Nose: Endoscopic Sinus Surgery

Chronic Sinusitis

Sinusitis is the most common health care complaint in the United States. More than 31 million people per year seek medical attention for problems related to sinusitis.

Sinusitis is basically an inflammation of the internal mucosal lining of the nasal sinuses. The most common cause for paranasal sinusitis is the common viral cold or upper respiratory tract infection. There are various types of classifications for sinusitis including acute, subacute, and chronic suppurative bacterial sinusitis.

Acute sinusitis is defined as moderately intense discomfort in the paranasal sinuses with associated facial pain, nasal obstruction, and nasal congestion. This is an inflammatory process that lasts for several days, but generally not longer than six weeks. After six weeks chronic sinusitis is thought to be the underlying cause for the problem.

Anatomy of the Paranasal Sinuses

The exact function of the paranasal sinuses is essentially unknown. There are four paired sinuses, four on the right side and four on the left. The frontal sinus is located above the eyes in the bridge of the nose. The ethmoid sinus is between the eyes. The sphenoid sinus is back of the eyes and the maxillary sinus is below the eyes, just behind the cheekbones.

The most common function of the paranasal sinuses is to decrease the weight of the skull. Another function includes reduction of sudden increased intranasal pressure that occurs with sneezing. The sinuses also enhance voice resonance.

At birth, the maxillary and ethmoid sinuses are present, although the sphenoid and frontal sinuses are not. In the second and third years of life these sinuses will begin to develop. Generally, by age 18, all four sinuses are well developed. 

The ethmoid sinus is quite close to the eye and orbit and the thin bony wall separating the eye from the ethmoid sinus is the lamina papyracea. The ethmoid sinus, particularly the anterior ethmoid sinus is the most commonly associated with sinus disease.

It is important to understand that all four sinuses drain into a specific area in the nose called the “osteomeatal complex”. This small, but crucial area within the nose is critical in the development of sinus disease. The doorways or openings from the sinuses into the nose are quite small, so with any minor disturbance, anatomically or physiologically, closure and full obstruction of the sinuses can occur. This can lead to significant disease and sinus-related problems.

What Causes Sinusitis?

Acute sinusitis is generally caused by a viral infection such as a cold. Typically, a cold will dissipate after a few days, but when the sinus-related symptoms of pressure, pain, nasal congestion, lethargy, and postnasal drainage persist, particularly longer than six weeks, then chronic sinusitis is thought to be the problem.

The single-most important cause for chronic sinusitis is swelling, edema, and obstruction in and around the “osteomeatal complex” (the area where the sinuses drain). Once obstruction occurs, a number of problems develop. Ciliary function is disturbed, mucous becomes very thick, defense mechanisms and immune function are diminished and secretions are retained within the sinus since drainage is prevented. Additionally, nasal breathing is diminished due to the swelling and retention of mucous secretions within the nasal cavity. When individuals blow their nose, cough, sneeze or sniffle, the normal nasal bacteria may enter the sinus doorways and ostea, instigating a bacterial sinus infection. As a result there is an overall increase in viscosity or thickening of the nasal secretions, providing an ideal medium for bacterial growth.

There are a number of other factors that lead toward persistent or recurrent sinusitis. These can include environmental, allergic factors, allergic rhinitis, and hypersensitivity of the upper airway. Allergens contribute to further edema and obstruction inside the nose as well as hypersensitivity and discomfort. Additionally, irreversible swelling, scarring, and injury to the mucous membrane and paranasal sinus lining can contribute to recurrent sinus problems.

Also See: Nasal Septoplasty, Rhinoplasty, and Chronic Sinusitis