Vascular graft infection: the role of indium scanning

Infection of a prosthetic graft is one of the most feared complications of vascular surgery. The difficulties of accurate, objective diagnosis are well recognised. We have used III Indium labelled white blood cell scans (InWBC) in two groups: 9 control patients who underwent uncomplicated aortic aneurysm surgery, and 23 patients with suspected graft sepsis. In the control group there was one positive scan in a patient with an inflammatory aneurysm. In the suspected sepsis group, 11 patients subsequently has proven graft sepsis. Nine were correctly predicted by Indium scanning. Ten of 12 patients who did not have proven graft sepsis had negative scans. There was a total of 5 inflammatory aneurysms in the control and suspected sepsis groups, of whom two had positive scans. False positive scans were not present in the early postoperative period i patients without inflammatory aneurysms. In our experience Indium labelled WBC scanning for suspected graft sepsis has a accuracy of 83% a negative predictive value of 83% and a positive predictive value of 82%. These results suggest that Indium white cell labelling techniques which do not involve substantial cross-labelling of platelets are the best objective methods of establishing the presence or absence of graft sepsis.