Tc-99m sulfur colloid scintigraphy for detecting perigraft flow following endovascular aortic aneurysm repair: A feasibility study

Purpose: To determine if scintigraphy with Tc-99m sulfur colloid can be used to detect perigraft flow after stent-graft repair of abdominal aortic aneurysm (AAA). Methods: Twenty-three men and two women aged 56-84 years (mean 71 years) underwent endoluminal AAA repair as part of the EVT Phase II trial [EVT = Endovascular Technologies (Menlo Park, CA, USA)]. Aneurysm size averaged 5.4 cm (range 3-8 cm). Sixteen bifurcated, seven tube, and two aorto-uniiliac grafts were placed. Two days after stent-graft placement, patients underwent both contrast-enhanced computed tomography (CT), including delayed views, and Tc-99m sulfur colloid scintigraphy. Results: Perigraft flow was found in only one patient at completion of angiography. Four additional patients had perigraft flow, discovered during their postoperative follow-up CT. Four patients had leaks at an attachment site and one had retrograde branch flow. Tc-99m sulfur colloid scintigraphy failed to diagnose any of the five leaks prospectively. In two of these patients, however, some abnormal paraaortic activity was noted in retrospect. Conclusion: Tc-99m sulfur colloid scintigraphy was unable to demonstrate endoleak with either rapid flow (attachment site leak) or slow filling (branch flow).