Abdominal Vascular Flashcards
Branches of the celiac axis include
hepatic, splenic, and gastric arteries. The celiac artery has three branches: the common hepatic, splenic, and left gastric arteries.
The first branch of the abdominal aorta is the
celiac artery. The celiac artery also termed, celiac trunk or celiac axis, is the most cephalad visceral branch of the abdominal aorta. Followed by the superior mesenteric artery, the renal arteries, and the inferior mesenteric artery.
The sonographic term “seagull appearance” refers to
celiac arteries. The celiac trunk and two of its branches: the common hepatic artery and the splenic artery, appear as a “seagull” or “T configuration” in the transverse plane of the real-time or color flow Doppler scan. These vessels lie superior to the superior mesenteric, renal, and gastroduodenal arteries.
The splanchnic arteries comprises the
celiac, superior mesenteric, inferior mesenteric arteries. Splanchnic arteries refer to the vessels that supply the bowel with blood. They are primarily the celiac artery, the superior mesenteric artery, and the inferior mesenteric artery.
The term fusiform refers to a type of
aneurysm. There are several types of aneurysms which include: saccular, fusiform, false, mycotic, and dissecting. Saccular and fusiform are shapes of true aneurysms (dilatation of the arterial wall) with different anatomical configurations. The false or pseudoaneurysm is caused by a hole in the wall of a vessel and is not confined to the arterial wall. A dissection is where blood enters the medial of the vessel and dissects the vessel into a true and false lumen. The micotic aneurysm develops secondary to a septic emboli lodging in the arterial lumen.
A pulsating echogenic flap seen in the vessel lumen indicates
arterial dissection. Classically, the dissecting aneurysm has two lumens separated by an echogenic intimal flap that can be seen on the real-time scan pulsating toward the true lumen.
The presence of a low resistance waveform in the SMA or IMA in a fasting patient indicates
mesenteric ischemia. In the normal fasting state, the superior mesenteric artery and inferior mesenteric arteries have a high resistance flow pattern. After the ingestion of a meal, the blood flow increases, and the high-resistance flow pattern changes to a low-resistance flow pattern. This is not true for the celiac artery, which the low-resistance pattern remains constant.
Stenosis of the renal arteries is indicated if the peak systolic velocity is
three and one-half times the aortic peak systolic velocity. Renal artery stenosis is diagnosed by Doppler ultrasound when the peak systolic velocity in the stenosis is 180-200 cm/s or greater or when the peak systolic velocity of the renal artery is 3.5 times the peak systolic velocity of the aorta. This is the primary criterion. Other criteria include: damping of the distal waveform, and the acceleration index.
The radiology procedure recommended for diagnosing occlusion of the splanchnic arteries and demonstrating the collateral circulation is
mesenteric angiogram with selective visceral views. Angiography is not only important to provide a definitive diagnosis for occlusion of the splanchnic arteries but also an important part of the successful management of acute intestinal ischemia. Angiography demonstrates the obstructing lesions as well as the collateral flow patterns and can provide such interventional procedures as thrombolytic therapy.
The most common pathological condition of the inferior vena cava is
thrombosis. The most common pathological condition of the inferior vena cava is thrombosis followed by neoplasia or tumor.
What vessel supplies 75% of the blood to the liver?
portal vein. The portal vein supplies 75-80% of the blood supply to the liver and 50% of the oxygen. The hepatic artery supplies the remainder of the blood supply to the liver. In cases of portal hypertension where the portal venous flow is compromised, there is usually an increase in the hepatic artery flow to the liver.
The portal vein is formed by the confluence of the
splenic and superior mesenteric vein and, sometimes, the inferior mesenteric vein. The splenic and superior mesenteric veins and, in some cases, the inferior mesenteric vein join to form the portal vein posterior to the neck of the pancreas.
The portal triad is comprised of
portal vein, hepatic artery, and bile duct. The portal triad also termed the hepatic triad, which is defined as a group of three entities, objects, or associations, includes the hepatic artery, portal vein, and bile duct, seen on the real-time image in the porta hepatis region.
Mycotic aneurysms occur secondary to
infectious processes. Mycotic or infected aneurysm are caused by a growth of microorganisms in the vessel walls. They occur in multiple sites and are often seen as a complication of bacterial endocarditis.
The predominate etiology for cirrhosis of the liver in the western hemisphere is
alcoholism. Alcoholism is the most common cause of cirrhosis in the western hemisphere. Cirrhosis is one of the ten leading causes of death and the most common cause of cirrhosis in the United States. Cirrhosis is the end-stage manifestation of hepatocyte injury leading to tissue necrosis, fibrosis, and attempted regeneration of liver tissue.
A prominent venous collateral seen coursing along the abdominal wall from the portal vein to the umbilicus via the ligamentum teres and the falciform ligament is the
paraumbilical. The umbilical or paraumbilical vein collateral is indicative of portal hypertension. It communicates with the superficial veins of the abdominal wall and connects freely with the superior and inferior epigastric veins. In advance stages, it is called caput Medusae.
The resistive index (RI) in the renal arteries should not exceed
0.70. The renal artery spectral waveform exhibits a low-resistance flow pattern with continuous forward flow in diastole. A resistive index of 0.70 has been considered the upper limit of normal in adults.
The most common vascular pathway for tumor extension is the
inferior vena cava. The common vascular pathway for tumor or thrombus extension is the inferior vena cava. Extrinsic tumors can compress or invade the inferior vena cava and include renal cell carcinoma, hepatocellular carcinoma, and a variety of other neoplasms that metastasize to the paracaval lymph nodes.
