Definition and Overview
The ethmoid sinus, which is located near the eyes and nose, is a sinus in the human face. The ethmoid sinuses are paired and are surrounded by several facial bones, namely the lacrimal, frontal, maxillary, sphenoid, and palatine bones, which form the walls of the sinus. The ethmoid sinus is essential because the other sinuses drain here or beside it.
Sinusitis is a condition characterised by the swelling or inflammation of the lining of the sinuses. In a healthy individual, the sinuses are spaces occupied by air. Sinus disease results in obstruction, preventing the air from entering the sinus and the mucus from draining. Blockage of the sinuses can result in the accumulation of fluid and infectious organisms, such as viruses or bacteria. Sinusitis typically presents with a headache, stuffy nose, pain over the face, and discharge coming from the nose. Severe forms of ethmoid sinusitis can lead to the spread of infection to adjacent structures, which can result in abscesses or cellulitis of the orbit, osteomyelitis of the facial bones, or even life-threatening conditions such as cavernous sinus thrombosis or meningitis.
The majority of cases of acute ethmoid sinusitis are managed medically wherein specific drugs are given to decrease the inflammation in the ethmoid mucosa, fight off the infection, and relieve the sinus obstruction. However, in certain cases, surgery may be necessary to treat the condition.
Who Should Undergo and Expected Results
The surgical management of ethmoid sinusitis is indicated if the condition does not respond to adequate medical therapy, is progressive, or has led to various complications such as the formation of abscesses.
The majority of patients who are subjected to ethmoidectomy experience resolution of the condition with significant improvement reported by about 50-90% of patients. After surgery, patients tend to have decreased episodes of sinus infection and experience relief from their symptoms.
How is the Procedure Performed?
An ethmoidectomy can be approached via several ways.
The classic surgical approach is the external approach, which is performed under general anaesthesia. It involves making a curvilinear incision between the eye and the nose that is brought down until the bone is reached. Dissection then proceeds under the periosteum to perform the removal of the anterior cells. A drain is left in place, which may be used for lavage postoperatively and closure is performed in layers. The external approach is associated with very high success rates, ranging from 70-90%.
Another method for this procedure is the intranasal approach, which is also known as the endoscopic approach to ethmoidectomy. In recent years, the use of this approach has been increasing, with increasing success. For this method, a combination of topical and local anaesthesia is given to anesthetise the nasal mucosa. A portion of the middle turbinate may be removed if found to be obstructing. The infundibulum is then incised and the anterior cells are opened and removed using different instruments. The nasal cavity is then packed with gauze covered with an antibiotic ointment.
The transantral approach is the last approach and is typically the least used. For this method, the maxillary sinus is opened to reach the ethmoid sinus to provide access to the majority of the anterior and posterior air cells.
The specimen is usually sent for culture and histopathologic examination. Postoperative antibiotics can then be directed to the specific pathogen once the culture results are available.
The drain or the nasal pack is usually removed after 2 to 3 days. Nasal decongestants are typically used for several days after the surgery. Endoscopic examination of the nose may also have to be repeated after surgery.
Possible Risks and Complications
The location of the ethmoid sinus is very sensitive. Thus, a number of important structures may be injured during surgery. It is therefore of utmost importance that the surgeon is aware of the vital structures and landmarks when operating on the ethmoid sinus. This will ensure the success of the surgery and minimise the risk of developing complications.
Intraoperatively, dissection should be performed with care. It is important to keep the cribriform plate intact, making sure it is not fractured during the dissection of the middle turbinate. This can result in a problematic leak of cerebrospinal fluid (CSF). Damage to the eye muscles can result in limited eye movement and injury to the optic nerve can result in blindness. Inappropriate scarring and hematoma formation can also produce vision problems for the patient.
The septal mucosa should be kept intact. Bleeding may occur when the septum is damaged. If bleeding occurs, it should be controlled with cautery. If this does not work, packing with epinephrine-soaked gauze or using other surgical hemostatic materials, such as Surgicel or Gelfoam, may be performed.
On rare instances, ethmoidectomy can result in loss of the sense of smell.
Crovetto-Martinez R, Martin-Arregui FJ, Zabala-Lopez-de-Maturana A, Tudela-Cabello K, Crovetto-de la Torre MA. Frequency of the odontogenic maxillary sinusitis extended to the anterior ethmoid sinus and response to surgical treatment. Med Oral Patol Oral Cir Bucal. 2014 Jul 1. 19 (4):e409-13.
Catalano PJ, Thong M, Weiss R, Rimash T. The MicroFlow Spacer: A Drug-Eluting Stent for the Ethmoid Sinus. Indian J Otolaryngol Head Neck Surg. 2011 Jul. 63(3):279-84.