Direct Laryngoscopy with Phonomicrosurgical Interventions
Direct laryngoscopy allows for visualization of the laryngeal structures using a rigid endoscope or an operating microscope. This provides clearer, higher resolution images than can be obtained with flexible fiberoptic laryngoscopy, but requires that the patient be anesthetized in order to tolerate the procedure. Phonomicrosurgical interventions include biopsies and resections of benign or malignant lesions. Removal of vocal fold lesions may be performed using a variety of techniques, including direct excision, microflap excision, carbon dioxide laser, or potassium-titanyl-phosphate (KTP) laser, among others. Care must be taken to minimize the amount of disruption to the vocal fold mucosa and superficial lamina propria (the vibratory layer of the vocal fold), as scarring can severely impact voice quality.
Indications for Surgery:
- Direct laryngoscopy is performed when there is suspicion for any laryngeal or tracheal anomaly that cannot be definitively diagnosed on awake flexible fiberoptic laryngoscopy.
- Surgical excision is indicated for the following:
- Vocal fold polyp
- Symptomatic vocal process granuloma refractory to voice therapy and anti-reflux medication
- Symptomatic intracordal vocal fold cyst
- Vocal fold sulcus (difficult to treat successfully)
- Vocal fold nodule with persistent symptoms despite adequate voice therapy
- Epithelial hyperplasia refractory to voice therapy, anti-reflux medication, and smoking cessation
- Symptomatic laryngeal papillomatosis
- Symptomatic vascular abnormalities including vocal fold ectasia, subglottic hemangioma, and varices
- Symptomatic polypoid corditis (Reinke's edema)
- Other benign vocal fold lesions including chondroma, lipoma, neurofibroma, etc.
- Early glottic malignancy
Contraindications to Surgery:
- Medical comorbidities that would preclude surgical or anesthesia risk
- Poor jaw opening (trismus)
- Limited neck extension
- A flexible fiberoptic laryngoscopy is performed prior to proceeding to direct laryngoscopy, unless the patient is unable to tolerate an awake examination.
- Laryngostroboscopy is used to evaluate glottic closure, vibratory quality and mucosal wave.
- The patient is placed supine on the operating table and general orotracheal anesthesia is induced via a microlaryngeal tube.
- The table is rotated 90 or 180 degrees. A dental guard is placed over the maxillary teeth.
- A Dedo or other operating laryngoscope is inserted into the larynx and placed in suspension.
- The larynx is suctioned, and an adequate view of the glottis is confirmed.
- A 0-degree endoscope is inserted through the barrel of the laryngoscope, and the supraglottis and glottis are examined.
- In cases where the surgeon requires the use of both hands to perform an excisive or ablative procedure, the operating microscope is brought into position to facilitate visualization.
- Phonomicrosurgical interventions may then be carried out. Examples include:
- Direct Excision: Used for the removal of small, superficial vocal fold polyps or nodules, where disruption of overlying mucosa is minimal. The lesion is excised in its entirety with a small piece of mucosa attached. This can be achieved using microinstruments, such as microlaryngeal scissors, knives, and forceps.
- Microflap Excision: Used for the removal of intracordal cysts and in some cases of vocal fold polyps. The vocal fold is injected with saline or 1:10,000 epinephrine using a 25-gauge needle, raising a microflap bleb. A sickle knife or 45 degree angled microscissors are then used to incise the mucosa adjacent to the lesion. Using dissectors and microscissors, the mass is dissected free of the overlying mucosa while preserving the surrounding superficial lamina propria and excised.The microflap is redraped over the wound to approximate the mucosal edges. Redundant mucosa may be trimmed with microscissors.
- Carbon Dioxide Laser: May be used to treat vocal fold nodules, polyps, papillomas, granulomas, and early glottic malignancy. Clear safety goggles or standard eye glasses are used to protect the eyes of the operating room staff. Wet towels and eye pads are placed to protect the patient from inadvertent burns. Because the wavelength of the laser beam is not in the visible spectrum, an aiming beam is used. A micromanipulator is used to focus the aiming beam onto the targeted tissue. Care is taken to ensure that no metallic objects (such as instrumentation) are in the path of the laser beam, as the beam is reflected by metal and mirrors.
- KTP Laser: The photoangiolytic capacity of this laser (due to preferential absorption by oxyhemoglobin) results in coagulation of small vessels, making it useful for treatment of papillomas, leukoplakia, polyps, granulomas, and vascular anomalies such as subglottic hemangiomas, vocal fold ectasia, and varices. The laser is used on a pulsed setting, and the beam is visible. The laser requires staff to wear protective goggles specific to green light.
- Pledgets soaked in lidocaine with epinephrine are applied to the larynx for several minutes to achieve hemostasis.
- The pledgets are removed and the larynx is suctioned.
- The laryngoscope is removed from suspension and withdrawn. The mouth is checked for injuries. Care of the patient is returned to the anesthesiologist for extubation and recovery.
- Direct laryngoscopy and phonomicrosurgery may be performed on an elective, outpatient basis.
- Pain medications are given as needed.
- The patient is started on a proton pump inhibitor to reduce laryngeal irritation from laryngopharyngeal reflux.
- The patient may resume a regular diet after the procedure.
Complications from direct laryngoscopy are uncommon, but can include injury to the lips, teeth or tongue. Complications arising from phonomicrosurgical interventions include bleeding or hematoma, granuloma or scar formation, change in voice quality, and persistence or recurrence of lesion.