Indirect systolic pressures and pulse waves in arterial occlusive diseases of the lower extremities

Measurements were carried out in 146 limbs with angiographically documented arterial occlusive disease (AOD) and in 85 limbs without AOD. Ankle systolic pressure (AP) was equal to or higher than brachial systolic pressure in limbs without AOD. It was below 82% of the brachial in all limbs with complete occlusion, usually below 50% in those with multiple occlusions, and above 50% in limbs with single block. AP was below normal in 19 of 25 limbs with severe and in five of nine with mild stenosis. All limbs with complete occlusion and 14 of 16 with stenosis had abnormal pressures in the thigh. The foot-to-peak time (CT) and the width of pulse waves at half amplitude (WD) were related to heart rate in normal limbs. Considering the heart rate, the majority of limbs with AOD had abnormally prolonged CT and WD. Normal pressures and pulse waves were found together in only two limbs with stenosis and symptoms. The findings indicate that pressures and pulse waves provide a sensitive method for diagnosis and follow-up of patients with AOD.

Measurement of renal artery pressures by catheterization in patients with and without renal artery stenosis

Pressures were successfully measured by catheterization in 13 out of 18 renal arteries with stenosis and in 15 out of 16 vessels without stenosis. The pressures were measured via a small-bore, radiopaque nylon catheter threaded through a curved polyethylene catheter whose tip was placed in the renal vessel. The position of the catheters was confirmed by injections of small volumes of angiographic dye and documented by spot films. Use of the small-bore catheter was necessary to avoid alteration of the measured pressure. Strict attention to technical details is mandatory in order to obtain satisfactory pressure recordings.

In patients without angiographic evidence of stenosis, pressure in the renal arteries did not differ consistently from the aortic pressure. Differences of more than 15 mm Hg in the systolic pressure are probably abnormal.

Abnormal systolic pressure gradients between the aorta and the renal artery were found in some patients with renal artery stenosis, but not in others. In the patients with gradients, good correlation was obtained between the gradient and the dimensions of the stenosis measured on the angiographic films and expressed as L s /(D s /D N ), 2 where L s is the length of the narrowing, and D s and D N are respectively the diameters of the lumen of the stenotic and nonstenotic parts of the vessel in a frontal projection.

Our experience suggests that more preoperative pressure measurements by catheterization across renal artery stenosis and correlation relation with angiographic and renal function studies and with the results of operation are warranted.