Fair Game
Case 51
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1. Specify the examination that is represented on the image above.
2. What is the major finding?
3. What is the probable etiology of this abnormality?
4. Does this abnormality need to be treated and how?
ANSWERS: CASE 51
Superior Mesenteric Artery Embolus
1. Selective superior mesenteric arteriogram (SMA).
2. Globular filling defect in the proximal superior mesenteric artery.
3. Embolus from a cardiac source.
4. Yes, by emergent surgical thrombectomy.
Reference
Lee, R.; Tung, H.K.; Tung, P.H.; et al., CT in acute mesenteric ischemia, Clin Radiol. 58 (2003) 279–287.
Cross-Reference
Comment
The image clearly demonstrates partial occlusion of the superior mesenteric artery by a globular filling defect, consistent with an embolus. The remaining SMA branches have a normal appearance.
Acute mesenteric ischemia is associated with a mortality rate of 70%, primarily due to bowel infarction with resultant sepsis. The clinical signs of mesenteric ischemia can include abdominal pain, leukocytosis, hematochezia, and lactic acidosis. Unfortunately, the clinical signs of this disorder are insidious and are often recognized after irreversible bowel ischemia has occurred. Prompt diagnosis and therapy are absolutely imperative in avoiding mortality. The etiologies of acute mesenteric ischemia include embolus (which produces ischemia within a major mesenteric vascular distribution), hypotension in patients with preexisting atherosclerotic stenoses (which can produce ischemia within a watershed distribution, usually near the splenic flexure, which represents the junction of the superior and inferior mesenteric artery territories), and acute aortic dissection.
Surgical therapy, specifically thrombectomy and/or aortomesenteric bypass with bowel resection as needed, is the treatment of choice. Endovascular methods can be used in rare cases where the embolus involves an extremely short segment near the origin of the SMA (enabling the stent to be placed), but stenting has not been shown to be equivalent to surgical therapy in this clinical setting. The special subset of patients with aortic dissection complicated by mesenteric ischemia may also be treated in endovascular fashion, using stent placement and/or percutaneous balloon fenestration of the aortic flap.
Notes
Case 52
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1. Where is the tip of the left-sided catheter in these images located?
2. Where should the tip be located?
3. What complication is observed in the second image?
4. Name three other complications of central venous catheter placement.
ANSWERS: CASE 52
Central Venous Catheter Malposition with Thrombosis
1. Left brachiocephalic vein.
2. Distal superior vena cava.
3. Thrombosis of the left brachiocephalic vein.
4. Infection with or without bacteremia, bleeding after placement, pneumothorax after placement (rare with radiologically guided placement).
Reference
Vesely, T.M., Central venous catheter tip position: A continuing controversy, J Vasc Intervent Radiol. 14 (2003) 527–534.
Cross-Reference
Comment
Radiologists can place the entire gamut of central venous catheters: (1) Peripherally inserted central catheters (PICC lines): These small-caliber catheters are used for short-term (2-6 weeks) venous access and are inserted via an arm vein; (2) Nontunneled or tunneled (for long-term access) catheters for administering blood transfusions, antibiotics, other parenteral medications, and/or total parenteral nutrition; (3) Nontunneled or tunneled pheresis catheters; (4) Nontunneled or tunneled hemodialysis catheters; (5) Implantable ports for intermittent access.
In general, the internal jugular (IJ) vein is the preferred approach for placing tunneled (long-term) catheters and ports. The IJ approach is associated with a lower incidence of catheter migration, pinch-off syndrome, and symptomatic venous occlusion. Furthermore, IJ access spares the subclavian veins; this is extremely important in patients with chronic renal failure for whom upper extremity dialysis access might eventually be needed. For nontunneled catheters, the subclavian vein is generally preferred because chest wall exit sites are associated with a lower infection rate than neck or groin exit sites. However, notable exceptions to this rule include the aforementioned patients with chronic renal failure and those with impaired coagulation, because the subclavian vein is located in a less-compressible location than the IJ.
Although most organizational guidelines recommend placing the catheter tip in the distal superior vena cava, a significant number of physicians are placing hemodialysis and pheresis catheters in the proximal right atrium in order to achieve better flow rates.
Case 53
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1. What abnormalities are apparent on this selective right hepatic arteriogram?
2. What is the most likely diagnosis?
3. What serum marker is commonly elevated in these patients?
4. What percutaneous treatments are available for this disorder?
ANSWERS: CASE 53
Hepatocellular Carcinoma
1. Hypervascularity, neovascularity, splaying of arterial branches, dense tumor stain.
2. Hepatocellular carcinoma.
3. Alpha-fetoprotein.
4. Embolization with bland particles and/or chemotherapeutic agents, radioembolization with yttrium-90, hepatic arterial port catheter insertion for chemotherapy, percutaneous ethanol ablation, radiofrequency ablation, and cryoablation.
