A haemodynamic evaluation of the femoro-femoral cross-over bypass

Abstract

The femoro-femoral cross-over bypass has become a popular choice for the management of unilateral iliac artery disease, being used in preference to aorto-femoral or extraperitoneal ilio-femoral bypasses. It is a relatively minor procedure and associated with a small incidence of side effects, the main one being the risk of development of a steal of blood from the donor limb by the bypass. Although this problem has been widely discussed, haemodynamic studies have been limited by the use of indirect measurements of blood flow, such as ankle systolic pressures or by the use of electromagnetic flowmetry at the time of surgery. No study employing volumetric blood flow measurements to identify and quantify blood steal in the postoperative patient has been reported to date. With aims of studying the haemodynamic effects of a femoro-femoral cross-over bypass on the circulation in both the recipient and donor limbs, and of identifying preoperatively, problems likely to lead to haemodynamic problems or to graft failure, the present study of 31 patients undergoing femoro-femoral bypass was undertaken. The patients, 18 of whom had rest pain and 13 intermittent claudication, were studied preoperatively using arteriography and a non-invasive assessment. At 3 months from the operation, all received a clinical assessment and a further non-invasive assessment, including a measurement of blood volume flow. Flow measurements were made in the bypass at rest and during a reactive hyperaemia test. In addition, flow measurements were made in the donor limb below the bypass origin at rest and during hyperaemic testing of the recipient limb in order to assess any steal effect the bypass might cause to the donor limb circulation. All 31 patients were improved by surgery, but five developed donor limb claudication which was attributed to steal in three cases. Resting blood flow in the bypasses, 161 (65-282)ml/min [median (range)], rose by 116% (5-428%) to 300 (82-1114)ml/min after hyperaemic testing. Simultaneously, bypass hyperaemia caused a fall in donor limb blood flow of 32% (0-74%). Of the preoperative non-invasive tests, only donor femoral artery pulse rise time was related to the later development of objective evidence of steal. Successful Gruntzig dilatation of four major stenoses resulted in a satisfactory outcome.