One hundred and five percutaneous radial-artery cunnulations were prospectively studied in 100 patients. The patients were examined daily for complications, utilizing physical examination and Doppler flow measurements. Forty of the 105 cannulations (38 per cent) resulted in radialartery thrombosis. Arterial occlusion occurred in 25 per cent of 43 vessels cannulated for less than 20 hours, in 50 per cent of 40 cannulations lasting 20 to 40 hours, and in 41 per cent of 22 cannulations lasting 40 to 144 hours. Radial arterial pulses, produced by retrograde ulnar-artery flow, were palpable distal to 73 per cent of the radialartery thrombi, and Doppler flow signals were audible distal to 90 per cent of the thrombi.
Arterial occlusion was found at the time of decannulation in only 42.5 per cent of those vessels which eventually thrombosed. An additional 30 per cent of the total number of thrombi developed within 24 hours of decannulation. However, 27.5 per cent first occurred later than one day after decannulation. All of the 20 thrombosed vessels which were followed during return visits recanalized. The longest time taken for recanalization was 75 days. No major ischemic complication was observed in any patient, despite the high incidence of temporary thrombosis. Histologic specimens from three cannulated radial arteries were obtained at subsequent postmortem examinations; photomicrographs of these specimens showed a pathologic picture consistent with the clinical impression.