Reference
Sze, D.Y.; Razavi, M.K.; So, S.K.; et al., Impact of multidetector CT hepatic arteriography on the planning of chemoembolization treatment of hepatocellular carcinoma, AJR Am J Roentgenol. 177 (2001) 1339–1345.
Cross-Reference
Comment
Hepatocellular carcinoma can manifest with a solitary mass, multiple masses, or diffuse hepatic involvement. Commonly found in patients with cirrhosis, it is a highly malignant neoplasm with a poor long-term prognosis. Angiographic features include enlarged feeding arteries, neovascularity, puddling, dense tumor stain, arterioportal shunting, portal vein invasion, and occasionally hepatic vein invasion. A central necrotic area may be present and can splay surrounding abnormal vessels. The uninvolved liver commonly shows arteriographic changes of cirrhosis, including small corkscrew-like vessels.
Arteriography is useful for assessing tumor blood supply before surgery and for providing guidance for hepatic arterial port catheter placement or chemoembolization. It is useful to obtain portal venous images at the time of arteriography to determine the direction of portal venous flow and to detect thrombus in the portal vein.
Because hepatocellular carcinomas derive their blood supply nearly entirely from the hepatic arterial system, they are significantly more sensitive to the ischemic effects of arterial occlusion than normal hepatic parenchyma, which derives more than two thirds of its blood supply from the portal venous system. Chemoembolization, which involves intraarterial infusion of chemotherapy immediately followed by embolization, results in two important effects that constitute the basis for this form of therapy: increased dwell time of the chemotherapeutic agents within the tumor owing to slow flow in and out of the tumor bed, and tumor ischemia.
Case 54
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1. What study is presented in the images above?
2. Why was this study requested by the interventional radiologist?
3. What common cause of global uterine enlargement may be distinguished from uterine fibroid disease using this study?
4. What common arterial variants can this study help to identify?
ANSWERS: CASE 54
Enlarged Uterine Arteries
1. Magnetic resonance angiogram (MRA) of the uterine arteries.
2. Planning for uterine fibroid embolization (UFE).
3. Adenomyosis.
4. Unilateral absence of the uterine artery, ovarian artery supply to the uterus.
Reference
Spies, J.B.; Roth, A.R.; Jha, R.C.; et al., Leiomyomata treated with uterine artery embolization: Factors associated with successful symptom and imaging outcome, Radiology 222 (2002) 45–52.
Cross-Reference
Comment
The first image demonstrates the characteristic tortuous appearance of enlarged uterine arteries as they descend into the pelvis and then ascend along the lateral uterine wall. The second image demonstrates strong heterogeneous enhancement of the uterus and the individual fibroid tumors on MRI following gadolinium infusion, a typical appearance.
MRI is useful in the preembolization workup of patients with uterine fibroids for several reasons: (1) MRI is extremely accurate in diagnosing uterine fibroids and can distinguish between the diverse causes of global uterine enlargement: (2) MRI can accurately depict the local invasiveness of a mass lesion (triggering suspicion for malignancy); (3) MRI enables accurate and reproducible measurements to be obtained; (4) MRI can accurately classify fibroids as being submucosal, intramural, subserosal, and/or pedunculated. This information can affect the type of therapy employed; (5) Speculated causes of clinical failure of UFE include aberrant uterine artery anatomy, untreated ovarian artery supply to fibroids, and coexistent adenomyosis, all of which can be identified by MRI.
Other MRI findings might also soon be used to predict treatment response to UFE. In recent studies, submucosal fibroid location, small fibroid size, low T1 signal, and hypervascularity have been correlated with greater fibroid volume reduction after UFE, and high T1 signal has been correlated with lesser volume reductions. Hence, although ultrasound is an acceptable diagnostic modality for fibroids, interventional radiologists are increasingly turning to MRI for its superior pretreatment planning capabilities.
Notes
Case 55
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1. Name the more medial artery on the left arm images above.
2. Name the more lateral artery on the left arm images above.
3. What symptoms are typically associated with this finding?
4. Where does the more lateral artery normally arise?
ANSWERS: CASE 55
Variant Anatomy: High Radial Artery Origin
1. Left brachial artery.
2. Left radial artery (high origin).
3. None.
4. From the brachial artery below the elbow joint.
Reference
Uglietta, J.P.; Kadir, S., Arteriographic study of variant arterial anatomy of the upper extremities, Cardiovasc Intervent Radiol. 12 (3) (1989) 145–148.
