title: Quantifying Long-Term Retention of Excised Fat Grafts: A Longitudinal, Retrospective Cohort Study of 108 Patients Followed for Up to 8.4 Years.
abstract: BACKGROUND
  Predicting the degree of fat graft retention is essential when planning reconstruction or augmentation with free fat grafting. Most surgeons observe volume loss over time after fat grafting; however, the portion lost to resorption after surgery is still poorly defined, and the time to reach steady state is unknown.
  
  
  METHODS
  The authors compiled a retrospective, longitudinal cohort of patients with vestibular schwannoma who had undergone ablative surgery and reconstruction with excised fat between the years 2006 and 2015. Fat volume retention was quantified by computed tomography and magnetic resonance imaging and used to model a graft retention trajectory and determine the volumetric steady state. In addition, the authors evaluated the association between graft retention and secondary characteristics, such as sex and transplant volume.
  
  
  RESULTS
  A total of 108 patients were included. The average baseline graft volume was 18.1 ± 4.8 ml. The average time to reach steady state was 806 days after transplantation. By this time, the average fat graft retention was 50.6 percent (95 percent CI, 46.4 to 54.7 percent). No statistically significant association was found between baseline graft volume and retention. Fat graft retention over time was significantly higher in men than in women (57.7 percent versus 44.5 percent; p < 0.001).
  
  
  CONCLUSIONS
  The authors' data provide evidence that the time to reach fat graft volumetric steady state is considerably longer than previously expected. Fat grafts continue to shrink long after the initial hypoxia-induced tissue necrosis has been cleared, thus indicating that factors other than blood supply may be more influential for fat graft retention.
  
  
  METHODS
  Therapeutic, IV.
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Herly
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Mathias
authors.initials: M
authors.lastname: Ørholt
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Glovinski
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Christian B
authors.initials: CB
authors.lastname: Pipper
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Helle
authors.initials: H
authors.lastname: Broholm
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Lars
authors.initials: L
authors.lastname: Poulsgaard
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Kåre
authors.initials: K
authors.lastname: Fugleholm
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Carsten
authors.initials: C
authors.lastname: Thomsen
authors.affiliation: Copenhagen, Denmark.|From the Departments of Plastic Surgery, Breast Surgery and Burns, Pathology, Neurosurgery, and Radiology, Copenhagen University Hospital, Rigshospitalet; and the Section of Biostatistics, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen.
authors.forename: Krzysztof T
authors.initials: KT
authors.lastname: Drzewiecki
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology / Q000601:surgery / Q000637:transplantation*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012189:Retrospective Studies; D013997:Time Factors; D019737:Transplants