FUNCTIONAL ENDOSCOPIC SINUS SURGERY

FUNCTIONAL ENDOSCOPIC SINUS SURGERY

Nishit J Shah
Hon. ENT Surgeon, Bombay Hospital and Medical Research Centre, Mumbai
The endoscope has revolutionised the diagnosis and treatment of diseases of the nose and paranasal sinuses. It has enabled us to detect and diagnose many conditions that would hitherto go unnoticed and therefore untreated with speculum examination. Whilst operating, we have the advantage of good illumination and clear vision with minimally invasive surgery. Functional endoscopic sinus surgery (FESS) aims at maintaining physiological function and anatomical structure. The extent of the operation is adapted according to each case. It is focused on the ostiomeatal complex in the middle meatus and the ethmoid cells. The term FESS is used to draw attention to the potential for re-establishing sinus drainage and mucosal recovery. With FESS, it is possible to achieve consistently good results, provided the surgery is done accurately and with care. Most of the reported complications are minor. Major complications require an immediate aggressive medico-surgical treatment to minimise the sequelae. Chronic sinusitis not responding to medical treatment and nasal polyposis are two classical indications for performing endoscopic sinus surgery.
The endoscope has revolutionised the diagnosis and treatment of diseases of the nose and paranasal sinuses. It is the most exciting recent development in the field of ENT. We are now able to ‘discover’ hitherto unknown areas, detect diseases at the earliest stages, look around corners in the nose and actually peep into the sinuses.

Whilst operating, we have the advantage of good illumination and clear vision with minimally invasive surgery. The endoscope even enhances postoperative management in helping rapid healing and for early detection of any recurrent disease. Endoscopic surgery has been done for over 15 years now, but only now has it gained universal acceptance as the treatment of choice for sinus disease. While the endoscope is not the panacea for all nasal or paranasal sinus diseases, it is certainly an instrument that MUST be present in the armamentarium of today’s ENT surgeon.

Endoscopic surgery aims at maintaining physiological function and anatomical structure. The health and normal function of the paranasal sinuses and their lining mucous membranes depends primarily on two important factors. Ventilation and drainage. Hence normal function of the sinuses depends on the amount of mucus produced, its composition, the effectiveness of ciliary beat, and the condition of the ostia and the ethmoidal clefts.

In the maxillary sinus, mucus transportation starts from the floor of the sinus in a stellate pattern towards the natural ostium. From there it exits into the ethmoid infundibulum and through the hiatus semilunaris over the inferior turbinate posteriorly into the naso-pharynx. The frontal sinus is the only sinus in which there is active inwardly directed transportation of mucus. The frontal recess may also collect secretions from other ethmoidal compartments. The anterior ethmoid sinuses drain through their ostia into the middle meatus. It is thus realised that the health of the anterior ethmoid cells is essential for normal functioning of the other sinuses, and hence treatment must be concentrated on these cells and the ostiomeatal complex in the middle meatus. Since each sinus has its own pattern of movement for the mucus blanket ending at the natural ostium, making an ostium in another location is ineffective, and the emphasis is on clearing and widening the natural ostium.

Diagnostic Nasal Endoscopy

The endoscope has enabled us to detect and diagnose many conditons that would hitherto go unnoticed and therefore untreated with speculum examination. Hence, it is extremely important to do a diagnostic nasal endoscopy, and many ENT specialists consider that it should form a part of routine examination in all patients with a nasal or sinus complaint (Fig. 1)

Fig 1. Endoscopic photograph shpwing middle meatus and concha bullosa of the middle turbinate.

Indications
1. nasal obstruction
2. sinusitis
3. headache
4. nasal mass, polyposis
5. epistaxis
6. post-operative
7. anosmia, parosmia or cachosmia
8. CSF rhinorrhoea
9. suspected foreign body
10. examination of the nasopharynx and Eustachian tube openings
11. documentation

To achieve long lasting relief from sinusitis, it is important that some principles be observed which include removal of disease; control of tissue oedema; facilitation of the drainage pathway; maintenance of ostial permeability; achieving normal aeration and maintenance of physiology. [2]

With FESS, it is possible to achieve all these objectives and realise consistently good results, provided the surgery is done accurately and with care. In spite of standardisation of the operative procedure, this type of surgery may be risky in novice hands. Most of the reported complications are minor. Major complications require an immediate aggressive medico-surgical treatment to minimise the sequelae. Precise and complete pre-operative evaluation, good preparation of the patient, meticulous and adapted surgical technique and experience acquired through a regular practice of this type of surgery play a major role to lower the risks of complications.

