title: Prospective nonrandomized comparison of two modes of argon beamer (APC) tumor desobstruction: effectiveness of the new pulsed APC versus forced APC.
abstract: OBJECTIVE
  Argon plasma coagulation (APC) has become an established noncontact method of tumor palliation in a variety of locations. The present prospective study evaluated a new APC system (APC-2) using amplified power settings and different application modes, such as intermittent energy delivery (pulsed APC) in comparison with the conventional technique (forced APC).
  
  
  METHODS
  A total of 100 patients with esophageal, gastric, or rectal tumors were alternately (but not randomized) enrolled and treated with either pulsed APC (n = 46) or forced APC (n = 54). Parameters to assess the palliative effect were: amount of lumen restoration ((1/3), (2/3), complete), objective planimetry, stenosis length, treatment time, and number of APC sessions.
  
  
  RESULTS
  Overall response rate was similar in both groups (pulsed 83 %, forced 87 %), the same was found in the subgroups with different amounts of lumen restoration and for the other objective parameters. However, the tumor debulking effect was achieved in a significantly shorter median treatment time with forced compared with pulsed APC (13.6 vs. 18.2 minutes, P = 0.03), with a similar number of treatment sessions in both groups. Complications also occurred with similar frequency in both groups.
  
  
  CONCLUSIONS
  There was no significant difference in overall local tumor response between the two modes of APC application. However, data from this nonrandomized study suggest a faster achievement of response with forced APC. A combination of both modes may be superior.
authors.affiliation: Medical Department C, Klinikum Ludwigshafen GmbH, Ludwigshafen, Germany. eickhofa@klilu.de
authors.forename: A
authors.initials: A
authors.lastname: Eickhoff
authors.forename: R
authors.initials: R
authors.lastname: Jakobs
authors.forename: D
authors.initials: D
authors.lastname: Schilling
authors.forename: D
authors.initials: D
authors.lastname: Hartmann
authors.forename: U
authors.initials: U
authors.lastname: Weickert
authors.forename: M D
authors.initials: MD
authors.lastname: Enderle
authors.forename: J C
authors.initials: JC
authors.lastname: Eickhoff
authors.forename: J F
authors.initials: JF
authors.lastname: Riemann
mesh_terms: D000368:Aged; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D004867:Equipment Design; D004938:Esophageal Neoplasms / Q000150:complications / Q000601:surgery; D004940:Esophageal Stenosis / Q000209:etiology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D017219:Gastric Outlet Obstruction / Q000209:etiology / Q000601:surgery*; D006801:Humans; D007415:Intestinal Obstruction / Q000209:etiology / Q000601:surgery*; D017075:Laser Coagulation / Q000295:instrumentation*; D008297:Male; D010166:Palliative Care / Q000379:methods*; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000150:complications / Q000601:surgery; D013274:Stomach Neoplasms / Q000150:complications / Q000601:surgery; D016896:Treatment Outcome