Uncontrolled bleeding during tooth extraction from an undiagnosed arteriovenous malformation

Abstract

Arteriovenous malformations (AVMs) are rare congenital disorders of vascular morphogenesis. These lesions are characterised by high vascular flow with risk of severe bleeding from accidental trauma or surgical manipulation. Although infrequent, potentially life-threatening and fatal oral bleeding has been reported during extraction of tooth associated with AVM. This paper presents a case of uncontrolled bleeding in an adult female patient undergoing mandibular anterior tooth extraction. The bleeding was related to undiagnosed soft tissue AVM in gingivobuccal space. Management of the case with review of previously reported similar cases is presented.

Background

Vascular anomalies include a heterogeneous group of lesions which are characterised by abnormal vascular development. They can be broadly grouped as vascular tumours and vascular malformations. While vascular tumours are composed of proliferating endothelial cells, vascular malformations are formed due to a defect in the morphogenesis of blood vessels. Arteriovenous malformations (AVMs) are rare vascular malformations characterised by high-flow vascular dynamics.¹ Although 50% of AVMs are seen in the head and neck region, those associated with the maxillomandibular region are rare.²

AVMs are mostly congenital in origin. However, it is usually not evident at birth. As the lesion increases in size, it gets noticed during childhood or puberty, and less frequently during adulthood. Hormonal changes (like those associated with puberty), trauma and infection are known to accelerate its growth. The presentation of AVMs depends on its size and location. While intraosseous lesion causes expansion of the jawbone, soft tissue AVMs produce a pulsatile soft tissue swelling. Excessive bleeding following brushing, minor trauma or during a surgical intervention can be the presenting feature of oral AVMs. Infrequently life-threatening bleeding has been reported after tooth extraction due to AVMs involving the jawbone and orofacial tissue.

This paper intends to highlight a case of uncontrolled oral bleeding and its management in an adult patient with undiagnosed gingivobuccal AVM during tooth extraction. The paper also reviews previously reported cases of severe and life-threatening oral bleeding in patients undergoing tooth extraction associated with AVM.

Case presentation

A 40-year-old female patient was brought to the emergency department with an uncontrolled torrential oral bleed. About an hour ago, the patient was taken up for routine extraction of a periodontally compromised left mandibular anterior tooth by a dental surgeon. During reflection of the gingival tissue, an uncontrolled oral bleed started. The bleed was persistent and did not stop by local pressure.

Uncontrolled bleed after minor gingival manipulation during tooth extraction evoked a strong suspicion of a local vascular anomaly or systemic bleeding disorder. Detailed history did not reveal any bleeding tendency. The patient was not on anticoagulant or antiplatelet therapy. No family history of bleeding disorder was present. History of an uneventful extraction of upper molar teeth a few months ago was reported. The patient gave a history of spontaneous exfoliation of two loose mandibular anterior teeth about 6 years ago, which was not associated with abnormal bleeding. No history of previous trauma over the face was reported. Laboratory tests to assess the bleeding and clotting profiles were within normal range. On careful inspection of the lower face, moderate diffuse swelling over the left side of the lower lip and labial tissue was noted (figure 1A). On palpation, the swelling was soft and pulsatile at the lower border of the mandible. The overlying skin had mild blackish discolouration, which was possibly from the subcutaneous ecchymosis. Intraoral examination showed poor oral hygiene, with inflamed edematous gingiva and submucosal ecchymosis over the left floor of the mouth (figure 1B).

Figure 1.

Photographs showing diffuse mild swelling over the left side of the lower lip and labial tissue (A). Intraoral photograph showing inflamed edematous gingiva and ecchymosis over the floor of the mouth (B). The photographs were taken after the initial local control of bleeding and before the embolisation procedure.

On initial examination, vital parameters of the patient revealed hypotension (98/60 mm Hg) with tachycardia (110/min). Oxygen saturation recorded on pulse oximeter ranged from 85% to 90%. A local pressure pack soaked in antifibrinolytic (2 mL tranexamic acid) was immediately applied over the bleeding site. Intravenous injection of tranexamic acid (500 mg) was given. After maintaining a tight pack for about 10 min, the bleeding was partially controlled. Complete haemostasis was further attained by using a combination of pressure pack, electrocautery over the gingiva and bone wax. There was a total loss of 1000 mL of blood, and the haemoglobin level was measured to be 70 g/L. Transfusion with 2 units of packed red blood cells was given, after blood grouping and cross matching. The patient was haemodynamically stabilised and was hospitalised for further assessment.

