Interesting Case Studies

The Silent Sinus

History:
A 40 year old man consulted for symptoms of persistent nasal congestion for several months. There was no nasal discharge, headache or facial pain.

What we did:
On Nasendoscopy showed that he had a significant nasal septal deviation to the left side but was otherwise normal. In view of the duration of his symptoms, further evaluation with CT scan of the paranasal sinuses was performed. The right maxillary sinus (cheek sinus) was found to be completely opacified (filled with mucus) and contracted (small). In particular, the contraction of the sinus was associated with depression of the floor of the orbit (eye socket). On further evaluation of his eye, his eye movements and vision were normal.

He underwent Functional Endoscopic Sinus Surgery (FESS). During surgery, the location where the usual opening to the affected maxillary sinus was completely sealed off. A new opening was created to remove the mucus that was trapped in the sinus and to restore ventilation (air) to the sinus. The intraoperative figures below show how this is done and how surgical precision is confirmed with image-guidance system (IGS).

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Fig 4a. Removal of trapped mucus after opening the sinus


Fig 4b. The tip of the suction catheter is easily manoeuvred into the sinus through the wide opening.

After 3 post-operative visits over about 1 month, the healing of the sinus mucosa was complete. The opening to the right maxillary sinus was maintained with no accumulation of mucus inside.

Diagnosis:
Silent Sinus Syndrome

Discussion:
Silent sinus syndrome is a rare condition where the opening to maxillary sinus is obstructed. As there is no longer access for air to get into the sinus, it is completely filled with mucus and starts to contract inwards. Since the bone that makes up the roof of the sinus is also the floor of the eye socket, the eye may gradually start to since backwards over a number of years. In severe cases, the eye may appear visibly sunken.

It is called a “silent” sinus because the usual symptoms associated with sinusitis (nasal discharge, sinus pain, loss of smell) are absent. Indeed, the sinus was not actually infected in this case.

Interestingly, some of the bony remodelling (leading to the sinking of the eye) is reversible once ventilation is restored to the sinus. This may, of course, take months to years as well. In the case presented here, the condition was picked up early before any significant changes to the eye had occurred.

 

Contributed by: Dr David Chin Chao-Wu