Endoscopic sinus surgery can be performed under local or general anaesthesia. Local anaesthesia is preferable when the patient is co-operative as there is less bleeding and any undue pain can warn the surgeon that he is close to vital structures, like the orbit or dura. General anaesthesia is necessary in children, apprehensive or uncooperative adults, extensive pathology and complicated sinusitis.

After an initial endoscopic check, the first step of the operation is to do an uncinectomy. An incision is made on the uncinate process, starting at the level of the upper attachment of the middle turbinate and ending just above the inferior turbinate. The uncinate process is then removed with a twisting movement, thus uncapping the infundibulum. This preliminary step of the surgery is also perhaps the most important. Incomplete or improper removal of the uncinate will cause difficulty not only with further dissection of the ethmoid cells, but can also make identification of the maxillary sinus ostium difficult. An incompletely removed uncinate process is perhaps the most common finding in revision cases and the cause for surgical failure.

The bulla ethmoidalis is now seen and removal of the anterior ethmoidal air cells is undertaken. The bone forming these cells is very thin and one can remove it quite easily and gently using ethmoid forceps. There is an increasing trend towards using through cutting forceps as they spare mucosa, which aids in better and quicker healing. It is advisable not to use force at any point in the surgery, as it could easily result in a CSF leak or injury to the orbit. Superiorly, the dissection stops at the ethmoid roof where the bone is more tough and smooth. It is important to clear the sinus lateralis, which is a space of variable size, extending between the bulla and the roof of the ethmoidal sinus medial to the lamina papyracea, lateral to the middle turbinate, and posteriorly between the bulla and the ground lamella. This will ensure complete clearance of the anterior ethmoids, define the boundaries of dissection and guard against possible recurrence.
The anterior and posterior ethmoidal arteries may be identified running across the roof. It should be noted that the roof of the ethmoids which separates the air cells from the dura, curves upwards as it goes laterally. Close to the attachment of the middle turbinate, it is thin, and dips down rather sharply to join the cribriform plate. While dissecting in this region it is always safer to keep the forceps pointed laterally, away from the cribriform plate area. Laterally, the dissection stops at the lamina papyracea, which is identified by its yellowish tinge. In this area it is advisable to use the side of the forceps for dissection to avoid accidental perforation and injury to the orbital periosteum. If the lamina papyracea is perforated accidentally the patient will complain of pain in the eye and fat will prolapse into the nasal cavity if the orbital periosteum has also been damaged. Under no circumstances should the fat be pulled out or resected. At the end of the procedure, the prolapsed fat can then be ‘splinted’ with a small Merocel sponge for 1-3 days. The patient is instructed not to blow the nose as that can result in orbital emphysema.1 Posteriorly, the dissection is completed till the ground lamella, which is a bony partition between the anterior and posterior ethmoid cells. The ground lamella is actually the postero-lateral attachment of the middle turbinate. It is also necessary to clear the frontal recess area. The anterior ethmoidal cells, which are situated around the frontal recess and anterior to the anterior ethmoidal artery, are removed using a 30o endoscope and upward biting forceps. At times it is necessary to open the agger nasi cells to get an adequate view of this area. After clearing the anterior cells it is possible to see the opening of the frontal sinus, which should be unblocked by removing diseased mucosa surrounding it. During endonasal frontal sinusotomy, a solid piece of bone is occasionally encountered anterior to the neo-ostium. This bone may be referred to as a "nasal spine". A prominent spine may render a sinusotomy difficult or even impossible. [3]
The next step is to widen the natural ostium of the maxillary sinus. The sinus ostium should be found easily once the anterior ethmoidectomy has been completed and provided the uncinate has been completely removed. Often however, there may be oedematous or polypoidal mucosa obscuring the sinus opening, in which case the maxillary ostium is found by probing the lateral nasal wall over the inferior turbinate usually near its middle in an anterior to posterior direction. One should be careful to remain just above the attachment of the inferior turbinate to avoid inadvertent damage to the lamina papyracea and the orbital contents which are situated at a slightly higher level. Sometimes during sinuscopy, it is almost impossible to identify the ostium of the maxillary sinus especially when the mucosa is swollen. Pressure against the fontanelles may make bubbles appear through the natural ostium; thereby revealing its position.1 Once the natural ostium is identified, punching out its bony walls using Ostrum’s reverse cutting forceps widens it. It is better to enlarge the ostium in the anterior direction but one must stop short of the nasolacrimal duct, the position of which is indicated by the bone becoming thicker and harder. Another landmark is the anterior end of the middle turbinate. As long as the antrostomy window remains posterior to it, the nasolacrimal duct will not be damaged. A branch of the sphenopalatine artery lies in the region of the posterior fontanelle and bleeding may occur if the ostium is widened posteriorly. If direct visualisation of the maxillary sinus is required, a canine fossa puncture with a trocar and canula can be done. A 30o or 70o telescope can be introduced to inspect the various walls of the maxillary sinus and its ostium and a biopsy taken or marsupialisation of a cyst done by using only the canine fossa approach.