Cross-Reference
Comment
Distal to the elbow joint, the brachial artery normally trifurcates into a radial artery, an ulnar artery, and an interosseous artery. Several anatomic variants of this pattern occur with enough frequency that it is important to be aware of them. For instance, in some patients the brachial artery divides proximally into two limbs that continue in parallel, then reunite distally.
Normally the radial artery arises as the first branch of the brachial artery below the elbow, and the ulnar artery divides into its named branches a few centimeters distally. However, up to 19% of persons have an early bifurcation of the brachial artery, an anomaly more commonly found on the right. Although a high radial artery origin from the brachial artery is the most common upper-extremity arterial variant (7%–8%), the ulnar artery can also arise from the brachial artery above the elbow. Less commonly, the radial artery (1%–3%) or ulnar artery (1%–2%) can arise from the axillary artery. Physiologically these variations are of little significance, but they can be significant when a brachial artery puncture is planned or when a patient suffers trauma to the upper extremity with associated vascular injury.
Notes
Case 56
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1. What findings are present in these two patients and what syndrome is present in the second patient?
2. What is thought to be the etiology of this disorder?
3. What is currently favored as the treatment of choice for this disorder?
4. What is the post-thrombotic syndrome?
ANSWERS: CASE 56
May–Thurner Syndrome
1. Both patients have left common iliac vein stenosis. The second patient has left iliofemoral venous thrombosis, consistent with iliac vein compression (May–Thurner) syndrome.
2. Compression of the left iliac vein by the crossing right common iliac artery.
3. Catheter-directed thrombolysis followed by iliac vein stent placement.
4. The major long-term complication of deep vein thrombosis (DVT), characterized by chronic edema, pain, skin discoloration, varicosities, venous claudication, venous stasis ulcers, and subcutaneous fibrosis.
Reference
Patel, N.H.; Stookey, K.R.; Ketcham, D.B.; et al., Endovascular management of acute extensive iliofemoral deep venous thrombosis caused by MayThurner syndrome, J Vasc Intervent Radiol. 11 (2000) 1297–1302.
Cross-Reference
Comment
Iliofemoral deep venous thrombosis is three to eight times more common in the left leg than in the right leg. This is thought to be due to the relative compression of the left iliac vein at the pelvic brim by the crossing right common iliac artery.
Iliac vein compression (May–Thurner syndrome) is a distinct entity that typically affects women in the second to fourth decades. It is differentiated from bland deep vein thrombosis of the lower extremity by the presence of a fibrous spur or adhesion in the left common iliac vein, thought to represent an inflammatory response to chronic compression of the vein and irritation of its endothelium from adjacent arterial pulsations.
Patients typically present with acute iliofemoral DVT or chronic DVT with venous insufficiency. Endovascular therapy is the treatment of choice for this disorder. Typically, catheter-directed thrombolysis is used first to remove any acute thrombus, and an endovascular stent is subsequently placed to address the venous stenosis. Surgical thrombectomy that does not also address the underlying left common iliac vein stenosis has a high failure rate.
Notes
Case 57
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1. What abnormality is seen in the first image?
2. How did this patient likely present?
3. What are the most common causes?
4. How and why was the second image obtained?
ANSWERS: CASE 57
Bronchial Artery Embolization
1. Enlarged right bronchial artery.
2. Massive hemoptysis.
3. In the non-Western world: pulmonary tuberculosis. In the Western world: cystic fibrosis, bronchogenic carcinoma, bronchiectasis, or aspergillosis.
4. Selective angiography of the left internal mammary artery was performed because this vessel is a common source of systemic collateral supply to the lungs.
Reference
Yoon, W.; Kim, J.K.; Kim, Y.H.; et al., Bronchial and nonbronchial systemic artery embolization for life-threatening hemoptysis: A comprehensive review, Radiographics 22 (2002) 1395–1409.
Cross-Reference
Comment
Bronchial artery embolization has become an established procedure for treating life-threatening hemoptysis. Massive hemoptysis is usually defined by the production of 300 to 600mL of blood per day, but the patient’s clinical condition should guide therapy because smaller amounts of bleeding can be life-threatening in some instances.
In 90% of patients, bleeding arises from a bronchial artery. Less-common sources include the pulmonary arteries, aorta, and systemic collaterals to the lungs. Localization of the bleeding site by radiography, bronchoscopy, and/or chest CT before angiography and embolization is important so as to focus therapy. Hypertrophied and tortuous bronchial arteries, neovascularity, hypervascularity, and pulmonary arteriovenous shunting are common angiographic findings. Extravasation of contrast is rarely seen.
