In the past 100 years, major advances in radiographic imaging have allowed the evaluation and treatment of paranasal sinus disease.

Naumann recognised the relationship between the ostiomeatal complex and the pathogenesis of maxillary and frontal sinus disease.

Messerklinger demonstrated that by relieving the ostiomeatal complex from obstruction and therefore inflammation, frontal and maxillary sinus disease can be reversed.

Functional Endoscopic Sinus Surgery (FESS) is the result of advances in paranasal sinus disease investigation.  Advanced endoscopic techniques are used to treat an extensive list of paranasal sinus disorders.
 
 
 

This schematic drawing demonstrates the key diseased area of the anterior ethmoid in green.  The situation after functional endoscopic sinus surgery is shown in red.

FESS is a procedure not without risks, therefore surgeons performing endoscopic sinus surgery must understand the anatomy, techniques and complications of this procedure.

As we have already found, the anatomy of the paranasal sinuses is complex.  Important anatomical landmarks are encountered during FESS.  These are not the same in every individual so it is important to be aware of possible anatomical landmarks to avoid complications during surgery. Follow this link to find out more about landmarks in the paranasal sinuses.

A pre-operative assessment must be completed in each patient.  This includes a detailed history, where the patient is asked questions to give an idea of the severity of the disease.  A thorough physical examination, including nasal endcoscopy.  This procedure allows the visualisation and evaluation of sinus disease.  Imaging studies are the most important pre-operative investigation in use.  CT is the technique of choice to evaluate bone anatomy.  MRI provides better visualisationn of the soft tissues than CT.

The technique of FESS involves visualising the area to be operated upon be endoscopy and removing the infected area with micro-through cutting instruments.  Ostia can also be widened during this procedure to let the sinuses drain better.  The following diagram should help you to visualise this better.
 

A schematic diagram showing the principle of FESS.  Note the important structures the endoscopy passes enroute to the ethmoid sinus.

Potential complications of this procedure are severe.  The most common is post-operative scarring that can lead to continued sinus obstruction, decreased mucociliary clearance and nasal obstruction.  This can be limited with regular post-operative cleansing of the nasal cavity to stop recolonisation of the paranasal sinus epithelium.

Direct trauma to the optic nerve can occur, usually in the posterior ethmoid or sphenoid sinus.  This is irreversible and causes blindness.  Orbital haematoma is caused by injury to the lamina papyracea.  The bony orbit has a fixed volume, so as blood enters, orbital pressure rises and visual loss occurs.

Cerebrospinal fluid leak most commonly occurs where the anterior ethmoid artery penetrates the lateral lamella of the cribriform plate.

Injury to the lacrimal drainage system can occur during FESS.

OPEN OPERATIONS FOR PARANASAL SINUSITIS

The evolution of the treatment of sinus disease, from the origins of sinus trephination to modern developments including FESS, has advanced the treatment of sinus infections, tumours of the sinuses and access of deeper spaces of the head and neck via the paranasal sinuses e.g. the hypophysis.  Open sinus operations are based on sound anatomical principles and should be considered in selected situations.  Open procedures are required when acute sinusitis is complicated by orbital or intracranial involvment.