The posterior ethmoidal cells and the sphenoid sinus need to be opened only if the posterior most of the anterior ethmoid cells are diseased or if the CT scan has indicated presence of disease in this region. The posterior ethmoids are entered by gently perforating the basal lamella. The posterior ethmoidal cells are carefully removed till the anterior wall of the sphenoid is reached. It should be remembered that the lateral wall of the posterior ethmoidal cells forms a very close relationship to the orbital apex and the optic nerve laterally. Superiorly, they are closely related to the dura.

The sphenoid sinus is entered by perforating its anterior wall and widening the opening. This must always be done in an infero-medial direction from the posterior ethmoids to prevent inadvertent injury to the dura. The sphenoid sinus can also be entered directly when required, such as when there is isolated sphenoid sinus disease via the sphenoethmoidal recess. The anterior wall of the sinus is indented with a suction, staying inferiorly and medially (close to the septum) until the ostium is located usually about 1.2 cm above the choana. The opening can then be widened by removing the anterior sphenoidal wall. It is sometimes necessary to trim the inferior-posterior part of the middle turbinate to have access to the anterior sphenoid wall. Pathology like polyposis in the sphenoid sinus should always be removed under direct vision and no blind dissection should be done especially towards the lateral wall, which is closely related to the optic nerve and the internal carotid artery. In 4% of cases, the optic canal in the superolateral part of the sphenoid sinus may be dehiscent, putting the optic nerve at risk. [1]

At the end of the surgery, the nose is packed with Merocel to stop bleeding and act as a tamponade to keep the middle meatus open. This may be removed 24-48 hours later.

There have been many advances to aid in surgical technique in recent times. Powered tools (microdebrider) have now become a part of routine surgery. The microdebrider acts by sucking in abnormal tissue and cutting it with a rotating knife. This is excellent for polypoidal tissue as the dissection is quick, almost bloodless, safe and importantly it spares normal mucosa which helps in quicker healing. The instrument can be modified for different uses including cutting and removal of bone by changing the rotating blade. In keeping with this need to preserve mucosa, many surgeons now advocate using through-cutting forceps for dissection, instead of the traditional Blakesly-Weil forceps, which used to grasp and pull tissue. Flexible forceps are now available for previously hard to reach areas, such as in the maxillary and frontal sinuses. Many centres also boast of the facility for CT scan guided surgery (Instatrak). A pre-operative scan of the patient is used to aid the surgeon for orientation and location of disease in an intra-operative setting. This not only makes the surgery safer but also ensures complete eradication of diseased areas. The use of laser has also been incorporated into endoscopic surgery. The laser can be used to debulk polypoidal tissue, for cautery or partial resection of turbinates, to control bleeding and to remove scar tissue and adhesions. The use of laser has however waned, in part due to increasing post-op scarring and necrosis. Finally, post-operative packing has changed entirely with the introduction of Merocel nasal packing. It is not only effective in haemostasis, but is also more comfortable for the patient and is available with a tube to allow nasal breathing.

