Current evaluation of radial artery spasm (RAS), a frequent finding during the transradial approach for coronary angiography and angioplasty (TRA), is subjective. A quantitative measure of RAS will help in evaluation and comparison of management strategies. The objectives of the study were to assess the feasibility and safety of using an automatic pullback device (APD) for removal of transradial introducer sheaths and to establish a parameter to quantify RAS. In 50 consecutive transradial procedures, the APD was used to measure the force required for sheath removal. The mean maximal pullback force (MPF) was 0.53 +/- 0.52 kg (range, 0.1-3.0 kg). In 48 (96%) cases, the MPF was reached within the first 5 sec of pullback. All patients with clinical RAS (n = 4) had an MPF greater than 1.0 kg, while the remaining had an MPF less than 1.0 kg. All patients with severe pain during sheath removal (n = 3) had an MPF greater than 1.0 kg, while no patient with an MPF less than 1.0 kg had severe pain. It is feasible and safe to remove transradial introducer sheaths using the APD. The MPF is achieved within the first 5 sec of pullback and is a reliable parameter to quantify RAS. An MPF more than 1.0 kg correlates with clinical RAS and is associated with severe pain during sheath removal. (C) 2001 Wiley-Liss, Inc.