title: Stray energy transfer during endoscopy.
abstract: BACKGROUND
  Endoscopy is the standard tool for the evaluation and treatment of gastrointestinal disorders. While the risk of complication is low, the use of energy devices can increase complications by 100-fold. The mechanism of increased injury and presence of stray energy is unknown. The purpose of the study was to determine if stray energy transfer occurs during endoscopy and if so, to define strategies to minimize the risk of energy complications.
  
  
  METHODS
  A gastroscope was introduced into the stomach of an anesthetized pig. A monopolar generator delivered energy for 5 s to a snare without contacting tissue or the endoscope itself. The endoscope tip orientation, energy device type, power level, energy mode, and generator type were varied to mimic in vivo use. The primary outcome (stray current) was quantified as the change in tissue temperature (°C) from baseline at the tissue closest to the tip of the endoscope. Data were reported as mean ± standard deviation.
  
  
  RESULTS
  Using the 60 W coag mode while changing the orientation of the endoscope tip, tissue temperature increased by 12.1 ± 3.5 °C nearest the camera lens (p < 0.001 vs. all others), 2.1 ± 0.8 °C nearest the light lens, and 1.7 ± 0.4 °C nearest the working channel. Measuring temperature at the camera lens, reducing power to 30 W (9.5 ± 0.8 °C) and 15 W (8.0 ± 0.8 °C) decreased stray energy transfer (p = 0.04 and p = 0.002, respectively) as did utilizing the low-voltage cut mode (6.6 ± 0.5 °C, p < 0.001). An impedance-monitoring generator significantly decreased the energy transfer compared to a standard generator (1.5 ± 3.5 °C vs. 9.5 ± 0.8 °C, p < 0.001).
  
  
  CONCLUSIONS
  Stray energy is transferred within the endoscope during the activation of common energy devices. This could result in post-polypectomy syndrome, bleeding, or perforation outside of the endoscopist's view. Decreasing the power, utilizing low-voltage modes and/or an impedance-monitoring generator can decrease the risk of complication.
authors.affiliation: Department of Surgery, The University of Colorado and The Denver VAMC, 1055 Clermont St, #112, Denver, CO, 80220, USA. edward.jones@UCDenver.edu.
authors.forename: Edward L
authors.identifier: http://orcid.org/0000-0002-1449-8255
authors.initials: EL
authors.lastname: Jones
authors.affiliation: Department of Surgery, McGill University, Montreal, Canada.
authors.forename: Amin
authors.initials: A
authors.lastname: Madani
authors.affiliation: Department of Surgery, The University of Colorado and The Denver VAMC, 1055 Clermont St, #112, Denver, CO, 80220, USA.
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Overbey
authors.affiliation: Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, USA.
authors.forename: Asimina
authors.initials: A
authors.lastname: Kiourti
authors.affiliation: Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, USA.
authors.forename: Satheesh
authors.initials: S
authors.lastname: Bojja-Venkatakrishnan
authors.affiliation: Department of Surgery, The University of Hawaii, Honolulu, HI, USA.
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Mikami
authors.affiliation: Department of Surgery, The Ohio State University, Columbus, OH, USA.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Hazey
authors.affiliation: Department of Surgery, The University of Colorado and The Denver VAMC, 1055 Clermont St, #112, Denver, CO, 80220, USA.
authors.forename: Todd R
authors.initials: TR
authors.lastname: Arcomano
authors.affiliation: Department of Surgery, The University of Colorado and The Denver VAMC, 1055 Clermont St, #112, Denver, CO, 80220, USA.
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Robinson
mesh_terms: D000818:Animals; D002058:Burns, Electric / Q000473:pathology*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000295:instrumentation; D017097:Electric Impedance / Q000009:adverse effects; D019723:Endoscopes / Q000009:adverse effects; D004724:Endoscopy / Q000009:adverse effects*; D004735:Energy Transfer / Q000502:physiology*; D007431:Intraoperative Complications / Q000473:pathology*; D023421:Models, Animal; D013552:Swine
keywords: Complication; Coupling; Endoscopy; Impedance; Polypectomy; Stray energy