In the post-operative period, the patient is given a course of broad-spectrum antibiotics. The nasal secretions and crusts are cleared using a nasal suction under endoscopic guidance, and an antibiotic-steroid ointment may be applied over the raw area. Care should be taken to prevent synechiae between the turbinate and the lateral nasal wall. A few days later, saline nasal douches may be taken by the patient to cleanse the nose.

Endoscopy permits the identification and lysis of synechial bands, the correction of early stenosis of sphenoidal, maxillary and frontal ostia and the removal of devitalised flecks of bone. Such areas of residual osteitis may become foci for chronic infection and ultimate surgical failure. Excellent post-operative care is essential to a good outcome of endoscopic sinus surgery. (Fig. 2a, 2b) Clinically, the nose takes about 6 weeks for healing and the mucosa looks normal at around 3 months. However, normal physiological function may take longer to return to normal. The ciliary beat frequency and olfactory function though significantly improved after surgery, reached normal values about 6 months postoperatively, emphasising the need for a longer period of follow-up. [1]

Fig 2A Fig 2B

Preoperative coronal CT Scan of patient with bilateral chronic sinusitis. Postoperative coronal CT Scan of patient taken four months later showing clear ethmoid cavities and normal maxillary sinuses.

Since its introduction, functional endoscopic sinus surgery (FESS) has demonstrated success rates of 76% to 98%. RESS (Revision) is associated with a 1% major complication rate and is successful in 67% of patients. [1,2]

Revision Surgery

Although FESS is a new standard of care, it can neither be expected nor represented to effect a cure. A limitation of the surgery is that it is not an ‘excisional’ surgery. In the absence of the ability to ‘excise’ the sinuses, healing must take place. Often, healing may not occur as desired or expected, resulting in the need for a secondary extension and /or revision procedure, which is usually minor. A more radical surgical approach is rarely, if ever, needed. In a study by Senior et al, 18% of patients required subsequent surgical procedures. The study also validates the concept that patients in whom the cavity can be normalised following surgery are unlikely to require further surgery. [3]

Indications for FESS

The Caldwell-Luc (CWL) operation for the maxillary sinus was described at the end of the nineteenth century and has held its own for a hundred years. Though some infrequent indications still remain, FESS has now replaced the CWL operation as the treatment of choice in sinusitis. Whilst more studies are needed to test antibiotic regimens, combined with surgical drainage and anti-inflammatory agents, conventional management of sinusitis is of little benefit in patients with chronic refractory sinusitis with an underlying immunodeficiency. [4]

Chronic sinusitis not responding to medical treatment and nasal polyposis are two classical indications for performing endoscopic sinus surgery (Fig. 3). In chronic sinusitis, symptoms such as nasal obstruction, headache and discharge can be effectively relieved. An antrochoanal polyp can be very easily removed and the maxillary extension can be tackled by widening the maxillary ostium at the expense of the anterior fontanelle so as to introduce instruments deep into the antrum (Fig. 4). Ethmoidal polypi can be effectively removed by doing a complete ethmoidectomy during FESS. The patient is then followed up at regular intervals so that any recurrent polypi can be plucked out as an office procedure to keep the patient symptom-free. Usually 2 to 3 such sittings are sufficient to give the patient a long-term relief. Other sinus conditions like mucocoeles or pyocoeles of the frontoethmoid, sphenoid or maxillary sinuses are very easily amenable to treatment by endoscopic sinus surgery. Even patients with large mucocoeles producing proptosis or visual symptoms can be tackled endoscopically. It has now been established that endoscopic surgery is the treatment of choice for mucocoeles. No attempt is made to excise the mucocoele or remove its outer wall. Instead it is widely marsupialised into the nasal cavity and the wall left intact to serve as the mucosal lining of the sinus. Chronic sinusitis, even when accompanied by certain complications, can be managed by endoscopic sinus surgery. Sinusitis associated with orbital cellulitis without osteomyelitis is easily treatable by this procedure. Chronic sinusitis with polyposis of a long-standing duration is often accompanied by fungal infection, usually aspergillosis. When this is not of an invasive variety, even extensive lesions are effectively managed by endoscopic surgery. The maxillary sinus can be entered via a canine fossa puncture with a trocar and canula. This is not routinely performed as the patient is often left with persistent pain in the region and even dental neuralgia. It may, however, have to be done in cases of fungal sinusitis when the fungal mass in the sinus cannot be removed endonasally; extensive polyposis on the lateral wall of the sinus; loculated pus; for diagnosis and treatment of an orbital blow-out fracture; and removal of a foreign body. Biopsy of isolated lesions especially on the postero-lateral wall can be done by antroscopy.

