title: A new argon gas-based device for the treatment of keloid scars with the use of intralesional cryotherapy.
abstract: BACKGROUND
  Intralesional (IL) cryotherapy is a new promising technique for the treatment of keloid scars, in which the scar is frozen from inside. Multiple devices are available, mostly based on a simple liquid nitrogen Dewar system, which have a limited freezing capacity. Argon gas-based systems ensure accurate and highly controlled freezing and have shown to be effective within the field of oncologic surgery. However, this technique has never been used for the treatment of keloid scars.
  
  
  OBJECTIVE
  This prospective study evaluates an argon gas-based system for the treatment of keloids in a patient population including all Fitzpatrick skin types with a 1-year follow-up.
  
  
  METHODS
  Twenty-five patients with 30 keloid scars were included and treated with a device called Seednet (Galil Medical, Yokneam, Israel). Scar quality and possible scar recurrence were assessed before treatment and post treatment (6 and 12 months) with objective devices determining scar color, scar elasticity, scar volume, and patient's skin type. In addition, scars were evaluated using the Patient and Observer Scar Assessment Scale.
  
  
  RESULTS
  After 12 months, a significant volume reduction of 62% was obtained, p = 0.05. Moreover, complaints of pain and itching were alleviated and scar quality had improved according to the Patient and Observer Scar Assessment Scale. Scar pigmentation recovered in 62% of all keloid scars within 12 months. Five out of 30 (17%) scars recurred within 12 months, three of which had previously been treated with liquid nitrogen-based IL cryotherapy. Both recurrent and persistent hypopigmentation were mainly seen in Afro-American patients.
  
  
  CONCLUSIONS
  IL cryotherapy with the use of an argon gas-based system proves to be effective in the treatment of keloid scars, yielding volume reduction and low recurrence rates. Although hypopigmentation recovered in most cases, it is strongly related to non-Caucasian patients. Finally, additional treatment of keloid scars previously unresponsive to IL cryotherapy is predisposed to a high recurrence rate.
  
  
  BACKGROUND
  NCT02063243.
authors.affiliation: Department of Plastic and Reconstructive Surgery, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: mc.vanleeuwen@vumc.nl.
authors.forename: Michiel C E
authors.initials: MC
authors.lastname: van Leeuwen
authors.affiliation: Department of Plastic and Reconstructive Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Anne-Eva J
authors.initials: AE
authors.lastname: Bulstra
authors.affiliation: Department of Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Paul A M
authors.initials: PA
authors.lastname: van Leeuwen
authors.affiliation: Department of Plastic and Reconstructive Surgery, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Niessen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001128:Argon; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D004548:Elasticity; D005260:Female; D005740:Gases; D006801:Humans; D017496:Hypopigmentation / Q000209:etiology; D007627:Keloid / Q000150:complications / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D011446:Prospective Studies; D011537:Pruritus / Q000209:etiology; D012008:Recurrence; D055815:Young Adult
chemical_list: D005740:Gases; D001128:Argon
keywords: Argon gas; Cryosurgery; Intralesional cryotherapy; Keloid scars; Keloids; Scar treatment