In the floor of the maxillary sinus if the cyst is small. When the cyst fills

the antrum there is a homogeneous opacity, and if it contains a tooth this will

be seen on radiography. Radiography with contrast and CT-scan are effective.

TREATMENT. Proof puncture of the affected antrum will produce clear greenish or

amber-coloured fluid which may issue through the cannula when the trocar is

withdrawn. The rest of the contents may be aspirated into a syringe through a

blunt-pointed needle inserted through the cannula. This in itself may cure the

condition if dental attention is given to the unhealthy tooth. If the cyst is

large or infected, or if it should contain a tooth, a endoscopic antrotomy is

performed and the entire cyst removed.

COMPLICATIONS OF SINUSITIS

Orbital Cellulitis and Orbital Abscess

Orbital complications are commonest. The ethmoidal sinuses are separated from

the orbit by only a very thin plate of bone, the lamina papyracea, and orbital

complications are thus associated more with infection of the ethmoidal cells

than with other sinuses. As acute upper respiratory tract infections are

particularly common in childhood, and as the ethmoidal sinuses are present at

birth and expand fairly rapidly, orbital cellulitis and abscess occur

particularly in older children.

Orbital cellulitis arises from a blood-borne spread of infection.

Thrombophlebitis occurs in the vessels of the mucosa and bone of the inflamed

sinus, and infection extends to the loose tissues of the orbit giving rise to a

cellulitis which spreads rapidly.

An orbital abscess usually arises from direct spread and is a subperiosteal

abscess lying between the lamina papyracea and the orbital periosteum (on

occasion it can be due to localized abscess formation in a patient whose orbital

cellulitis is not controlled. The infecting organisms are staphylococcus,

streptococcus - including the anaerobic type pneumococcus and Haemophilus

influenzae.

CLINICAL FEATURES. Initially there are, of course, symptoms of acute sinusitis.

In orbital cellulitis these are followed by venous congestion and swelling of

the eyelids, particularly the upper one, and the eye is soon closed. There is

infection of the conjunctiva, and in severe cases chemosis develops. There may

be mild proptosis, but eye movements should remain full.

In orbital abscess there is swelling of the eyelids with outward displacement of

the globe, limitation of eye movements, and pain is felt particularly on

attempted medial movement of the eyeball. If the abscess is situated

posteriorly, coming from the posterior ethmoidal cells, the optic nerve and

ophthalmic artery are particularly at risk from pressure effects, and a close

watch should be kept on visual acuity, visual field and signs of pallor of the

optic disc.

Examination of the nose will show signs of an acute bacterial infection with a

swollen inflamed airway and mucopus in the middle meatus and postnasally.

Radiography will reveal opaque ethmoidal cells, and there may be a fluid level.

There is commonly a unilateral pansinusitis affecting the maxillary, sphenoidal

and frontal sinuses as well.

TREATMENT. Orbital cellulitis is treated medically with systemic antibiotics.

Decongestants will aid sinus drainage. In the case of abscess formation, if the

patient is seen early and appropriate antibiotics have not been given, a similar

regime is appropriate. If there is no obvious improvement within 24 hours, the

abscess should be drained externally through an incision in the supramedial

quadrant of the orbit, and a drainage tube inserted for several days.

Osteomyelitis

Osteomyelitis occurs as a complication of sinusitis where there is diploic bone

in relationship to an acutely infected sinus. It tends to occur in the maxillary

bone in children and in the frontal bone in adults. The spread of infection to

the bone-marrow space is by thrombophlebitis.

CLINICAL FEATURES. The symptoms are minimal in the early stages of the disease.

There is a dull boring pain in the affected bone with a tender puffy swelling

developing slowly over it. There is considerable systemic upset with rigors. An

X-ray will show signs of sinusitis with sclerosis of the affected bone. This

will change to a mottled appearance and finally, if untreated, a sequestrum will

become apparent.

TREATMENT. In the early stages the treatment is medical. Antibiotic

sensitivities should be obtained by culturing pus from the nose. An antibiotic

such as lincomycin which attains high tissue levels in bone is to be

recommended. Lavage of the sinus is carried out. If a sequestrum develops, it

should be removed surgically. This is more likely in osteomyelitis of the

frontal bone in adults, and is an indication for the osteoplastic flap operation

on the frontal sinus.

