Clinicoradiographic aspects of arteriovenous malformations involving the orofacial region: A case series
Shilpa J Parikh, Harmi P Patel, Jigna S Shah, Sadhana Kothiya
Department of Oral Medicine and Radiology, Government Dental College and Hospital, Ahmedabad, Gujarat, India
Correspondence Address:
Dr. Harmi P Patel
Department of Oral Medicine and Radiology, Government Dental College and Hospital, Ahmedabad, Gujarat
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/ijves.ijves_29_22
Vascular malformation consists of a group of tumors that emerge from the vascular origin caused by vascular or lymphoproliferation. Arteriovenous malformations (AVMs) contribute high-flow, creating direct vein artery contact without regular capillary network. AVMs are present at birth or in congenital. Acquired AVMs occur later in life due to hormonal changes or trauma. AVM of the head and neck is a rare vascular anomaly but when present is persistent and progressive in nature and can represent a lethal benign disease and an incomplete resection frequently leads to recurrence of the lesion. Here, we present a series of three cases of AVM reported during 2019–2022 involving the orofacial region.
Keywords: Arteriovenous malformations, orofacial region, vascular malformation
Vascular malformations (VMs) are a general term used to describe a group of lesions formed by an anomaly of the capillary, venous, lymphatic, and arterial systems. These are structural anomalies of blood vessels without endothelial proliferation which most commonly present at birth, manifest in childhood or adolescence, and persist throughout life. They are categorized according to the type of vessels involved (capillary, venous, and arterial) and according to hemodynamic features (low flow or high flow).[1],[2]
Arteriovenous malformations (AVMs) are lesions with direct communications between endothelial-lined artery/arteries and vein/veins bypassing the capillary bed. Head-and-neck AVMs are reported to occur in 0.1% of the population, of which extracranial accounts for only 8.1%. AVMs may be congenital or acquired. Acquired AVMs are usually posttraumatic with a previous history of injury, trauma, or surgery with higher incidence of hemorrhage.[3],[4],[5] These lesions can occur at any area of the body. They have gradual onset and progression. In the oral cavity, these can present at any site but most commonly occur on the anterior two-thirds of the tongue, palate, and gingival and buccal mucosa.[6]
AVMs are radiographically characterized by a central nidus, a tangle of blood vessels where the abnormal arterial–venous communication exists without a normal intervening capillary bed. Hemorrhage and disfigurement are common reasons requiring intervention in AVMs involving the head-and-neck region. High-flow lesions are treated with catheter-directed embolization, and low-flow lesions are treated with percutaneous sclerotherapy.[4],[7],[8],[9] In this series, three cases of AVM involving the oral cavity are discussed.
CasesCase 1
An 18-year-old female patient presented to the department of oral medicine and radiology with a chief complaint of swelling of the lower lip. History revealed that it started at birth as a painless swelling and gradually progressed without a history of bleeding or discharge and pain. Family and medical histories were noncontributory.
On extraoral examination, the swelling was present on the right side of the face and lower lip causing facial asymmetry. Swelling on the lip extending mediolaterally from the midline to the angle of the mouth and superoinferiorly from the vermillion border to the lower border of the lower lip. No visible pulsations were seen [Figure 1].
Figure 1: Extraoral photograph showing swelling: (a) case 1, (b) case 2, (c) case 3On intraoral examination, approximately 6 cm × 4 cm size swelling was noticed on the right buccal mucosa extending anteroposteriorly from the angle of the mouth to the second molar and superoinferiorly from depth of the vestibule to 1 cm above occlusal level without displacement of any teeth [Figure 2]. The swelling was nontender, soft in consistency, and compressible with no local rise in temperature without palpable thrill. Based on examination, a clinical diagnosis of AVM was made. Hemangioma was kept as a differential diagnosis.
Figure 2: Intraoral photograph showing swelling, red and blue discoloration: (a) case 1, (b) case 2, (c) case 3Ultrasonography of the face and neck revealed a 9 mm × 20 mm sized lesion with tubular anechoic vascular channels showing arterial and venous flow within suggestive of AVM. Magnetic resonance imaging (MRI) shows an altered signal intensity lesion in the right lower lip extending along the lateral wall of the mandible. It involves orbicularis oris, depressor anguli oris, zygomaticus minor, and buccinator muscles extend deep into the sublingual and submandibular space, masticator space, parapharyngeal space, pharyngeal mucosal space, and oropharynx. The lesion shows multiple foci of blooming suggestive of phleboliths [Figure 3]. Based on clinicoradiologic findings, the final diagnosis of AVM was given. The patient was not willing for any treatment.
