Do superficial epigastric veins of rats have valves?

Blood Supply to the Integument of the Abdomen of the Rat: A Surgical Perspective

BACKGROUND

Many fundamental questions regarding the blood supply to the integument of the rat remain to be clarified, namely the degree of homology between rat and humans. The aim of this work was to characterize in detail the macro and microvascular blood supply to the integument covering the ventrolateral aspect of the abdominal wall of the rat.

METHODS

Two hundred five Wistar male rats weighing 250-350 g were used. They were submitted to gross anatomical dissection after intravascular colored latex injection (n = 30); conversion in modified Spalteholz cleared specimens (n=10); intravascular injection of a Perspex solution, and then corroded, in order to produce vascular corrosion casts of the vessels in the region (n = 5); histological studies (n = 20); scanning electron microscopy of vascular corrosion casts (n = 10); surgical dissection of the superficial caudal epigastric vessels (n = 100); and to thermographic evaluation (n = 30).

RESULTS

The ventrolateral abdominal wall presented a dominant superficial vascular system, which was composed mainly of branches from the superficial caudal epigastric artery and vein in the caudal half. The cranial half still received significant arterial contributions from the lateral thoracic artery in all cases and from large perforators coming from the intercostal arteries and from the deep cranial epigastric artery.

CONCLUSIONS

These data show that rats and humans present a great deal of homology regarding the blood supply to the ventrolateral aspect of the abdominal integument. However, there are also significant differences that must be taken into consideration when performing and interpreting experimental procedures in rats.

[Venous drainage in retrograde pedicle flaps: experimental study in rats]

This study was performed to investigate the venous drainage in reverse island groin flaps in a rat model. Two groups of 10 rats were studied. All rats of group A had a groin reverse flap with a complete pedicle (artery and venae comitantes). In rats of group B, an arterial groin reverse flap (artery without venae comitantes) was performed. For the two groups, the perivascular tissue was excised. Nine flaps in the group A and seven flaps in the group B, survived without partial or complete necrosis. Microscopic examination showed venous dilatation in the two groups. There was no significant difference between the two groups. These results confirm that venous drainage of the arterial reverse flow flap without venae comitantes is performed by venae arteriosa. However, venae comitantes probably ensure venous drainage when they are respected.