title: The significance of latissimus dorsi flap innervation in delayed breast reconstruction:  a prospective randomized study-magnetic resonance imaging and histologic findings.
abstract: BACKGROUND
  It is controversial whether surgical denervation of the thoracodorsal nerve should be performed in breast reconstruction with a myocutaneous latissimus dorsi flap. Denervation may prevent discomforting symptoms caused by muscle contraction, but the flap may also lose significant volume. The authors prospectively evaluated the influence of latissimus dorsi flap innervation on the latissimus dorsi muscle structure in delayed breast reconstruction.
  
  
  METHODS
  Between 2007 and 2008, 28 breast reconstructions were performed and divided randomly into the denervation group (surgical denervation by excision of 1 cm of thoracodorsal nerve, n = 14) and the intact group (thoracodorsal nerve saved intact, n = 14). Muscle biopsy specimens were taken during the operation and 6 months after reconstruction. Histologic (hematoxylin and eosin), immunohistochemical (human developmental, neonatal, slow, and fast myosin heavy chains), and morphometric analyses were performed. Magnetic resonance imaging of the breasts was performed 1 and 12 months after surgery.
  
  
  RESULTS
  There was a significant decrease in type I and type II myofiber diameters from 0 to 6 months in both groups. Denervation caused more significant atrophy than disuse alone. However, there was no significant difference in flap thickness between groups that can be explained by more pronounced fatty tissue infiltration in the denervation group.
  
  
  CONCLUSIONS
  The authors' data suggest that the volume and consistency of the flap remain more or less the same, regardless of whether the thoracodorsal nerve is cut or not. Thus, in their practice, the authors do not cut the nerve to save surgical time.
  
  
  METHODS
  Therapeutic, II.
authors.affiliation: Tampere, Vaasa, Helsinki, and Turku, Finland From the Department of Plastic Surgery, Tampere University Hospital; Department of Surgery, Vaasa Central Hospital; Department of Plastic and Reconstructive Surgery, Helsinki University Hospital; Medical Imaging Center and Science Center, Pirkanmaa Hospital District; Tampere School of Public Health, University of Tampere; Department of Pathology, Haartman Institute of the University of Helsinki; Department of Pathology, Helsinki University Hospital; and Department of Forensic Medicine, University of Turku.
authors.forename: Minna
authors.initials: M
authors.lastname: Kääriäinen
authors.forename: Salvatore
authors.initials: S
authors.lastname: Giordano
authors.forename: Susanna
authors.initials: S
authors.lastname: Kauhanen
authors.forename: Anna-Leena
authors.initials: AL
authors.lastname: Lääperi
authors.forename: Pentti
authors.initials: P
authors.lastname: Mattila
authors.forename: Mika
authors.initials: M
authors.lastname: Helminen
authors.forename: Hannu
authors.initials: H
authors.lastname: Kalimo
authors.forename: Hannu
authors.initials: H
authors.lastname: Kuokkanen
mesh_terms: D000328:Adult; D001284:Atrophy; D018427:Breast Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D016462:Mammaplasty / Q000379:methods*; D008408:Mastectomy; D008875:Middle Aged; D009121:Muscle Denervation / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D013524:Surgical Flaps / Q000294:innervation* / Q000473:pathology; D013900:Thoracic Nerves / Q000601:surgery