Inferior Alveolar Nerve Dysfunction following Embolization of Inferior Alveolar Artery Pseudoaneurysm

Abstract

We report a case of left inferior alveolar nerve dysfunction following management of left inferior alveolar artery pseudoaneurysm in a 32-year old female following third molar extractions. After failing to manage the bleeding with conservative methods, embolization of the left inferior alveolar artery and the anastomosing branches of the facial artery was performed by interventional neuroradiology utilizing a fibered coil and N-butyl cyanoacrylate. Immediate hemostasis was achieved without major complications. The patient suffered transient anesthesia of left inferior alveolar nerve but recovered fully after two months.

Highlights

  • Interdisciplinary collaboration is required to manage major head and neck bleeding events.

  • Selective embolization by an interventional or neuro-interventional radiologist is first-line management for this injury.

  • Embolization can lead to unexpected complications such as nerve injuries.

Introduction

Extraction of third molars is the most common procedure performed by oral and maxillofacial surgeons. Although uncommon, a pseudoaneurysm can develop from localized injury to the branches of the internal maxillary artery (IMA) and facial artery (FA). This condition can result with profound bleeding that can be life threatening. Selective embolization, traditionally performed by interventional or neurointerventional radiology, is now considered first-line management. Embolization involves several risks, including renal, cerebrovascular, and nerve injury. There have been several case reports on post-extraction embolization, but none have elaborated on its impact on the inferior alveolar nerve (IAN). Based on this case report, embolization of the inferior alveolar artery (IAA) has transient adverse consequences on IAN function.

Case report

A healthy 32-year-old female was seen in the emergency department of the University of Cincinnati Medical Center after being transferred from an outside hospital for left mandibular bleeding. The patient had her lower third molars extracted thirty days prior by an oral and maxillofacial surgeon in the community ( Fig. 1 ). Over the next several weeks, the patient experienced six different episodes of intermittent bleeding from the extraction site of tooth #17.

Fig. 1
Panoramic radiograph, prior to extraction of #17. The patient developed a pseudoaneurysm at this site four week postoperatively.

Upon arrival to the emergency room, the patient was experiencing profuse pulsatile bleeding uncontrolled by gauze compression, tranexamic acid application, and localized hemostatic measures. Vital signs were unremarkable, and baseline hemoglobin/hematocrit measured 12.0/35.8 with PT/INR of 1.1. All other studies on coagulation factors were within normal range. A computed tomography angiography (CTA) of the head and neck revealed an 8 mm × 8 mm x 10 mm region of extravasation of the left IAA resembling a pseudoaneurysm without the presence of arteriovenous malformation or abnormal shunting ( Fig. 2 ).

Fig. 2
Computer tomogram angiography, axial view, with contrast. Hyperdense active extravasation is observed in the extraction socket of #17.

The patient was taken urgently to the radiology suite by neurointerventional radiology under general anesthesia for a diagnostic angiogram and embolization of branches of the external carotid artery ( Fig. 3 ). Vessel catheterization was performed with a diagnostic guide catheter entering the right femoral artery. The left IMA was accessed using a micro guidewire, and an embolization coil was deployed in the left IAA. Control angiogram revealed contributions of the left FA to the pseudoaneurysm, including venous shunting from retrograde flow of the recently embolized artery. N-butyl cyanoacrylate was injected into the left mental artery, which refluxed into the left inferior labial artery. Post-embolization angiogram revealed slow filling of the embolized arteries with cessation of the pseudoaneurysm. During the procedure, the patient’s hemoglobin/hematocrit fell to 8.4/25.9, and two units of packed red blood cells were administered. The patient was extubated and kept overnight in the surgical intensive care unit. Hemostasis was achieved with proper profusion of the mandible and lower face. She was discharged the following day uneventfully without signs of renal failure or cerebrovascular injury.

Fig. 3
Computer tomogram angiography, three dimensional reconstruction, with contrast, pre-embolization. Branches of the IAA (red arrow) and left FA (white arrow) are appreciated. The pseudoaneurysm appears as a sac at the distal part of the left IAA.

The patient did not sustain any IAN damage from her third molar extractions, and her left mandibular trigeminal division was in complete function prior to embolization. In the immediate postoperative phase, the patient had complete anesthesia of the left IAN based on standardized nerve testing, which included nociceptive, proprioceptive, and light touch pathways (MRCS Grade S 0 ). The rest of her cranial nerve examination was unremarkable. Postoperative CT was consistent with post-embolization presentation of the left IAA with no obvious damage to the left IAN ( Fig. 4 ). The nerve was noted to be recovering two weeks later in her follow-up appointment including nociception and light touch (MRCS Grade S 2+ ). After two months of close nerve monitoring, the patient had a complete return to baseline sensation (MRCS Grade S 4 ) with no functional deficits or provider intervention ( Fig. 5 ).

Mar 21, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Inferior Alveolar Nerve Dysfunction following Embolization of Inferior Alveolar Artery Pseudoaneurysm
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