Comparative study of different combinations of microvascular anastomosis types in a rat vasospasm model: versatility of end-to-side venous anastomosis in free tissue transfer for extremity reconstruction.
BACKGROUND
There have been many studies comparing the patency rates of end-to-end and end-to-side microvascular anastomoses in both arteries and veins. Most of them failed to demonstrate a significant difference. The purpose of this study was to compare three different combinations of microvascular anastomoses in a rat vasospasm model, and determine which type of anastomosis is the most tolerant to vasospasm.


METHODS
Ninety Wistar rats were divided into three groups (n = 30 for each). In each group, a free pectoral skin flap was elevated and microsurgically transferred to the anterior cervical region. In group 1, end-to-end anastomoses were performed on both arteries and veins, in group 2 end-to-side anastomoses were performed on arteries and end-to-end anastomoses were performed on veins, and in group 3 end-to-end anastomoses were performed on arteries and end-to-side anastomoses were performed on veins. After revascularization, vasospasm was induced with topical epinephrine. Flap survival was assessed on day 3, and the success rates of the three groups were compared.


RESULTS
The flap success rate was 73.3% (22 of 30) in group 1, 66.7% (20 of 30) in group 2, and 96.7% (29 of 30) in group 3. The differences between groups 1 and 3 and between groups 2 and 3 were statistically significant. Overall, venous thrombosis was much more frequent than arterial thrombosis.


CONCLUSIONS
In a rat epinephrine-induced vasospasm model, venous thrombosis was much more frequent than arterial thrombosis. The type of arterial anastomosis did not affect the success rate, but end-to-side venous anastomosis had a higher success rate than end-to-end venous anastomosis.
Miyamoto
Shimpei
S
Department of Plastic and Reconstructive Surgery, Kyorin University School of Medicine, Tokyo, Japan. shimiyam@east.ncc.go.jp
Takushima
Akihiko
A
Okazaki
Mutsumi
M
Ohura
Norihiko
N
Momosawa
Akira
A
Harii
Kiyonori
K
D000714:Anastomosis, Surgical / Q000379:methods*; D000818:Animals; D001158:Arteries / Q000601:surgery*; D003251:Constriction, Pathologic / Q000601:surgery; D004837:Epinephrine / Q000494:pharmacology; D006083:Graft Occlusion, Vascular / Q000209:etiology*; D006085:Graft Survival / Q000502:physiology; D007511:Ischemia / Q000209:etiology; D008297:Male; D008866:Microsurgery / Q000379:methods*; D009336:Necrosis; D051381:Rats; D017208:Rats, Wistar; D013524:Surgical Flaps / Q000098:blood supply*; D014655:Vascular Resistance / Q000187:drug effects; D014680:Veins / Q000601:surgery*; D020246:Venous Thrombosis / Q000209:etiology*
D004837:Epinephrine