Investigations

Based on the clinical findings, a local vascular lesion was suspected to be the possible cause of bleeding. The patient was subjected to contrast-enhanced CT and angiography of the head and neck region. An irregular venous mass was noted in the gingivobuccal space, measuring 3.9×6.7×2.9 cm (craniocaudal×axial×anteroposteriorly). Anteriolaterally, the lesion was reaching up to subcutaneous tissue and causing a contour bulge. The lesion was determined to take its arterial supply from the facial branch of the left external carotid artery and was draining into the anterior jugular vein. Multiple dilated spaces showing attenuation of vessels and multiple torturous venous channels were seen within the lesion (figure 2A). The 3D formatted CT image showed superficial erosion of the buccal cortex of the mandible over the left parasymphysis region, indicating osseous remodelling or trophic change (figure 2B). No changes were seen within the medullary bone of the mandible. The aforementioned features were diagnostic for AVM in the gingivobuccal space with remodelling of the adjacent mandible.

Figure 2.

3D CT angiography showing an arteriovenous malformation of the facial soft tissue with arterial supply from the facial branch of the left external carotid artery (A) and 3D formatted CT image showing superficial erosion of the buccal cortex of the mandible.(B)

Treatment

In view of the imaging findings AVM was diagnosed as the cause of profuse bleeding. After discussion with the team of oral and maxillofacial surgeon and intervention radiologist, a decision to treat the AVM by embolisation was planned. The endovascular procedure was carried under general anaesthesia. Preoperative angiography of the branches of the external carotid artery was done to assess the arterial feeders and venous drainage (figure 3A). Transfemoral embolisation of the AVM was done using N-butyl cyanoacrylate glue and polyvinyl alcohol particles, along with manual compression of the venous outflow to prevent emboli into the circulation. The procedure was terminated once an adequate embolisation was confirmed on the angiogram.

Figure 3.

Arteriogram before embolisation showing the arteriovenous malformation (A) and postembolisation showing resolution of the lesion (B).

Outcome and follow-up

The patient showed uneventful recovery and was subsequently kept on regular postoperative follow-up. At 3 months’ follow-up, the patient showed signs of resolution of the labial swelling with no further episode of oral bleed. No recurrence of AVM was demonstrated on the follow-up angiogram (figure 3B).

Discussion

Uncontrolled bleeding during tooth extraction can occur due to various reasons, which can be broadly grouped as local and systemic causes. While the systemic factors include coagulopathies, uncontrolled hypertension and use of anticoagulants or antiplatelet drugs, the local causes include severe inflammation of gingival or periodontal tissues, traumatic extraction causing excessive soft tissue injury or bone fracture, and vascular lesion associated with the tooth.^{3 4} Mulliken and Glowacki classified these vascular lesions as vascular tumours (eg, haemangioma) and vascular malformations.⁴ Vascular malformations are rare disorders of morphogenesis of blood vessels, typically resulting in large sacs and torturous folds of abnormal vascular channels. They are composed of either arteries, veins, capillaries, lymphatic channels or a combination of them.¹ When the vascular malformation has an arterial component, it shows high-flow characteristics, which significantly increases the risk of life-threatening bleeding from the lesion in the event of accidental trauma or iatrogenic injury. AVMs are common in the head and neck region, which is rich in blood supply and collateral anastomosis, accounting for 50% of the cases.² However, involvement of the maxillofacial area is rare. AVM of the jawbone accounts for less than 5% of the total craniofacial lesions.⁵

Clinical presentation of AVM depends on its location and size. Although they are present at birth, they invariably get diagnosed by childhood or puberty when the lesion grows sufficiently in size to be symptomatic and clinically noted. Small and deep-seated lesions may be seldomly discovered later in adulthood. Symptoms of AVM depend on its location. Superficial and soft tissue AVMs are pulsatile, with palpable thrill and bruit on auscultation. While intraosseous lesions present as lytic jaw lesion, with tooth mobility and bleeding from gums on minor trauma like tooth brushing.⁶ The overlying mucosa and/or skin is invariably discoloured. Rarely due to lack of any obvious presenting sign, as described in the present case, an AVM is diagnosed following an uncontrolled bleeding during tooth extraction. Such an event presents as an alarming emergency in a dental surgery and, if not managed promptly, can be associated with significant morbidity and mortality. Search of English literature in the PubMed database (from year 1995 onwards) and further review of their references revealed 15 papers reporting life-threatening bleeding from AVM during tooth extraction.^7–21 These papers were further reviewed for demographic details, location of AVM, feeder vessels, primary management for bedding control and definitive management of AVM and outcome (table 1).

Table 1.

