93: Abdominal angiography

Abdominal angiography

Kyung Jae Cho

Department of Radiology, Division of Vascular and Interventional Radiology, Michigan Medicine; and University of Michigan Frankel Cardiovascular Center, Ann Arbor, MI, USA

Catheter angiography is performed to establish a specific diagnosis of abdominal neoplasms and splanchnic vascular lesions (including arterial occlusive lesions, vasculitis, aneurysms and pseudoaneurysms, arteriovenous fistula, and malformations), to evaluate complications of cirrhosis and portal hypertension, to diagnose portomesenteric thrombosis, and to obtain specific information about hepatoportal hemodynamics, vascular anatomy and variation before endovascular or surgical intervention. In this chapter, the technique and use of catheter angiography in the diagnosis and management of gastrointestinal, pancreatic, hepatic, and splenic lesions are illustrated.

General angiographic technique

Gastrointestinal angiography is performed by means of percutaneous retrograde femoral arterial catheterization (Seldinger technique). The common femoral artery usually is punctured with a 21 gauge (0.032 inch) single‐wall puncture needle under ultrasound guidance. When the femoral artery cannot be used because of occlusion, the brachial or radial artery is used. Most visceral angiography is performed with 4 Fr or 5 Fr catheters with preshaped configurations. Three commonly used preshaped catheter configurations for visceral angiography are the shepherd’s hook, cobra, and sidewinder catheters.

Intraarterial digital subtraction angiography (IA DSA) is currently used for visceral angiography. Both iodinated contrast medium and carbon dioxide (CO2) are used as contrast agents. CO2 is the preferred contrast agent for visualization of the origins of the celiac and superior mesenteric arteries and their occlusive lesions (Figure 93.1), detection of gastrointestinal (GI) bleeding (Figure 93.2), wedged hepatic venography, bleeding from traumatic injury of the spleen and liver, and splenoportography. Because CO2 causes no known allergic reactions or nephrotoxicity, it should be used as an alternative contrast agent in patients with hypersensitivity to iodinated contrast material or renal insufficiency. A basic knowledge of the physical properties of CO2 (including high solubility, buoyancy, low viscosity, and compressibility) is essential in obtaining a safe and successful angiogram. Air contamination must be avoided during CO2 delivery for angiography. CO2 should not be used in the arterial circulation above the diaphragm. In general, the rate of injection for CO2 angiography should be slightly greater than the expected blood flow of the vessel being injected.

The techniques used in visceral angiography are aortography, selective and superselective visceral angiography, indirect portography (arterial portography), direct portography (transhepatic, transjugular, transsplenic or transumbilical approach), hepatic venography, and wedged hepatic venography. The coaxial catheterization method using a 3 Fr microcatheter is used for superselective catheterization for embolization of GI bleeding, tumors, and vascular lesions. When visceral artery aneurysms and pseudoaneurysms cannot be accessed transarterially, percutaneous direct access using a 22 gauge Chiba needle is used for embolization therapy. Wedged hepatic venography and manometry are two of the most important techniques for the evaluation of patients with cirrhosis and portal hypertension, and hepatic venous outflow obstruction. Wedged hepatic venous pressure is measured using an end‐hole catheter or balloon occlusion, usually from the internal jugular venous approach, and is a direct reflection of sinusoidal pressure and, in the absence of presinusoidal obstruction, of portal venous pressure.

Gastrointestinal angiography

Visceral angiography often begins with lateral aortography to visualize the origins of the celiac and superior mesenteric arteries in patients suspected of having mesenteric ischemia (Figure 93.3). Visceral angiography includes injection into the celiac and superior mesenteric arteries to demonstrate vascular anatomy (Figures 93.493.7). Visceral angiography is used for the diagnosis of pancreatic endocrine tumors, the source of GI bleeding, traumatic bleeding, arterial occlusive disease (Figure 93.8), collateral circulation (Figure 93.9), aneurysms (Figure 93.10), arteriovenous malformations and fistulas (Figure 93.11), portal and mesenteric venous thrombosis, splenic vein thrombosis, portosystemic collateral veins, and portal vein aneurysm (Figure 93.12).

Schematic illustration of CO2 digital subtraction arteriogram.

Figure 93.1 CO2 digital subtraction arteriogram. (a) CO2 digital subtraction aortogram in anteroposterior projection. The aorta and its branches are visualized with CO2. (b) With the patient in the supine position, a cross‐table lateral CO2 aortogram shows good filling of the celiac and superior mesenteric arteries with buoyant CO2. The posterior surfaces of the aorta and lumbar arteries are not seen due to gas buoyancy. (c) The injection of CO2 in the celiac artery fills the splenic, hepatic, and gastroduodenal arteries. CO2 refluxes back to the aorta, filling the superior mesenteric and renal arteries. (d) Superior mesenteric CO2 arteriogram in a patient with celiac artery occlusion. The pancreatic arcades and the gastroduodenal and dorsal pancreatic arteries provide the primary collateral pathway to the celiac trunk and its branches.

Angiography plays an important role in the diagnosis of upper and lower gastrointestinal bleeding (Figures 93.1393.16). Angiography is especially useful in identifying chronic gastrointestinal bleeding from tumors (Figure 93.17), vascular malformations (Figure 93.18), and colonic vascular ectasia (Figure 93.19). Visualization of the portal venous system is important in the evaluation of cirrhosis and portal hypertension, and pancreatic, biliary, and hepatic tumors.

