SAM is a nonatherosclerotic, noninflammatory vascular disease that most commonly affects the visceral abdominal vessels, although involvement of the iliac arteries has been reported [27]. Lysis of the medial layer of the arterial wall in SAM results in dissection, stenosis, occlusion, or aneurysm formation; it commonly presents with catastrophic hemorrhages within the abdominal cavity or retroperitoneum as a result of spontaneous aneurysm rupture [28-30]. Cystic adventitial disease is a rare vascular disease predominantly affecting healthy young men with no cardiovascular risk factors. Arterial involvement is more common than venous involvement, with most cases seen involving the popliteal artery. Cystic adventitial disease affecting the lower extremity typically results in claudication or pain of sudden onset, while imaging demonstrates adventitial cysts localized to the site of symptomatology. Surgical resection is usually curative thereby obviating follow-up [31]. Injury to the lower-extremity vasculature is not an uncommon occurrence in the setting of penetrating or blunt trauma. Rapid diagnostic imaging is paramount to exclude or confirm vascular injury in these potentially unstable individuals. Discussion of Procedures by Variant Variant 1: Suspected popliteal entrapment syndrome. Initial imaging. CTA Lower Extremity CT angiography (CTA), including multiplanar reformation and 3-D volume-rendered reconstructions, is helpful in depicting popliteal vascular changes (vessel deviation, stenosis, occlusion, aneurysm formation) and abnormal musculotendinous structures in the setting of PAES [5,19]. Following revascularization for PAES, CTA is recommended to assess graft patency after an abnormal ultrasound (US) [17]. The use of dynamic CTA has also been proposed for the initial workup of PAES, as images of both lower extremities can be obtained at both rest and plantar flexion in a single examination requiring only one contrast bolus [15].
Nonatherosclerotic Peripheral Arterial Disease. SAM is a nonatherosclerotic, noninflammatory vascular disease that most commonly affects the visceral abdominal vessels, although involvement of the iliac arteries has been reported [27]. Lysis of the medial layer of the arterial wall in SAM results in dissection, stenosis, occlusion, or aneurysm formation; it commonly presents with catastrophic hemorrhages within the abdominal cavity or retroperitoneum as a result of spontaneous aneurysm rupture [28-30]. Cystic adventitial disease is a rare vascular disease predominantly affecting healthy young men with no cardiovascular risk factors. Arterial involvement is more common than venous involvement, with most cases seen involving the popliteal artery. Cystic adventitial disease affecting the lower extremity typically results in claudication or pain of sudden onset, while imaging demonstrates adventitial cysts localized to the site of symptomatology. Surgical resection is usually curative thereby obviating follow-up [31]. Injury to the lower-extremity vasculature is not an uncommon occurrence in the setting of penetrating or blunt trauma. Rapid diagnostic imaging is paramount to exclude or confirm vascular injury in these potentially unstable individuals. Discussion of Procedures by Variant Variant 1: Suspected popliteal entrapment syndrome. Initial imaging. CTA Lower Extremity CT angiography (CTA), including multiplanar reformation and 3-D volume-rendered reconstructions, is helpful in depicting popliteal vascular changes (vessel deviation, stenosis, occlusion, aneurysm formation) and abnormal musculotendinous structures in the setting of PAES [5,19]. Following revascularization for PAES, CTA is recommended to assess graft patency after an abnormal ultrasound (US) [17]. The use of dynamic CTA has also been proposed for the initial workup of PAES, as images of both lower extremities can be obtained at both rest and plantar flexion in a single examination requiring only one contrast bolus [15].