Hemodynamics of failing dialysis grafts.

Pressures were measured in the graft and the central vein during 104 consecutive angiographic examinations of failing hemodialysis grafts. Stenosis severity greater than 40% led to a statistically significant rise in graft pressure. In grafts in which all stenoses were of 40% or less severity, the systolic pressures in the venous and arterial limbs of the grafts were 31% +/- 16 and 45% +/- 17, respectively, of systemic systolic pressure. In grafts in which the highest grade of stenosis was greater than 40%, pressures in the venous and arterial limbs of the grafts were 53% +/- 25 and 75% +/- 24, respectively, of systemic systolic pressure. Graft thrombosis tended to occur at a higher degree of lumen reduction (but at similar pressures) with central vein stenoses compared with venous anastomotic stenoses. Dialysis graft pressures can help determine the hemodynamic importance of stenoses and the need for intervention. Percutaneous intervention should achieve arterial and venous limb pressures of less than 50% and 33% of systemic pressure, respectively.