Unique case of a post-traumatic nasoseptal arteriovenous malformation
- 1 Otorhinolaryngology, Tan Tock Seng Hospital, Singapore
- 2 Diagnostic Radiology, Tan Tock Seng Hospital, Singapore
- Correspondence to Dr Kelvin Yong Jie Lim; limyjk@gmail.com
Abstract
Extracranial manifestation of arteriovenous malformations (AVMs) is uncommon. Nasoseptal AVMs are an even rarer entity. In this case report, we present an interesting and first-of-its-kind case of the development of a left nasoseptal AVM in a 60-year-old man after a fall. This was likely post-traumatic, unlike the usual congenital AVMs described in the literature. The patient was managed conservatively with regular follow-up for the AVM as he was asymptomatic.
Background
An arteriovenous malformation (AVM) is a vascular malformation that is composed of multiple arteriovenous shunts and dilated capillary beds. AVMs are generally split into intracranial and extracranial manifestations. Common sites include the head and neck, extremities and trunk. In this first-of-its-kind case, there was a diagnostic delay as the diagnosis of a nasoseptal AVM from a nasoseptal lump was not initially apparent.
Case presentation
A 60-year-old man was referred to the Otolaryngology (Ear, Nose and Throat/ENT) Clinic in March 2019 for further management of an incidental finding of ethmoidal thickening in the ethmoidal sinuses found on a CT scan. He had been on follow-up with the Ophthalmology Clinic since 2009 for proptosis secondary to a known left ‘orbital varix’ with intracranial extension post-trauma (an unwitnessed fall). He did not experience any symptoms of nasal obstruction, epistaxis, nasal pain or clear rhinorrhoea. A nasoendoscopic examination (figures 1 and 2) revealed a pulsatile mass with a bluish tinge and multiple telangiectasia over the superior aspect of the left septum. Surrounding mucosa was intact. The rest of the nasal examination was unremarkable.
This depicts clinical photos of a mass with a bluish tinge and telangiectasia at the left superior aspect of the nasal septum—a nasoseptal arteriovenous malformation.
Close-up view of the left nasoseptal arteriovenous malformation.
Investigations
An MRI study was performed with dynamic multiphasic post-contrast images (figures 3 and 4). T1w and T2w hypointense lesions are seen in the left orbit and nasoseptal region; flow voids are seen on the T2w images. The arterial phase images demonstrate feeding vessels that arise from a branch of the left anterior cerebral artery, which extends through the left cribriform plate defect (figure 5). One of the arterial feeders is seen extending from the defect to the left nasoseptal region (figure 6), while another branch is seen extending to the left orbital mass, with inferior extension along the submucosal surface to the left inferior turbinate (figure 7). Submucosal oedema is seen at both the left nasal septum and inferior turbinate, appearing hyperintense on T2w images. There was also evidence of previous trauma with gliosis in the left basifrontal lobe (figure 8); this is noted in conjunction with the cribriform plate defect. Further CT angiogram (CTA) (figure 9) was performed, which demonstrated faint hyperdense foci; the arterially enhancing vessels seen on MRI were not clearly demonstrated. No phleboliths were seen in the nasoseptal mass or the orbital mass.
T1-weighted MRI with contrast depicting a left nasoseptal arteriovenous malformation with narrowing of the left nasal cavity.
T1 pre-contrast, arterial and venous phases. In the arterial phase, feeding vessels that arise from a branch of the left anterior cerebral artery extend through the left cribriform plate defect. One of the arterial feeders is also seen extending from the defect to the left nasoseptal region.
Reconstructed coronal images (arterial) show arterial feeder from anterior cerebral artery branch through the cribriform plate defect to the septum, left orbit and left inferior turbinate.
MRI reconstruction of sagittal section of nasal septum shows arterial enhancement with further diffuse enhancement on the venous phase.
Sagittal arterial maximum intensity projection demonstrates feeder going to the inferior turbinate.
MRI revealing a left orbital arteriovenous malformation with signs of slight proptosis and gliosis in the left basifrontal lobe.
CT angiogram did not clearly demonstrate the evidence of arterially enhancing vessels seen on MRI.
Differential diagnosis
While the initial diagnosis was an AVM, other differential diagnoses such as a nasoseptal varix and haemangioma were considered. MRI revealed a left orbital varix and a nasal septal mass with feeding arteries arising from a branch of the left anterior cerebral artery. Arterial phase enhancing feeding vessels seen on the MRI confirms the diagnosis of AVM.
