Return to: Laser Surgery Protocols

See also:

• KTP Laser for RRP local anesthesia case example
• Laryngeal papilloma (RRP) treatment in clinic with KTP laser video
• KTP (potassium-titanyl-phosphate) laser in office treatment of vocal fold polyps
• Superior Laryngeal Nerve Blocks Instruction Video
• Glossopharyngeal nerve block (gag reflex, transoral vocal cord surgery)
• KTP laser for papilloma microdirect laryngoscopy
• Recurrent Respiratory Papillomatosis (RRP) - General Information
• Microdirect Laryngoscopy case example

Office-Based Potassium Titanyl Phosphate Laser-Assisted Endoscopic Vocal Polypectomy (Wang, et al 2013)

• KTP = potassium titanyl phosphate 532 nm
• PDL = pulsed-dye laser 585 nm
• Close to absorbance peak of hemoglobin - selective angiolysis and photocoagulation of vascular lesions with minimal thermal injury to the lamina propria
• Procedure: nasal decongestion/anesthesia; spray 2% lidocaine to pharynx, tonsils, vallecula. Drip 5 cc of lidcaine (2% on laryngeal introitus)
  • 0.6 mm KTP laser fiber passed through working channel of flex laryngoscopes photo coagulate polyp
  • Settings = 6-8 W per pulse with pulse width of 15 to 25 milliseconds and a 2-Hz repetition rate
• Endpoint = blanching or darkening of the lesion
  • After initial report of KTP in the larynx later research showed that pulsed KTP laser energy better photoangiolytic effect than short-duration continuous laser energy. Rupture of vessel walls can be prevented by increasing pulse width and fiber-to tissue distance and decreasing laser energy

Analysis of Potassium Titanyl Phosphate Laser Settings and Voice outcomes in the Treatment of Reinke's Edema (Young et al, 2015)

• KTP: initial indications were vascular lesions - now expanded to include nonvascular posttraumatic less of the vocal folds including leukoplakia, papilloma, polyps, granuloma, and selected carcinoma
  • Methods with KTP - isolated angiolysis, on ablative and frank tissue ablative with or without tissue removal
  • Problems: user-dependent variability in total energy delivered and laser parameters of wattage, pulse width, and pulses per second.; KTP uses a fiber delivery system which contains an inherent variability in laser fluence
    • Fluence: "energy delivered per cross-sectional surface area"
    • Is largely determined by fiber-to tissue distance - and is not always reliably controlled.
• These authors therefore classified 'immediate end-tissue effects' to classify treatment - incorporating both intrinsic laser parameters and fluency to standardize procedure goals:
• This study provides a detailed description of KTP laser treatment, including laser settings, energy delivery duration of traumata and systematic treatment effect - to serve as a reference
• The overall energy delivered depends on fiber to tissue distance and use of contact or non contact modes as well as tissue characteristics - in addition to laser parameters and total energy delivered - some of the variability in fluency can be accounted for.
• They found it is possible to cause more visible tissue damage with a total lower energy and vice versa -likely contingent on fiber to tissue distance and watts per pulse
  • Suggest: KTP 2 or 3 efect and less than 200 J of total energy most efficacious for this group with
    • Suggested settings for Reinke's edema:
      • 15-35 watts per pulse
      • 15-ms pulse width
      • 2 pulses per second
      • up to 200 J delivered in non-ablative manner
• "Pulsed KTP laser setting varied based on surgeon judgment; total energy delivered in joules (J) was recorded for the entire procedure"

• KTP wavelength of 532 nm (hemoglobin absorbs more strongly than the 585 nm wavelength of PDL) (Yan et al 2008)
• Pulsed KTP laser - wider pulse than the KTP - able to spread laser energy over a longer time - offering slower heating and more even coalition than PDL
• Use of a higher power and shorter time pulse results in less tissue damage than a lower power for a longer period of time.
• "Skip technique": spacing out laser impact (even for a continuous incision) decreases thermal damage by allowing time for the tissue to cool between impacts.
  • Note the importance in keep the laser fiber clean and appropriately "cleaved" (cut) at its tip so as to optimize light dispersion - discussed in detail by Tracy et al (Tracy 2019)

