CLINICAL USEFULNESS OF TECHNETIUM-99M-HMPAO-LABELED LEUKOCYTE SCAN INPROSTHETIC VASCULAR GRAFT INFECTION

The infection of a prosthetic vascular graft (PVGI), although rare, is the most severe complication in reconstructive vascular surgery. The early diagnosis of this complication reduces the death rate from surge ry. Aortofemoral graft infections differ clinically from peripheral gr aft infections in significant ways. The aim of this article is to eval uate separately the reliability of the Tc-99m-HMPAO-labeled leukocyte scan or white blood cell count (WBC) in the early detection of both ao rtofemoral and peripheral graft infections. Methods: One hundred sixty -two WBCs were performed on 129 consecutive patients with suspected ao rtofemoral (122 scans) and peripheral (40 scans) graft infection and i n a 12-patient control group. Patients with suspected PVGI were catego rized into three groups on the basis of their signs and symptoms on re admission: (a) patients with specific signs of graft infection (Group A); (b) patients with nonspecific signs of graft infection (Group B); and (c) patients with anastomotic aneurysms (Group C), Gram's stains o f the perigraft exudate and graft cultures were performed and used as the gold standard in patients who underwent surgery. An 18-mo clinical follow-up was done to assess the presence or absence of graft infecti on in patients who did not have surgery. Results: In patients with sus pected aortofemoral graft infections, the overall sensitivity, specifi city and accuracy of WBCs (Groups A, B, C) were 100%, 92.5% and 97.5%, respectively, whereas sensitivity, specificity and accuracy calculate d in the patients with nonspecific signs of graft infection (Groups B, C) were 100%, 92.3% and 96.9%, respectively. In patients with suspect ed peripheral graft infections, sensitivity, specificity and accuracy were 100%, Conclusion: The white blood cell scan seems a reliable diag nostic method for early diagnosis of PVGI, and it is more useful in ao rtofemoral graft infections.