The bronchial arteries typically originate from the descending thoracic aorta at the T5-T6 level. In about 40% of patients, there are two arteries on the left and one on the right arising from an intercostobronchial trunk. However, there is extensive variability in number, origin, and branching pattern. It is very important to identify spinal arterial branches that arise from the bronchial and intercostal arteries, because nontarget embolization of these vessels can result in spinal ischemia. In general, embolization with polyvinyl alcohol particles is preferred. Coils are not used because they produce proximal occlusion, precluding repeat embolization should hemoptysis recur.
Notes
Case 58
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1. What is the primary abnormality?
2. What symptoms are likely present?
3. What is the best initial invasive treatment option for this patient?
4. If catheter placement did not result in adequate drainage, what adjunctive therapy could be performed?
ANSWERS: CASE 58
Empyema
1. Left posterior empyema.
2. Fever, leukocytosis, pleuritic chest pain, and possibly dyspnea and/or sepsis.
3. Percutaneous thoracostomy.
4. Intracavitary infusion of a fibrinolytic agent.
Reference
VanSonnenberg, E.; Wittich, G.R.; Goodacre, B.W.; et al., Percutaneous drainage of thoracic collections, J Thorac Imaging. 13 (2) (1998) 74–82.
Cross-Reference
Comment
The images demonstrate a rim-enhancing, gas-containing fluid collection within the left posterior pleural space, consistent with empyema. Imaging-guided chest tube placement is an excellent initial therapy and can be performed under fluoroscopy, CT, or ultrasound guidance. Preprocedural clinical assessment should include an evaluation of whether the patient will be able to tolerate the required position on the procedure table, because many patients with empyema have significant associated pulmonary compromise. Coagulation studies and platelet level should also be obtained.
Under imaging guidance, a needle is placed into the collection and contrast is injected to confirm proper positioning. It is important to avoid placing the needle just under a rib, because this can result in hemorrhage due to traversal of an intercostal artery. Over a guidewire, the tract is dilated and a large-bore drainage catheter is placed and attached to negative pressure. Follow-up CT scans are used to evaluate the progress of drainage. When the patient has improved clinically and the cavity is resolved, the catheter can be incrementally withdrawn to allow gradual healing of the residual cavity and tube tract.
If drainage ceases or stabilizes before the collection completely resolves, the cavity may be loculated and intracavitary fibrinolytic agents can be given. Alternatively, the catheter might be occluded or might not be in optimal position; a repeat CT scan can be used to guide an attempt at repositioning the catheter under fluoroscopy. If the catheter is patent and in optimal position, then a larger catheter may be needed. Infrequently, the fluid may simply be too viscous for percutaneous drainage, and surgery may be required.
Notes
Case 59
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1. What vascular problem is present in the first image?
2. What are the common causes of this problem?
3. What intervention was performed between the first two images?
4. What are the two most feared complications of endovascular intervention in the treatment of this problem?
ANSWERS: CASE 59
Bypass Graft Occlusion and Thrombolysis
1. Occlusion of a bypass graft originating in the right common femoral artery.
2. Proximal or distal anastomotic stenosis, intragraft stenosis, progression of atherosclerosis proximal or distal to the graft, hypercoagulability, and mechanical compression.
3. Catheter-directed thrombolysis or surgical thrombectomy.
4. Distant hemorrhage and distal embolization of thrombus.
Reference
Ouriel, K., Current status of thrombolysis for peripheral arterial occlusive disease, Ann Vasc Surg. 16 (2002) 797–804.
Cross-Reference
Comment
The first image demonstrates the stump of an occluded right femoropopliteal artery bypass graft. Graft occlusion is commonly the result of stenosis at the anastomosic sites.
The precise role of thrombolysis in the treatment of bypass graft thrombosis is somewhat controversial. However, several published trials support its use for patients with acute (<2 weeks) graft occlusion to achieve the following benefits: (1) It avoids surgical risks in patients who often have vascular comorbidities; (2) It has potential to both declot the graft and treat an underlying stenosis using angioplasty or stent placement; (3) Even if treatment of the underlying disorder cannot be achieved percutaneously, the diagnostic information provided by angiography after thrombolysis often guides definitive surgical therapy and enables reduction of the planned level of surgery. Endovascular therapy tends to be more successful in treating occluded synthetic grafts compared with vein grafts.
Disadvantages of thrombolysis include the longer time to reperfusion compared with surgical thrombectomy, and the risk of complications. Approximately 10% of patients require a transfusion due to bleeding, which most commonly occurs at the arterial access site. Distant bleeding occurs in 1% to 2% of patients, and intracranial bleeding occurs in 0.5% to 1.0%. Distal embolization occurs in 5% to 12% of patients, but it is usually treatable and rarely results in amputation. Compartment syndrome occurs in 2% of patients.
