Anterior glottic webs

The endoscopic flap is performed by first obtaining rigid laryngoscopic exposure of the anterior glottic web and anterior commissure region with suspension laryngoscopy. The optimal head and neck position for exposure of the endolarynx with the laryngoscope is neck flexion on the body and head extension on the neck. A shoulder roll typically places the patient in a suboptimal position (ie, neck extension), and thus it should not be used. Dental and alveolar ridge protection before insertion of the laryngoscope is important. For patients who are edentulous at the maxilla, the best way to protect the mucosa and underlying alveolar ridge is to place a small high-density foam pad between the laryngoscope and the alveolar ridge. As the laryngoscope is placed into the oral cavity, the lips and tongue should be retracted with the nondominant hand. The laryngoscope is then slid along the ventral surface of the tongue and advanced down toward the base of the tongue and posterior pharyngeal wall. The laryngoscope is placed under the epiglottis without folding or traumatizing it. The optimal position of the laryngoscope for this procedure is immediately superior to the web, using the laryngoscope to retract the false vocal fold tissues. Care should be taken to avoid contacting the superior surface of the vocal fold, given that this will significantly alter the anatomic orientation of the vocal fold and often distort the appearance of the pathologic region. External counterpressure can be applied if necessary using silk tape over gauze.

After appropriate positioning, the superior and inferior depth of the anterior glottic web is evaluated with both 0-degree and angled telescopes (Figure 3) . Photodocumentation is obtained. The operating microscope is then brought into the field for further evaluation. Minor but important adjustments of the position of the microscope and laryngoscope will bring the viewing access of the microscope perfectly coaxial with the longitudinal aspect of the laryngoscope; binocular vision at high-power magnification is thus achieved for the remainder of the procedure.

The anterior glottic web is now incised in an asymmetric fashion at either the free edge or even the superior surface of the vocal fold; this mucosa is elevated and preserved for incorporation into the flap (Figure 4) . The flap is grasped and retracted laterally, and the remaining anterior glottis web is released all the way to the thyroid cartilage at the anterior commissure using cold steel instrumentation or the CO₂ laser (Figure 5) . The endoscopic flap can now be draped down over the infraglottis and secured in place with a single 5-0 or 6-0 absorbable suture (Figure 6, Figure 7) . It is rare that the endoscopic flap does not need suturing to stay in the proper location. Tissue glue does not appear to be adequate to secure the endoscopic flap. Application of mitomycin C onto the demucosalized portion of the contralateral vocal fold and anterior commissure is optional.

Keel placement is another option after release of the anterior glottic web. Laryngoscopic exposure with suspension and angled telescopic evaluation are obtained as noted above. There should again be adequate false vocal fold retraction and complete exposure of the anterior glottic web and anterior commissure; there should also be enough room above the vocal folds to account for the superior position of the planned keel, approximately 3-4 mm above the level of the web. It is emphasized that evaluation of the superior-inferior extent of the web is crucial, as it will dictate the minimum length of the planned keel.

Release or excision of the web can be done with a CO₂ laser (smallest spot size and low power), up-cutting scissors, or a sickle knife (Figure 8) . When incising the anterior glottic web, it is important to put tension on the vocal folds with lateral retraction and to stay in the midline between the vocal folds to minimize any lamina propria damage. Cold steel excision is preferable to minimize surgery-related scar formation. After release of the anterior glottic web up to the anterior commissure, the CO₂ laser can be used to make a 1-mm-deep groove in the inner aspect of the thyroid cartilage, extending 3-4 mm above the anterior commissure and 4-5 mm below (Figure 9) . This groove will be used to place the keel as far anteriorly as possible.

30-degree and 70-degree telescopes can then be used to visualize the superior and inferior extent of the anterior glottic web release and to determine the length of the intended keel. When visualizing this area with a 30-degree or 70-degree telescope, the telescope should be passed to the superior-most location to which the keel will need to be secured, and then the telescope shaft can be marked at the location of the junction of the shaft and the proximal laryngoscope. The telescope is then advanced to the inferior limit of the planned keel location, and another mark is made on the telescope. The distance between the two marks is measured and used to determine the superior-inferior length of the keel (Figure 10) . The necessary width of the keel is determined by the degree to which the vocal fold is involved in an anterior-posterior direction.

After trimming the keel to the required length and width, the keel is placed with a heavy cup forceps into the larynx to evaluate the fit. The eventual placement of the suture through the keel will ultimately determine the exact location of the keel in the larynx. Thus, it is helpful to place the keel in the appropriate location and obtain endoscopic visualization with the 70-degree telescope to determine where the fixation sutures should be placed in the keel.

A 0 prolene suture with needles on both ends is then passed from the subglottis to the anterior neck with the Lichtenberger endo-extralaryngeal needle passer. This is done with the operating microscope or with a 30-degree telescope. A clamp is placed on the free end of the suture penetrating the anterior neck (Figure 11) .

An alternative method that does not rely on the endo-extralaryngeal needle passer is to have an assistant pass an 18-gauge angiocatheter or a 2.5-cm-long, 18-gauge needle from the anterior neck to the desired location in the anterior subglottis during simultaneous microlaryngoscopy or telescopic visualization of the larynx. Once the needle is in the proper location in the subglottis, a 0 prolene suture is passed without a needle passer through the hollow tip of needle or angiocatheter and out through the neck where it is secured with a clamp.

Now that one end of the prolene suture has been placed at the inferior or subglottic position, the other end is brought out through the laryngoscope. The suture is passed through the spine of the keel twice, first inferiorly (starting at the convex side) and then superiorly (coming back from the concave side to the convex side). The suture is then loaded into the endo-extralaryngeal needle passer and placed down the laryngoscope. It is passed from the region superior to the anterior commissure out through the anterior neck (Figure 11). If an endo-extralaryngeal needle passer is not available, the method described earlier can also be used to pass the suture out through the neck.

The keel is guided into position in the endolarynx as an assistant applies moderate but equal tension to the sutures coming out of the anterior neck. The proper location of the keel is confirmed using 30-degree and 70-degree telescopic visualization. If the keel is not in the proper location, the placement of the sutures through the keel should be adjusted and repeated. Once the appropriate position is obtained, the keel is secured in place by tying the sutures over a surgical button (or over two buttons, if the sutures have been placed widely apart). The keel should remain in endoscopic or microscopic visualization while the suture is tied (Figure 12) .

Keel removal is performed 7-10 days later, preferably with apneic anesthesia. Endotracheal intubation can complicate endoscopic keel removal and injure the operative site. Direct laryngoscopy is performed, and an assistant uses a 0-degree telescope to visualize the superior portion of the keel. A large cup forceps is used to grasp the keel. Once the endoscopist is confident that he or she has a firm grasp of the keel, the anterior neck sutures are cut and the keel is removed through the laryngoscope.

The patient is mask ventilated; once adequate oxygenation is achieved, repeat direct laryngoscopy and endoscopic visualization of the operative site are performed. If there is severe granulation tissue or reformation of the web, the endoscopic glottic web procedure is repeated. Mitomycin C can also be applied at this point. These decisions are made based on the amount of mucosalization that has occurred at the anterior glottis.

Postoperative care includes reflux treatment, pain control, postoperative steroid taper, cough suppression, and possible overnight observation in the hospital. Patients are reevaluated in approximately 8-10 days in the office, with flexible laryngoscopy or indirect laryngoscopy to determine the amount of mucosalization that has occurred underneath the keel.