AVMs typically appear hypointense to isointense on T1w images and hypointense on T2w images due to fast-flowing blood. Arterial feeders are demonstrated on cross-sectional angiographic imaging. Venous varices are dilatation of existing veins, associated with low blood flow and distensible walls. Varices are well-defined lesions appearing T2w hyperintense. They do not show flow voids or arterial enhancement. On CT images, they may demonstrate phleboliths which are wall calcifications. Orbital varices are often associated with dilatation of the superior ophthalmic vein, which was absent in this case. Orbital cavernous haemangiomas are also known as cavernous venous malformations; these are isointense on T1w images, hyperintense on T2w images and show gradual irregular enhancement with delayed wash-out.
Prior to 2009, there was no AVM with nasoseptal/orbital component. In this unique case, it is likely that the nasoseptal AVM occurred due to the traumatic fall sustained by the patient in 2009, as evidenced by the fracture in the cribriform plate, previous intracranial haemorrhage with gliosis of the left basifrontal lobe, depicting an orbital/nasoseptal AVM, communicating via the fracture in the cribriform plate.
Treatment
This patient was managed conservatively as he did not have any symptoms of blocked nose, epistaxis or nasal/facial pain. If treatment is required, minimally invasive options such as angioembolisation or surgical excision via open approaches such as an external orbital approach and/or a mini craniotomy can be considered.
Outcome and follow-up
The patient was offered regular follow-up with the otolaryngologist and ophthalmologist, as he opted for conservative management. At his last appointment, he was advised to seek medical treatment at the ENT Clinic if he develops epistaxis, nasal pain or nasal congestion.
Discussion
The mechanism for the formation of AVMs is unclear. They are thought to be embryological anomalies, arising due to errors in vascular regulation.1 AVMs most commonly occur intracranially, but theoretically can occur anywhere in the body. AVMs are 20 times more common in the central nervous system, where apoptosis is rare.2 For extracranial AVM manifestations of the head and neck, the most common sites were cheek (31%), ear (16%), nose (11%) and forehead (10%).1 Associated syndromes with extracranial AVMs are Wyburn-Mason syndrome, Parkes-Weber syndrome and Cobb syndrome.3
In currently available literature and to the best of the authors’ knowledge, there has been no recorded case of a nasoseptal AVM. Both congenital and post-traumatic AVMs have been described in literature, but it is contentious as to whether trauma assumes an independent causative factor, or perhaps acts as a precipitating factor for the formation of the AVM. Proposed mechanisms include direct trauma resulting in the direct formation of communicating channels between veins and arteries, and the creation of bridging vessels in the vasa vasorum due to the increased endothelial cell production and neovascularisation in the healing process.4
AVMs are clinically significant due to its natural history. While infantile haemangiomas tend to involute with age, AVMs are the opposite; they tend to grow in size and can cause multiple complications.5 AVMs bypass the high resistance of capillary beds, resulting in a high-flow lesion that directly shunts blood from arterial to venous circulation, thereby increasing arterial flow and causes expansion, vascular remodelling of arteries and veins as well as the proliferation of collateral vessels.6
AVMs can be divided into focal or diffuse disease. A focal AVM is usually a single AVM with proper margins and borders, often consisting of only one to two arterial feeders seen on radiological imaging.5 The Schobinger classification provides a good clinical staging process to prognosticate the severity of the AVM lesion.
Clinical history and physical examination are important in identifying an AVM. As seen in our case, early lesions tend to demonstrate a vascular blush of the overlying skin/structure. The deep portion of the AVM may not, however, be evident during the physical examination.
Various imaging modalities can confirm the diagnosis of an AVM. Ultrasonography with doppler can differentiate AVMs from other vascular lesions by demonstrating arteriovenous waveforms and high flow. MRI can elucidate the degree of soft tissue involvement as well as the size and depth of the lesion, while CT can identify bony involvement.7 While angiography is the gold standard for identifying nidus and feeding arteries in the AVM, CTA and magnetic resonance angiography are viable non-invasive imaging substitute modalities to consider. In fact, CTA can also provide three-dimensional reconstruction images to identify feeding vessels.8
Complications of extracranial AVMs can range from mild to severe symptoms. These include haemorrhage, ulceration, pain from tissue destruction as well as steal syndrome, cosmetic issues and in larger AVMs, even cardiac overload.
