DETECTION OF PROSTHETIC VASCULAR GRAFT INFECTION USING AVIDIN INDIUM-111-BIOTIN SCINTIGRAPHY/

Prosthetic vascular graft infection, though rare, carries high morbidi ty and mortality rates; therefore, timely diagnosis is important. Pati ents, however, often present with vague symptoms, and radiological inv estigations are frequently inconclusive. These factors may lead to pro longed periods of observation and hospitalization, with the resultant increase in costs and complication rates, before reaching a final diag nosis. This prospective study evaluates the use of nonspecific avidin/ In-111-biotin imaging in diagnosing prosthetic vascular graft infectio n. Methods: Twenty-five patients with a total of 29 grafts were invest igated. Eighteen patients (19 grafts) had low probability of disease, whereas the remaining 7 patients (19 grafts) warranted surgical explor ation based on clinical, laboratory or radiological evidence. Avidin w as first injected intravenously and then followed 24 hr later by admin istration of In-111-biotin. Whole-body images were obtained 10 min and 2 hr postinjection of In-111-labeled biotin. SPECT imaging was perfor med 1 hr postinjection. Increased uptake along part or the whole lengt h of the graft was considered evidence of graft infection. Results: Av idin/In-111-biotin scintigraphy correctly identified all infected graf ts, as confirmed by culturing surgical specimens. In contrast, infecti on was correctly excluded in all but one of the grafts, and long-term follow-up was used to assess the presence of infection in patients who did not undergo surgical intervention. Conclusion: Avidin/In-111-biot in scintigraphy is a simple and accurate imaging method for the routin e diagnosis of vascular graft infection, and it may have a role in ide ntifying the disease process in its initial stages, thus improving pro gnosis.