A new composite flap model in the rat: combined cremaster muscle and pubic bone flap

We introduce a new model of combined cremaster muscle and pubic bone flap based on a single pedicle consisting of the osseous branch of pubic bone and external spermatic vessels of cremaster muscle in continuity with the pudic-epigastric artery (PEA).

Thirty male Sprague-Dawley rats weighing 200 to 250 g were used in this study. In 10 rats PEA, a branch of the iliac artery was dissected throughout its entire course for the anatomic study. We observed that after giving the external spermatic artery to the cremaster muscle and external pudendal branch to the penis, the PEA continued its course over the ipsilateral pubic bone that was thought to nourish the pubic bone. In 20 rats, the flap was raised on the PEA for the flap study. Five flaps were used for microangiographic study. Remaining 15 rats were used for scintigraphic assessment and dye injection and histologic study.

Microangiographic evaluation revealed the vascularity of all components of the flap as provided by the pedicle. Bone scintigraphy performed at 7th postoperative day demonstrated radionuclide uptake by the bone segment of the flap, indicating the bone viability. In addition, the dye injection study revealed ink staining within blood vessels of the cortex and the marrow of the pubic bone.

To the best of our knowledge, this is the first report describing the combined cremaster muscle and pubic bone flap model in the rat. It seems to have an important advantage over the other composite osteomuscular flap models in terms of the cremaster muscle being suitable for the intravital microscopy. Besides being harvested from a small animal species, it is reliable, versatile, and relatively easy to dissect with quite long isolated vascular pedicle, which allows a greater range of flap displacement. It can be used for different applicability including microcirculatory, pharmacologic, physiological, biochemical, and immunologic studies, as well as for the transplantation studies.