title: Comparative study of wound healing in rat skin following incision with a novel picosecond infrared laser (PIRL) and different surgical modalities.
abstract: OBJECTIVE
  As a result of wound healing the original tissue is replaced by dysfunctional scar tissue. Reduced tissue damage during surgical procedures beneficially affects the size of the resulting scar and overall healing time. Thus the choice of a particular surgical instrument can have a significant influence on the postoperative wound healing. To overcome these problems of wound healing we applied a novel picosecond infrared laser (PIRL) system to surgical incisions. Previous studies indicated that negligible thermal, acoustic, or ionization stress effects to the surrounding tissue results in a superior wound healing.
  
  
  METHODS
  Using the PIRL system as a surgical scalpel, we performed a prospective wound healing study on rat skin and assessed its final impact on scar formation compared to the electrosurgical device and cold steel. As for the incisions, 6 full-thickness, 1-cm long-linear skin wounds were created on the dorsum of four rats using the PIRL, an electrosurgical device, and a conventional surgical scalpel, respectively. Rats were euthanized after 21 days of wound healing. The thickness of the subepithelial fibrosis, the depth and the transverse section of the total scar area of each wound were analyzed histologically.
  
  
  RESULTS
  After 21 days of wound healing the incisions made by PIRL showed minor scar tissue formation as compared to the electrosurgical device and the scalpel. Highly significant differences (P < 0.001) were noted by comparing the electrosurgical device with PIRL and scalpel. The transverse section of the scar area also showed significant differences (P = 0.043) when comparing PIRL (mean: 141.46 mm2; 95% CI: 105.8-189.0 mm2) with scalpel incisions (mean: 206.82 mm2; 95% CI: 154.8-276.32 mm2). The subepithelial width of the scars that resulted from using the scalpel were 1.3 times larger than those obtained by using the PIRL (95% CI: 1.0-1.6) though the difference was not significant (P < 0.083).
  
  
  CONCLUSIONS
  The hypothesis that PIRL results in minimal scar formation with improved cosmetic outcomes was positively verified. In particular the resection of skin tumors or pathological scars, such as hypertrophic scars or keloids, are promising future fields of PIRL application.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Hannes
authors.initials: H
authors.lastname: Petersen
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Tavakoli
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kruber
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Adrian
authors.initials: A
authors.lastname: Münscher
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Gliese
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany.
authors.forename: Nils-Owe
authors.initials: NO
authors.lastname: Hansen
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Uschold
authors.affiliation: Heinrich-Pette-Institute, Leibnitz Institute of Experimental Virology, Hamburg, 20246, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Eggert
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany.
authors.forename: Wesley D
authors.initials: WD
authors.lastname: Robertson
authors.affiliation: Department of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Gosau
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Centre Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Sehner
authors.affiliation: Department of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Kwiatkowski
authors.affiliation: Department of Clinical Chemistry, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schlüter
authors.affiliation: Department of Anatomy and Experimental Morphology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Schumacher
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, 20246, Germany.
authors.forename: Rainald
authors.initials: R
authors.lastname: Knecht
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany.
authors.forename: R J Dwayne
authors.initials: RJ
authors.lastname: Miller
mesh_terms: D000818:Animals; D002921:Cicatrix / Q000209:etiology / Q000517:prevention & control*; D062109:Dermatologic Surgical Procedures / Q000295:instrumentation*; D004598:Electrosurgery / Q000295:instrumentation; D005260:Female; D007259:Infrared Rays / Q000627:therapeutic use*; D053685:Laser Therapy / Q000295:instrumentation*; D007834:Lasers; D011183:Postoperative Complications / Q000517:prevention & control*; D051381:Rats; D016896:Treatment Outcome; D014945:Wound Healing
keywords: animal model; electrosurgery; electrosurgical device; histology; laser surgery; scalpel