title: Office-based 532-nm pulsed KTP laser treatment of glottal papillomatosis and dysplasia.
abstract: OBJECTIVE
  Treatment of glottal papillomatosis and dysplasia was mirror-guided and done in surgeons' offices in the 19th century. It migrated to the operating room in the 20th century to accommodate direct laryngoscopic surgery, which required assistants to administer anesthesia and procedural support. The primary treatment goals, which are disease regression and voice restoration and/or maintenance, are tempered by the morbidity of general anesthesia and potential treatment-induced vocal deterioration. To obviate general anesthesia, office-based laser laryngeal surgery was first done in 2001 with the 585-nm pulsed dye laser (PDL), because it employs a fiber delivery system and its energy is selectively absorbed by oxyhemoglobin. Since then, this new angiolytic laser treatment paradigm has become a mainstay of management for many surgeons; however, there are a number of shortcomings of the PDL. To further develop this concept and address the limitations of the PDL, we used a 532-nm pulsed potassium titanyl phosphate (KTP) laser.
  
  
  METHODS
  A prospective assessment was performed on 48 patients in 72 cases of recurrent glottal dysplasia (36) or papillomatosis (36). All individuals had previously undergone microlaryngoscopic management with histopathologic evaluation.
  
  
  RESULTS
  Two dysplasia patients did not tolerate the procedure. Of the treatable dysplasia cases, there was follow-up in 29 of 34. Disease regression was at least 75% in 18 of 29 cases (62%), 50% to 75% in 7 of 29 (24%), and 25% to 50% in the remaining 4 of 29 (14%). Papilloma patients returned for treatment when symptoms recurred, so disease regression could not be assessed accurately. Similar to data obtained with the PDL, these data confirmed that dysplastic mucosa could normalize without resection.
  
  
  CONCLUSIONS
  Our observations revealed that the 532-nm pulsed KTP laser provided enhanced performance over the PDL laser in a number of ways. The ability to use smaller glass fibers precluded mechanical trauma to the channels of the flexible laryngoscopes and allowed for improved suctioning of secretions. Oxyhemoglobin absorbs energy better at 532 nm than at 585 nm, and the KTP laser can be delivered through a longer pulse width. These factors provide enhanced hemostasis and improved intralesional energy absorbance. Finally, unlike the PDL, the KTP laser is a solid-state laser and is not prone to mechanical failure.
authors.affiliation: Department of Surgery, Harvard Medical School, and the Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital Boston, MA 02114, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Zeitels
authors.forename: Lee M
authors.initials: LM
authors.lastname: Akst
authors.forename: James A
authors.initials: JA
authors.lastname: Burns
authors.forename: Robert E
authors.initials: RE
authors.lastname: Hillman
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Broadhurst
authors.forename: R Rox
authors.initials: RR
authors.lastname: Anderson
mesh_terms: D000556:Ambulatory Surgical Procedures; D000779:Anesthetics, Local / Q000008:administration & dosage; D005931:Glottis / Q000002:abnormalities / Q000601:surgery*; D006801:Humans; D007642:Keratosis / Q000601:surgery; D007822:Laryngeal Neoplasms / Q000601:surgery*; D017075:Laser Coagulation / Q000379:methods*; D008012:Lidocaine / Q000008:administration & dosage; D010212:Papilloma / Q000601:surgery*; D011446:Prospective Studies; D055502:Secondary Prevention
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine