AN EXPERIMENTAL HEMODYNAMIC-STUDY OF THE PELVIC COLLATERAL CIRCULATION

Iliac arteries were occluded in adult mongrel dogs to investigate pelvic hemodynamics. When the unilateral common iliac artery was occluded, the blood flow making a ''stopover'' within the pelvis was found to be significantly less than that of anatomical hemodynamics even under a resting condition. The blood flow decreased more significantly under exercise loading than under a resting condition, which demonstrates the presence of the ''steal'' phenomenon. This only occurs in the collateral circulation in the pelvis formed by two arterial systems which are related in a series. In deciding the appropriacy of reconstruction for the internal iliac artery in patients with aorto-iliac occlusive disease, this ''steal'' phenomenon should be kept in mind. In most cases, ischemic symptoms in pelvic organs may be due to a simple decrease of the blood flow supplied to the pelvis, or due to the ''steal'' phenomenon. If the pelvic region is in the state of ischemia owing to the ''steal'' phenomenon, reconstruction of the blood vessels flowing into the pelvis is not required.