Ir -- Gi

Front 1

1. What are some complications of percutaneous transhepatic cholangiography/percutaneous biliary drainage (PBD)?
2. What are causes of hemobilia after placement PBD?
3. How do you diagnose a pseudoaneurysm leading to hemobilia?
4. How do you treat a pseudoaneursym of the hepatic artery?

Back 1

1.
- Hemobilia: may cause filling defects and lead to blairy obstruction.
- Infection: cholangitis, sepsis.
2. Bloody output form the drainage catheter may be due to:
- Catheter side hole within the liver parenchyma.
- Transient fistula between a bile duct and portal/hepatic vein branch.
The above two problems are addressed with catheter repositioning or upsizing.
- Severe hemobilia occurs if there is a communication of the bile duct with a hepatic artery branch or a major venous branch.
3. Hepatic arteriogram. However, the arteriogram may or may not demonstrate the site of bleeding. If no bleeding is seen, then remove the drain over a guidewire and repeat the arteriogram.
4. A balloon catheter can be used within the biliary tree to tamponade the bleeding. Then coil embolization of the bleeding vessel is performed. Remember to place coils distal to, at, and proximal to the pseudoaneurysm.

Front 2

1. What are the causes of lower gastrointestinal bleeding?
2. What are the treatment options for lower GI bleeding?
3. What is preferred embolic agent for angiodysplasia?
4. What should pts undergo after successful embolization?

Back 2

1.
- Diverticular disease
- Angiodysplasia
- Neoplasm
2. Vasopressin infusion:
- labor intensive requiring an ICU admission.
- Significant side effects including abdominal pain.
- Contraindicated in pts with CAD.
Superselective embolization using microcoils
3. Polyvinyl alcohol is used for bleeding from angiodysplasia.
4. All pts should undergo colonoscopy after embolization to further ascertain etiology of bleeding.

Front 3

What are the branches of the SMA?

Back 3

Superior mesenteric artery passes behind the neck of the pancreas.
1. Inferior pancreaticoduodenal
2. Middle colic - to the transverse colon and splenic flexure.
3. Right colic - to ascending colon.
4. Ileocecal - to last part of ileum, cecum, and appendix
5. Intestinal branches - to jejunum and ileum

NOTE: the middle, right, and ileocecal branches anastomose with each other to form a "marginal" artery along the inner border of the colon. This artery is completed by branches of the left colic which is a branch of the inferior mesenteric

Front 4

1. Name all the anastamoses of a transplanted liver.
2. What complication can occur at the IVC anastomoses?
3. What is the etiology of early stenosis of the IVC? How is it usually treated?
4. What is the etiology of late stenosis of the IVC? How is it usually treated?

Back 4

1. Hepatic artery, portal vein, bile ducts, IVC (upper and lower).
2. IVC stenosis may develop either at the upper or lower anastomosis. Use pressure gradient across the stenosis to determine siignificance.
3. Etiology of early stenosis includes kinking or torsion of the graft, a tight suture line, or compression from an oversized transplant. Early stenosis is treated with angioplasty and stent placement.
4. Fibrosis and intimal hyperplasia causes late stenoses. It is treated with angioplasty.

Front 5

What are the angiographic findings of visceral arterial trauma?

Back 5

1. Displacement or splaying of arterial branches due to hematoma formation.
2. Pseudoaneurysm
3. Contrast extravasation
4. Arterial filling defects due to thrombosis or dissection.
5. Diffuse vasoconstriction due to hypovolemic shock.

Front 6

What are the indications for a TIPS?

Back 6

1. Recurrent variceal bleeding refractory to medical management.
2. Ascites
3. Hepatic hydrothorax

Front 7

1. What are the early complications of TIPS?
2. What are the late complications of TIPS?
3. After performing a TIPS, you see persistent filling of varices. What do you do?

Back 7

1. Early complications of TIPS include:
- Intraperitoneal hemorrhage due to transcapsular needle puncture.
- Worsening of hepatic encephalopathy
- Infection
- TIPS occlusion (usually due to fistulous communication with the biliary tree).
2. The most common long term complication of TIPS is stenosis which most commonly occurs at the hepatic vein end. Stenosis can also occur within the stent or at the portal end of the stent.
3. If portosystemic gradient is lowered to 8-12mmHg then varices should resolve spontaneously. However if they persist, look for residual stenosis or thrombus w/n the TIPS tract or portal vein which should be corrected by additional angioplasty or stent placement. If variceal hemorrhage is still observed, then coil embolize the varices.