The portal vein can be evaluated by means of indirect portography (arterial portography with the injection of contrast medium in the superior mesenteric or splenic artery) (Figures 93.20 and 93.21) or direct portography (using a transhepatic, transjugular or transsplenic approach) (Figures 93.22 and 93.23). Angiography is used to differentiate occlusive from nonocclusive mesenteric ischemia. It is also useful in the diagnosis of carcinoid tumor (Figure 93.24) and both pancreatic (Figure 93.25) and hepatic (Figure 93.26) metastases. Diagnostic angiography is performed prior to balloon angioplasty of superior mesenteric artery stenosis and transcatheter embolization for control of upper and lower GI bleeding, and occlusion of splanchnic artery aneurysms and pseudoaneurysms (Figure 93.27).

Pancreatic angiography

Ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are the initial diagnostic procedures for inflammatory and neoplastic pancreatic lesions. Endoscopic retrograde cholangiopancreatography with cytological examination is commonly performed for suspected pancreatic cancer. If endoscopy is unsuccessful in patients with a mass in the pancreatic head and obstructive jaundice, percutaneous transhepatic cholangiogram with biliary drainage is performed. Once pancreatic lesions have been demonstrated by other imaging modalities, angiography may be performed to obtain a specific diagnosis and assess the vascular anatomy and resectability of the tumor before surgical intervention.

Schematic illustration of cO2 celiac digital subtraction arteriogram in a 61-year-old woman with a history of gallbladder cancer who presented with massive upper GI bleeding following wedge liver resection.

Figure 93.2 CO2 celiac digital subtraction arteriogram in a 61‐year‐old woman with a history of gallbladder cancer who presented with massive upper GI bleeding following wedge liver resection. (a) CO2 injection into the celiac axis shows a pseudoaneurysm (arrow). CO2 reflux visualizes the aorta and its branches. There are a biliary plastic stent and a percutaneous drainage catheter for bile leak. (b) Cross‐table lateral projection with CO2 shows the pseudoaneurysm (arrow) arising from the celiac artery. Coil embolization occluded the pseudoaneurysm, resulting in cessation of GI bleeding.

Schematic illustration of median arcuate ligament compression of the celiac artery in a 28-year-old woman with postprandial abdominal pain.

Figure 93.3 Median arcuate ligament compression of the celiac artery in a 28‐year‐old woman with postprandial abdominal pain. (a) Full expiration. The origin of the celiac axis has a 60% stenosis (arrow) caused by median arcuate ligament compression. (b) Full inspiration. The origin of the celiac axis shows no stenosis (arrow).

Schematic illustration of celiac axis anatomy.

Figure 93.4 Celiac axis anatomy. The celiac axis gives off the splenic (SA), left gastric (LG), and common hepatic (CH) arteries. There is an aberrant left hepatic artery (LHA) originating from the left gastric artery. The common hepatic artery divides into the gastroduodenal artery (GDA) and proper hepatic arteries. The gastroduodenal artery gives rise to the posterior arcade (PA) and anterior arcade (AC) arteries, which join to form the inferior pancreaticoduodenal artery. The dorsal pancreatic (DP) artery originates from the celiac artery.

Endoscopic ultrasound scanning is commonly used to localize pancreatic islet cell tumors. When it reveals a pancreatic mass in a patient with hyperinsulinism, surgical therapy is possible without additional localization procedures. For occult insulinomas, selective arterial calcium stimulation localizes the source of hyperinsulinism through assay of insulin from the hepatic vein at 30 s and 60 s, following stimulation of the potential supplying arteries. Angiography localizes insulinoma in approximately 60% of cases (Figure 93.28). Angiography is often negative for gastrinomas because they are usually hypovascular. However, selective secretin injection regionalizes occult gastrinomas through blood sampling from the hepatic vein at 30 s and 60 s following stimulation of the potential feeding artery. Angiography is usually positive for other neuroendocrine tumors, including vasoactive intestinal polypeptide‐secreting tumor (VIPoma), pancreatic polypeptide‐producing tumor (PPoma), somatostatinoma, and glucagonoma (Figure 93.29).

Schematic illustration of aberrant right hepatic artery originating from the superior mesenteric artery.

Figure 93.5 Aberrant right hepatic artery originating from the superior mesenteric artery. (a) The common hepatic artery (CH) divides into the gastroduodenal (GD) and left hepatic (LH) arteries. The middle hepatic artery (arrow) originates from the left hepatic artery (LH). (b) Arterial phase of superior mesenteric arteriogram of the same patient. The replaced right hepatic (RH) originates from the superior mesenteric artery (SM), and the inferior pancreaticoduodenal (I) artery originates from the aberrant right hepatic artery. The gastroduodenal (GD) and left hepatic (LH) arteries are filled from the superior mesenteric artery because of celiac stenosis.

Schematic illustration of hepatic artery variation.

Figure 93.6 Hepatic artery variation. Superior mesenteric arteriogram in a patient with hepatic metastases (M) from nonfunctioning islet cell carcinoma of the pancreas (I). The right hepatic artery (arrow) is replaced from the superior mesenteric artery (S) and supplies hypervascular metastases (M) in the liver. The splenic, left gastric, and common hepatic arteries originate from the celiac axis (not shown).

Angiography is important in the diagnosis and management of gastrointestinal bleeding complicating pancreatitis and pseudocysts (Figure 93.30). In this setting, bleeding may originate from an aneurysm or varices associated with portal or splenic venous thrombosis.

Hepatic angiography

Ultrasound, CT (with and without contrast enhancement), and MRI are used for the diagnosis of hepatic mass lesions. Angiography is sensitive in detecting vascular tumors in the liver, including hepatoma, cavernous hemangioma (Figure 93.31), focal nodular hyperplasia (Figure 93.32), and bleeding associated with hepatic adenoma (Figure 93.33).

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Nov 27, 2022 | Posted by in GASTROENTEROLOGY | Comments Off on 93: Abdominal angiography
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