Case 37 73 Clinical Presentation The patient is a 62-year-old woman with gastrointestinal (GI) bleeding.
74 RadCases Interventional Radiology Imaging Findings () Image from a selective digital subtraction arteriogram (DS) of the superior mesenteric artery (SM) with enlargement of the area of interest. The image shows a discrete irregularity of the vasa recta of a branch from the ileocolic artery supplying the ascending colon in close proximity to the hepatic flexure ( arrow ). ll other areas seen in this figure are normal. () Image of the same area from a later phase in the arteriogram shows early opacification of a small draining vein ( arrow ). Differential Diagnosis Colonic angiodysplasia : The vascular blush/irregularity and early draining vein are very suggestive of this diagnosis. There is no active GI bleeding. ctive bleeding in the ascending colon: The films do not show active bleeding at the site. Inflammatory lesion in the ascending colon: There is no active bleeding, so this possibility is difficult to defend. Essential Facts Colonic angiodysplasia is a lesion with small, dilated, thinwalled submucosal veins and capillaries. These are acquired lesions, usually in patients older than 60 years of age. The most common colonic location is the cecum, and multiple lesions are common. The classic angiographic appearance is that of a vascular tuft with an early draining vein. Pearls & Pitfalls Chances of a positive result on the angiogram increase if the patient has active bleeding during the examination ( 0.5 ml/min). high-quality arteriogram is essential. The use of intraprocedural drugs such as glucagon, to paralyze the bowel, and papaverine, which is a vasodilator, is useful to improve image quality.
Case 55 109 Clinical Presentation 47-year-old man who has head and neck cancer previously treated with radiation to the neck presents to the emergency department with bleeding into the mouth. Further Work-up C
110 RadCases Interventional Radiology Imaging Findings C () Contrast-enhanced computed tomographic (CT) scan of the neck 3 days before carotid rupture shows an irregularly marginated left carotid artery (arrow) passing through necrotic neck tumor (arrowhead). () Conventional angiogram in the frontal projection shows pseudoaneurysm (arrow) of the common carotid artery within the neck tumor. (C) Repeat angiogram after placement of a covered stent (arrows) shows successful exclusion of pseudoaneurysm. Vasospasm is noted above the stent (arrowhead). Differential Diagnosis Carotid blowout syndrome: Indicated by bleeding, pseudoaneurysm, and an associated head and neck tumor. Essential Facts Defined as bleeding from the carotid artery caused by direct invasion from an adjacent necrotic neck tumor, radiation treatment, and/or surgical treatment. Less commonly, pseudoaneurysms may be caused by trauma. Minor bleeding may precede massive, life-threatening hemorrhage. Carotid artery embolization with coils and detachable balloons was formerly the only method of endovascular treatment. Placement of a covered stent has become a first-line treatment option. Surgical treatment is carotid artery ligation, which carries a high risk for stroke. Poor wound healing secondary to irradiation of tissue and poor nutritional health makes these patients poor surgical candidates. Other Imaging Findings For minor bleeding and an appropriate clinical history, obtain an infused CT scan to make a diagnosis and plan treatment. For massive bleeding and an appropriate clinical history, angiography is often a first-line option for both diagnosis and treatment. Typical findings include pseudoaneurysm and extravasation. Pearls & Pitfalls Pre-procedural care may require external wound packing, and for severe bleeding, packing of the throat with concurrent tracheostomy. Success rates > 90% have been reported. The long-term durability of stents for carotid blowout syndrome has not been established. The risks of endovascular treatment include stent-related infection, rupture, recurrent bleeding after progression of disease, endoleak, and stroke.
Case 65 129 Clinical Presentation 48-year-old man presents to the emergency department with a cold right foot.
130 RadCases Interventional Radiology Imaging Findings () Computed tomographic angiogram (CT) shows large aneurysms in the right superficial femoral and popliteal arteries ( arrows ). () xial images show extensive intraluminal thrombus narrowing the lumen ( arrowhead ); conventional angiography underestimates the aneurysmal size ( arrows ). Differential Diagnosis Popliteal artery aneurysm (P) : Indicated by fusiform dilatation > 1.2 cm and at least 1.5 times the luminal diameter of the proximal arterial segment. Vascular ectasia: Would be indicated by a dilated P without frank P. Essential Facts P is the most common type of peripheral artery aneurysm; it is more common in male patients, bilateral in 50% of cases, and often associated with aortoiliac aneurysms. These lesions rarely rupture. Symptomatic patients present with a cold foot or leg resulting from acute thrombosis or distal embolization; asymptomatic patients present with a pulsatile popliteal mass on physical examination. For symptomatic patients, treatment is strongly encouraged because two thirds will experience acute lower extremity ischemia over a 5-year period. For asymptomatic patients, treatment of Ps > 2 cm in diameter is recommended; intraluminal thrombus and poor distal runoff have been identified as risk factors for future complications. Thrombolysis is usually performed before bypass or endovascular repair for patients presenting with acute ischemia in a viable limb. Catheter-directed infusion of a recombinant tissue type plasminogen activator (rt-p) treats acute popliteal thrombosis and distal embolization. Surgical repair consists of ligation and bypass. Endovascular stent-graft placement is associated with less blood loss and with a shorter procedure time and hospital stay than is surgical repair. The advantages of stent-grafts must be weighed against their slightly lower patency rates versus those of surgical repair. Other Imaging Findings Doppler ultrasonography is a fast screening tool that can distinguish Ps from other masses in the popliteal fossa. ecause up to one third of patients with Ps repaired by surgical or endovascular techniques will require a secondary intervention, surveillance with Doppler improves limb salvage and secondary patency. Multidetector CT with CT provides information for treatment planning, such as the location of associated peripheral artery disease, the position of branches to avoid type 2 endoleaks, and the size of the P for stentgraft selection. Evaluate source images when determining vessel patency; three-dimensional images can underestimate diameter as a consequence of mural thrombus. Magnetic resonance angiography is an alternative to CT. Conventional angiography is used to guide endovascular treatment but has largely been replaced by Doppler ultrasonography and CT for diagnosis and treatment planning. Pearls & Pitfalls The largest prospective studies of endovascular repair of Ps involve the use of nitinol stents covered with polytetrafluoroethylene (PTFE). ntiplatelet therapy (aspirin and/or clopiderol) is recommended following stent placement. Patency rates for stent-grafts are similar or slightly infer ior to those associated with open surgical repair (primary, 80 87% at 1 year and 77% at 2 years; secondary, 90 100% at 1 year and 87% at 2 years). Patency rates for surgical bypass (primary patency) are as high as 100% at 1 year, > 90% for asymptomatic patients at 5 years, and > 75% for symptomatic patients at 5 years. The disadvantage of endovascular repair is limited flexibility of stent-grafts placed in a location subject to constant flexion and extension. Major and minor complications have been reported in up to 37% of stent-grafts, including migration, endoleak with continued enlargement of the aneurysm, stenosis at the edge of the stent-graft, and stent breakage.