Review of literature for uncontrolled bleeding during tooth extraction associated with AVM

No	Author and year	Age/sex	Tooth extracted	Location of AVM	Feeding vessel(s) to AVM	Primary management for bleeding	Definitive management of AVM	Outcome
1	Engel et al71995	13/F	Left mandibular third molar (38)	Intraosseous (left mandible)	ND	Local pack and blood transfusion	Embolisation and left hemimandibulectomy with reconstruction	Resolution
2	Kademani et al8 2004	9/F	Left maxillary deciduous molar	Both intraosseous and extraosseous (left facial soft tissues, maxillary alveolus and maxillary sinus)	Internal maxillary and facial artery	Emergency embolisation and blood transfusion	Multiple embolisation	Resolution
3	Kluba et al9 2007	31/F	Left mandibular third molar (38)	Both intraosseous and extraosseous (pterygomandibular space with osseous infiltration)	Lingual and facial artery	Local pack and emergency embolisation	Multiple embolisation	Resolution
4	Bouloux and Perciaccante10 2009	17/M	Left maxillary third molar (28)	Extraosseous (buccal and pterygomasseteric space)	Internal maxillary, ascending pharyngeal and facial artery	Local pack, electrocautery, and suturing	External carotid artery ligation and embolisation	Resolution
5	Singh and Bhardwaj11 2010	16/F	Left mandibular second premolar (35)	Intraosseous (left mandible parasymphysis body region)	ND	Local pack	Mandibular resection and reconstruction	Resolution
6	Rattan and Sethi12 2010	10/F	Right mandibular deciduous first molar (84)	Intraosseous (right mandibular body)	Internal maxillary artery	Local pack, blood transfusion	Curettage of the lesion with buccal window approach	Resolution
7	Nath et al13 2011	16/M	Right maxillary first molar (16)	Intraosseous (right maxilla)	ND	Local pack, antifibrinolytic agent, bone wax	_	Fatal
8	Churojana et al14 2012	10/M	Deciduous mandibular tooth	Intraosseous (entire mandible)	ND	Emergency arterial embolisation	Multiple embolisation combined with partial mandibular resection	Good Bleeding control.
9	Dwivedi et al15 2014	10/F	Left mandibular molar	Intraosseous (left ramus-angle region of mandible)	Multiple feeders from left external carotid artery	Local pack and blood transfusion	ND	ND
10	Kriwalsky et al16 2014	52/F	Right mandibular third molar (48)	Extraosseous (tongue, floor of the mouth, lower lip and buccal space)	Lingual and maxillary artery	External carotid artery ligation	ND	ND
11	Byun et al17 2016	55/F	Left maxillary second molar (27)	Intraosseous (Left posterior maxilla)	Greater palatine artery	Local pack, cautery, collagen sponge and sutures	Embolisation and resection of the lesion	Resolution
12	Sabani et al18 2017	58/F	Left mandibular, first molar (36)	Extraosseous (left floor of the mouth, tongue, inferior lip, buccal, chin, anterior cervical and submandibular region)	ND	Local pack	Embolisation	Resolution
13	Bocchialini et al19 2017	14/F	Right deciduous mandibular second molar (85)	Intraosseous (extensive involvement of mandible and maxilla, zygoma and other facial bones)	ND	Local pack, bipolar cautery, application of bone wax and fibrin glue	ND	ND
14	Hasnaoui et al20 2017	11/F	Right deciduous mandibular first molar (84)	Intraosseous (right mandible)	Facial and multiple branches from external carotid artery	Local pack, antifibrinolytic agent and silicone compression tray	Multiple embolisation	Partial resolution
15	Kim et al21 2018	10/F	Right mandibular second premolar (45)	Intraosseous (right mandible)	Facial and internal maxillary artery	Local pack and blood transfusion.	Multiple embolisation	Partial resolution.
16	Present case	40/F	Left mandibular lateral Incisor (32)	Extraosseous (lower lip and gingivobuccal space)	Facial artery	Local pack, blood transfusion	Embolisation	Resolution

AVM, arteriovenous malformation; F, female; M, male; ND, not described.

AVMs are rare lesions, with reported incidence of 1.34 per 100 000 individuals.²² It is more common in women, with a male to female ratio of 1:2.¹⁵ Intraosseous AVMs are twice as common in the mandible as compared with the maxilla. It associated with high risk of complication related to excessive haemorrhage in 10%–15% of cases.²³ Literature review shows that events of excessive bleed during tooth extraction associated with AVM were predominantly reported in young female patients, with a male to female ratio of 1:4. The mean age of the patients was 22 years (SD of 17.87). Mandibular molars were the most commonly removed teeth. Eleven cases of severe bleeding occurred during mandibular extraction, while 4 cases were associated with removal of maxillary teeth. Deciduous dentition was involved in 5 cases, whereas permanent teeth was extracted in 10 patients.