Figure 3: (a) case 1 – MRI showing an altered signal intensity lesion in the right lower lip and buccal mucosa, (b) case 2 – MRI showing an altered signal intensity lesion within intramuscular compartment of the left masseter muscle, (c) case 3 – CT face with neck angiography showing an ill-defined diffuse hypodense mildly enhancing soft-tissue lesion in the midline extending to left side of the lower lip. Feeding artery: major supply from the left facial artery and minor supply from the right facial artery branches. Draining vein is left internal jugular vein. MRI: Magnetic resonance imaging, CT: Computed tomographyCase 2
A 36-year-old female patient came to the department of oral medicine and radiology with a chief complaint of swelling on the left side of the face for the past 1 year. The swelling was static and painless. Family and medical histories were noncontributory.
On extraoral examination, the swelling was present on the left side of the face approximately 5 cm × 5 cm in size extending anteroposteriorly from the ala of the nose to the tragus region and superoinferiorly from 1 cm below the infraorbital margin to the inferior border of the mandible. The overlying skin was normal in color with visible pulsations near the angle of the mandible [Figure 1].
On intraoral examination, the swelling was present on the left buccal mucosa extending from the corner of the mouth to the third molar region and superoinferiorly from the upper depth of the vestibule to the lower depth of the vestibule. The swelling was firm in consistency, nontender, and not associated with displacement of teeth, and visible pulsations were present [Figure 2]. Diagnosis of AVM was made with differential diagnosis of hemangioma based on clinical findings.
MRI revealed an abnormal signal intensity lesion showing marked blood flow void on T1, T2, and STIR images within the intramuscular compartment of the left masseter muscle extending into infratemporal fossa and retro-maxillary antral fat. The lesion was supplied by maxillary and facial branches of the left external carotid artery and drained by the left external jugular vein [Figure 3]. Based on clinicoradiologic findings, the final diagnosis of AVM was given. The patient was referred to the department of oral surgery for further management where ligation of the external carotid artery, facial artery, and removal of the lesion mass with masseter muscle was done. Histopathology revealed many small-to-large engorged blood vessels suggestive of AVM. Immediate follow-up of the patient showed reduced swelling [Figure 4].
Figure 4: (a) Postoperative photograph on immediate follow-up, (b) histopathology photograph of case 2Case 3
A 21-year-old male patient came to the department of oral medicine and radiology with a chief complaint of swelling on the lower right back tooth region for the past 3 months. The patient also had a red macular lesion present on the face and lip since birth which increased after 6 years of age and was static afterward.
On extraoral examination, port-wine stains were present on the right and left sides of the face. A single swelling approximately 3 cm × 2 cm size present over the lower lip extending mediolaterally from the midportion of the lower lip to the corner of the mouth on the left side and superioinferiorly from the vermillion border of the lower lip to the lower border of the lip. The swelling was soft, nontender, and nonpulsatile. The overlying surface was dark red in color [Figure 1].
On intraoral examination, a single swelling of approximately 2 cm × 1 cm was present on the floor of the mouth extending mediolaterally from midline to 2 cm lateral to it on the left side and superioinferiorly from the floor of the mouth to 1 cm above to it. The swelling was soft, nontender, and nonpulsatile and has no bleeding tendency. A red macular lesion was present on the soft palate and tongue on the left side [Figure 2]. Based on these findings, a clinical diagnosis of hemangioma was made and AVM was considered a differential diagnosis.
MRI revealed an ill-defined diffuse hypodense mildly enhancing soft-tissue lesion in the midline of the lower lip extending to the left side, infiltrative and not seen separately from the orbicularis oris muscle of the lip suggestive of AVM supplied by the main feeding artery from the left facial artery and minor supply from the right facial artery. Computed tomography (CT) angiography revealed an ill-defined diffuse hypodense mildly enhancing soft-tissue lesion in the lower lip, measuring 3.3 cm × 1.7 cm × 1 cm with feeding artery of major supply from the left facial artery and minor supply from the right facial artery branches. Draining vein is the left internal jugular vein [Figure 3]. Based on clinicoradiologic findings, the final diagnosis of Sturge– Weber syndrome More Details with AVM in the lower lip was given. The patient was treated with Nd: YAG laser. On follow-up after 1 year, regression of lesion was seen.