Notes
Case 60
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1. What abnormality is present on the images?
2. What is the most common cause of this problem?
3. How long have this patient’s symptoms likely been present?
4. Should endovascular treatment be performed?
ANSWERS: CASE 60
Chronic Axillosubclavian Vein Occlusion
1. Left axillosubclavian vein occlusion.
2. Central venous catheters and pacemakers.
3. More than 2 weeks.
4. No.
Reference
Meissner, M.H., Axillary-subclavian venous thrombosis, Rev Cardiovasc Med. 3 (Suppl 2) (2002) S44–S51.
Cross-Reference
Comment
The images demonstrate occlusion of the left axillosubclavian vein with collateral reconstitution of the superior vena cava. Venographic features that strongly suggest a chronic process include the lack of significant dilation of the occluded veins, the somewhat tapered aspect of the occlusion, the lack of globular filling defects or a meniscus sign, and the presence of abundant collaterals.
Most patients with subclavian vein thrombosis experience initial upper-extremity swelling and/or pain, but these symptoms usually subside as a mature venous collateral network develops. In fact, about 80% of patients with subclavian vein thrombosis eventually become asymptomatic or minimally symptomatic with anticoagulation therapy alone. For these reasons, endovascular interventions to restore patency in patients with subclavian vein thrombosis are reserved for carefully selected patients with primary axillosubclavian thrombosis (i.e., due to thoracic outlet syndrome), for young patients with acute secondary subclavian venous thrombosis who have good functional status, and for rare patients with special concerns such as a continuing need for central venous access where no other access sites are available. In these patients, a trial of thrombolytic therapy may be used, but most patients with chronic secondary subclavian vein thrombosis are treated with anticoagulation and removal of any central venous catheter that is present in the thrombus-containing vein.
Notes
Case 61
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1. What is the abnormality in the first image?
2. What procedure is being performed in the second image?
3. What potential complication can this patient develop based on the anatomic location of the lesion?
4. What adjunctive measure was performed in the second image to avoid this complication?
ANSWERS: CASE 61
Liver Metastasis: Radiofrequency Ablation
1. Metastatic liver lesion (from colorectal carcinoma).
2. Radiofrequency ablation (RFA).
3. Thermal injury to the diaphragm.
4. An angiographic catheter has been interposed between the liver surface and the diaphragm; it was used to instill saline during the ablation procedure.
Reference
McGhana, J.P.; Dodd 3rd, G.D., Radiofrequency ablation of the liver: Current status, AJR Am J Roentgenol. 176 (2001) 3–16.
Cross-Reference
Comment
Surgical resection remains the standard of care for metastatic liver lesions; however, only 5% to 15% of patients are eligible for resection. RFA of nonresectable lesions can be performed in a subset of this patient population. Generally accepted selection criteria include fewer than five lesions, each less than 5cm in diameter, and no extrahepatic disease. Anatomic factors that must be taken into consideration include the location of the tumor(s) in relation to intrahepatic structures such as the bile ducts and vessels. Large vessels in close proximity to the lesion can make it difficult to attain good ablation due to a heat sink effect: Relatively high blood flow rates cause a cooling effect on the adjacent tissue. Extrahepatic structures such as the gallbladder, diaphragm, and adjacent bowel should also be evaluated for proximity to the anticipated ablation zone to prevent thermal injury to these structures.
The mechanism of action is the transmission of radiofrequency waves to the tissues, which causes an elevation of tissue temperature leading to coagulative necrosis of the exposed tissues. Image guidance by US, CT, or even MRI is used for correct needle placement through a percutaneous approach. The procedure can be performed under moderate sedation or general anesthesia. Certain adjunctive procedures can be performed to create a safe zone between the lesion and adjacent structures to prevent thermal injury, including patient positioning and hydrodissection (as in this case). Combination therapy with transarterial chemoembolization may also be performed.
Notes
Case 62
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1. What positioning maneuver would worsen the abnormality in the first image?
2. What finding in the third image provides an important clue to the diagnosis?
3. What complication has this patient developed?
4. How would this be treated?
ANSWERS: CASE 62
Arterial Thoracic Outlet Compression Syndrome
1. Abduction at the shoulder joint.
2. A cervical rib.
3. Distal embolization of thrombus.
4. Surgical thoracic outlet decompression with embolectomy.
Reference
Demondion, X.; Bacqueville, E.; Paul, C.; et al., Thoracic outlet: assessment with MR imaging in asymptomatic and symptomatic populations, Radiology 227 (2003) 461–468.
