title: A systematic review and meta-analysis comparing the efficacy and surgical outcomes of total thyroidectomy between harmonic scalpel versus ligasure.
abstract: BACKGROUND
  Both ultrasonic coagulation (Harmonic Scalpel) (HS) and bipolar coagulation (Ligasure) (LS) are new energy devices commonly used in open thyroidectomy. This systematic review aimed at comparing the efficacy and surgical outcomes of total thyroidectomy (TT) between HS and. LS.
  
  
  METHODS
  A systematic review of the literature was performed to identify studies comparing HS and LS. Intraoperative outcomes, surgically related complications, overall morbidity, and hospital stay were evaluated. Meta-analysis was performed using a fixed-effects model.
  
  
  RESULTS
  There were 8 studies that matched the selection criteria. Of the 963 patients who underwent TT, 433 (45.0 %) used HS (HS group) while 530 (55.0 %) used LS (LS group). Compared with LS, the HS group had significantly less volume of blood loss by 2.22 ml (95 % CI = 0.26-4.23 ml) (standardized mean difference [SMD] = -0.2, 95 % CI = -0.38 to -0.02) and reduced total operating time by 3.32 minutes (95 % CI = 1.62-5.03 minutes) (SMD = -0.28, 95 % CI = -0.42 to -0.15). There was no significant difference in temporary postoperative hypocalcemia (OR = 1.29, 95 % CI = 0.88-1.90), permanent postoperative hypocalcemia (OR = 1.45, 95 % CI = 0.23-9.26), temporary recurrent laryngeal nerve (RLN) injury (OR = 1.34; 95 % CI = 0.66-2.71), permanent RLN injury (OR = 1.00; 95 % CI = 0.25-4.03), hematoma (OR = 1.00; 95 % CI = 0.3-3.31), overall morbidity (OR = 1.21, 95 % CI = 0.87-1.69), and hospital stay (SMD = -0.03; 95 % CI = -0.07 to 0.01).
  
  
  CONCLUSIONS
  Compared with LS, using HS in TT significantly reduced the volume of blood loss and operating time. However, the clinical significance of these findings remained questionable because the overall mean difference appeared small. There was no significant difference in the rate of complications, overall morbidity, and hospital stay between the two devices.
authors.affiliation: Department of Surgery, The University of Hong Kong, Hong Kong, SAR, China. blang@hku.hk
authors.forename: Brian Hung-Hin
authors.initials: BH
authors.lastname: Lang
authors.forename: Sze-How
authors.initials: SH
authors.lastname: Ng
authors.forename: Lincoln L H
authors.initials: LL
authors.lastname: Lau
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Cowling
authors.forename: Kai Pun
authors.initials: KP
authors.lastname: Wong
mesh_terms: D016063:Blood Loss, Surgical; D004564:Electrocoagulation / Q000009:adverse effects; D006801:Humans; D061646:Operative Time; D013965:Thyroidectomy / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome; D059708:Ultrasonic Surgical Procedures / Q000009:adverse effects