title: "Hemodynamic efficacy" of two endoscopic clip devices used in the treatment of bleeding vessels, tested in an experimental setting using the compact Erlangen Active Simulator for Interventional Endoscopy (compactEASIE) training model.
abstract: OBJECTIVE
  Hemoclip therapy is a well-established procedure in the treatment of gastrointestinal bleeding. Although new products are provided periodically by the industry, comparative investigations are lacking. We compared two different hemoclip devices in an experimental setting, assessing them using objective hemostatic parameters.
  
  
  METHODS
  We compared two disposable clip devices (Olympus HX-200L-135 (n = 40) vs. Wilson-Cook Tri-Clip (n = 40)) in an experimental setting using the compact Erlangen Active Simulator for Interventional Endoscopy (compactEASIE) training model equipped with an upper gastrointestinal-organ package for bleeding simulation. This was a randomized, prospective, controlled trial. Four investigators with different levels of endoscopic experience applied ten hemoclip devices of each type to the spurting vessels, the clips allocated using a randomized list for each investigator. The efficacy of hemostasis was determined by continuous measurement of the pressure within the afferent vessel before and after clip application and calculation of the relative reduction of vessel diameter by the clip device. The system pressure was recorded over the period from 1 minute before to 1 minute after clip application. A secondary end point was a subjective assessment of the whole clip application procedure by the endoscopist and the assisting nurse, using a visual analog scale (0 - 100, with 100 representing the best experience).
  
  
  RESULTS
  A total of 39/40 clips of each type were applied successfully. Both clip devices led to a significant increase in system pressure, representing significant relative reduction of vessel diameter (Olympus 5.4 +/- 7.5 %, p < 0.001; Cook 4.9 +/- 8.0 %, p < 0.001). Overall, there was no significant difference between the two devices ( P = 0.756). However, the investigator with the least experience in endoscopy (< 100 procedures) produced significantly inferior results compared with the other three investigators, who had performed between 2000 and 6000 procedures each ( P < 0.05). We found no evidence of a learning curve from the intra-observer results. The devices received good, but not significantly different, overall ratings by the endoscopists (Olympus 69 +/- 24 vs. Wilson-Cook 65 +/- 16) and by the assisting nurses (Olympus 77 +/- 9 vs. Wilson-Cook 70 +/- 22).
  
  
  CONCLUSIONS
  Using an established cadaveric training model, no significant difference was found between the two types of hemoclip devices with respect to their "hemostatic efficacy". However, the experience of the endoscopist appears to play a major role in successful clip application. The use of a feedback mechanism in emergency endoscopy training, using continuous intravessel pressure monitoring, may substantially enhance the efficacy of training, resulting in a similar improvement in clinical results.
authors.affiliation: Department of Medicine I, University of Erlangen-Nürnberg, Erlangen, Germany. juergen.maiss@med1.imed.uni-erlangen.de
authors.forename: J
authors.initials: J
authors.lastname: Maiss
authors.forename: C
authors.initials: C
authors.lastname: Dumser
authors.forename: Y
authors.initials: Y
authors.lastname: Zopf
authors.forename: A
authors.initials: A
authors.lastname: Naegel
authors.forename: N
authors.initials: N
authors.lastname: Krauss
authors.forename: J
authors.initials: J
authors.lastname: Hochberger
authors.forename: K
authors.initials: K
authors.lastname: Matthes
authors.forename: E G
authors.initials: EG
authors.lastname: Hahn
authors.forename: D
authors.initials: D
authors.lastname: Schwab
mesh_terms: D002102:Cadaver; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D004867:Equipment Design; D006471:Gastrointestinal Hemorrhage / Q000628:therapy*; D016558:Hemostasis, Endoscopic / Q000295:instrumentation*; D006801:Humans; D066298:In Vitro Techniques; D017145:Models, Educational; D011446:Prospective Studies; D016896:Treatment Outcome