Leg Blood Flow during Exercise in Patients with Occlusion of the Iliac Artery: Pre- and Postoperative Studies

Abstract

Five patients with complete occlusion of the iliac artery were studied at rest and during exercise before and four to six days after reconstructive vascular surgery. Preoperatively, blood flow of the external iliac vein, determined by indicator dilution technique, rose initially during bicycle exercise but failed to increase further in response to rising work intensity. The arterial-femoral venous oxygen difference rose markedly during exercise, thereby allowing an approximately linear augmentation of leg oxygen uptake. In the postoperative study, resting blood flow was higher, and both blood flow and oxygen uptake of the leg rose in approximately linear proportion to the work intensity. Simultaneous measurements of blood flow in the external iliac artery (electromagnetic flowmeter) and the external iliac vein (indicator dilution method) gave similar values in the resting state but a significantly larger venous flow during exercise, suggesting postoperative persistence of collateral circulation to the leg. The findings demonstrate that in these patients blood flow and oxygen uptake of the leg are much increased and largely corrected to normal values following reconstructive vascular surgery.

Key Words:

• Collateral circulation
• electromagnetic flowmeter
• indicator dilution technique
• lactate
• oxygen uptake