Prospective study of safety of lower extremity phlebography with nonionic contrast medium

Background Lower extremity deep venous thrombosis (DVT) following high osmolar ionic contrast phlebography has been reported to vary between 9% to 31%. The purpose of this study was to determine the incidence of minor and major adverse reactions and postphlebographic DVT when using nonionic contrast (iopamidol). Patients and methods One hundred fifty-seven patients with clinically suspected DVT were studied prospectively. One hundred eleven patients had prephlebography duplex ultrasound, and 102 patients were examined in the vascular laboratory for delayed side effects 1 week after phlebography. The presence of phlebography-induced DVT was assessed using color duplex ultrasound. The mean amount of contrast used was 102 mL. Results Minor adverse reactions, including nausea, local pain, and dizziness, occurred in 11 (7%) of 157 patients; however, no major complications or postphlebographic DVT was found in the 102 patients who underwent postphlebography duplex ultrasound. Phlebography and pre- and postphlebography duplex ultrasound showed no acute DVT in 70 patients. The maximum hypothetical true rate of major complications (ie, postphlebography DVT) that would result in no detectable events in a population of 102 patients with follow-up (for a probability of P<0.05) is 2.9. Conclusions Lower extremity phlebography using nonionic contrast material is safe, with no incidence of postphlebography DVT in our series. Its utilization should be encouraged if duplex ultrasound is not available.