AVMs have been poised by many to be the most difficult vascular lesion to treat. This is in part due to the wide disparity in severity and location of the AVM lesions, baffling many physicians with regard to the management of the disease. Generally, it requires a multidisciplinary and multimodal approach.
For focal Schobinger stage I/II lesions (table 1), outcomes are generally very favourable due to the localising features of the AVM, which allows for easy surgical resection or angioembolisation.9 One key factor is that the nidus of the AVM must be completely resected. This is in contrast with diffuse AVMs with multiple nidus and arterial feeders, which often pose a management dilemma due to their high flow, increased bleeding risk and highly infiltrative nature. Moreover, this is coupled with great difficulty for surgical excision and a high rate of recurrence. While it is known that most untreated AVMs will slowly progress, the timeline of progression varies significantly between each lesion.3
Various forms of classification of arteriovenous malformations
| Focal versus diffuse | Schobinger classification | |
| Focal | Diffuse | Stage I: quiescence; cutaneous blush, warmth |
| Discrete borders with central nidus | Multiple or no discrete nidus | Stage II: expansion; active growth, pulsations, bruit |
| Firm to palpation | Compressible with rapid rebound | Stage III: destruction; same as stage II but symptomatic (pain, bleeding, disfigurement) |
| 1–2 arterial feeders | Multiple arterial feeders | Stage IV: decompensation; same as stage III but with high-output cardiac failure |
| Good treatment outcomes | Higher risk of recurrence | – |
Due to the limited success of the treatment of AVMs, there is controversy in the temporal indication for intervention. Some physicians elect to delay treatment until patients are symptomatic, since the management is not without its own risks and complications. However, postponement may allow the AVM to progress and result in further difficulty in management.5
In the event where patients develop epistaxis, the management should be dependent on the location as well as the severity of bleed. Anterior epistaxis is known to be easily controlled with silver nitrate or electrocautery, and in more severe cases nasal packing with tampons or gauze is used. For posterior packing, however, bleeds tend to be trickier. Traditionally, packing is performed with balloon catheters. This poses as an issue as the procedure is associated with a high rate of patient discomfort, pain and swallowing difficulty. There are also local complications such as sinusitis, synechiae, otitis media, columellar/alar necrosis, septal perforation, and systemic complications such as toxic shock syndrome and sepsis to consider. Sireci et al suggests that in the case of mild-to-moderate posterior epistaxis, nasal packing may be avoidable, and clinicians can potentially use posterior endoscopic cauterisation as a first-line treatment. However, in the case of severe posterior bleeds, packing still remains as the main standard of treatment for patients.10
Given that the pathogenesis of AVMs is poorly understood, the future of AVM management remains an enigma. In terms of medical therapy, angiogenesis inhibitors or hormone antagonists could potentially halt the progression of AVMs, reducing the need for surgical intervention. Although not a cure, pharmacotherapy might potentially arrest expansion, and patients can use an antiangiogenic strategy, similar to cancer control.11 More research is required to elucidate information with regard to this enigmatic disease.
Patient’s perspective
Personally, I am surprised that I was diagnosed with such a rare and interesting condition. Most people would not expect that to occur to themselves. While I am worried that the disease may progress, I have utmost confidence in the medical team to provide the best possible care to help me manage my condition.
Learning points
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Arteriovenous malformations (AVMs) are thought to be congenital malformations due to vascular dysregulation during embryogenesis. However, a rare subset of AVMs can occur due to trauma.
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AVMs may potentially have a harrowing clinical progression—complications may include disfigurement, tissue destruction, pain, bleeding, ulceration, and very rarely, cardiac overload.
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Treatment options of AVMs can include surgical resection, angioembolisation, combination therapy with selective angioembolisation before surgical resection, and reconstruction of adjacent structures can be considered. Close observation is also a viable option.
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Recurrence rate of diffuse AVMs is very high, hence long-term monitoring is required.
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Careful consideration of differential diagnosis is important to prevent misdiagnosis; while common conditions may occur commonly, rare cases may occasionally be missed if assumptions regarding differential diagnosis are made.
Acknowledgments
Tan Tock Seng Hospital Otorhinolaryngology and Diagnostic Radiology Departments for their support in the writing of this case report.
Footnotes
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Contributors KYJL is the main author of this case report, while AYQS is a consultant radiologist who assisted in analysing and commenting on the various modalities of imaging in the report. JLT is the supervising author who mentored KYJL in the writing of the case report and provided valuable information in the direction of the report.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Patient consent for publication Obtained.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.
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