Cross-Reference
Comment
Patients with arterial thoracic outlet compression syndrome typically present with symptoms in the hand and fingers including pain, numbness, paresthesias, intermittent claudication, cool skin temperature, and occasionally severe digital ischemia. Nearly half exhibit symptoms of Raynaud’s phenomenon. Symptoms often worsen with arm abduction. Reduction or obliteration of the radial pulse during clinical maneuvers such as passive arm hyperabduction or Adson’s maneuver (deep inspiration with hyperextension of the neck while the head is rotated to the symptomatic side) are highly suggestive of the diagnosis. A systolic bruit can sometimes be heard at the site of compression.
Cervical ribs are present in up to 0.5% of persons in the general population, but less than half of these patients develop symptoms of neurovascular compression. However, of patients with thoracic outlet compression syndrome, about 70% have a cervical rib. Other problems that can result in compression include the presence of a scalenus minimus muscle (seen in one third of normal persons), a wide or abnormal insertion or enlargement of the anterior scalene muscle, an anomalous first rib narrowing of the costoclavicular space, healed fracture deformities of the clavicle or first rib, or a muscular body habitus narrowing the pectoralis minor tunnel.
Arteriography should be performed with selective subclavian artery injection in a neutral position and with passive abduction of the extremity. Arteriographic findings include subclavian artery compression or narrowing with or without post-stenotic dilation, arterial occlusion, aneurysm, mural thrombus formation, and/or distal embolization.
Notes
Case 63
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 |
1. How did this patient probably present and how commonly does this occur?
2. What is the diagnosis?
3. What was done between the second and third images?
4. Name another major complication that can occur following percutaneous transhepatic cholangiography (PTC) and percutaneous biliary drainage (PBD)?
ANSWERS: CASE 63
Iatrogenic Hepatic Artery Pseudoaneurysm
1. Hemobilia. This occurs in 2% to 10% of PTC and PBD procedures.
2. Iatrogenic pseudoaneurysm of a right hepatic artery branch.
3. The catheter was withdrawn over a wire and an angioplasty balloon catheter was inflated at the site of the pseudoaneurysm.
4. Biliary infection in the form of fever or chills, septicemia, and/or cholangitis.
Reference
Winick, A.B.; Waybill, P.N.; Venbrux, A.C., Complications of percutaneous transhepatic biliary interventions, Tech Vasc Intervent Radiol. 4 (3) (2001) 200–206.
Cross-Reference
Comment
Hemobilia following PTC or PBD can be a life-threatening condition, and patients should be instructed to contact the interventional radiologist immediately if they note bloody output from the drainage tube or skin site. Most bleeding, resulting from a catheter side hole within the liver parenchyma or a transient fistula between a bile duct and a portal or hepatic vein branch, is transient and resolves with conservative management. Catheter repositioning or upsizing may be necessary in some of these cases.
Severe hemobilia is usually the result of a bile duct communication with a hepatic artery branch or a major venous branch. Arterial bleeding should be suspected when pulsatile bright red blood drains from the biliary drainage catheter; in these cases, emergent hepatic arteriography is indicated for further evaluation. If arteriography does not demonstrate a site of bleeding, the biliary drainage catheter should be removed over a guidewire and the angiogram should be repeated. A balloon catheter can be replaced to tamponade bleeding while the bleeding vessel is embolized. A variety of embolic agents can be used in this setting, but most interventionalists use coils for this indication. When performing coil embolization of a pseudoaneurysm, it is important to place coils distal to, across, and proximal to the entry site to the pseudoaneurysm sac to prevent recurrent hemorrhage due to backbleeding from peripheral arterial branches.
Notes
Case 64
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1. Describe the findings on the images above.
2. What treatment options are available?
3. If the right superficial femoral artery is also occluded, what symptom would likely be present?
4. If the right superficial femoral artery is also occluded, what therapy is indicated?
ANSWERS: CASE 64
Iliac Artery Occlusion (Atherosclerosis)
1. Right external iliac artery occlusion with common femoral artery reconstitution.
2. Aortofemoral bypass, femorofemoral bypass, thrombolysis and stent placement.
3. Rest pain.
4. Inflow reconstruction, probably via surgical bypass, is performed first. The patient is reassessed, and if lifestyle-limiting symptoms are still present, then femoropopliteal or femoral–distal bypass could be considered.
Reference
Rzucidlo, E.M.; Powell, R.J.; Zwolak, R.M.; et al., Early results of stent-grafting to treat diffuse aortoiliac occlusive disease, J Vasc Surg. 37 (2003) 1175–1180.
Cross-Reference
Comment
The first image demonstrates an occluded right external iliac artery due to in situ thrombosis of an atherosclerotic stenosis. The second image demonstrates reconstitution of the common femoral artery, information that is critical in planning revascularization.
