title: Standard versus video-assisted thyroidectomy: objective postoperative pain evaluation.
abstract: BACKGROUND
  This prospective, randomized study was designed to objectively demonstrate that minimally invasive video-assisted thyroidectomy (MIVAT) improves postoperative pain compared with standard thyroidectomy, via the dosage of biochemical mediators measured before and after surgery.
  
  
  METHODS
  Forty-nine patients undergoing total thyroidectomy were allotted to MIVAT (n = 23) or traditional thyroidectomy (OPEN) (n = 26) groups. At hospitalization (T0), interleukin (IL)-1, -2, -4, -6, -10, -3, tumor necrosis factor (TNF)-α, TGF-β, and MCP-1 were measured. The basal pain tolerance also was evaluated by VAS. Blood samples for interleukin measurement and VAS evaluations were obtained from all patients in the recovery room (T1) and 24 h after surgery (T2).
  
  
  RESULTS
  At T0, the MIVAT and the OPEN groups were not different in terms of basal pain tolerance and biochemical profile. At T1, VAS scores were significantly higher (p = 0.04), whereas TGF-β (p = 0.03) and MCP-1 (p = 0.03) levels were significantly lower in the OPEN than in the MIVAT group. No significant difference was demonstrated for other interleukins. A significant inverse relationship between VAS and TGF-β was demonstrated and confirmed through the correlation (p = 0.003) and regression (p = 0.003, p < 0.0001, R (2) = 0.172) coefficients; the stepwise regression also demonstrated that TGF was the most predictive factor of postoperative pain (p = 0.0038) through an inverse relationship. No statistically significant difference has been demonstrated at T2.
  
  
  CONCLUSIONS
  TGF-β serum levels immediately after surgery seem to correlate with pain evaluation, confirming that reduced postoperative distress is an objective outcome of MIVAT. This result confirms the results of studies based only on subjective pain evaluations.
authors.affiliation: Department of Surgery, University of Pisa, Via Roma 67, 56126, Pisa, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Miccoli
authors.forename: Rocco
authors.initials: R
authors.lastname: Rago
authors.forename: Marco
authors.initials: M
authors.lastname: Massi
authors.forename: Erica
authors.initials: E
authors.lastname: Panicucci
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Metelli
authors.forename: Piero
authors.initials: P
authors.lastname: Berti
authors.forename: Michele N
authors.initials: MN
authors.lastname: Minuto
mesh_terms: D000328:Adult; D018932:Chemokine CCL2 / Q000097:blood; D005260:Female; D006801:Humans; D007378:Interleukins / Q000097:blood; D008297:Male; D019060:Minimally Invasive Surgical Procedures; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis*; D013965:Thyroidectomy / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D020535:Video-Assisted Surgery / Q000379:methods*
chemical_list: C111835:CCL2 protein, human; D018932:Chemokine CCL2; D007378:Interleukins; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha