title: An objective comparison of four stress tests in the assessment of "at risk" femoro-distal grafts.
abstract: Femoro-distal vein grafts for limb salvage have a 30% failure rate at 6 months. Graft surveillance may enable the "at risk" grafts to be recognised and corrected, but there remains the need for a simple test to identify these patients. The ankle pressure response to exercise and reactive hyperaemia has been investigated prospectively in 40 "at risk" femoro-distal non-reversed grafts (median age 73 years, range 51-87 years, M/F = 33:7), defined as those with a resting ankle brachial index less than 0.9 or a drop of greater than 0.2 following a stress test. Four different stress tests have been assessed; active ankle plantar-dorsiflexion for 2 minutes (I), occlusive calf cuff 50 mmHg above systolic pressure for 2 minutes (II), treadmill exercise test for 1 minute, slope = 10%, at 3 km/hr (III) and 4 km/hr (IV). Ankle brachial indices (ABI's) were recorded before and immediately following each test and expressed as mean % drop +/- standard error of mean. Test I was only tolerated by 45% of patients whereas 55% and 50% could complete tests III and IV respectively. By contrast, 85% of patients could tolerate occlusive cuff hyperaemia (test II). Test I produced a significantly lower mean percentage drop in ABI when compared with each of the others (p less than 0.02, Mann U Whitney). There was an excellent correlation between test II and both the 3 km/hr (r = 0.77, p less than 0.001) and 4 km/hr (r = 0.84, p less than 0.001) exercise tests.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Vascular Studies Unit, Bristol Royal Infirmary, UK.
authors.forename: M G
authors.initials: MG
authors.lastname: Wyatt
authors.forename: R M
authors.initials: RM
authors.lastname: Muir
authors.forename: W G
authors.initials: WG
authors.lastname: Tennant
authors.forename: D J
authors.initials: DJ
authors.lastname: Scott
authors.forename: M
authors.initials: M
authors.lastname: Horrocks
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical; D000842:Ankle / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D001916:Brachial Artery / Q000503:physiopathology; D005069:Evaluation Studies as Topic; D005080:Exercise Test / Q000379:methods; D005260:Female; D005268:Femoral Vein / Q000601:surgery*; D006083:Graft Occlusion, Vascular / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013312:Stress, Physiological / Q000503:physiopathology*