Key points
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Nasal obstruction, like other obstructive sleep breathing disorders, is multifactorial with many areas of potential anatomic obstructions. This article reviews the role of nasal obstruction in these complicated patients.
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The nasal examination should follow a structured approach in describing and quantifying areas of nasal obstruction before planning surgery for patients with obstructive sleep apnea.
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Identifying the area of nasal obstruction and its related surgical options are reviewed with a focus on the physical examination and anatomic considerations.
Introduction
Nasal obstruction accounts for half of airway resistance and may contribute to the development of sleep-disordered breathing, including upper airway resistance syndrome and obstructive sleep apnea (OSA) in certain individuals. When this is identified in a patient with sleep-disordered breathing, surgery can be offered, but it is important that the techniques used be tailored to the specific sites of obstruction identified.
Identifying the site of nasal obstruction
Examination of the nasal cavity should proceed in a systematic and reproducible manner to improve communication among physicians and guide surgical treatment. Rhinoscopy typically involves assessment pre- and postapplication of a topical decongestant to observe the effects of inflammation on nasal obstruction. Partial nasal obstruction is far more common than complete obstruction.
Presence of a deviated septum is extremely common. In some studies, a deviated septum is even more prevalent than a nondeviated septum. The anatomic location of the septal deformity is important in determining if an individual will have nasal obstruction symptoms, if any. For example, even small deflections of the anterior septum can cause significant obstruction because of the septum’s location within the nasal valve, whereas posterior deflections generally need to be much larger to similar obstructive symptoms.
Classifying the position of septal deflection therefore plays an important role in guiding the type of surgery. The most commonly accepted measurements of the septum involve qualitative and quantitative measurements. Quantitatively, septal deviation can be graded as 0% to 25% deflection, 26% to 50% deflection, 51% to 75% deflection, and 76% to 100% deflection from the midline to the lateral nasal wall. Qualitatively, septal deviation may be described as either cephalocaudal or anteroposterior and further divided into C-shaped, reverse C-shaped, S-shaped, or reverse S-shaped.
Similar to septal deflections, inferior turbinate hypertrophy is clinically important because of its involvement at the lateral boundary of the internal nasal valve. Hypertrophy can be classified as bony, soft tissue, or mixed, which may direct the type of surgery indicated, that is, turbinectomy for bony hypertrophy versus soft tissue submucous resection. Inferior turbinate size can be reported based on the degree of obstruction caused by the head of the inferior turbinate relative to the total airway space. This is graded as 0% to 25%, 26% to 50%, 51% to 75%, and 76% to 100%.
Surgical technique
In the following narrative, the authors outline common techniques/maneuvers in a traditional patient with nasal obstruction resulting from static middle septal deviation and enlarged inferior turbinates ( Fig. 1 ). For more complicated cases, it may be prudent to refer to an experienced specialist for surgery. Although the traditional closed septoplasty technique is best suited for middle septal deflections, dorsal or caudal deflections may be best suited for open rhinoplasty with grafts and techniques beyond the scope of this article.
Anesthesia and analgesia
Before any surgical steps, inspection of the nasal cavity should proceed before decongestion to assess potential areas of obstruction. Decongestion is achieved with either 4% cocaine or more commonly oxymetazoline on pledgets that are placed into the nasal cavity for vasoconstriction. This reduces bleeding, creates space for instrumentation, and also allows improved visualization of the septum. Minimizing bleeding is paramount for visualization during nasal surgery, and for this reason the patient is also placed in reverse Trendelenburg position.
In addition to vasoconstriction, injection of 1% lidocaine with 1:100000 epinephrine into the septal mucoperichondrial plane also aids in hydrodissection before elevation. Injection begins posteriorly to prevent bleeding anteriorly, which would otherwise distort visualization of the posterior septum during injection. Typically a 25 or 27 gauge needle is advanced with the bevel parallel to the septum until slight resistance is met taking care not to go through to the contralateral side. Injection will be met with some resistance from the septum impeding flow of anesthetic, at which point the needle is withdrawn slightly until the anesthetic is able to be easily injected with almost instant transient blanching of the mucosa. This is repeated in multiple areas along the superior-inferior plane while moving anteriorly and injecting the incision site. The contralateral membrane should also be injected as well as the area around the maxillary crest. After the injection is performed, waiting at least 15 to 20 minutes will ensure maximum vasoconstriction, which is why it is a common practice to inject immediately after intubation.
Incision
Incision location is variable and generally reliant on surgeon preference. Traditionally, for the right-handed surgeon, he or she stands at the right of the patient and creates the incision in the left nare. However, many surgeons prefer to make the incision on the side with the largest spur or most prominent deflection. Of note, mucosal incisions are placed anterior to the start of the deflection or obstruction. There are 3 types of incisions—Killian, hemitransfixion, and full transfixion—each with specific advantages and disadvantages. A Killian incision ( Fig. 2 ) is made approximately 1 to 2 cm posterior to the caudal septal margin within the respiratory epithelium and is useful for middle septal deviations. Caudal septal deviations are more difficult to access and easier to create tears in the flap due to delicate nature of the anterior respiratory mucosa.
A hemitransfixion (see Fig. 2 ) or transfixion incision made at the caudal border of the cartilaginous septum allows access to caudal deflections. In contrast to the Killian, the incision is created within the squamous epithelium of the vestibule in the membranous septum. Conversion to a full-transfixion incision is easily accomplished by incising completely through to the opposite membrane; however, this may reduce nasal tip support and is not usually necessary. Other approaches such as the transcolumellar incisions used in open rhinoplasty are beyond the scope of this article and will not be discussed.
Elevating the mucoperichondrial flap
A hemitransfixion incision outline is created by using the nasal speculum to push the membranous septum toward the contralateral nare to expose the caudal septal edge and create tension before making the incision. A No. 15 blade is used to incise through mucosa and perichondrium to the cartilage layer, which has the appearance of a white and rough surface. This incision may be extended to the nasal floor, which is helpful for inferior septal deviations. The dissection proceeds in the subperichondrial layer to minimize bleeding and creates a more durable flap, which decreases the likelihood of perforation. This may be achieved by “scraping” the perichondrium off the cartilage with a sharp edge such as the Cottle elevator or No. 15 blade. Once in the subperichondrial plane, further elevation of the flap is typically initiated with the Cottle elevator and then continued with the dull side of the Cottle or a freer ( Fig. 3 ). It is important to raise the flap atraumatically by “sweeping” the instrument in the direction of the least resistance and continuing to enlarge the pocket, making sure the instrument is in contact with the septum at all times. This can be accomplished with direct visualization using a narrow speculum or more commonly by feel and tracking the plane of least resistance. Of note, areas of fracture or severe deflections often have trapping, duplication, or adherence of planes and more sharp dissection under direct visualization is necessary to prevent rents. Rents are often created due to forceful instrumentation in the anterior to posterior direction or from angling the instrument off the septum, which may occur during concave portions of the septum. If a hole is created, one should reduce propagation of the rent by avoiding strong suction at the edge of the rent. Two tunnels should be elevated superiorly and inferiorly to the rent and connected, which may require scraping off adherent mucosa with the Cottle elevator.