Occlusion of the hepatic veins is termed
Budd-Chiari. Budd-Chiari disease or syndrome is defined as symptomatic obstruction or occlusion of the hepatic veins. It can be either acute or chronic with an unknown etiology. Possibly arising from neoplasms, strictures, liver disease, trauma, systemic infections, and hematologic disorders.
Reversal of flow in the common hepatic artery indicates
occlusion of the celiac artery origin. In patients with celiac artery occlusion at the origin, the collateral flow may be sufficient to produce normal Doppler signals in the hepatic and splenic arteries; however, the flow is reversed in the gastroduodenal and common hepatic arteries.
A collateral circulation for the splanchnic arteries include
pancreaticoduodenal arcade, arch of Riolan, artery of Drummond. Stenosis or occlusion of the splanchnic arteries can cause bowel ischemia. This is often prevented by collateralization through three main collateral channels: the pancreaticoduodenal arcade, the arch of Riolan, and the marginal artery of Drummond.
Sonographic criteria for an abdominal aortic aneurysm is dilated to
3 cm or more or 1.5 times the normal segment. The majority of abdominal aortic aneurysms are located in the infrarenal portion of the aorta and may extend into the iliac arteries. However, the renal arteries along with the iliac arteries are included in the sonographic examination to assist in the type of surgical reconstruction required.
Branches of the hepatic artery include
the gastroduodenal, right gastric, right and left hepatic branches, cystic, intrahepatic branches, and occasionally the supraduodenal arteries.
Which artery of the celiac axis is usually not seen on the ultrasound examination?
gastric artery. The celiac artery has a right branch ( hepatic artery), a left branch (gastric artery), which is usually not seen on ultrasound, and splenic, which is a left branch. The hepatic artery and the splenic artery are identified as the “seagull appearance” or the “T configuration” on ultrasound.
Which artery gives rise to the gastroduodenal artery?
hepatic artery. The first branch of the hepatic artery is the gastroduodenal artery, and it courses between the duodenum and the neck of the pancreas. The gastroduodenal artery is located anterolateral to the head of the pancreas; the common bile duct is posterolateral to the inferior portion of the head of the pancreas. This landmark has long been used to identify the location of the common bile duct.
Tributaries of the portal vein include
splenic, superior mesenteric, left gastric, right gastric, paraumbilical, and cystic veins. Those routinely seen on ultrasound include the splenic and superior mesenteric veins.
A patient in the supine resting position should have a portal vein measurement of no more than
13 mm in diameter. The diameter of the portal vein should not exceed 13 mm and should vary with inspiration and expiration.
What veins enlarge as they approach the diaphragm?
hepatic veins. The hepatic veins enlarge as they approach the diaphragm, and the portal veins appear larger as they approach the porta hepatis. This has long been a method of differentiation of the hepatic veins and the portal veins.
Hepatic veins demonstrate what type of Doppler spectrum?
chaotic, pulsatile phasic variations, and transmitted pulsations. The hepatic veins venous flow is chaotic, with phasic variations and transmitted pulsations. They differ from the collateral venous vessels with continuous high-pitched Doppler waveforms and the low phasic flow seen in other venous structures. The pulsatile pattern is a result of the transmission of right atrial pulsations into the veins.
The gonadal veins drain the venous blood into the
renal veins. The testicular veins and the ovarian veins which constitute the gonadal veins drain into the renal veins and subsequently the inferior vena cava. This is an important concept when determining patency of the gonadal veins.
Which of the following is not a surgical graft type for aortic aneurysms? simple aortic tube graft, aortoiliac graft, aortofemoral graft, or Brescia-Cimino
Brescia-Cimino. The Brescia-Cimino fistula is an autogenous dialysis access graft. The others are aortic aneurysm surgical grafts named according to location of the graft and the arteries involved.
In a normal fasting patient, the SMA has what type of flow pattern?
high-resistance. The superior mesenteric has a high-resistance flow pattern in the fasting patient. It may be turbulent at the origin, and there may be absent or reverse flow in diastole. Blood flow increases after eating. The normal peak systolic velocity in the fasting patient is approximately 140 cm/s and does not exceed 156 cm/s.
A venous collateral that arises from the portal vein approximately opposite of the superior mesenteric vein and seen on longitudinal images is the
coronary vein. The portosystemic collateral that arises from the portal at the level of the superior mesenteric is the coronary vein or left gastric vein. The normal coronary vein does not exceed 4 mm. In cases of portal hypertension, a search is made to identify this collateral vessel.
Characteristics of the right renal artery are
it lies posterior to the renal vein. It is unique in that it passes posterior to the inferior vena cava as it coursed from the hilum to the aorta. It arises from an anterolateral aspect of the aorta and has a low resistance waveform.
Which of the sonographic manifestations is not characteristic of rejection in a renal transplant?
- increased size of transplanted kidney
- prominence of renal pyramids
- decreased echogenicity of the renal sinus
- decreased flow resistance in the parenchymal arteries
decreased flow resistance in the parenchymal arteries. The classical gray scale characteristics of renal transplant rejection include: hypoechogenicity, enlargement of the renal pyramids, increased size of the transplant with diminished echogenicity of the renal sinus echo complex, and increased echogenicity of the cortex. The pulsatility index is greater than 1.8, and the resistivity index is greater than 0.9, indicating increased peripheral resistance.
The most common vascular complication of the renal transplant is
renal artery stenosis. In the renal transplant, renal artery stenosis is the most common vascular complication, while occlusion of the renal artery is less common.