title: The Use of a Novel Canister-free Negative-Pressure Device in Chronic Wounds: A Retrospective Analysis.
abstract: OBJECTIVE
  Negative-pressure wound therapy (NPWT) is a mainstay in the treatment of acute and chronic wounds. Following the success of the Vacuum-Assisted Closure system (Kinetic Concepts Inc [KCI], an Acelity Company, San Antonio, Texas), many similar systems were developed with minor variations. However, these systems are best suited to wounds with soft-tissue defects. Moreover, the need for a canister to collect wound exudate adds to the size and weight of the device. A canister-free (CF) NPWT device was cleared by the FDA for the treatment of chronic wounds (Kalypto Medical, Mendota Heights, Minnesota). A retrospective study was designed to evaluate the effectiveness of the CF-NPWT device in promoting wound healing.
  
  
  METHODS
  The authors examined the records of 51 patients treated with the CF-NPWT device over a 21-month period. Study participants were treated in an outpatient setting, had at least 30 days of prior treatment, and carried insurance coverage through Medicare or Medicaid. The comparison of time to heal between groups was conducted using the log-rank, Breslow, and Tarone-Ware tests in conjunction with a Kaplan-Meier analysis.
  
  
  RESULTS
  In the study population, 65% of the wounds achieved complete closure. For unhealed wounds, the mean wound area reduction was 31.9%, and the mean wound depth reduction was 57.5%. The mean time to heal was 56.9 days (95% confidence interval, 46.4-67.4 days).
  
  
  CONCLUSIONS
  The results show that the CF-NPWT system meets or exceeds healing rates previously reported in the literature for canister-based systems. This CF device offers a more portable NPWT option, particularly effective in the treatment of shallow wounds.
authors.affiliation: Thomas E. Serena, MD, FACS, FACHM, MAPWCA, is Chief Executive Officer and Medical Director, SerenaGroup, Cambridge, Massachusetts. John S. Buan, PhD, is General Manager, Bioadaptive LLC, St. Paul, Minnesota. Dr Serena has disclosed that he is a consultant to MiMedix, Cytomedix, EnzySurge, Smith & Nephew, and KCI; his company has received grant funding from Healthpoint (Smith & Nephew), EnzySurge, Systagenix, RedDress, KCI, MiMedix, HealOr, and Celleration; and is a member of the speakers' bureau for KCI. Dr Buan has disclosed that he was previously employed by Kalypto Medical, Mendota Heights, Minnesota.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Serena
authors.forename: John S
authors.initials: JS
authors.lastname: Buan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D054843:Negative-Pressure Wound Therapy / Q000295:instrumentation*; D012189:Retrospective Studies; D012883:Skin Ulcer / Q000628:therapy*; D014945:Wound Healing