Abstract
Microlaryngeal surgery evolved with the development of suspension laryngoscopy and binocular microscopes for enhanced visualization. Development of microlaryngeal instrumentation followed rapidly to meet the demands of the Otolaryngology–Head and neck surgeon. Advancement of laser technology further enhanced the surgeon's ability to sharply dissect tissue using a hands-off approach and added hemostatic capability to the cutting edge. Similarly, endoscopic sinus surgery has evolved with application of minimally invasive instrumentation. The recent introduction of powered surgical instruments, combining cutting capability and suction, facilitates removal of diseased or anatomically variant tissue from sinus cavities.
Powered surgical instrumentation applied to micro-laryngeal surgery and surgery of the airway, as demonstrated in this report, provides the head and neck surgeon with a novel approach for surgery of the airway. Combining telescopic video control and powered instrumentation with suspension laryngoscopy provides superior visualization and access for rapid removal of obstructing lesions and controlled excision of vocal fold pathoses.
PATIENT PREPARATION AND SURGICAL TECHNIQUE
General anesthesia is induced and the airway secured by endotracheal tube (ETT) intubation or tracheotomy if indicated. ETT size will vary depending on airway conditions (presence of stenosis) and intubation technique. In an adult, a small-cuffed 5.0 or 5.5 ETT is adequate for ventilation and allows access for surgical instrumentation. With stenotic lesions, smaller, cuffless ETTs may be required. In this situation, the laryngoscope may even accommodate powered instrumentation, a rigid telescope, and the ETT, allowing for uninterrupted surgery.
A standard laryngoscope is positioned and suspended to allow access to the anatomic entity to be excised. Access to the anterior commissure and subglottic region may necessitate the use of a smaller anterior commissure laryngoscope. Visualization is accomplished through use of a 5-mm, 0° or 30° rigid telescope (Karl Storz) and digital imaging system. Although an operating microscope may be used, surgery is generally performed with digital video control to improve visualization of the lesion and shaver tip.
The XOMED XPS shaver system is used with laryngeal blades (Fig 1 A). Three cutting tips have been designed for applications ranging from rapid debulking of large lesions obstructing the airway to delicate removal of superficial lesions on the vocal fold (Fig 1 B). Angled-tip blades allow for excision of discrete lesions involving the anterior commissure and are particularly beneficial for accessing and removing tissue from the undersurface of the vocal fold, subglottis, and tracheal wall. The standard laryngeal blade is 22.5 cm in length; a 27.5-cm blade is used for tracheal lesions (Fig 2).
The console should be set to “oscillate,” with the maximum speed set at 500 rpm for small lesions or those on or near the vocal folds and at 3000 rpm for debulking larger lesions or excising fibrous tissue. Irrigation must be used with the blade and allowed to flow continuously throughout the procedure to prevent clogging. Wall suction levels may be adjusted to provide enough vacuum to allow the blade to remove tissue at an efficient rate (150–180 mmHg). An in-line tissue trap is used to capture specimens for pathologic analysis. Specimens in the trap are spun down and processed as a block.
RESULTS
During a 1-year period in 1997 and 1998, the XOMED XPS shaver system has been used in 22 endoscopic procedures in 18 patients for surgical excision of benign stenosis (8), tumor obstructing the airway (5), recurrent laryngeal papilloma (5), and excisional biopsy of laryngeal mucosal lesions (4). The laryngeal shaver was found to be ideal for rapid debulking of laryngeal and tracheal tumor (Fig 3). Larger, tricut blades were generally required for large lesions. Bleeding was controlled with vasoconstricting agents applied directly with pledgets. In 3 cases in which tumors were removed for obstruction, tracheotomy was avoided. One patient with distal tracheal obstruction due to metastatic breast cancer had a previously placed tracheotomy. This patient underwent 2 procedures for debulking of tumor in the distal trachea.
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A, Xomed XPS system with angled laryngeal blade. B, Angled 4.0-mm tricut and round window Skimmer blades. A 35-mm round window blade (not shown) is also available for superficial lesions on the vocal fold.
