Vas autograft microsurgical procedure in the rat. (a) Vas preparation prior to transaction showing a loop of exposed intact straight vas (v) with transaction sites marked (dashed lines). e, epididymis; f, epididymal fat pad; cv, convoluted vas. (b) Isolated 2.5 cm vas segment prepared for use as an autograft. Note the increasing diameter from proximal (p) to distal (d), which is associated with the increasing thickness of the smooth muscle layers. (c) Vas autograft (vg) in position after microsurgery showing the proximal (p) and distal (d) lines of 10/0 sutures along each anastomosis site.