After-exercise thermography for predicting postoperative deep vein thrombosis.

After-exercise thermography of the legs was carried out on 50 patients before undergoing major abdominal surgery (group 1) and on 59 patients before elective hip surgery (group 2). The incidence of postoperative deep vein thrombosis (DVT)--diagnosed by the 125I-fibrinogen uptake test in group 1 and phlebography in group 2--was significantly higher in patients whose after-exercise thermogram (AET) had been abnormal. Out of 19 patients in group 1 and 30 in group 2 with a normal AET, two and nine repsectively developed postoperative DVT. Among patients with a unilaterally abnormal AET the incidences were 12 out of 19 patients in group 1 and five out of nine in group 2. The incidences among patients with a bilaterally abnormal AET rose to 11 out of 12 patients in group 1 and 15 out of 20 in group 2. Preoperative after-exercise thermography is a simple, objective test that identifies patients at high risk of developing postoperative thromboembolic disease.