Postoperative infections after neurosurgery and cardiosurgery: the value of labelled white blood cells.

Post surgical-infections in neurosurgery and cardiosurgery are infrequent, but potentially fatal complications. The aim of this study was to compare the utility of 99mTc-HMPAO white blood cells scintigraphy (WBCS) with traditional diagnostic approaches in post-surgical complications, in order to obtain timely demonstration of a current infection. We studied 23 patients with a suspicion of infection after major cardiosurgery or neurosurgery. Planar imaging was performed at 4 and 20 hours after injection of autologous white blood cells labelled with 99mTc-HMPAO. Eight patients underwent CT scan, but only in one case did CT findings lead to a clear definition of a bulky inflammation process of the chest. WBCS identified one or more sites of focal increased uptake of the radiopharmaceutical in 6 patients: five of these patients were scheduled for a "second look" surgical operation that confirmed the sites and extention of the primary infection, thus confirming the presence of an abscess. In 3 cases WBCS showed only a weak increase of focal uptake and in 14 cases there was no evidence of abnormal uptake. The absence of deep infections was confirmed at surgery or at clinical follow-up. Thus WBCS seems to be useful in evaluating patients with the clinical suspicion of infective complications after surgery.