Ischemic Muscle Necrosis of Lower Extremities in Peripheral Arterial Disease: The Impact of 99mTc-MDP Scintigraphy on Patient Management

Abstract

Background and objectives: The objective of this study was to assess the value of a whole-body bone scintigraphy using 99m technetium labelled-methyl diphosphonate (99mTc-MDP) for the diagnosis and the assessment of grades of muscle damage after prolonged acute or chronic obstruction of the main arteries in lower extremities. Material and Methods: Fifty consecutive patients were selected for the study. The patients’ condition had not improved after primary peripheral arterial reconstruction operation or limb amputation and after conservative treatment. The clinical suspicion was of arterial obstruction and muscle necrosis. All the patients underwent whole-body scintigraphy with 99mTc-MDP. Muscle necrosis was identified as an increased soft tissue uptake of 99mTc-MDP. Results: Forty-five patients had gross muscle necrosis detected on whole-body scintigraphy with 99mTc-MDP and were histologically confirmed after repeated surgery (necrectomy or amputation) or by muscle biopsy, if only fasciotomy was performed. The location and extent of muscle injury were assessed preoperatively and the findings were confirmed in all 45 patients. Twelve patients with clinically suspected minor muscle damage, which was confirmed as relatively minor muscle necrosis on 99mTc-MDP scintigraphy, were treated conservatively. The clinical outcome of all 50 patients was favorable. The 99mTc-MDP scintigraphy, in detection of muscular necrosis, demonstrated sensitivity, specificity, and accuracy of 97.3% (95% confidence interval (CI) 85.4 to 99.3%), 30.77% (95% confidence interval (CI) 9.09 to 61.43%), and 80% (95% confidence interval (CI) 66.28 to 89.97%), respectively. Conclusion: The 99mTc-MDP scintigraphy is a valuable tool in the detection of muscular necrosis. It is able to define location, extent, and grade of involvement. Therefore, it has a clinical impact in patient management, allowing clinicians to select adequate treatment policy and specify the scope of necrectomy.