Pre-fabricated Venous Flap, An Advanced Free Venous Flap for - distant Transfer --- an Experimental Rat Study

Arterialized venous flap (AVF) can improve the survival of traditional free venous flap. AVFs are, however, still not popularly selected as the first choice for microsurgical reconstruction due to its nutrient insufficiency. Eighty-four Lewis rats (10-12 weeks old, 350-400 grams) were used. Left hemi-vertical chest-and- abdominal skin flap (4x14 cm2) was the experimental model. Five protocols were designed and performed: Protocol I (n = 18): nutrition territory study; Protocol II (n = 18): immediate A-V anastomosis; Protocol III (n = 12): pre-fabricated venous flap (PFVF) transformed from pedicle-based skin flap; Protocol IV (n = 18): PFVF transformed from perforator-based skin flap; and Protocol V (n = 18) PFVF transformed from capillary-based skin flap. The all transformed PFVFs had a two week delay procedure from the original skin flaps. The hemi-vertical chest-abdomen skin flap contains three nutrient vessels: superior, inferior and mid-abdominal. The PFVF coming from the perforator-based skin flap showed significantly superior than other two methods with the best survival rates after arterialization, then capillary-based, and then pedicle-based skin flap. The PFVFs after delay procedure and arterialization have been proved to much increase the flap survival than traditional free venous flap. Delay procedure has benefits for the transformation from the nutritional skin flaps into PFVFs, which is especially true in perforator-based skin flaps. Such transformation is a two stage procedure. PFVFs might offer a “last case scenario” surgery as an option to reconstruct wound defects where no other suitable skin flaps are available. Further investigation is warranted.