Aortofemoral bypass is associated with 90% patency at 5 years. In patients who have a normal contralateral iliac artery and in whom medical comorbidities are present, femorofemoral bypass is sometimes used to revascularize the ischemic limb.
Endovascular recanalization of the occluded iliac artery has been performed for many years. In patients with chronic occlusions and short-segment acute occlusions, primary stent placement is considered by many to be the optimal endovascular method. In patients with acute occlusions with longer segments of thrombus, an initial course of thrombolytic therapy is favored by most physicians to eliminate as much thrombus as possible and thereby prevent embolization during later stent placement. Hence, in contrast to iliac artery stenoses, iliac artery occlusions are usually not treated with angioplasty alone; stents are nearly always used. Although stent-based endovascular recanalization is associated with lower primary patency than surgical bypass, the secondary patency (patency with repeat interventions) is comparable to surgical bypass and the overall procedural morbidity is lower. In recent years, stent grafts have shown promise as a way to recanalize the occluded iliac artery with a lower potential for late restenosis.
Notes
Case 65
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1. If the infrainguinal arteries are normal, what symptoms would this patient have?
2. Describe the angiographic findings in the first image.
3. What options are there for treatment?
4. What intervention was performed (second image) and why?
ANSWERS: CASE 65
Bilateral Common Iliac Artery Stenoses (Kissing Stents)
1. Bilateral hip and buttock claudication, possibly with impotence.
2. Bilateral common iliac artery stenoses, prominent right-sided lumbar collateral.
3. Percutaneous transluminal angioplasty, stent placement, aortobifemoral bypass.
4. Kissing stents were placed. Percutaneous intervention was chosen because of its lower morbidity than surgical therapy. Stenting was chosen over angioplasty because of the eccentric nature of the right-sided stenosis. Kissing stents were placed because of the involvement of the aortoiliac junction.
Reference
Scheinert, D.; Schroder, M.; Balzer, J.O.; et al., Stent-supported reconstruction of the aortoiliac bifurcation with the kissing balloon technique, Circulation 100 (Suppl 19) (1999) II295–II300.
Cross-Reference
Comment
Patients with disease in the aorta or common iliac arteries typically present with hip and buttock claudication and/or impotence, because of limited flow into the internal iliac artery territories. Intermittent claudication generally occurs when ankle–brachial indices are 0.5 to 0.9. When additional levels of disease are present in the femoral and/or tibial vessels, the patient is likely to experience rest pain in the feet. Rest pain signifies limb-threatening ischemia and is associated with a high amputation rate if the vascular abnormality is not treated. Ankle–brachial indices are generally 0.2 to 0.4 in patients with rest pain and no visible tissue loss, and they may be lower in patients with ulcers or gangrene.
Surgical aortofemoral bypass is associated with 90% patency at 5 years. The secondary patency of iliac artery angioplasty with selective stent placement is 80% to 90% at 4 years. Because endovascular therapy is associated with lower mortality and major morbidity, it is the preferred first-line treatment in patients with anatomically suitable iliac lesions.
Patients with aortoiliac junction lesions with or without actual distal aortic stenosis are often treated with kissing stents regardless of whether the contralateral iliac artery is diseased. This is done to effectively cover the aortic bifurcation plaque, to provide support to the other inflated balloon, and to prevent embolization down the contralateral side due to dislodged aortic bifurcation plaque.
Notes
Case 66
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1. What vascular problem is depicted in the first image of this adult patient?
2. Describe the examination depicted in the second image.
3. What is the primary abnormality in the second image?
4. How might this problem be treated?
ANSWERS: CASE 66
Traumatic Splenic Artery Injury
1. The diminutive caliber of the aortic branch vessels indicates systemic vasoconstriction due to hypovolemic shock.
2. Selective celiac arteriogram.
3. Splenic artery injury with pseudoaneurysm formation.
4. Transcatheter embolization or surgical repair.
Reference
Kluger, Y.; Rabau, M., Improved success in nonoperative management of blunt splenic injury: Embolization of splenic artery pseudoaneurysm, J Trauma. 45 (1998) 980–981.
Cross-Reference
Comment
Angiographic findings of visceral arterial trauma can include displacement or splaying of arterial branches due to hematoma formation, pseudoaneurysms, contrast extravasation, arterial filling defects due thrombosis or dissection, and diffuse vasoconstriction due to hypovolemic shock. In the latter instance, the extremely small caliber of the visceral vessels can occasionally render selective catheterization difficult. The patient depicted in these images is in dire need of fluid and blood product resuscitation.
