title: [Natural orifice transluminal endoscopic surgery in urology: feasability of a transrectal, flexible retroperitoneoscopy in a porcine model].
abstract: BACKGROUND
  Natural orifice transluminal endoscopic surgery (NOTES) in urology is becoming more and more interesting due to technical innovations. One of those innovations is the HybridKnife®, a multifunctional sonde that combines high-frequency electrosurgery and water jet surgery. The aim of this study was to establish a transrectal, flexible endoscopic retroperitoneoscopy in a porcine model by means of the HybridKnife® for further development of a transrectal retroperitoneal NOTES lymphadenectomy (NOTES-RLA).
  
  
  METHODS
  Five female pigs (25-30 kg body mass) were anesthetized and placed in a supine position. The rectal mucosa was opened 3-5 cm cranially of the linea dentata. After submucosal tunneling, the retrorectal space was opened. We performed a flexible endoscopic retroperitoneoscopy by means of a double-channel gastroscope 13.806 PKS (Karl Storz-Endoskope, Tuttlingen, Germany) and the HybridKnife® I-type (ERBE Elektromedizin, Tübingen, Germany).
  
  
  RESULTS
  Transrectal access was safe and feasible without any difficulties. Using the HybridKnife® water jet technology, the retroperitoneal space could be distended which enabled safe access to the iliacal vessels, the bifurcation of the aorta/vena cava, and the pre- and paraaortal/-caval space up to the renal vessels. The water jet did not lacerate or injure blood vessels, nerves, or lymph vessels in any of the surgical procedures.
  
  
  CONCLUSIONS
  By means of the HybridKnife®, transrectal access into the retrorectal space is safe and easily feasible. The water jet technology combined with electrosurgery prevented injuries of blood vessels, nerves, and lymph vessels and enabled transrectal flexible endoscopic retroperitoneoscopy as a precondition for further establishment of a transrectal NOTES-RLA.
authors.affiliation: Klinik und Poliklinik für Urologie, Kinderurologie und Andrologie, Universitätsklinikum Gießen und Marburg GmbH, Standort Gießen, Justus-Liebig-Universität Gießen, Rudolf-Buchheim-Straße 7, 35385, Gießen, Deutschland, Th.B@gmx.de.
authors.forename: T
authors.initials: T
authors.lastname: Bschleipfer
authors.forename: A
authors.initials: A
authors.lastname: Hackethal
authors.forename: S
authors.initials: S
authors.lastname: Tacke
authors.forename: P
authors.initials: P
authors.lastname: Collet
mesh_terms: D000818:Animals; D055119:Elastic Modulus; D019723:Endoscopes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005260:Female; D008197:Lymph Node Excision / Q000295:instrumentation*; D057605:Natural Orifice Endoscopic Surgery / Q000295:instrumentation*; D012007:Rectum; D013552:Swine; D016896:Treatment Outcome