title: Stray electrical currents in laparoscopic instruments used in da Vinci® robot-assisted surgery: an in vitro study.
abstract: OBJECTIVE
  The da Vinci(®) surgical system requires the use of electrosurgical instruments. The re-use of such instruments creates the potential for stray electrical currents from capacitive coupling and/or insulation failure. We used objective measures to report the prevalence and magnitude of such stray currents.
  
  
  METHODS
  Thirty-seven robotic instruments were tested using an electrosurgical unit (ESU) at pure coagulation and cut waveforms at four different settings. Conductive gel-coated instruments were tested at 40W, 80W, and maximum ESU output (coagulation 120W, cut 300W). The magnitude of stray currents was measured by an electrosurgical analyzer.
  
  
  RESULTS
  At coagulation waveform in open air, 86% of instruments leaked a mean of 0.4W. In the presence of gel-coated instruments, stray currents were detected in all instruments with means (and standard deviation) of 3.4W (± 2), 4.1W (± 2.3), and 4.1W (± 2.3) at 40W, 80W, and 120W, respectively. At cut waveform in open air, none of the instruments leaked current, while gel-coated instruments leaked a mean of 2.2W (± 1.3), 2.2W (± 1.9) and 3.2W (± 1.9) at 40W, 80W, and 300W, respectively.
  
  
  CONCLUSIONS
  All tested instruments in our study demonstrated energy leakage. Stray currents were higher during coagulation (high voltage) waveforms, and the magnitude was not always proportionate to the ESU settings. Stray currents have the potential to cause electrical burns. We support the programmed end of life of da Vinci instruments on the basis of safety. Consideration should be given to alternate energy sources or the adoption of active electrode monitoring technology to all monopolar instruments.
authors.affiliation: Division of Urology, Department of Surgery, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Mendez-Probst
authors.forename: George
authors.initials: G
authors.lastname: Vilos
authors.forename: Andrew
authors.initials: A
authors.lastname: Fuller
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fernandez
authors.forename: Paul
authors.initials: P
authors.lastname: Borg
authors.forename: David
authors.initials: D
authors.lastname: Galloway
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Pautler
mesh_terms: D004560:Electricity / Q000009:adverse effects*; D004564:Electrocoagulation; D004598:Electrosurgery / Q000295:instrumentation* / Q000379:methods*; D010535:Laparoscopy / Q000295:instrumentation*; D012371:Robotics / Q000295:instrumentation*