title: New microvascular anastomotic ring-coupling device using negative pressure.
abstract: BACKGROUND
  Many microvascular anastomoses have been performed with Unilink devices, and their advantages have been discussed in the literature over the past few decades. However, there are two drawbacks that have not been addressed and that have limited the development of next-generation microvascular anastomotic devices. First, the Unilink device has metallic pins for fixing vessel walls that remain permanently in the body. Second, the surgeon must manually attach vessel walls to the device. A novel microvascular anastomotic ring device, which uses negative pressure as an atraumatic force to semiautomatically fix the vessel walls, was built and tested in rats.
  
  
  METHODS
  The device was designed with three-dimensional computer-aided design (3D-CAD) software, constructed with laser lithography, and tested in the femoral veins of eight rats. At 2 weeks' post implantation, the vein was exposed again, and the patency was examined subjectively. The specimens were examined with light and scanning electron microscopy.
  
  
  RESULTS
  Of the eight devices, one broke during the implantation procedure and was omitted from the study. The other seven veins were successfully anastomosed by the devices. Two weeks later, six of the seven veins remained patent, and one had separated. In the patent specimens, endothelialisation was complete, and no thrombus formation was found.
  
  
  CONCLUSIONS
  A novel microvascular anastomotic ring device that uses negative pressure to semiautomatically fix the vessel walls without requiring metallic pins was successfully designed.
authors.affiliation: Plastic and Reconstructive Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Tachi
authors.forename: Katsuko S
authors.initials: KS
authors.lastname: Furukawa
authors.forename: Isao
authors.initials: I
authors.lastname: Koshima
authors.forename: Takashi
authors.initials: T
authors.lastname: Ushida
mesh_terms: D000714:Anastomosis, Surgical / Q000295:instrumentation*; D000818:Animals; D017076:Computer-Aided Design; D005268:Femoral Vein / Q000601:surgery*; D008297:Male; D008855:Microscopy, Electron, Scanning; D008866:Microsurgery; D051381:Rats; D017207:Rats, Sprague-Dawley; D014618:Vacuum; D014654:Vascular Patency