On panoramic radiographs, intraosseous AVM presents as a poorly defined radiolucent lesion. Gelfand et al described three types of radiographical appearances: sunray appearance (formed by trabecular bone in between the vessels and the osteolytic lesion) and soap bubble or honeycomb appearance and ill-defined radiolucency.²⁴ However, these features are not pathognomonic to AVM. Any lytic jawbone lesion (aggressive cyst or tumour) can have a similar presentation, and the radiological differential diagnosis should include ameloblastoma, keratocyst, central giant cell granuloma, odontogenic myxoma, malignant tumours and metastatic bone lesion.²⁰ Thus, plain radiograph has a limited role in the diagnosis of intraosseous AVMs. It is recommended to do aspiration from these intraosseous lesions before any surgical intervention. Although a negative response does not completely eliminate AVM, a positive response confirms it. This supports the hypothesis that haemorrhage from the fine puncture done for aspiration can be more easily controlled than that after a more invasive procedure like tooth extraction.

Although panoramic radiograph showed evidence of intraosseous lesion in three of the reviewed cases,^{11 15 20} interestingly, three other cases did not show any sign of bone pathology on plain radiography.^{16 17 19} Intraosseous involvement was predominantly seen, accounting for 67% of the total cases (n=10). While soft tissue AVM was the cause of severe bleeding following tooth extraction in three cases (205), combined bone and soft tissue AVM were present in two patients (13%). The intraosseous AVM involved the mandible in seven cases, while the maxilla was involved in two cases. Involvement of the maxillary sinus was seen in one case.⁸ Bocchialini et al reported a case of extensive intraosseous AVM in a 14-year-old girl with Pierre Robin sequence, involving the entire mandible, maxilla, zygoma and multiple facial bones.¹⁹ Although AVM presents as an isolated developmental malformation, it has been infrequently associated with various syndromes including Osler-Weber-Rendu syndrome, Parkes-Weber syndrome, blue rubber bleb nevus syndrome, Bannayan syndrome, Klippel-Trenaunay syndrome, Sturge-Weber-Krabbe syndrome, Servelle-Martorell syndrome and Maffucci syndrome.¹⁶ Among the soft tissue AVMs associated with significant bleeding during tooth extraction, one involved the pterygomasseteric space and the buccal space,¹⁰ while the other two were localised over the floor of the mouth, lower lip and tongue.^{16 18} The present case involved the lower lip. The gingivobuccal part of lesion was in close proximity to the lower anterior tooth and gingiva, which resulted in severe bleeding during reflection of gingival tissue during extraction.

Acute bleeding during tooth extraction is one of the most severe complications of AVM and is associated with high morbidity and mortality. In the event of acute bleeding, tight pressure pack should be immediately applied to prevent excessive blood loss before definitive management can be given. Blood transfusion and use of intravenous fluids are essential to maintain the circulatory volume and to prevent hypovolaemic shock. Local haemostasis at the extraction site is further supplemented with use of local or systemic antifibrinolytic agents, bone wax, electrocautery, suturing, collagen sponge and fibrin glue.7 8 10–13 15 17–21 However, in the event of failure to contain the bleeding from the extraction site, an angiography should be performed to confirm the arterial malformation. The feeder vessel(s) should be embolised as an emergency procedure to prevent exsanguination.^{9 14} Alternatively or when embolisation cannot be performed, acute bleeding can be stopped by ligation of the external carotid artery or its branch.¹⁶ Profuse bleeding from the extraction site associated with AVM, if unabated, causes haemodynamic instability and airway compromise. This subsequently triggers tachycardia, hypotension, fall in haematocrit and haemoglobin level and ultimately hypovolaemic shock.¹⁹ The most dreaded complication of fatality due to exsanguination was reported in 1 out of the 15 cases (7%) reported in the literature.¹³

Advanced imaging modalities including colour Doppler, CT and angiography plays a crucial role in the diagnosis and management of AVM. CT scan provide useful information about the intraosseous lesion in terms of its location, extent, cortical plate perforation and proximity to vital structures. However, CT provide limited information regarding blood flow to the AVM. Angiography remains the gold standard for diagnosis. It provides information regarding the exact location of the lesion. It helps to assess the flow characteristics, arterial supply, venous outflow and presence or absence of arteriovenous shunts.²⁵ Among the reviewed cases of AVM, facial and internal maxillary artery were the most common arterial supply, followed by lingual, ascending pharyngeal and greater palatine arteries.^7–21

