persistent bleeding of patients, we suspected intracranial bleeding and performed angiograms. In both patients, we diagnosed pseudoaneurysms of sphenopalatine artery, the deepest branch of maxillary artery. Endovascular embolization was performed and bleeding was ceased.
The mechanism of pseudoaneurysm formation after fracture is partial transection of the vessel and hematoma in arterial wall by bone fragment [
9,
12]. Traumatic pseudoaneurysm of sphenopalatine artery is extremely rare because of its deep anatomic location and protection from bony structure. However, due to its close proximity to pterygoid plates, ZMC fracture involving these areas may cause injury of the sphenopalatine artery. Sphenopalatine artery is divided into lateral and septal posterior nasal arteries. Therefore, the only presentation of sphenopalatine artery injury is nasopharyngeal bleeding which is common [
12].
As far as we know, no study has reported the incidence of pseudoaneurysm after ZMC fracture so far. There are some reports about pseudoaneurysm after maxillofacial fracture. Types of fracture included severe ZMC fracture and panfacial fracture [
4-
8]. In these reports, diagnosis was done after the patient presented life-threatening massive hemorrhage. The diagnosis of pseudoaneurysm is based on physical examination such as bruit or expanding masses [
2,
12,
13]. However, in craniofacial trauma, these arterial injuries are not evident during primary physical examination due to its deep location [
7,
9,
12,
13]. Likewise, arterial injuries were not detected initially in our cases. During close observation, patients presented not massive bleeding, but some common symptoms such as persistent nasopharyngeal bleeding.
Pseudoaneurysm can be confirmed by imaging modalities such as contrast enhanced CT or angiography [
7,
9]. If a pseudoaneurysm is diagnosed, the treatment of choice is transcatheter embolization [
5,
13]. Ligation of bleeding artery by surgical treatment is an option. However, its effect is variable because of collateral circulation from the contralateral side and communication with the internal carotid system [
5,
10]. One advantage of embolization is that relatively distal vessels may be obliterated while more proximal vessels may be spared [
5,
7,
13,
14]. This may minimize the risk of persistent hemorrhage from collateral flow and aseptic necrosis of maxilla [
7,
13]. In multiple studies, it has been shown that embolization can successfully arrest bleeding in patients with hemorrhage with a success rate of up to 96% and a major complication rate of 3% [
14].
Based on our clinical experience, we suggest a few key findings that surgeons should consider. First, we found that both patients presented with preoperative nasal bleeding. Nasal bleeding after injury or operation is common while the antrum clears [
1]. Therefore, it can be ignored by surgeons. However, our cases suggest that nasal bleeding alone may suggest injury to intracranial vessels, especially in sphenopalatine artery injury.
Second, bleeding can originate in branches of the maxillary artery that enter the pterygoid plate. In this case, local hemostasis such as nasal packing cannot control the bleeding adequately [
1]. Therefore, if hemorrhage persists after facial trauma, according to protocol for controlling hemorrhage in facial trauma, early intervention with imaging modalities such as enhanced CT and angiogram is recommended [
11].
In conclusion, although pseudoaneurysm resulting from maxillofacial trauma is rare, it may be life-threatening. Therefore, close postoperative follow-up of patients is necessary for detecting bleeding foci, even in cases without bleeding during surgical procedure. Surgeons should not overlook nasal bleeding or acute onset of swelling as they might be precursors of life-threatening hemorrhage.