When evaluating the patient with abdominal trauma, a reasonable plan for identifying the bleeding artery can only be developed after reviewing an abdominal CT scan, the results of diagnostic peritoneal lavage, and surgical findings (if the patient has already been explored). Because time is of the essence, the angiographer must direct his or her attention to the most likely source of bleeding. An abdominal aortogram may be performed initially. Although this only detects the grossest forms of branch vessel hemorrhage, it can help in selecting branch vessels in patients with distorted anatomy. The visceral vessels should then be evaluated with selective arteriography, and the vessels most likely to represent the source of bleeding should be studied first.
Traditional treatment of trauma-induced splenic arterial injuries has been splenic artery ligation with splenectomy. In recent years, transcatheter embolization has evolved into a less morbid alternative that might allow the spleen to be conserved. However, because splenic infarcts occur with moderate frequency following embolization, patients should receive appropriate immunizations to prevent later episodes of bacteremia.
Case 67
 |
1. What vascular abnormality is present?
2. Name three clinical sequelae that can result from this lesion.
3. What finding might confound endovascular management of this lesion?
4. What is the standard treatment for this problem?
ANSWERS: CASE 67
Subclavian Artery Stenosis with Adherent Thrombus
1. Left subclavian artery stenosis with adherent filling defects.
2. Distal embolization, vertebrobasilar insufficiency due to subclavian steal, left arm claudication.
3. The visualized filling defects probably represent thrombus that could embolize during catheter manipulations.
4. Carotid–subclavian artery bypass.
Reference
Rodriguez-Lopez, J.A.; Werner, A.; Martinez, R.; et al., Stenting for atherosclerotic occlusive disease of the subclavian artery, Ann Vasc Surg. 13 (3) (1999) 254–260.
Cross-Reference
Comment
The image demonstrates a moderate-caliber stenosis of the proximal left subclavian artery. Associated filling defects are present that could indicate the presence of associated thrombus, versus less-likely bulky atherosclerotic plaque. Distal embolization from this lesion is a significant concern.
The standard treatment for a proximal subclavian artery lesion is carotid–subclavian artery bypass, which is associated with extremely high (90%-95%) long-term patency. In selected patients, angioplasty and/or stent placement can be performed with an expectation of good short-term and mid-term results. This particular lesion, with adherent thrombus that could potentially embolize to the vertebrobasilar circulation or to the distal upper-extremity vessels, would be a fairly poor candidate lesion for endovascular management.
Case 68
 |
1. What interventional procedure was previously performed in this patient?
2. Name two common indications for this procedure.
3. Name two important early complications of this procedure.
4. What common cause of late failure of this therapy is depicted in the first image?
ANSWERS: CASE 68
Post-TIPS Stenosis
1. Transjugular intrahepatic portosystemic shunt (TIPS) placement.
2. Variceal hemorrhage and refractory ascites.
3. Intraperitoneal hemorrhage, development or progression of hepatic encephalopathy.
4. Stenosis at the hepatic vein end of the stent and within the stent.
Reference
Patel, N.H., Portal hypertension, Semin Roentgenol. 37 (4) (2002) 293–302.
Cross-Reference
Comment
TIPS is commonly performed in patients with portal hypertension and recurrent variceal bleeding after failed endoscopic therapy, refractory ascites, and/or hepatic hydrothorax. To perform TIPS, a catheter is placed in a hepatic vein (usually the right) via an internal jugular vein approach. A directional needle is passed through the hepatic parenchyma into the portal venous system (usually the right portal vein). Following portal venography and pressure measurements, the hepatic tract is angioplastied, and a stent is placed bridging the hepatic tract from the portal vein to the hepatic vein.
Major early complications of TIPS include intraperitoneal hemorrhage due to transcapsular needle puncture, worsening of hepatic encephalopathy due to shunting of blood away from the liver via the TIPS, stent infection with sepsis (rare), and early TIPS occlusion. For these reasons, relative contraindications to TIPS include preexisting hepatic encephalopathy, hepatic failure, uncorrected coagulopathy, and active infection.
Early TIPS occlusion is often caused by a fistulous connection with the biliary tree; this can now be treated with placement of a stent graft to exclude the biliary–TIPS fistula.
The 1-year patency rate for TIPS is about 50%. The most common cause of long-term TIPS failure is the development of stenosis along the course of the TIPS, most commonly at the hepatic vein end but also at the portal vein end or within the stent. When this occurs, variceal bleeding or ascites can recur. For this reason, post-TIPS duplex ultrasound surveillance is performed at regular intervals in order to identify developing stenoses. When abnormally low or high flow velocities are present within or adjacent to the TIPS, the patient is referred for TIPS venography. TIPS stenoses or occlusions can be effectively treated with balloon angioplasty or repeat stent placement.
Notes
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