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External laryngeal counterpressure and internal laryngeal distention produce forces that are helpful for enhancing laryngoscopic exposure of the anterior glottis. These principles were formally described in the early 20th century, but are seldom used today. Hand pressure has been the typical source for external counterpressures. Since this maneuver is unstable if provided by an assistant and wasteful if provided by the surgeon, it is often neglected. Current phonomicrosurgical techniques require wider glottal exposure; therefore, a reexamination of the value of external counterpressure and internal distention is worthwhile. During the last 2 years, 125 microlaryngoscopic procedures were performed for a variety of benign, premalignant, and malignant lesions. All patients were placed in the Boyce-Jackson position and sustained with a modified Killian gallows, with resulting elevated-vector suspension. Internal distention was achieved by placing the largest-lumen glottiscope possible between the endotracheal tube and the infrapetiole region. Exposure was also improved by using silk adhesive tape to apply external counterpressure to the lower laryngeal framework. The use of both external counterpressure and internal distention as an adjunct to microlaryngoscopy was most helpful for the surgical management of lesions located near the anterior commissure. Seemingly, the two resultant forces are in opposition to each other, but in fact they are complementary, both to each other and to the orthodox laryngoscopic principle of elevated-vector suspension.

The tendency of epiglottic cancer to invade the preepiglottic space and the significance of this invasion was evaluated in 36 surgical specimens of epiglottic carcinoma originally staged T1 or T2. None of the 9 lesions originating above the hyoepiglottic ligament invaded the preepiglottic space. Twenty-four of the 27 (89%) lesions originating below the hyoepiglottic ligament showed invasion of the preepiglottic space and were clinically understaged. Of the 3 infrahyoid lesions showing no invasion of the preepiglottic space, 1 was a verrucous carcinoma and another was a mucoepidermoid carcinoma arising on the petiole. All other lesions were squamous cell carcinoma. In 12 of the 24 patients (50%) with preepiglottic space invasion, cervical node metastasis was present despite the preoperative staging of T1 or T2.

An initial endoscopic surgical approach to early supraglottic cancer provides the surgeon with the ability to accurately stage these lesions, avoiding possible undertreatment while allowing for a valuable treatment option for those supraglottic cancers with histologically incontrovertibly superficial disease. Early invasion of the preepiglottic and paraglottic spaces can be determined accurately without altering or delaying any treatment option (open surgical excision, radiotherapy, or chemotherapy). The tendency of supraglottic cancers to transgress the natural foramina of the epiglottis is well established, and the concern about this depth of invasion is reflected by the 1977 revised staging criteria, which required assessment of the preepiglottic space (PES). Along with the microscope and the carbon dioxide laser, the adjustable supraglottiscope facilitates the determination of PES invasion and facilitates en bloc excision of superficial supraglottic cancers. The resulting morbidity typically is no different from that with routine direct endoscopy and biopsy.

Stenosis of the larynx and/or trachea presents perplexing problems. No one technique has proved totally satisfactory in the management of all varieties of stenosis. Recent reports have described the successful use of the CO2 laser in the endoscopic management of stenosis of the larynx and trachea. Failures of this technique need emphasis to assure appropriate selection of therapeutic method. Retrospectively, 49 cases of laryngeal stenosis, 6 cases of tracheal stenosis and 5 cases of combined laryngeal and tracheal stenosis were studied (total 60 patients) following treatment at the Boston University Affiliated Hospitals. Follow-up ranged from 1 to 8 years. Multiple procedures were required in 35 laryngeal patients. Of the laryngeal patients 39 were successfully managed (average number of procedures in successful cases 2.18). Of 11 tracheal patients with combined laryngeal and tracheal procedures, 3 were successfully managed (average number of procedures in successful cases 6). Failures in laryngeal stenosis included four patients in whom an adequate airway was not established though voice was present while maintaining tracheostomies. Thirteen patients failing endoscopic management required open surgery with good result. Factors associated with poor result or failure include circumferential scarring with cicatricial contracture, scarring wider than 1 cm in vertical dimension, tracheomalacia and loss of cartilage, previous history of severe bacterial infection associated with tracheostomy, and posterior laryngeal inlet scarring with arytenoid fixation. In these circumstances, multiple procedures, more extensive alternative open surgical techniques, or maintenance of tracheostomy were necessary. In successful cases only three or fewer procedures on average were required. The factors associated with failure or success of endoscopic methods in the management of laryngotracheal stenosis, including use of the CO2 laser and soft Silastic stents, are analyzed.

