Central assessment of bilateral phlebograms in a major multicentre thromboprophylactic trial - Reasons for inadequate results

Purpose. To determine the cause of inadequate bilateral phlebograms at cent ral assessment. A major antithrombotic trial was evaluated to identify and apply corrective measures for reducing inadequate results in future multice ntre trials. Material and Methods: The inadequate results in 253 out of 1,827 patients h aving undergone bilateral phlebography following total hip replacement were reviewed by two central assessors using strict criteria for evaluability. The reasons for inadequate findings were assessed and ranked. Results and Conclusion: Insufficient contrast filling, especially of the an terior tibial, common femoral and iliac veins, was the most common reason f or disqualifying examinations. Unilateral examinations and obscuring metall ic devices were the second and third most common reasons, respectively. Eff orts should be made to standardize the phlebography technique, to use a lar ge volume of contrast without tourniquets, and to obtain an appropriate num ber of views to visualize the deep veins.