title: Microvascular transplants in head and neck reconstruction: 3D evaluation of volume loss.
abstract: BACKGROUND
  Despite oversized latissimus dorsi free flap reconstruction in the head and neck area, esthetic and functional problems continue to exist due to the well-known occurrence of transplant shrinkage. The purpose of this study was to acquire an estimation of the volume and time of the shrinkage process.
  
  
  METHODS
  The assessment of volume loss was performed using a 3D evaluation of two postoperative CT scans. A retrospective review was conducted on all latissimus dorsi free flap reconstructions performed between 2004 and 2013. Inclusion criteria for the assessment were: resection of an oral carcinoma and microsurgical defect coverage with latissimus dorsi free flap; a first postoperative CT (CT1) performed between 3 weeks and a maximum of 3 months after reconstruction surgery; and an additional CT scan (CT2) performed at least one year postoperatively. The exclusion criterion was surgical intervention in the local area between the acquisition of CT1 and CT2. The effect of adjuvant radiation therapy was considered. Volume determination of the transplant was carried out in CT1 and CT2 by manual segmentation of the graft.
  
  
  RESULTS
  Fifteen patients were recruited. 3D evaluation showed an average volume loss of 34.4%. In the consideration of postoperative radiotherapy the volume reduction was 39.2% in patients with radiotherapy and 31.3% in patients without radiotherapy.
  
  
  CONCLUSIONS
  The reconstruction flap volume required for overcorrection of the surgical defect was investigated. This study indicates that a volume loss of more than 30% could be expected one or more years after latissimus dorsi free flap reconstruction. Clinical trial number DRKS00007534.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany. Electronic address: gido.bittermann@uniklinik-freiburg.de.
authors.forename: Gido
authors.initials: G
authors.lastname: Bittermann
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Thönissen
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Poxleitner
authors.affiliation: Oral and Maxillofacial Surgery, University Hannover, Carl-Neubergstr. 1, D-30625 Hannover, Germany.
authors.forename: Ruediger
authors.initials: R
authors.lastname: Zimmerer
authors.affiliation: Center for Medical Biometry and Medical Informatics, Institute for Medical Biometry and Statistics, Medical Center - University of Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany.
authors.forename: Kirstin
authors.initials: K
authors.lastname: Vach
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Freiburg, Hugstetter Str. 55, D-79106 Freiburg, Germany.
authors.forename: Marc C
authors.initials: MC
authors.lastname: Metzger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064592:Autografts / Q000000981:diagnostic imaging / Q000528:radiation effects / Q000637:transplantation*; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D058752:Free Tissue Flaps / Q000637:transplantation*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000532:radiotherapy / Q000601:surgery*; D009929:Organ Size; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D018714:Radiotherapy, Adjuvant / Q000379:methods; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D064171:Superficial Back Muscles / Q000000981:diagnostic imaging / Q000528:radiation effects / Q000637:transplantation*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Adjuvant radiotherapy; Free flap; Latissimus dorsi flap; Overcorrection; Volume loss