Sunday, January 23, 2011

Endoscopic inferior meatal antrostomy has it got any role today?


Since the introduction of Functional endoscopic surgery inferior meatal antrostomy as a procedure has taken a back seat due to the apprehension that it could tamper with the normal mucociliary clearance mechanism. Infact studies performed in 1980's reported that if inferior meatal antrostomy is created the mucous bridges across the antrostomy and travels towards the natural ostium of the maxillary sinus. This can utmost be considered to be only partially true. Current studies have demonstrated that drainage of mucous does occur via the opening created in the inferior meatus.

Current indications for inferior meatal antrostomy:

  1. Patients with chronic sinusitis not responding to FESS
  2. Patients in whom mucociliary clearance is already affected due to cystic fibrosis / Young's syndrome. These patients usually benefit from inferior meatal antrostomy
  3. Mycetoma present in the maxillary sinus cavity
  4. To visualize the difficult to see areas inside maxillary sinus cavity
  5. When regular post op surveillance is needed

Endoscopic inferior meatal antrostomy:

Nasal endoscope is a very useful tool for otolaryngologist. By using this tool the whole procedure can be performed under direct visualization. This procedure can be performed under both LA / GA.

Nasal decongestion:
Nasal mucosa is decongested by using pledgets soaked in 4% xylocaine mixed with 1 in 10,000 adrenaline. The pledget should be squeezed dry before insertion. This is done to avoid xylocaine overdosage. Pledgets should be placed in inferior meatus, floor of the nasal cavity, and middle meatus. If general anesthesia is used throat pack should be given to prevent aspiration.

2% xylocaine with `1 in 100,000 units adrenaline is used to infiltrate the inferior turbinate and the corresponding portion of nasal septum. 0 degree nasal endoscope is used for purposes of visualization. A Freer's elevator is inserted into the inferior meatus and the inferior turbinate is up fractured so that it lies perpendicular to the floor of the nasal cavity. This procedure is a must for adequate visualization of the inferior meatal area. The location of Hasner's valve (lower end of nasolacrimal duct) is identified at the junction of anterior third and middle third of the lateral nasal wall. A 90 degree angled J curette is ideal to perform antrostomy. The lateral nasal wall is perforated with J curette about 1 cm posterior to Hasner's valve. The opening is then enlarged with the help of back biting forceps. Now insertion of a 30 degree nasal endoscope will help in better visualization of the interior of maxillary sinus cavity.

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