Assessment of lower limb flow and adequate intra-arterial papaverine doses to achieve maximal hyperemia in elder subjects

Previous studies reported that invasive physiological assessment for significance of the lesions in the patients with claudication under the condition of pharmacological hyperemia was important to identify the patients who will benefit from revascularization. However, the maximal hyperemic response in lower limb and the method to induce maximum dilatation of vascular bed in lower limb were not well established. The aim of this study was to investigate the range of maximal hyperemic response in lower limb of the normal subjects and to identify the ideal lower limb vasodilatory stimulation. Twelve limbs without stenotic lesions from 12 subjects (average age: 72 ± 6 years) were analyzed. Thermodilution-derived mean transit time (Tmn) was obtained at baseline and during pharmacological hyperemia with incremental dose of intra-arterial papaverine (10, 20, 30, and 40 mg) using a 0.014-inch pressure/temperature sensor-tipped wire in the superficial femoral artery (SFA). Percent increase in blood flow (%IBF) of lower limb was defined as the ratio between baseline Tmn and hyperemic Tmn. Mean ankle brachial index score of the subjects was 1.14 ± 0.09. The %IBF values were enhanced by papaverine in a dose-dependent manner. A dose of 30 mg of intra-arterial papaverine was sufficient to achieve maximum hyperemia (%IBF: range 219–769 %). In conclusion, the increase in blood flow of lower limb during maximal hyperemia varied between individuals and maximal hyperemia can be achieved with 30 mg of papaverine for the SFA lesion.