Although local pressure pack, emergency embolisation or arterial ligation controls the acute bleeding, definitive management of AVM is essential to prevent recurrence and risk of severe bleed from the lesion in future. The options for management of AVM can be broadly grouped as surgery and endovascular embolisation. Often combination of the two procedures has to be used for management or large and complex AVMs in the head and neck region. The surgical options for AVM treatment described in literature include en bloc resection of jaw, curettage, cryosurgery and surgical devascularisation through ligation of the major arterial supply.¹² When resection is used for management of jawbone AVMs, which are typically common in young age groups, maintenance of symmetry of the face, aesthetics and dental occlusion are of particular concern. Reconstructive surgery is often warranted to reduce the postoperative morbidity and loss of function and aesthetics. Oka et al described a simpler technique of reconstruction where the resected mandible was prepared as a crib, which was packed with cancellous iliac bone graft and replanted to the mandible using a reconstruction plate, thus maintaining continuity defect and form of mandible.²⁶ In one of the reviewed cases of mandible AVM presenting with profuse bleeding during tooth extraction, Rattan and Sethi treated the lesion conservatively with curettage via the buccal cortical window approach. After curettage, the buccal bone is implanted back to maintain the jaw form.¹² However, this method cannot be used when there is excessive bleeding that necessitates resection or when there is destruction of the lingual cortical plate with involvement of the lingual soft tissues.

Embolisation for management of AVMs is indicated for occlusion of large surgically unresectable lesions, staged occlusion of feeder vessel(s) to reduce the vascularity as preparation for resection or as an emergency method for preoperative bleeding control. Embolisation is also indicated for treatment if soft tissue AVMs. Various endovascular approaches used for embolisation of AVM include transarterial, transvenous, transosseous and percutaneous routes. The materials used for embolising are polyvinyl alcohol, cyanoacrylate glue, coils, alcohol, ethibloc and balloons.²⁷ The choice of the material is based on the calibre of lumen of feeder vessels, vascular flow characteristics, preference of the operator and availability. Embolisation reduces blood flow to the AVM and lowers the bleeding risks. However, there is a high chance of new blood vessel formation due to high angiogenic potential of the lesion, resulting in recurrence. Sometimes, multiple sittings of embolisation are required to attain adequate bleeding control. Currently, the commonly accepted treatment for AVM involves initial embolisation to reduce the vascularity of the lesion and risk of bleeding. This is followed by surgical resection of the affected area.²⁸ The complications reportedly associated with embolisation are allergic reactions, avascular necrosis of bone and defective mandibular growth.^{14 21} While embolisation alone was most commonly used for management for AVM in the majority of the reviewed cases, including the present case report,8–10 18 20 21 embolisation was followed up with surgical resection in three cases.^{7 14 17} Only surgical resection¹¹ and curettage¹² were done for one case each. Most of the cases showed resolution with no episode of bleeding. Recurrence of bleeding requiring multiple embolisation was reported in some cases.8 9 20 21 Development of necrosis and osteomyelitis was reported on long-term follow-up of one case of AMV of the mandible,¹⁴ while one patient developed sepsis from oral infection.²¹

Learning points.

• Arteriovenous malformations (AVMs) involving the jawbone and facial soft tissue are rare vascular lesions which, if undiagnosed, can result in severe life-threatening bleeding during oral surgical procedures like simple tooth extraction. The diffuse, pulsatile swelling over the lower lip and chin region was indicative of a local vascular malformation in the present case, which was missed at the initial evaluation by the dental surgeon. Hence, it is important to recognise these lesions so as to avoid potentially fatal outcome.

• Clinical features of skin discolouration, pulsations, bruit and thrills should warn clinicians of a vascular malformation of possible high-flow characteristics. Presence of loose teeth with spontaneous bleeding around the gingival margin or previous history of oral bleed also should alert the clinician of a possible vascular malformation. Purely intraosseous AVMs have a non-specific feature of a multilocular or diffuse radiolucency on a plain radiograph. Hence, aspiration is a must in such situation to possibly rule out a vascular pathology before any invasive procedure is undertaken in the vicinity of the lesion.

• Uncontrolled bleeding during tooth extraction from an AVM requires prompt intervention and multidisciplinary approach for management. Although pressure pack application, along with other supplementary haemostatic means and blood transfusion, often limits the amount of blood loss, embolisation of arterial supply and/or ligation of the external carotid artery or its branches has to be performed as an emergency procedure when the bleeding is severe and persistent.

• A definitive management of AVM includes embolisation, surgery or a combination of both for complete cure and elimination of risk of future bleeding episode.

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