title: Healing of two microarterial anastomoses with diameter mismatch.
abstract: BACKGROUND
  The use of fascial perforating vessels as recipients for microvascular composite tissue autotransplants has led to vessel diameter discrepancy becoming an increasingly common finding. Little evidence, however, is available to direct the choice of anastomotic technique where a discrepancy exists. We have been studying two methods of anastomosing arteries where a small-to-large discrepancy exists-a 45° section of the smaller vessel, and invaginating the smaller vessel inside the larger. As part of this work, this study examines intimal hyperplasia and healing of the two methods.
  
  
  METHODS
  A previously described paired Wistar rat femoral axis model was used. Anastomoses were performed, one on each side, and specimens were harvested in groups at 24 h, 1 wk, 6 wk, and 8 mo. Inflammation, necrosis, and fibrosis in each layer of the vessel wall and intimal hyperplasia were each scored by an assessor blinded to the group and anastomotic technique.
  
  
  RESULTS
  Significant differences in healing were found. The invagination technique induced less inflammation, and caused less endothelial and medial necrosis than the oblique cut end-to-end method. Intimal hyperplasia was most pronounced at 6 wk, but no evidence of a difference in the severity of intimal hyperplasia between the two methods was found.
  
  
  CONCLUSIONS
  The invaginating anastomosis causes less inflammation and less vessel wall necrosis than the oblique end-to-end method in this model. This finding, alongside results from previous work, suggests that this is the better method to deal with a small-to-large microarterial diameter discrepancy in the range 1:1.5 to 1:2.5.
authors.affiliation: Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, United Kingdom; Department of Plastic Surgery, Derriford Hospital, Plymouth, United Kingdom; Division of Plastic, Reconstructive and Maxillofacial Surgery, Department of Surgery, University of Cape Town, Cape Town, South Africa. Electronic address: roryrickard@nhs.net.
authors.forename: Rory F
authors.initials: RF
authors.lastname: Rickard
authors.affiliation: Department of Pathology, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Allan R
authors.initials: AR
authors.lastname: McPhaden
authors.affiliation: Division of Plastic, Reconstructive and Maxillofacial Surgery, Department of Surgery, University of Cape Town, Cape Town, South Africa.
authors.forename: Donald A
authors.initials: DA
authors.lastname: Hudson
mesh_terms: D000714:Anastomosis, Surgical / Q000379:methods; D000818:Animals; D021461:Animals, Outbred Strains; D004730:Endothelium, Vascular / Q000473:pathology / Q000502:physiology; D005263:Femoral Artery / Q000473:pathology / Q000502:physiology / Q000601:surgery; D006965:Hyperplasia / Q000473:pathology / Q000517:prevention & control; D008297:Male; D055806:Microvessels / Q000473:pathology / Q000502:physiology* / Q000601:surgery*; D009336:Necrosis; D009929:Organ Size; D017208:Rats, Wistar; D013536:Suture Techniques; D013927:Thrombosis / Q000517:prevention & control; D020858:Tissue and Organ Harvesting / Q000379:methods; D014182:Transplantation, Autologous; D017539:Tunica Intima / Q000473:pathology / Q000502:physiology; D014656:Vascular Surgical Procedures / Q000379:methods*; D014657:Vasculitis / Q000473:pathology / Q000517:prevention & control*; D014945:Wound Healing / Q000502:physiology*
keywords: Anastomosis; Diameter discrepancy; Histology; Intimal hyperplasia; Microvascular