Intracranial Complications

Intracranial complications of sinus infection can occur by direct spread, by

venous thrombophlebitis or along the perineural tissues of the olfactory nerve.

Direct spread is aided by any breach in the bone separating the sinus from the

intracranial structures. It is encountered in association with congenital

dehiscence of the bone, with previous fractures, and following poorly visualized

surgical procedures like intranasal ethmoidectomy and nasal polypectomy.

Meningitis is the commonest complication and is treated vigorously with systemic

antibiotics. Pneumococcal meningitis has a particularly poor prognosis,

especially in the elderly. Cortical venous thrombosis manifests itself by severe

headaches, rigors, neck stiffness, lowered level of consciousness and epileptic

fits. It should be treated in a similar manner to meningitis.

Cavernous sinus thrombosis is due to spreading thrombophlebitis from the

frontal, ethmoidal and sphenoid sinuses. There is decreased venous return from

the eye, causing swelling of the orbit and congestion of the retinal vessels.

There is a high fever with rigors, severe headache, a reduced conscious level

and cerebral irritation. The III-rd, IV-th, Vl-th and upper division of the Vth

nerve, which lie in the lateral wall of the cavernous sinus, become paralysed,

giving rise to an ophthalmoplegia. As there is free communication between the

two cavernous sinuses, the signs frequently become bilateral. Treatment is with

high doses of systemic antibiotics and heparine. This is a serious condition

which still carries a mortality.

Brain abscesses secondary to sinusitis most commonly occur in the frontal lobe.

Localizing signs are few, and the abscess becomes apparent through signs of

raised intracranial pressure. Treatment is by neurosurgical drainage.

Extradural abscesses are again related to the frontal sinus. When suspected, the

frontal sinus should be explored through an osteoplas-tic flap approach, and

particular attention should be paid to the posterior wall, where there may be a

dehiscence. An extradural abscess can be drained into the frontal sinus, and

hence externally.

A subdural abscess carries the poorest prognosis of all the complications of

acute sinusitis. In its early stages it is very difficult to diagnose, the only

symptoms being general malaise, headache and some neck stiffness. The abscess

may quite suddenly increase in size giving acute raised intracranial pressure.

Treatment is neurosurgical, with drainage through multiple burr holes, or

necessitating the removal of an area of cranium, to achieve adequate drainage.

Nasal polyposis

The polypus is a projection of oedematous mucous membrane composed of loose

fibro-oedematous tissue, the surface of which is covered by ciliated epithelium.

Small blood vessels traverse the surface and are sometimes visible to the naked

eye. There is a variable degree of infiltration of round cells, while with

allergic polypi large numbers of eosinophils are found.

Nasal polypi are caused by a combination of allergy and infection. They are

uncommon in childhood or adolescence, being more frequent in adult life. Those

arising earlier in life have a more obvious allergic aetiology. Nasal polypi are

more common in men than in women.

AETIOLOGY. Nasal allergy causes oedema due to the release of histamine giving

rise to increased blood-vessel permeability. The oedema results in blockage of

the ostia of the ethmoidal cells, and a secondary bacterial infection

supervenes. As the polypi enlarge they cause poor aeration of the middle meatus

of the nose, and the resulting chronic rhinitis and the underlying allergy lead

to oedema of the middle turbinate and lateral nasal wall. Once the polypi appear

within the nose they enlarge, partly by growing and partly by negative pressure

on nose blowing, causing increased oedema. While they can vary in size, by

enlarging during a cold or an exacerbation of hay fever, once they are visible

on rhinoscopy they will not disappear completely. The vast majority of nasal

polypi arise from the ethmoidal sinuses and they should be regarded as the

end-product of chronic ethmoiditis, while remembering that the sequence of

oedematous blockage of the ostia followed by secondary infection frequently has

an allergic causation. Nasal polypi are almost always multiple and bilateral,

and an individual polypus can exceed the size of a grape.

SYMPTOMS. The principal symptom is nasal obstruction. As polypi are slow-growing

there may be a considerable collection before the patient becomes aware of the

obstruction. At times the patient suddenly becomes conscious of a blockage after

a cold, when infection and nose blowing cause a rapid increase in size. Patients