Preliminary Report of Endolaryngeal and Endotracheal Laser Surgery of Juvenile-Onset Recurrent Respiratory Papillomatosis by Nd:YAG Laser and a New Fiber Guidance Instrument (Janda, et al 2004)

Use of Nd:YAG laser (wavelength 1064 nm) for 'good coagulation and hemostatic capabilities 

Pulsed Potassium-Titanyl-Phosphate Laser Treatment of Laryngeal Papillomatosis under General Anesthesia (Burns et al, 2007)

Suggested setting for KTP laser for RRP under general anesthesia

• 5.25-7.5 Joules / pulse
• 15 ms pulse width
• 2 Hz repetition rate
• 0.4 mm fiber
• ~ 20-80 J/cm2 fluence

Topical Anesthesia

Administration of 4% lidocaine to the mucosa of the base of tongue, supraglottis, and glottis using one of several approaches (trans-nasal through working port of endoscope / trans-oral with curved applicator / trans-tracheal) Recommend capping dose at 5 cc (200mg of 4% lidocaine) - but dose may vary and calculation by weight can use a maximum safe dose of 3 mg/kg (Wang 2013)

See also: Maximum Recommended Doses and Duration of Local Anesthetics

References

Yan Y, Olszewski AE, Hoffman MR, Zhuang P, Ford CN, Sailey SH, and Jiang JJ: Use of Lasers in Laryngeal Surgery Journal of Voice, vol 24,No.1. pp 102-109

Wang C-T, Huang T-W, Liao L-J, Lo W-C, Lai M-S and Chng P-W: Office-Based Potassium Titanyl Phosphate Laser-Assisted Endoscopic Vocal Polypectomy. Jama Otolarygnol Head Neck Surg/ Vol 139 (No.6), June 2013

Young VN, Mallur PS, Wong AW, Mandal R, Staltari GV, Gartner-Schmidt J, and Rosen CA: Analysis of Potassium Titanyl Phosphate Laser Settings and Voice outcomes int he Treatment of Reinke's Edema  Annals of Otology Rhinology and Larygnolgoy 2015. Vol 124(3) 216-220

Mallur PS, Johns MM, Amin MR, Rosen C Proposed classification system for reporting 532-nm pulsed potassium titanyl phosphate laser treatment effects on vocal fold lesions. Laryngoscop 2014;124(5):11701175

Zeitels SM: Glottic Cancer: A Metamorphosing Disease. Annals of Otology, Rhinology & Laryngology 1-5 DOI:10.1177/0003489415619177

Janda P, Leunig A, Sroka R, Betz C and Rasp G: Preliminary report of endolarygneal and endotracheal laser surgery of juvenile-onset recurrent repoiratory papillomatosis by Nd:YAG laser and a new fiber guidance instrument

Burns JA, Zeitels SM, Akst LM, Broadhurst MS, Hillman RE and Anderson R: 532 nm Pulsed Potassium-Titanyl-Phosphate Laser Treatment of Laryngeal Papillomatosis under General Anesthesia. Laryngoscope 117:1500-1504

Wang SX, Simpson CB. Anesthesia for office procedures. Otolaryngol Clin North Am. 2013;46(1):13-9

Journal of VoiceVolume 26, Issue 6, November 2012, Pages 806-810Multi-Institutional Experience With the In-Office Potassium Titanyl Phosphate Laser for Laryngeal Lesions  [acknowledges problems with determining fluence]

Koszewski IJ¹, Hoffman MR¹, Young WG¹, Lai YT¹, Dailey SH². Otolaryngol Head Neck Surg. 2015 Jun;152(6):1075-81. Office-Based Photoangiolytic Laser Treatment of Reinke's Edema: Safety and Voice Outcomes.

Lauren F. Tracy, MD ; James B. Kobler, PhD; Jarrad H. Van Stan, PhD; James A. Burns, MD, FACS:  Carbon Debris and Fiber Cleaving: Effects on Potassium-Titanyl-Phosphate Laser Energy and Chorioallantoic Membrane Model Vessel CoagulationLaryngoscope, 129:2244–2248, 2019

Coughlan CA, Verma SP. Evaluating the effects of a 532-nm fiber-based KTP laser on transoral laser surgery supplies. Otolaryngol Head Neck Surg. 2013 Nov;149(5):739-44. doi: 10.1177/0194599813505423. Epub 2013 Sep 20. PMID: 24057676.