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Introduction
Sleep-disordered breathing and snoring are exceedingly common presentations to physicians. In general, the etiology is highly variable from base of tongue obstruction, laryngomalacia, retrognathia, or weak pharyngeal muscle tone, among others. These etiologies can all be exacerbated by coexistent nasal valve obstruction as it directly relates to airflow. Common etiologies of nasal valve collapse include aging, trauma, congenital, septal deviation, and, most frequently, iatrogenic after septorhinoplasty. These typically stem from weakness in the lateral wall due to overresection of the lateral crus. Increasingly, the nasal valve has been shown to affect patients with obstructive sleep apnea (OSA), which has led to the emergence of new treatments and therapies targeting nasal valve collapse.
The contribution of the nasal valve to OSA and sleep-disordered breathing has a controversial past. Studies have shown that improvement in the nasal airway, either surgical or nonsurgical, has minimal effect on the Apnea/Hypopnea Index (AHI) and the subsequent need for either continuous positive airway pressure (CPAP) or additional surgery. In contrast, other studies have shown a reduction in the AHI in patients with reduction in nasal airway resistance, be it by medical management, nasal dilators, or functional septorhinoplasty. However, despite the controversy in reduction of AHI, there is an association between decreased nasal airway resistance and improvements in CPAP compliance and patient symptomatology as defined by improvements in the Epworth Sleepiness Scale (ESS), Respiratory Distress Index (RDI), and reduction in unintentional CPAP leak rates. In summary, patients with sleep-disordered breathing can benefit significantly from adequate diagnosis of abnormal nasal anatomy, particularly as it relates to nasal valve obstruction.
The nasal airway accounts for over 50% of upper airway resistance. The area of greatest resistance is found at the internal nasal valve, which is bound by the septum medially, the upper lateral cartilage superolaterally, and the head of the inferior turbinate inferiorly. This creates a 10- to 15-degree angle for airflow to pass, which is the narrowest part of the nasal airway, and an angle <10 degrees is considered abnormal. The external nasal valve forms the nasal vestibule. The boundaries of this include the alar lobule laterally, the nasal sill inferiorly, and the columella medially, which is formed from the caudal septum and medial crura. External valve collapse is typically seen in patients with narrow nostrils, an overprojected tip, and thin or weak nasal sidewalls. Nasal valve collapse is most easily diagnosed with an adequate physical examination with observation of the lateral wall during inspiration. The diagnosis can be confirmed with a modified Cottle maneuver in which a wire loop curette is inserted intranasally underneath the upper lateral cartilage and having the patient breathe through the nose. If significant improvement is seen, a diagnosis of nasal valve collapse can be reasonably confirmed.
Management of nasal valve collapse has changed significantly over the past 20 years with new innovations in nonsurgical treatments, and surgical interventions have become increasingly evidence-based with new advances in grafting materials.
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Nonsurgical Management of Nasal Valve Collapse
Nonsurgical methods to improve nasal valve patency have been well established and are commercially available. A variety of devices exist, including external strips (i.e. Breathe-Right nasal strips [GlaxoSmithKline PLC., Middlesex, UK]) that provide resistance to nasal valve collapse and internal stents (i.e. NoZovent [Scandinavian Formulas Inc., Sellersville, PA]) that physically maintain valve patency. Breathe-Right strips in particular have been extensively studied in patients with OSA and snoring, with a majority of studies being case–control or prospective case studies. In general these commercially available devices trend toward lowering the AHI without reaching statistical significance and have minimal effect on snoring. Regardless of the type of device, all have the same goal of opening the nasal valve. Over time, interest in these devices has increased, but subsequently the limitations of these devices were realized. The majority of devices are disposable or single-use, which, over time, can become expensive and inconvenient. Additionally patients with adhesive allergies are unable to tolerate certain strips or devices. Internal stents can be irritating to the vestibular skin and can become dislodged at night.
Without clear evidence of benefit and due to the aforementioned disadvantages of commercially available devices, over the last several years, minimally invasive treatments have become increasingly popular. Devices can be easily implanted or placed in the office with minimal risk to the patient. A variety of devices have been created due to the popularity of a semipermanent, safe solution to nasal valve collapse.
The Latera implant (Spirox, Inc., Redwood City, CA) is a uniquely designed resorbable implant composed of polylactic acid polymer that is implanted into the sidewall of the nose to support the upper and lower lateral nasal cartilages. The implant can be placed in the office percutaneously through the intranasal vestibular skin for the correction of nasal valve collapse. Many surgeons will place the implant in the operating room in conjunction with septoplasty and turbinate surgery. This implantable device has become an excellent, minimally invasive option for many patients. Targeting the implant toward patients who would receive maximum benefit is important both for the surgeon and the patient. The ideal patient will show demonstrable evidence of internal nasal valve collapse that improves with a properly performed modified Cottle maneuver, though Latera may improve external valve collapse as well. Using a wire loop curette to support the nasal sidewall underneath the lateral crura above the supra-alar groove during inspiration is best practice. If you observe the patient, you will frequently see the sidewall between the nasal bones and supra-alar groove move medially when they breathe in through their nose. Previous rhinoplasty or nasal surgery does not exclude patients from implantation, but care should be taken to understand the previous operations performed and whether alloplastic implants were used in the past, as this can increase the infection risk due to biofilm formation. Scar tissue or cartilage grafts along the sidewall of the nose can make placement of the implant more difficult, as the tissue planes are no longer clearly defined. It is preferable for patients to be off aspirin or nonsteroidal anti-inflammatory drugs for 3 weeks before implantation to minimize risk of bruising and swelling with implantation.
Both preliminary studies and the clinical trial associated with the device show a significant reduction in Nasal Obstruction Symptom Evaluation (NOSE) scale scores, making it a viable treatment for nasal valve collapse. The studies have shown that more than 75% of patients who have undergone implantation had significant symptomatic improvement as defined by a NOSE score severity category change or overall NOSE score reduction greater than 20%. The implant has the additional benefit of being composed of an absorbable polymer material that will gradually resorb over approximately 18 months, subsequently leaving a fibrous capsule in place that may provide additional support after the implant is gone. Patients who benefitted showed durable improvement through 2 years, beyond the period of implant absorption. The implant itself can be inserted either in the office utilizing local anesthesia or in the operating room depending on the surgeon’s comfort level ( ).
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The Latera device is implanted first by utilizing a positioning device to make external markings at the site of lateral wall collapse. Both sides can be implanted during the same procedure, individualized toward patient need.
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After the patient has been marked, the nose is injected with 1% lidocaine with 1 : 100,000 epinephrine. About 3 mL per side is more than adequate. Injection is directed endonasally just above the supra-alar groove at the planned site of entry. The needle should be directed subcutaneously toward the nasal bone. Using the contralateral hand to palpate the skin can help direct the needle toward the proper location just above the ipsilateral nasal bone.
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A small aliquot can be injected initially at the entry point, and the rest should be infiltrated as the needle is withdrawn.
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It is recommended to wait 10 to 15 minutes for anesthesia and vasoconstriction to achieve maximal efficacy.
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It is important to consider that some patients may have a vasovagal response to intranasal injection, and if possible, a nurse or medical assistant should observe the patient while anesthesia takes effect.
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The Latera delivery device is then prepped on the back table and the implant placed into the loading position.
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The device is inserted endonasally with its final position above the supra-alar groove, with the distal end implanted to just above (approximately 5 millimeters onto) the ipsilateral nasal bone ( Fig. 24.1 ). Countertraction with a medium two-prong hook can pull the nostril margin inferiorly to stretch the lateral wall tissues and promote proper positioning.