Fig 3. Coronal CT Scan showing bilateral chronic ethmoid and maxillary sinusitis.

Fig 4. Coronal CT Scan with left antrochoanal polyp and associated ethmoiditis.

Acute sinusitis is usually treated conservatively. However, when a patient with acute frontal or maxillary sinusitis gets persistent, severe pain, and does not respond to decongestant treatment, endoscopic sinus surgery can be used to unblock the frontal recess and infundibulum to promote drainage. An acute ethmoiditis leading to abscess formation can be treated similarly. Isolated involvement of the sphenoid sinus is a relatively uncommon entity. Acute sphenoid sinusitis is a potentially catastrophic infectious disease. It is frequently initially misdiagnosed, and, due to the severe intracranial complications, a genuine medical and surgical treatment is recommended. Chronic sphenoid lesions may pose a problem of aetiologic diagnosis. It may be difficult to differentiate between benign and malignant lesions. The most common presenting symptom is headache, followed by visual symptoms and cranial nerve palsies. Radiographically, computed tomography is the gold standard. Treatment includes antibiotic therapy and surgical drainage. This drainage is now done through an endoscopic approach. [5]

In patients with nasal obstruction, endoscopic resection of a septal spur or a concha bullosa can also be performed safely in combination with endoscopic sinus surgery and contributes with minimal additional morbidity to the surgical success [6] (Fig. 5). Paranasal sinus surgery and general anaesthesia can be safely performed in cystic fibrosis patients. The indications for paranasal sinus surgery are changing from symptomatic nasal obstruction to pre-lung transplantation care. [7] Endoscopic sinus surgery improves symptoms of sinusitis and exercise tolerance and may delay the progressive respiratory failure that often affects the adult cystic fibrosis patient. [8] Increasingly, otolaryngologists are treating patients with acquired immunodeficiency syndrome (AIDS) who suffer from associated sinusitis refractory to medical therapy. Patients with AIDS and chronic sinusitis may benefit from endoscopic sinus procedures. [9] FESS appears to offer a safe and effective technique to control sinus disease in children who do not respond to aggressive medical management. In skilled hands, this technique is associated with few complications and appears to offer relief even in young patients. [10] FESS in patients with frequent URTI and asthma is also potentially very beneficial for the patient. According to Park et al, eighty per cent of patients noted improvement of their asthma following FESS. [1] Recurrent sinus barotrauma is an uncommon condition but it may terminate the career of an aviator. Sinus barotrauma occurs almost exclusively on descent and probably results from occlusion of the sinus ostia through a combination of mucosal disease and anatomical abnormalities. Traditional methods of treating sinus barotrauma have achieved mixed results. In a study by O’Reilly et al, functional endoscopic sinus surgery (FESS) was employed to treat the patients. After surgery, ninety-five per cent were able to resume their full flying duties without further treatment or recurrence of sinus barotrauma. [11]

Fig 5. Coronal CT Scan with left sinusitis with concha bullosa on the right.

Fig 5. Coronal CT Scan of patient with fungal sphenoid sinusitis.

FESS may also be employed for diagnosis, biopsy and treatment of fungal sinusitis (Fig. 6). Endoscopic guided biopsies from the middle meatus and the sinuses are much more likely to yield positive cultures than blind nasal swabs. In cases of non-invasive fungal infections and allergic fungal sinusitis, FESS is the treatment of choice. Even in cases of invasive fungal sinusitis, which is confined to the boundaries of the sinus walls, FESS can be used successfully. The other procedures that can be performed using the nasal endoscopes are cauterisation of bleeding points in epistaxis, closure of CSF leaks, endonasal dacryocystorhinostomy, vidian neurectomy, optic nerve decompression, orbital decompression for exophthalmos, hypophysectomy and surgery for choanal atresia.

