title: Harmonic technology versus neodymium-doped yttrium aluminium garnet laser and electrocautery for lung metastasectomy: an experimental study.
abstract: We compared the efficacy of non-anatomical lung resections with that of three other techniques: monopolar electrocautery; neodymium-doped yttrium aluminium garnet laser and harmonic technology. We hypothesized that the thermal damage with harmonic technology could be reduced because of the lower temperatures generated by harmonic technology compared with that of other devices.
  
  
  
  Initial studies were performed in 13 isolated pig lungs for each group. A 1.5-cm capsule was inserted within the lung to mimic a tumour and a total of 25 non-anatomical resections were performed with each device. The damage of the resected lung surface and of the tumour border were evaluated according to the colour (ranging from 0-pink colour to 4-black colour), histological (ranging from Score 0-no changes to Score 3-presence of necrotic tissue) and radiological (ranging from Score 0-isointense T2 signal at magnetic resonance imaging to Score 3-hyperintense T2 signal) criteria. A total of seven non-anatomical resections with harmonic technology were also performed in two live pigs to assess if ex vivo results could be reproducible in live pigs with particular attention to haemostatic and air-tightness properties.
  
  
  
  In the ex vivo lung, there was a statistical significant difference between depth of thermal damage (P < 0.0001) in electrocautery (1.3 [1.2-1.4]), laser (0.9 [0.6-0.9]) and harmonic (0.4 [0.3-0.5]) groups. Electrocautery had a higher depth of thermal damage compared with that of the laser (P = 0.01) and harmonic groups (P = 0.0005). The harmonic group had a less depth of thermal damage than that of the laser group (P = 0.01). Also, histological damages of tumour borders (P < 0.001) and resected lung surface (P < 0.001), radiological damage of tumour borders (P < 0.001) and resected lung surface (P < 0.001) and colour changes (P < 0.001) were statistically different between three study groups. Resections of in vivo pig lungs showed no bleeding; 2 of 7 cases of low air leaks were found; however, they ceased by sealing lung parenchyma with harmonic technology.
  
  
  
  Our experimental data support the resections performed with the use of harmonic technology. The lack of severe tissue alterations could favour healing of parenchyma, assure air tightness and preserve functional lung parenchyma. However, randomized controlled studies are needed in an in vivo model to corroborate our findings.
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy alfonso.fiorelli@unina2.it.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fiorelli
authors.affiliation: Morphopatology Unit, Second University of Naples, Naples, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Accardo
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Carelli
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Del Prete
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy.
authors.forename: Gaetana
authors.initials: G
authors.lastname: Messina
authors.affiliation: Radiology Unit, Second University of Naples, Naples, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Reginelli
authors.affiliation: Radiology Unit, Second University of Naples, Naples, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berritto
authors.affiliation: Department of Biotechnology, Second University of Naples, Naples, Italy.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Papale
authors.affiliation: Department of Biotechnology, Second University of Naples, Naples, Italy.
authors.forename: Emilia
authors.initials: E
authors.lastname: Armenia
authors.affiliation: Medical Statistics Unit, Second University of Naples, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Chiodini
authors.affiliation: Radiology Unit, Second University of Naples, Naples, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Grassi
authors.affiliation: Thoracic Surgery Unit, Second University of Naples, Naples, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Santini
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004564:Electrocoagulation; D053685:Laser Therapy / Q000295:instrumentation*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008175:Lung Neoplasms / Q000556:secondary / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D059146:Metastasectomy; D013552:Swine
keywords: Electrocautery; Harmonic technology; Laser; Lung resection; Wedge resection