title: Harmonic scalpel versus flexible CO2 laser for tongue resection: a histopathological analysis of thermal damage in human cadavers.
abstract: BACKGROUND
  Monopolar cautery is the most commonly used surgical cutting and hemostatic tool for head and neck surgery. There are newer technologies that are being utilized with the goal of precise cutting, decreasing blood loss, reducing thermal damage, and allowing faster wound healing. Our study compares thermal damage caused by Harmonic scalpel and CO2 laser to cadaveric tongue.
  
  
  METHODS
  Two fresh human cadaver heads were enrolled for the study. Oral tongue was exposed and incisions were made in the tongue akin to a tongue tumor resection using the harmonic scalpel and flexible C02 laser fiber at various settings recommended for surgery. The margins of resection were sampled, labeled, and sent for pathological analysis to assess depth of thermal damage calculated in millimeters. The pathologist was blinded to the surgical tool used. Control tongue tissue was also sent for comparison as a baseline for comparison.
  
  
  RESULTS
  Three tongue samples were studied to assess depth of thermal damage by harmonic scalpel. The mean depth of thermal damage was 0.69 (range, 0.51 - 0.82). Five tongue samples were studied to assess depth of thermal damage by CO2 laser. The mean depth of thermal damage was 0.3 (range, 0.22 to 0.43). As expected, control samples showed 0 mm of thermal damage. There was a statistically significant difference between the depth of thermal injury to tongue resection margins by harmonic scalpel as compared to CO2 laser, (p = 0.003).
  
  
  CONCLUSIONS
  In a cadaveric model, flexible CO2 laser fiber causes less depth of thermal damage when compared with harmonic scalpel at settings utilized in our study. However, the relevance of this information in terms of wound healing, hemostasis, safety, cost-effectiveness, and surgical outcomes needs to be further studied in clinical settings.
authors.affiliation: Department of Otolaryngology Head Neck Surgery, Louisiana State University Health Sciences Center, New Orleans, USA.
authors.forename: Duncan F
authors.initials: DF
authors.lastname: Hanby
authors.forename: Grayson
authors.initials: G
authors.lastname: Gremillion
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Zieske
authors.forename: Bridget
authors.initials: B
authors.lastname: Loehn
authors.forename: Richard
authors.initials: R
authors.lastname: Whitworth
authors.forename: Tamir
authors.initials: T
authors.lastname: Wolf
authors.forename: Anagha C
authors.initials: AC
authors.lastname: Kakade
authors.forename: Rohan R
authors.initials: RR
authors.lastname: Walvekar
mesh_terms: D016063:Blood Loss, Surgical / Q000517:prevention & control*; D002056:Burns / Q000209:etiology / Q000473:pathology*; D002102:Cadaver; D004867:Equipment Design; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D054020:Lasers, Gas / Q000627:therapeutic use*; D014059:Tongue / Q000473:pathology* / Q000601:surgery; D014062:Tongue Neoplasms / Q000601:surgery*; D014945:Wound Healing