title: Harmonic scalpel tonsillectomy: a systematic review of evidence for postoperative hemorrhage.
abstract: OBJECTIVE
  To systematically review the literature on harmonic scalpel tonsillectomy with a view of comparing its postoperative hemorrhagic rate with the conventional methods for tonsillectomy.
  
  
  METHODS
  Cochrane Library, Medline, Embase, CINAHL, INAHTA, CRD (Centre for Review and Dissemination, York, UK), and related databases. The date of the last search was September 19, 2006; papers were considered irrespective of language of publication.
  
  
  METHODS
  Inclusion and exclusion criteria were applied independently by two reviewers with a third reviewer available for adjudication. The papers were quality assessed using Chalmers' criteria. Eleven randomized controlled trials (RCT) were included in the final review with five RCTs comparing harmonic scalpel tonsillectomy with "cold steel" tonsillectomy and six RCTs comparing harmonic scalpel with "hot" tonsillectomy techniques.
  
  
  RESULTS
  All studies were underpowered to detect a significant difference in the postoperative hemorrhagic complication between harmonic scalpel and the comparator tonsillectomy techniques. The heterogeneity of studies made quantitative combination of results impossible.
  
  
  CONCLUSIONS
  The evidence reviewed is of low quality and does not support any significant difference in postoperative hemorrhage rates when harmonic scalpel is compared with other tonsillectomy techniques. As studies have numerous methodological flaws and incorporate biases and confounding factors, these results need to be interpreted with caution. Larger and better-conducted studies would be needed in order to compare the safety of harmonic against conventional tonsillectomy methods. The need for a large sample size might make an RCT impractical; therefore a large, well-controlled cohort study could be more suitable.
authors.affiliation: Department of ENT, Addenbrooke's Hospital, Cambridge, UK. codruta.neumann@gmail.com
authors.forename: Codruta
authors.initials: C
authors.lastname: Neumann
authors.forename: Ian
authors.initials: I
authors.lastname: Street
authors.forename: David
authors.initials: D
authors.lastname: Lowe
authors.forename: Holger
authors.initials: H
authors.lastname: Sudhoff
mesh_terms: D006801:Humans; D019106:Postoperative Hemorrhage / Q000209:etiology*; D014068:Tonsillectomy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D014465:Ultrasonics