How To: Extended External Rhinoplasty Approach for Nasal Dermoids With Intracranial Extension

INTRODUCTION

Nasal dermoids are uncommon lesions with an incidence of approximately 1:20,000–1:40,000. They can be intranasal or extranasal with or without intracranial extension and are most commonly located on the nasal dorsum (Curr Opin Otolaryngol Head Neck Surg. 2021;29:487-491). The reported incidence of intracranial extension is highly variable, ranging from 4% to 45% (Cleft Palate Craniofac J. 1991;28:87-95). Apart from cosmetic issues and recurrent drainage, nasal dermoids are associated with complications including recurrent infection that may lead to meningitis or brain abscess (Plast Reconstr Surg. 1994;4:745-754). Complete surgical resection is recommended for management, as recurrence is high in incomplete resections with reported rates as high as 100% (Curr Opin Otolaryngol Head Neck Surg. 2021;29:487-491; J Neurosurg Pediatr. 2020;25:298-304).

Traditionally, nasal dermoids with intracranial extension are removed following bicoronal incision and frontal or frontonasal craniotomy (J Neurosurg Pediatr. 2020;25:298-304). This provides great exposure of the dermoid tract; however, it increases the risk of alopecia, unfavorable scarring, meningitis, hyposmia, cerebrospinal fluid leakage, damage to frontal and sagittal sinuses, and other complications related to brain retraction (Curr Opin Otolaryngol Head Neck Surg. 2021;29:487-491; J Neurosurg Pediatr. 2020;25:298-304). Another approach more recently described involved a midline incision with nasal bone osteotomy and keyhole craniotomy (J Neurosurg Pediatr. 2020;25:298-304). Endoscopic approach to resection of dermoid cysts with intracranial extension has also been described. Endoscopic resection virtually eliminates the possibility of unfavorable scarring and other complications associated with craniotomy. Despite the advantages of endoscopy, large intracranial cysts in smaller children are technically challenging to manage due to limited space, which can lead to incomplete resection and potential recurrences (J Neurosurg Pediatr. 2020;25:298-304).

We describe the approach of extended external rhinoplasty with bilateral marginal and alar base incisions, which not only provides access to the nasal part of the dermoid but also excellent visualization of the anterior skull base for complete excision of large intracranial cysts in a cosmetically favorable manner.

METHOD

A retrospective chart review was performed of a three-year-old child presenting with a cystic lesion on the nasal tip that had progressively grown since birth. Computerized tomography (CT) and magnetic resonance imaging (MRI) evaluations showed a non-enhancing anterior nasal lesion measuring 0.9 cm x 0.6 cm x 0.7 cm consistent with dermoid cyst and a sinus tract with a 1-cm intracranial extension.

Surgical Technique

After orotracheal intubation and administration of perioperative antibiotics, the patient’s head was placed in a Mayfield holder. The external nose and nasal septum were injected with 4.0 cc of 1% lidocaine with 1–100,000 epinephrine. Bilateral nasal cavities were decongested with Afrin-soaked pledgets. Frameless stereotactic CT imaging was registered to the patient. Standard rhinoplasty instruments were used for the resection of the intranasal dermoid cyst. An ultrasonic bone aspirator with a barracuda tip was used for intracranial dissection of the dermoid cyst.