title: Intelligent, impedance-regulated, pulsed coagulation in a porcine renal artery model.
abstract: OBJECTIVE
  To compare the efficacy of conventional pulsed coagulation (CPC) and newly developed intelligent, impedance-regulated, pulsed coagulation (IPC) in the sealing of porcine renal arteries.
  
  
  METHODS
  Prospective, randomized experimental study.
  
  
  METHODS
  Isolated porcine artery model in an academic research environment.
  
  
  METHODS
  Female Swabian Hall pigs.
  
  
  METHODS
  Renal arteries were harvested from Swabian pigs, flushed with saline, and sealed with bipolar open forceps by using high-frequency modulations of CPC (CPC-I: 800-ms pulse, 30-ms pause; CPC-II: 800-ms pulse, 300-ms pause) or IPC (self-regulation of the current flow to tissue impedance during thermal alteration). Additional vessels underwent multiple CPC. Burst pressure and seal failure were measured by increasing the pressure in the sealed arteries with saline infusion until rupture of the seal or the vessel wall.
  
  
  METHODS
  Mean burst pressure, number of instant and secondary seal failures, and relation of burst pressure to vessel diameter.
  
  
  RESULTS
  Mean burst pressure after IPC (585.5 +/- 56.8 mm Hg) was statistically significantly higher than that after CPC (CPC-I: 372.6 +/- 40.0 mm Hg; CPC-II: 334.2 +/- 44.2 mm Hg). Only 5.0% of the vessel seals after IPC, but 34.0% and 39.5% after CPC-I and CPC-II, showed instant or secondary seal failures, which also was a statistically significant difference. Seal quality after multiple CPC was comparable to that observed after the single IPC application (burst pressure, 597.3 +/- 60.1 [MCPC-I] mm Hg and 656.2 +/- 56.5 mm Hg [MCPC-II]; seal failure rate, 0).
  
  
  CONCLUSIONS
  In an isolated porcine renal artery model, self-regulating modulation of energy-based vessel coagulation achieved superior thermal fusion of vascular tissue than did CPC. This promising novel technique should be analyzed further to determine its in vivo efficacy in long-term studies.
authors.affiliation: Department of Obstetrics and Gynecology, University of Tübingen, Tübingen, Germany. cwallwiener@gmx.net
authors.forename: Christian
authors.initials: C
authors.lastname: Wallwiener
authors.forename: Markus
authors.initials: M
authors.lastname: Wallwiener
authors.forename: Eva
authors.initials: E
authors.lastname: Neunhoeffer
authors.forename: Michael
authors.initials: M
authors.lastname: Menger
authors.forename: Keith
authors.initials: K
authors.lastname: Isaacson
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Zubke
mesh_terms: D000818:Animals; D017097:Electric Impedance; D004564:Electrocoagulation / Q000379:methods*; D005260:Female; D066298:In Vitro Techniques; D023421:Models, Animal; D011446:Prospective Studies; D011897:Random Allocation; D012077:Renal Artery / Q000502:physiology*; D013552:Swine