99TCm-labeled leucocyte scan for detecting infection of vascular graft involving groin

The clinical value of Technitium-99TCm leucocyte in detecting early post-operative infection of prosthetic vascular grafts, to and from the femoral artery involving groin dissection is assessed. Twenty-five patients underwent bypass procedure using either Dacron or PTFE grafts. 99TCm labeled leucocyte scans were undertaken between 6-8 days following the bypass procedure. Fourteen patients had normal scans and no subsequent evidence of graft infection. The remaining 11 patients had abnormal scans discharge. These patients underwent serial scanning until the scan normalised or graft infection developed. Of 11 patients, who had abnormal initial scans, 2 developed clinical groin infection and were thus true positive, 7 patients subsequently had normal scans, 2 patients died of other causes. The sensitivity of 99TCm labeled leucocyte scan is 100%, but unlike some previous reports, we found a low specificity. The graft material used did not make any difference as far as the sensitivity or specificity of detection of graft infection was concerned.