Contraindications

Sinus infections associated with intracranial complications or orbital cellulitis with visual field defects as well as osteomyelitis are better tackled by an external approach. Infiltrative lesions are also better treated by external approach. Aggressive fungal infections of the paranasal sinus such as mucormycosis may require an external approach.

Complications of FESS

The endoscope brings better vision and exposure with lesser bleeding - together leading to better results. In the light of this, let us not forget that the ethmoid sinuses are one of the most complex anatomical structures of the body with vital structures such as the orbit, dura and optic nerve bordering it. Theoretically, the endoscope with its advantages should make surgery safer. However, we see that if anything, there may be a slight increase in the number of surgical complications. This has occurred as more surgeons, with less experience, attempt to perform more daring surgery, under the impression that they are ‘safe’ if they use the endoscope. It is essential to remember that endoscopic surgery requires a thorough knowledge of anatomy and proper training to avoid any ‘misadventures’ during or after surgery.

A careful study of the CT scans in axial and coronal planes is essential to familiarise the surgeon with the normal variations and pathology. A thorough history with clinical evaluation is mandatory and should include, visual and olfactory problems, details of previous surgeries and any complications related to them and use of medications that may enhance bleeding. A history of bronchial asthma and aspirin hypersensitivity is to be inquired into in cases of allergic polyposis. It is also necessary to inform the patient about the risks involved and obtain an informed consent.

Bleeding

One of the advantages of FESS is minimal bleeding. However, in some cases, a significant amount of bleeding can occur during the operation, especially with patients on certain medications, in revision operations, in patients with extensive pathology and sometimes in hypertensive patients. Bleeding may also occur if there is congestion in the nose, as in an acute infection. It is therefore important to treat the nose preoperatively with decongestants and antibiotics. The anterior ethmoidal artery and branches of the sphenopalatine artery posteriorly are the major bleeding points. If bleeding does occur, packing for a little while will usually control it. If the bleeding point can be identified, a bipolar cautery may be used. If the bleeding does not stop, or is obscuring the vision, it is better to pack the nose and do the rest of the surgery at a later date. Very occasionally ligation of the ethmoidal vessels may be required. The best way to avoid intra-operative bleeding is to prepare the patient carefully and use a careful atraumatic technique.

Synechia

In functional endoscopic sinus surgery there is a large raw area left behind in the lateral nasal wall and often on the opposing lateral surface of the middle turbinate. This can lead to scarring and synechiae in the post-operative period causing obliteration of the middle meatus and recurrence of the disease. This must be prevented by preserving mucosa during surgery and careful cleaning of the operated cavity. It is a good practice to teach the patient to take saline nasal douches for keeping the nasal cavity clear in the post-operative period. Occasionally spacers may be kept to prevent adhesions. If synechiae are formed, they can be easily managed. The synechia are divided endoscopically and the excessive scar tissue removed. Merocel or a spacer is then kept for a few days.

Closure of antrostomy

Closure of the neo-ostium may occur if circumferential removal of tissue is done to widen the opening, which means that all the edges of the antrostomy are raw. When creating a middle meatus antrostomy, it is best to widen the natural ostium anteriorly and inferiorly and leave the superior and posterior margins with intact mucosal lining. Obvious polypoidal tissue surrounding the antrostomy opening on the antral side should be removed as sometimes these polyps can prolapse through and block the antrostomy. Adequate post-operative nasal cleaning and douching will help prevent antrostomy closure.

Blindness

Any impairment to vision is an extremely serious complication of FESS, and hence all efforts must be made by the surgeon to prevent this from happening. Intra-operative dissection in the region of the orbit should be very gentle, the surgeon fully aware of detecting a possible injury to the globe or the optic nerve, and competent enough to manage the complication, so as to avoid permanent visual impairment.