Recurrent respiratory papillomatosis is most common in childhood but it affects all age groups; it represents a diathesis of the aerodigestive tract so that lesions amy develop at various sites - the nares, lips, pharynx, nasopharynx, larynx, tracheobronchial tree, approximately one-third of patients for one year or more; since relapses amy occasionally occur 2 to 20 years later, cure can never be assumed. At the present time, management is directed towards total ablation of all visble papilloma consistent with preservation of the airway and voice; reduction of the tumor burden to minimal proportions is thought to allow the maximum opportunity for remission. As the host-papilloma relationship is unraveled, it may be possible in the future to provoke an immune response so that remissions can be predicted and produced consistently.

Topical chemotherapy with the antimetabolite 5-fluorouracil (5-FU) has been used as an adjunct to surgical laser excision of squamous papillomas arising in the larynx and in the tracheobronchial tree. The drug has been administered intensively to eight patients with tracheotomies and disease in both anatomic regions. These patients received repeated instillations of 5-FU at concentrations from 0.5 to 5% into the larynx and tracheobronchial tree while in the hospital and at home. More than 4,500 doses of the drug have been administered during our phase 1 study. There has been no significant toxicity associated with repeated 5-FU instillation into the airway. Several patients developed blood-tinged tracheal secretions after the repeated use of high concentrations of the agent. Other complications included coughing, bronchospasm, and peristomal irritation. These symptoms all disappeared after temporary discontinuation of the drug. No patient has developed a systemic hypersensitivity response to the drug either detectable clinically or by repeated skin testing. There were no adverse effects on the hematologic or hepatic systems. Use of 5-FU was associated with inhibition of papilloma regrowth in six of eight patients. The major limitation to drug effectiveness is the requirement for its frequent administration.

Congenital choanal atresia frequently demands immediate recognition in the newborn, and provision of a nasal airway as soon as possible. A variety of techniques are available to correct this problem, but none is entirely satisfactory. Transpalatal procedures are associated with significant morbidity in the newborn, and transnasal microsurgical procedures are less predictable when a thick bony plate is present in the choanal obstruction. Transnasal resection with the CO2 laser has been carried out in seven patients (ten sides), whose ages ranged from 16 hours to 14 years. From this early experience, it appears that the procedure is entirely feasible and convenient. It seems to have significant advantages over conventional microsurgical techniques. Eight out of ten choanae have remained patent for four months or more. A lumen keeper is needed during the immediate postoperative period for at least two to three weeks. The procedure is associated with minimal morbidity.

The carbon dioxide and neodymium:yttrium aluminum garnet lasers have well documented but characteristically different biological effects, yet little is known about their cumulative, synergistic, or paradoxical effects when used sequentially on living tissue. Using a Merrimack ML 880 laser, a series of superimposed CO2 and Nd:YAG lesions in various combinations were produced on the undersurface of dog tongues. Therapeutic time and power settings were chosen and the number of applications varied, with suitable controls. Observations and measurements were made on acute, healing, and healed lesions. All lesions were excised and submitted for routine hematoxylin and eosin histology. Acute lesions were also assessed for cell viability using rhodamine 123 as a supravital marker. The results show that, even though all the lesions eventually heal, the actual cell damage produced by the Nd:YAG laser is much more than is suggested by the size of the acute lesion. This cell damage can be reduced by the surface carbonization produced by initial application of the CO2 laser. Higher surface temperatures are reached in this combination with less fibrosis and scarring than equal energy counterparts where the Nd:YAG laser was applied first. The knowledge of these synergistic effects can be used to advantage in the clinical setting. The rhodamine 123 technique also appears to be a valid measure of acute thermal tissue injury.

Meeting the exacting requirements for microsurgery of the larynx is a challenge for the anesthesiologist. To accomplish, the necessary dissection, the otolaryngologist has several requirements. They are a quiet relaxed field, excellent illumination with magnification, binocular vision for depth perception, and, above all, an unobstructed field. The management of anesthesia for suspension microsurgery on the larynx presents many problems, the most vexing of which is the fact that the otolaryngologist and anesthesiologist are in competition for access to the patient's airway. In sharing this, neither has been able to perform with the degree of control that he would like due to either inadequate operating conditions or insufficient access to ventilatory mechanisms. Several anesthetic techniques have been used for inspection or operative laryngoscopy: topical anesthesia, apneic techniques, translaryngeal topical anesthesia, chest respirator, neuroleptanalgesia, and general endotracheal anesthesia with muscle relaxants. The latter has proven most popular, particularly in children, because ventilation and surgical conditions are considered to be most controllable. However, the presence of the requisite endotracheal tube obscures the full view of the larynx and vocal cords, and the tube may itself become obstructed. Additionally, use of the laser involves the further risk of heat effects on the endotracheal tube if the beam hits the tube. This report presents our experience and development of the combined technique of endotracheal intubation and Venturi (jet) ventilation. We believe it represents the safest available approach while providing near ideal working conditions for the otolaryngologist during laser microsurgery of the larynx.