Advances in imaging and flexible endoscope technology have been transformative in the diagnosis and treatment of upper airway pathology within the past decade. The trend toward treatment under local anesthesia in an office setting has emerged with many compelling advantages. Notably, the expense and health risks associated with traditional direct laryngoscopy under general anesthesia are avoided or drastically reduced. Evidence shows that in-office laser procedures (IOLP) are safe, cost-effective, and promote health system efficiency while producing far less waste than traditional operating room laser surgery for RRP.

Office-based treatment of highly vascular pathology, such as RRP, has advanced dramatically with the development of fiber-based photoangiolytic lasers that can be deployed through the working channel of a flexible laryngoscope. Anecdotally, the first in-office awake laser procedure was performed by Franco in 2001 at the Mass Eye and Ear using a 585 nm Pulsed Dye Laser to treat laryngeal papillomatosis. Currently, there are two lasers in this category available for in-office use; these are the 532 nm wavelength potassium titanyl phosphate (KTP) laser (Aura XP, Boston Scientific, Marlborough, MA) and the 445 nm wavelength Blue laser (WOLF TruBlue laser A.R.C., Nurnberg, Germany). Both lasers emit electromagnetic energy with wavelengths that coincide with the peaks of the primary chromophore of oxyhemoglobin, allowing for the selective absorption and targeting of vascular tissue. Both laser types have become mainstays for the primary in-office treatment of papilloma. The KTP laser and laser fibers are no longer manufactured by Boston Scientific for the Otolaryngology community.

In-office treatment of airway papilloma with a Class IV fiber-based laser carries an inherent safety risk to patients and staff. Informed consent is standard protocol, as is complying with laser-specific safety measures. These are delineated by the American National Standards Institute (ANSI). Recommendations for the procedure room include closed entrances with any windows blocked, appropriate signage outside the room delineating the type of laser in use, spare goggles placed outside the room, and ideally filtered suction for laser plume evacuation. All personnel in the room, including the patient, must wear laser-specific goggles during laser activity. For papilloma in particular, the surgeon and assistant should wear appropriate laser-safe filtration masks with minimum level III filtration capability. For further information regarding laser safety standards, please refer to the ANSI Z136.2 Safe Use of Lasers in Healthcare document ( Fig. 39.1 ).

Room schematic.

These procedures are typically performed with a distal-chip working channel laryngoscope and an assistant (trainee, nurse, or medical assistant) to assist in the transendoscopic manipulation of instruments ( Fig. 39.2 ).

Channel laryngoscope with laser fiber, drip catheter, injection needle, and flexible forceps setup.

The assistant may deliver topical anesthesia, introducing and manipulating the laser through the port, maneuvering flexible forceps, and administering therapeutics through a flexible needle. Additionally, the assistant may be tasked with placing the laser in “ready” and “standby” mode at the surgeon’s direction. Because of these factors, the assistant is a key component, and it is extremely important that closed-loop communication is ongoing during the procedure.

For detailed anesthetic techniques, please see Chapters 1 and 37 , which is dedicated to this topic. In short, and to summarize, the authors start with nasal anesthesia and decongestant via cottonoid strips soaked in a 1:1 mixture of decongestant (oxymetazoline or xylometazoline) and 2% or 4% topical lidocaine placed in the nasal cavity for 5 minutes. Further anesthesia may be applied by sprays of topical lidocaine to the oropharynx, per oral nebulization of topical lidocaine, and/or transtracheal administration of plain 2% lidocaine. Endoscopic-directed anesthesia may be performed by application of topical lidocaine through the channel of the laryngoscope with or without a drip catheter with laryngeal gargle. Total anesthetic dose is recorded along with the body weight of the patient to avoid toxicity by limiting the dose to less than 4.5 mg/kg. After topicalization, bulky lesions may be injected with a small amount of local anesthetic via a flexible needle through the channel port. As the superficial tissue is treated, there may be areas beneath that are insufficiently anesthetized. Injection is particularly helpful in the supraglottis, specifically the very sensitive inter-arytenoid tissue.

IOLP utilizes the same principles that guide traditional operative laser microlaryngoscopy to treat papilloma and minimize collateral tissue damage and the risk of fibrosis or scarring. Treatment to improve airway aperture and voice quality must be tempered with reducing thermal energy transfer to adjacent normal tissue. This is of particular importance when treating lesions along the free edge of the vocal fold, as excessive thermal energy application may lead to scarring and loss of normal viscoelastic properties of the superficial lamina propria. Treatment should be aimed at improving the airway and voice by recreating the normal three-dimensional laryngeal anatomy and optimizing vocal fold free edge contour. Secondarily, reduction of viral load and shedding should be achieved by treating papilloma even in areas not contributing to symptoms.

The laser energy is carried by a silica-based fiber (300–600 microns) through the working channel of a laryngoscope, which is then used to visualize tissue and direct the laser fiber to the target. The authors use a 400-micron fiber for both lasers as standard, though fibers are also available in 300 and 600-micron diameters. Both lasers are capable of pulsed energy delivery and allow adjustment of pulse width (the time the laser is “on”) and time between pulses. Pulsed energy delivery allows time for the thermal relaxation time of tissue to dissipate the heat before additional pulses are delivered; the optimal result is adequate heat dispersion to minimize the build-up of heat over time that can denature proteins and alter function. For the 532 nm KTP laser, 15 millisecond (ms) pulse width and 2 pulses per second (PPS) are standard settings with variable power, typically 35–50 watts (W) for larger/bulkier papilloma and 25–35 W for smaller or free-edge papilloma of the vocal fold. For the 445 nm TruBlue laser, settings are typically more variable; the authors use 10.0 W with 20 ms pulse width and 300 ms between pulses for exophytic papilloma, 10.0 W with 60 ms pulse width and 120 ms between pulses for bulky exophytic papilloma, and 6.0 W with 80 ms pulse width and 300 ms between pulses for sessile flat papilloma. Wattage can be lowered during the procedure for patient tolerance, as patients typically will not tolerate an excess of 5–7 joules (J) per pulse. Total energy delivered is variable and influenced mainly by the fiber-to-target distance. Mean total joules per procedure of 200 J has been described, and total joules for small, isolated free edge lesions are typically in the range of 50 J.

The final consideration in treatment technique involves tissue treatment effect. Fluence or energy density is directly controlled by varying the fiber-to-tissue distance and degree of energy delivery with or without fiber-to-tissue contact. Tissue effect classification has been described and validated, allowing for a standardized language in treatment; level 1 is described as noncontact tissue blanching, level 2 as noncontact epithelial disruption, level 3 as contact mode with tissue ablation, and level 4 as contact mode with tissue ablation and debridement. Bulky lesions can be treated in level 3 or 4, with level 4 including debridement with the laser fiber or flexible forceps. Less bulky lesions can be treated in a level 2 fashion and allowed to slough. Very thin, nonraised lesions are most often treated with level 1, allowing for delayed lesion regression.