Permanent blindness can occur due to direct trauma to the optic nerve in the region of the posterior ethmoids or the sphenoid sinus or due to a retro-orbital haematoma compressing the optic nerve and causing ischaemic damage. Sometimes, perforation of the lamina papyracea and the peri-orbita will cause intra-orbital bleeding. No attempt should be made to remove the prolapsed fat as it may cause compression and ischaemia of the optic nerve. The intra-orbital pressure must be relieved urgently to prevent permanent damage. It is advisable to give such a patient intravenous steroids, and do an orbital massage in an attempt to redistribute the orbital haematomas and thus reduce the intra-orbital pressure. If there is any evidence of visual field loss or decrease in the vision, orbital decompression should be done by a lateral canthotomy and an external ethmoidectomy with incisions on the periorbita and ligation of the ethmoid artery if required. Resection of the medial orbital wall and retrobulbar decompression may also be needed.

Cerebrospinal fluid leak

This is one of the most dangerous complications of FESS. The commonest sites are the cribriform plate, the roof of the ethmoid sinus and the antero-superior aspect of the sphenoid sinus.

If a CSF leak does occur, the area should be sealed with either temporalis fascia or with fascia lata, which is held in place using tissue glue (if available), and by packing muscle or fat into the cavity. If the CSF leak persists, closure by an external or intracranial operation may be necessary. Any patient who develops meningitis post-operatively must be investigated for an unsuspected CSF leak and treated accordingly.

Diplopia

Diplopia can occur due to damage to the medial rectus muscle or its nerve supply. The diplopia is usually temporary and recovers once the oedema reduces. Persistent diplopia is due to direct injury to the muscle, and will require ophthalmic surgery.

Conclusion

Although theostiomeatal complex is important in the development of chronic sinusitis, the condition is multifactorial and ostiomeatal surgery should be combined with medical treatment. Surgery must be tailored to the disease, yet enough to eradicate disease and prevent recurrence . Dissection should be gentle and with clear visibility to avoid complications. In most cases, where there has been a serious complication, there has been one common element. The visibility was not good due to bleeding. Hence, if you cannot see, Stop! Finally, post-operative care is as important as the surgery and must be done carefully, till the patient is recovered

REFERENCES

Abdel-Hak B, Gunkel A, Kanonier G, Schrott-Fischer A, Ulmer H, Thumfart W. Ciliary beat frequency, olfaction and endoscopic sinus surgery. ORL Journal of Otorhinolaryngology Relat Spec 1998 Jul-Aug; 60(4): 202-5

Park AH, Lau J, Stankiewicz J, Chow J. The role of functional endoscopic sinus surgery in asthmatic patients. Journal of Otolaryngology 1998 Oct; 27(5): 275-80

Moses RL, Cornetta A, Atkins JP Jr, Roth M, Rosen MR, Keane WM. Revision endoscopic sinus surgery: the Thomas Jefferson University experience. Ear Nose Throat Journal 1998 Mar; 77(3): 190, 193-5, 199-202

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Coste A, Idrissi F, Beautru R, Lenoir G, Reinert P, Manach Y, Peynegre R. Endoscopic endonasal ethmoidectomy in severe sinusitis of cystic fibrosis. Mid-term results in 12 patients. Ann Otolaryngology Chir Cervicofac 1997; 114(4): 99-104

Halvorson DJ, Dupree JR, Porubsky ES. Management of chronic sinusitis in the adult cystic fibrosis patient.Annals of Otology Rhinology Laryngology 1998 Nov; 107(11 Pt 1): 946-52.

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Fig 1.	Endoscopic photograph shpwing middle meatus and concha bullosa of the middle turbinate.


Fig 2A		Fig 2B
Preoperative coronal CT Scan of patient with bilateral chronic sinusitis.		Postoperative coronal CT Scan of patient taken four months later showing clear ethmoid cavities and normal maxillary sinuses.


Fig 3.	Coronal CT Scan showing bilateral chronic ethmoid and maxillary sinusitis.


Fig 4.	Coronal CT Scan with left antrochoanal polyp and associated ethmoiditis.


Fig 5.	Coronal CT Scan with left sinusitis with concha bullosa on the right.


Fig 5.	Coronal CT Scan of patient with fungal sphenoid sinusitis.