Nasal Septal Abnormalities
Anatomy & Pathophysiology:
The nasal septum is a bony and cartilaginous structure that forms the division between the two nasal cavities. Structurally, the septum provides support to the nasal dorsum and its cartilaginous attachments also serve as a major nasal tip support mechanism. Septal disorders can result not only in cosmetic deformity, but also in significant functional consequences such as nasal obstruction or disruption of normal nasal airflow.
A detailed discussion of nasal anatomy can be found in Chapter 2. To review, the posterior nasal septum is formed by contributions from the palatine bone, maxilla, vomer, and ethmoid bones. Anteriorly, the septum is composed of the quadrangular cartilage.
Deviation of the septum is usually traumatic in origin. It has been hypothesized that perceived congenital or developmental abnormalities of the septum are in fact also due to trauma in utero or during birth. Even minor injury to the septal cartilage prior to adulthood can result in microfracturing and disruption of normal chondrocyte growth that progressively worsens over time.
Septal perforation is usually the result of trauma or iatrogenic injury during nasal surgery. Other causes of septal perforation include cocaine abuse, inflammatory disease (e.g., Wegener granulomatosis), infection (such as tuberculosis or syphilis), and neoplasm.
Septal hematoma occurs due to traumatic hemorrhage of the perichondrial vessels in the septum, resulting in accumulation of extravasated blood between the perichondrium and the septal cartilage. Since the septal cartilage does not have its own blood supply, prolonged separation from the perichondrium can cause avascular necrosis.
Nasal obstruction is an extremely common complaint, affecting one-third of the population. Up to one-quarter of patients have some degree of septal deviation. Septal perforation has a reported incidence of 0.9%, but prevalence in certain populations (e.g., cocaine users, those with history of nasal surgery) is higher. Septal hematoma occurs in approximately 1% of nasal trauma and is more common in males.
Septal deviation may progressively worsen with time as one side (usually the side of injury) exhibits a dominant growth pattern. Septal perforation due to inflammatory disease or neoplasm may also progressively worsen with increased disease burden. Untreated septal hematoma can result in septal cartilage necrosis and saddle nose deformity.
Patients with septal deviation present with unilateral nasal obstruction. Some patients may report onset of symptoms after a traumatic event. Obstruction may be exacerbated by allergy, rhinosinusitis, or upper respiratory infection.
Patients with septal perforation may have symptoms of nasal crusting, nasal obstruction, episodic epistaxis, or a whistling sound from the nose with breathing.
Inciting trauma can almost always be identified in cases of septal hematoma. Patients generally have significant nasal pain and swelling.
The patient history should include the timing of symptom onset and progression, whether the obstruction is unilateral or bilateral, and whether any nasal discharge or epistaxis has been noted. Any history of trauma, prior nasal surgery, or allergen exposure should also be documented.
The exterior of the nose should be evaluated, noting contour deformities of the nasal dorsum. In addition, size and symmetry of the nostrils and position of the columella may provide clues to septal deviation. The patient should be asked to breathe through the nose while the nasal side walls are observed for collapse. If this occurs, the Cottle maneuver, wherein the external nasal valves are distracted laterally, can be attempted to determine whether there is symptomatic relief. The upper lateral cartilages can also be pushed laterally with a cotton-tipped applicator inserted into the nasal cavity, which produces similar effect with more reliable results. External inspection should be followed by anterior rhinoscopy, details of which are provided in Examination of the Nose and Oral Cavity. Special attention should be given to the septum, including whether deviation, bony spurs, or perforation are present, as well as if there are any lesions or masses. A complete picture of nasal patency also includes evaluation of inferior turbinate size and internal and external nasal valve dimensions. The internal nasal valve is the most narrow portion of the nasal passage and is bounded by the septum medially, the upper lateral cartilage superolaterally, and the inferior turbinate inferolaterally. If significant mucosal edema is present, the examination may be repeated after topical nasal decongestant (e.g., oxymetazoline) is applied to obtain a clearer view of the nasal anatomy. Finally, rigid nasoendoscopy may be performed to more clearly visualize the posterior septum.
Radiographic studies are not a necessity in cases of isolated septal deviation, as it can be clinically diagnosed. However, a computed tomography (CT) scan is often ordered to evaluate suspected concurrent sinus disease or as part of a trauma assessment.
Measurements of nasal airflow and resistance can be obtained with rhinomanometry or acoustic rhinometry. Although these data are not necessary for treatment planning, they can be useful for objective assessment of postoperative outcomes.
Medical therapy for nasal obstruction includes the use of topical decongestants and treatment of exacerbating conditions, such as allergic rhinitis or rhinosinusitis. Definitive treatment of septal deviation, however, is surgical correction with septoplasty. Depending on the extent of structural deformity, the procedure may be combined with rhinoplasty or turbinate reduction. An overview of functional septorhinoplasty is given in Septorhinoplasty. The procedure varies from patient to patient based on each individual's specific structural defects and nasal anatomy. Generally, the deviated portion of the septum is excised, taking care to leave at least 1 cm of residual cartilage dorsally and caudally to avoid nasal collapse. If bony spurs are present, they may be removed as well.
Small septal perforations do not need to be surgically corrected if symptoms are minimal. Application of nasal saline sprays and saline irrigation of the nasal cavities may help reduce nasal dryness and crusting. Larger perforations may be corrected with placement of a septal prosthesis or may require surgical repair. Surgical options for reconstruction depend on the defect size and include mucosal advancement flaps, pedicled inferior turbinate flaps, pedicled flaps based on the facial artery, bilateral septal mucosal flaps with an interposition graft, or microvascular free flaps.
Septal hematoma is treated by surgical drainage. Timely intervention is required to avoid septal necrosis. The nasal cavity is usually packed to prevent reaccumulation of blood.
Complications, Prognosis & Follow-Up:
Complications associated with septal surgery include epistaxis, septal hematoma, septal perforation, nerve injury resulting in dental hypesthesia, nasal synechiae, vestibular stenosis, and cerebrospinal fluid leak. The risk of septal perforation after septoplasty has been reported to be as high as 5%, although the majority are asymptomatic. Reconstruction of septal perforations also carries the risk of flap failure, necrosis, cosmetic deformity, and fistula formation.
Data regarding patient outcomes after septoplasty are variable. Some reports state a success rate of 70% based on patient satisfaction with symptom improvement. Large scale studies of septal perforation repair outcomes are not available, but limited data suggest a good prognosis, with minor repeat perforation being the primary complication.
- Septal problems include deviation, perforation, and hematoma and often arise as a result of trauma or iatrogenic injury.
- Septal hematoma is a rare complication of nasal trauma, which must be treated promptly to avoid necrosis of the septal cartilage and ensuing deformity.
- Treatment of septal deviation with septoplasty involves remodeling of the deviated portion of the septum; enough septal cartilage must be left in place to avoid nasal collapse.
- Symptomatic relief of nasal dryness and crusting due to septal perforation may be attained by use of nasal saline sprays.
- Larger septal perforations may be treated by placement of an occluding prosthesis or with reconstructive surgical approaches of varying complexity.