title: Randomized clinical trial of torsional versus linear mode ultrasonically activated devices for laparoscopic cholecystectomy.
abstract: BACKGROUND
  Conventional ultrasonically activated devices use linear mode vibration. Torsional mode ultrasonically activated device (TM) that oscillate around an arc have been recently introduced in the hope that the design may result in faster cutting and better hemostasis.
  
  
  METHODS
  Patients undergoing elective laparoscopic cholecystectomy were randomized to TM or linear mode ultrasonically activated device (LM). Intraoperative events were recorded. Postoperatively, a sample of suction fluid was analyzed for hemoglobin concentration to calculate intraoperative blood loss.
  
  
  RESULTS
  Seventy-five patients were randomized to TM and 76 patients to LM. Median blood loss was 5 (interquartile range (IQR), 1-19.7) ml with TM and 10.5 (IQR, 2.3-23) ml with LM (p = 0.105). The 95% confidence interval for the difference in median operative blood loss was -1.3 to +9.5 ml. Median gallbladder dissection time was similar in both groups (17 (IQR 11-29) minutes for TM vs. 21 (IQR, 12-29) minutes for LM; p = 0.248). Other modalities of hemostasis were required in 14 patients (19%) in the TM group compared with 21 patients (28%) in the LM group. One patient in the LM group developed postoperative hemoperitoneum and required urgent laparoscopic exploration. No patient required blood transfusion or suffered any other significant complication.
  
  
  CONCLUSIONS
  TM has similar effectiveness to LM for laparoscopic cholecystectomy.
  
  
  BACKGROUND
  ISRCTN87527062 ( http://www.controlled-trials.com ).
authors.affiliation: Academic Unit of Surgery, The General Infirmary at Leeds, D Floor, Clarendon Wing, Leeds, West Yorkshire, UK. ching_ss@hotmail.com
authors.forename: Siok S
authors.initials: SS
authors.lastname: Ching
authors.forename: Abeezar I
authors.initials: AI
authors.lastname: Sarela
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Hayden
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McMahon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical; D017081:Cholecystectomy, Laparoscopic / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006465:Hemoperitoneum / Q000209:etiology; D006488:Hemostasis, Surgical / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007432:Intraoperative Period; D020706:Laparoscopes; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D011446:Prospective Studies; D054159:Torsion, Mechanical; D014464:Ultrasonic Therapy / Q000295:instrumentation*; D014732:Vibration; D055815:Young Adult