title: Single-site laparoscopic (SSL) cholecystectomy in human cadavers using a novel percutaneous instrument platform and a magnetic anchoring and guidance system (MAGS): reestablishing the "critical view".
abstract: BACKGROUND
  SSL introduces ergonomic challenges while establishing the critical view during dissection of the Triangle of Calot (TOC). This study investigates the use of a novel percutaneous instrument platform and MAGS in performing SSL cholecystectomy with a technique that closely mimics four-port cholecystectomy.
  
  
  METHODS
  SSL cholecystectomy was performed on four female cadavers via a 15-18-mm incision made at the umbilicus for introduction of these devices and the working port. MAGS comprises an internal effector with a retractable monopolar cautery hook coupled across the abdominal wall to an external magnet held by the surgeon. The novel grasper was introduced percutaneously in the RUQ and comprises a 3-mm transabdominal shaft mated to a 5-mm end effector intracorporeally. Retraction was accomplished using the percutaneous grasper to manipulate the fundus and a standard 5-mm grasper at the umbilicus for the infundibulum. Dissection was performed by using a combination of the MAGS and a standard Maryland dissector. Total procedure time, time from procedure start to obtain a critical view of the TOC and clipping and dividing the cystic duct/artery, time for dissection of the gallbladder from the liver bed, and thickness of the abdominal wall at the umbilicus were measured.
  
  
  RESULTS
  The critical view was obtained in each case, and all four procedures were completed successfully. Mean procedure time was 40 (range, 33-51) min; time from procedure start to obtaining the critical view and clipping and dividing the cystic duct/artery was 33 (range, 28-38) min, and time for dissection of the gallbladder from the liver bed was 6.7 (range, 3-13) min. The mean abdominal wall thickness was 1.9 (range, 1.5-2) cm.
  
  
  CONCLUSIONS
  The use of a novel graspers and MAGS overcomes the limitations of SSL cholecystectomy and improves surgeon dexterity. Making SSL feel more like traditional laparoscopy will enable a wider adoption of this procedure in the community.
authors.affiliation: Department of Surgery, The Methodist Hospital, 6550 Fannin, SM 1661, Houston, TX 77030, USA. rajoseph@tmhs.org
authors.forename: Rohan A
authors.initials: RA
authors.lastname: Joseph
authors.forename: Nilson A
authors.initials: NA
authors.lastname: Salas
authors.forename: Michael A
authors.initials: MA
authors.lastname: Donovan
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Reardon
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Bass
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Dunkin
mesh_terms: D002102:Cadaver; D017081:Cholecystectomy, Laparoscopic / Q000295:instrumentation* / Q000379:methods; D004210:Dissection / Q000295:instrumentation / Q000706:statistics & numerical data; D004867:Equipment Design; D005260:Female; D006801:Humans; D020706:Laparoscopes / Q000592:standards; D008280:Magnetics; D013525:Surgical Instruments / Q000592:standards / Q000706:statistics & numerical data; D013997:Time Factors