DiscussionVascular anomalies were classified originally by Mulliken and Glowacki in 1982 based on clinical features and biologic behavior. Currently, the International Society for the Study of Vascular Anomalies classification system [Table 1] is widely accepted and utilized to categorize vascular anomalies into two basic types: (1) vasoproliferative or vascular neoplasms such as hemangioma and (2) developmental vascular abnormalities called congenital vascular malformations.[8],[10]
Table 1: International Society for the Study of Vascular Anomalies classification systemAVMs are fast-flow VMs, consisting of anomalous capillary beds between the arterial and venous systems, thus causing shunting of blood. AVMs are the most aggressive form of VM which can lead to significant deformity and functional impairment and usually become evident during childhood and puberty.[4],[11] Kohout et al.[12] in their study found that AVMs were present at birth in 59% of cases, in childhood 10% of cases, in adolescent 10% of cases, and in adulthood 21% of cases. In the present case series, two patients had AVMs present since birth and one patient had noticed it before 1 year.
AVMs grow synchronously with the growth of the child. Trauma, ischemic events secondary to thrombosis, ectasia, hormonal changes, and puberty can induce the proliferation of AVM and trigger the growth of the lesion. The enlargement occurs due to a change in pressure and flows within malformation rather than cellular proliferation.[6],[9] In the present series, all three patients noticed a gradual increase in the size of the lesion. Their clinical course can be traced according to the Schobinger clinical staging system [Table 2]. They typically present as latent lesions during childhood that evolve into a warm pink-bluish skin lesion with a pulsatile thrill in adolescence. Over time, the lesion continues to expand leading to dystrophic skin changes, bleeding, ulceration, and tissue necrosis. If left untreated, high flow into the venous system eventually leads to volume and pressure overload and subsequent heart failure.[13]
Table 2: Schobinger clinical staging system of arteriovenous malformationsHyodoh et al.[14] stated that radiological exploration based on multiple modalities (CT scan, Doppler ultrasound [US], angiography, and MRI) has a major place. It can describe characteristics of AVM in terms of size, shape, flow velocity, direction, and precise relationship to surrounding structures. Doppler US shows arterial and venous signals from vessels in the lesion and often appears hypervascular. MRI is helpful to further characterize sonographic findings and determine the extent of larger lesions for planning medical, interventional, and/or surgical therapy.[15] In the present series, case 1 appeared as vascular in Doppler US and hyperintense on MRI T2-weighted sequence with phleboliths and, in case 2, abnormal signal intensity lesion with marked blood flow void seen within the intramuscular compartment of the left masseter muscle in T1, T2, and STIR images and lesion supplied by maxillary and facial branches of the left external carotid artery and drained by left external jugular vein. CT angiography is an alternative to MRI that gives comparable images; however, the three-dimensional reconstruction lacks resolution. In case 3, CT angiography showed an ill-defined diffuse hypodense mildly enhancing soft-tissue lesion with feeding artery of major supply from the left facial artery and minor supply from the right facial artery branches. Draining vein is the left internal jugular vein. 4D CT angiography is an emerging technology that may be able to overcome this barrier and has shown to be useful for brain AVMs. In general, MRI and magnetic resonance angiography (MRA) are the preferred primary imaging modalities as they deliver both excellent anatomical resolution of the AVM and surrounding soft tissue, which are necessary for analyzing the extent of peripheral AVMs.[7],[13]
Lam et al.[7] suggested that diagnostic angiography should be performed on almost all AVMs and is absolutely required before treatment to assess flow rate, visualize the anatomy of the nidus, and identify vessels required for distal circulation. AVMs can be identified as a tangled mass of blood vessels with early venous filling. If performed during embolization, accessory feeder vessels may begin to be visualized as primary feeder vessels are embolized.
The AVMs present a therapeutic challenge because of their hemodynamic characteristics and their growth modality. They have to be treated according to their histopathology, location, and hemodynamic features as shown radiographically with angiography. AVMs may not need treatment when asymptomatic, but medication is needed if it is associated with discomfort, ulceration, bleeding, or heart problems. Multimodal treatment involving preoperative sclerosing agents or embolization accompanied by complete surgical resection remains the most traditional modern approach.[4],[6],[13] In the cases presented here, one patient was treated using a combined approach of embolization and surgery and one patient with Nd: YAG laser and one patient was not willing for treatment.
ConclusionThe AVMs are fairly uncommon in the area of the head and neck. Because of their potential for uncontrollable bleeding, they may pose a dental emergency while performing dental procedures. They can cause troubling hemodynamic manifestations such as venous obstruction, distal ischemia, and high-performance cardiac failure. The role of imaging and interventional radiology has become increasingly vital in the management of VMs, with significant success in improving patient morbidity and mortality. Selection of proper imaging technique is very essential to establish AVM relationship with vessels and surrounding structures. CT scan and MRI are sufficient in most cases, but angiography remains the gold standard to determine the location and flow characteristics of the lesion. A clear clinical background with imaging usually delineates the lesion well and provides an opportunity to make a cautious intervention decision.
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The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
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