Experimental model for the study of retrograde flow.

Background: Venous arterialization has been adopted as a strategy for salvage of limbs in critical ischemia without the distal arterial bed, with successful outcomes, but the mechanisms by which irrigation of the extremities takes place are still unknown.

Objectives: To develop an experimental model to test hypotheses that could explain the mechanisms of blood supply in venous arterialization.

Methods: Eleven pigs underwent a period of hind limb ischemia followed by reperfusion achieved by venous arterialization, after interposition of conduits filled with 10 ml (5 animals - group 1) or 1 ml (6 animals - group 2) of China Ink. After euthanasia, the limbs were amputated and underwent histological analysis.

Results: Under optical microscopy, ink staining was observed in the arteriolar lumen of six (55%) of the eleven pigs used in the experiment; four (80%) out of five from group 1 and two (33%) out of six from group 2.

Conclusions: The experimental model was capable of testing the hypothesis. The presence of China Ink in the arteriolar lumen shows that it is possible to supply the arterial vessels by means of venous arterialization.