Persistent frontal fistula.

HK Marfatia, SN Muranjan, MM Navalakhe, MV Kirtane 
 Department of ENT, Seth G.S. Medical College, Parel, Mumbai, India., India

Correspondence Address:
H K Marfatia
Department of ENT, Seth G.S. Medical College, Parel, Mumbai, India.
India

Full Text

::   Introduction

A rare case of persistent frontal sinus fistula on the forehead is presented. It was managed by obliteration of frontal sinus without osteoplastic frontal sinus operation.

::   Case report

A thirty-year-old male, presented with a persistently discharging fistula over the left side of the forehead for four years [Figure:1]. He had a history of trauma to the forehead. The fistula was preceded by a small swelling in that area. The patient had an associated left sided frontal headache. He had undergone two operations in the past for the same without any benefit. At the time of presentation, there was a fistula on the forehead with a vertical scar of previous surgery.

Anterior rhinoscopy and nasal endoscopic examination were normal. There was tenderness of the left frontal sinus. Radiograph of the paranasal sinuses showed an abnormally large and hazy frontal sinus on the left side. The computerised tomography (CT) scan delineated a fistulous tract leading to the pathological frontal sinus with an associated defect in the posterior sinus wall [Figure:2]. On coronal images, a large hazy frontal sinus was seen.

Functional endoscopic sinus surgery was attempted with the idea of establishing fronto-nasal duct patency. This was unsuccessful due to bony sclerosis of the fronto-nasal duct probably due to repeated infection. An elliptical incision was taken on the forehead to include the fistulous tract. After excising the fistula, the periosteum was incised and a bony defect of size 1.5 cm x 1 cm was delineated. The defect was widened with the help of a electric drill. The frontal sinus was inspected and all the diseased mucosal lining was exenterated. An unsuccessful attempt was made to cannulate the fronto-nasal duct from above. An obliteration of frontal sinus was therefore planned. Under endoscopic guidance the mucosal tags of the frontal sinus were removed. The interior of the sinus was smoothened with a diamond burr. A 30? nasal endoscope was introduced through the defect to confirm complete exenteration of mucosa. Abdominal wall fat was used to obliterate the sinus completely after giving an antibiotic wash. Scalp flaps were mobilised for primary closure and a pressure dressing was applied. Recovery was uneventful.

::   Discussion

The frontal sinus drains into the nose via the fronto-nasal duct, which runs a tortuous course along the ethmoid labyrinth. This duct is susceptible to blockage by various anatomical and pathological variations which give rise to complications of frontal sinusitis. Variations exist in the size of frontal sinus. The outer table of skull bears an anterior relationship with the frontal sinus, which is a tough diploic bone and is resistant to erosion. The posterior wall is related to the cranial cavity. The complications of frontal sinusitis occur secondary to blockage of the fronto-nasal duct. This duct runs a tortuous course through the ethmoid labyrinth. It can get blocked by a deviated nasal septum, a hypetrophied turbinate, a concha bullosa or by an abnormally large ethmoidal cell. Old healed nasal fractures or repeated infections can cause obliteration by bony sclerosis[3]. Blockage of the duct causes accumulation of secretions. This results in pressure necrosis of the posterior and inferior walls. Very rarely there is an erosion of the anterior sinus wall as it is made up of relatively thick bone. In the presented case the frontal sinus was distributed over a large surface area. Hence a trivial trauma resulted in giving way of the anterior sinus wall leading to a fistula formation. Repeated infections results in sclerosis of the fronto-nasal duct, which could not be opened up endoscopically or by an external approach. A complete obliteration of the sinus with exenteration of all its mucosa and packing of fat was successfully performed in our case. With the help of nasal endoscopes, which permit angled vision, it is now possible to do this without raising an osteoplastic flap.

::   Acknowledgment

We are grateful to the Dean, King Edward Memorial Hospital and Seth GS Medical College, Mumbai 400 012, for allowing us to publish the hospital data.

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