Excision of benign stenotic lesions was performed in 8 patients. All lesions were the result of intubation injury. Each patient had a previously placed T tube or tracheostomy tube. Tricut (4-mm) blades were necessary to adequately excise the firm fibrotic scar. Three of these patients required excision of acute subglottic granulation tissue after laryngotracheoplasty. Although excision of granulation tissue was accomplished, bleeding was, in general, more problematic despite the use of topical vasoconstrictors.
Excision of benign mucosal lesions was performed in 9 cases (5 papilloma and 4 granuloma/polyps). Excision of papilloma was accomplished rapidly through use of the 4.0-mm round window Skimmer blade. Lesions on the true fold were generally removed through use of the 3.5-mm round window Skimmer blade, with preservation of underlying structures. Access to anterior commissure lesions was improved through use of the 30° rigid telescope and Hollinger anterior commissure laryngoscope. Bleeding was controlled with topical vasoconstrictors. Subjective improvement in vocal quality was reported by all patients undergoing excision of papilloma, although no objective measures were obtained and no comparison was made between excision with powered instrumentation and laser excision.
DISCUSSION
Debate continues regarding the applications and advantages of cold surgical procedures versus the use of laser technology for laryngeal surgery. 1 - 4 Proponents of cold surgical technique argue that thermal energy results in marginal tissue injury and secondary scar formation. 1 Furthermore, distal injury resulting from a misdirected laser spot and the inherent risk of fire associated with use of the laser cannot be entirely eliminated. In addition, wrapped laser tubes are cumbersome, and the use of apnea techniques may not be applicable in a patient with a tenuous airway and/or underlying pulmonary disease.
Although no direct comparison with laser surgery was undertaken in this report, powered surgical instrumentation offers distinct advantages over laser technology. In comparison with laser excision, powered instrumentation allows for rapid debulking of tumor in close proximity to an ETT with no risk of fire. Continuous suction prevents blood from obscuring visualization, and the specimen may be preserved for pathologic examination. When 5-mm rigid laryngeal telescopes and digital imaging are used, surgical procedures can be performed through small anterior commissure laryngoscopes, allowing access to the anterior commissure and sublglottic regions, which are frequently difficult to approach with conventional laser or cold surgical techniques.
In my experience, excision of superficial lesions on the true vocal folds may be accomplished through use of the smaller 3.5-mm blades with round windows and angled tips and at a low speed setting (≤500 rpm). Variable speed control allows for suction-controlled, single-revolution excision of mucosal lesions. In this manner, mucosal lesions are evacuated into the suction tip, elevated off underlying structures, and amputated by a single revolution of the blade. Although this maneuver minimizes the risk of injury to underlying structures, powered surgical excision of true vocal fold lesions has not been demonstrated to be more effective than conventional sharp excision. Moreover, extreme caution must be exercised when work is being done at the level of the true fold, and excision should be attempted only with the 3.5-mm round window Skimmer blade at low speed (≤500 rpm).
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Schematic coronal view of endoscopic approach with powered shaver (27.5-cm blade) and rigid telescope used for distal tracheal stenosis.
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Limitations of powered instrumentation for laryngeal surgery include the unobtainability of histologic margin control and the difficulty of obtaining hemo-stasis with vascular lesions. Because specimens are collected in a trap and processed as a spun block, orientation of specimens is not possible with powered instrumentation. Therefore, cold sharp excision is recommended for excisional biopsy when surgical margins or determination of level of invasion is critical for subsequent treatment decisions. As with endoscopic laser excision of tumor, separate margin control must be performed to confirm adequate resection.
Difficult bleeding was not encountered except with excision of subglottic granulation tissue; in these cases, bleeding limited visualization. In situations in which increased vascularity is suspected, laser excision may be necessary.
CONCLUSION
As in the evolution of sinus surgery, powered instrumentation for laryngeal surgery facilitates endoscopic removal of pathologic tissue from the airway. De-bulking of obstructing tumor and excision of laryngeal papilloma may be performed rapidly without concern for airway fire. Telescopic video control and small-aperture, angled instruments allow for controlled excision of small superficial mucosal lesions on the vocal folds and improved access to the anterior commissure and subglottic regions. Further clinical studies will be necessary to assess outcomes with respect to vocal quality, postoperative pain, and recurrence rate in patients with laryngeal papilloma and to evaluate the role of powered surgery as a primary treatment modality for laryngeal cancer.