Front 8

1. When would you place a metallic biliary stent?
2. Why do silastic biliary catheters need to be changed every 6 weeks?
3. Do you have to relieve the biliary obstruction completely to provide symptomatic relief in malignant causes of biliary obstruction?
4. What are the advantages and disadvantages of covered stents?

Back 8

1. Metallic stents are placed for malignant cause of biliary obstruction in pts who have short life spans. It does not get occluded easily and thus its lifespan is greater than the patient's lifespan.
2. Silastic biliary catheters are placed for benign causes of biliary obstruction. They must be changed every 6 weeks due to the viscous nature of the biliary secretions.
3. In order to obtain symptomatic relief you do not have to drain the entire biliary ductal system.
4. Covered stents result in decreased risk of tumor ingrowth compared with uncovered stents, but may be associated with an increased risk for acute cholecystitis and pancreatitis.

Front 9

Collateral pathway between celiac and SMA axis:

Back 9

Pancreaticoduodenal arcade (superior pancreaticoduodenal artery from celiac artery and inferior pancreaticoduodenal artery from SMA)

Front 10

1. What is the strategy in treating liver laceration?
2. Are ischemic complications common after embolization of the hepatic artery?

Back 10

1. Diffuse bleeding resulting from a high grade liver laceration is treated using injection of particles (gelfoam, PVA, and embolospheres) into multiple arterial distributions. Focal sources of bleeding such as AVF and pseudoaneurysms can be treated with coil embolization.
2. Ischemia is uncommon after embolization because of portal venous blood supply to the liver.

Front 11

1. Why is endoscopy helpful for upper gastrointestinal bleeding before an IR procedure?
2. What are the terminal branches of the gastroduodenal artery? What anastomoses are present?

Back 11

1. Endoscopy is able to differentiate between arterial (PUD) and variceal (portal HTN) hemorrhage. If there is fundal bleeding => L gastric a. embolization; if there is duodenal bleeding => GDA embolization (may need to embolize fr. SMA side also)
2. GDA divides into the right gastroepiploic artery and the superior pancreaticoduodenal artery. The superior pancreaticoduodenal artery anastomoses with the inferior pancreaticoduodenal artery from the SMA.

In general, bleeding in the gastric antrum or proximal duodenum is treated by GDA embolization. If only the proximal protion of the GDA is occluded, bleeding may persist via the pancreaticoduodenal arcade supplied by the SMA. Occasionally, it is necessary to embolize these arteries in superselective fashion via the SMA.

Front 12

1. What is median arcuate ligament syndrome?
2. What is the "stressed view" in MALS?
3. What is the treatment?
4. Why is SMA arteriogram needed for a full evaluation?

Back 12

1. MALS is due to extrinsic compression of the celiac artery by the median arcuate ligament of the diaphragm resulting in classic presentation of epigastric bruit, postprandial pain, and weight loss.
2. Imaging should be done in inhalation and exhalation (stressed view) to bring out the compression.
3. Surgical release of the median arcuate ligament followe by surgical or endovascular revascularization of the celiac artery.
4. Stenosis of the celiac axis leads to enlargement of the panreaticoduodenal arcade. Focal aneurysms may be seen due to increased blood through the arteries.

Front 13

1. How many vessels must be occluded for chronic mesenteric ischemia?
2. What kind of stents (balloon or self expanding) are used for treatment of chronic mesenteric ischemia?

Back 13

1. 2 of the 3 mesenteric vessels must be occluded to develop chronic mesenteric ischemia.
2. Balloon expandable stents are used due to the ostial nature of the stenosis.

Front 14

1. When should you remove a cholecystostomy tube placed for acalculous cholecystitis?
2. If the pt becomes asymptomatic after tube placement, does he require a cholecystectomy?

Back 14

1. The drain should not be removed earlier than 3-6 weeks after placement to allow time for maturation of the tract and to prevent peritoneal leakage of bile. Prior to removal, contrast should be injected to verify cystic duct patency, absence of stones, and presence of a mature tract.
2. No.

Front 15

What are the indications of direct portography (percutaneous access into the portal vein)

Back 15

1. Infusion of islet cells in a diabetic patient.
2. Targeting for transhepatic puncture during TIPS.
3. Clear thrombus w/n the portal vein prior to TIPS.
4. Measurement of portal pressures.

Front 16

1. What are the possible etiologies of bleeding at the level of the EG junction?
2. How do you differentiate between the 2 possibilities? Why is it important to differentiate the two?
3. What artery supplies the EG jxn?
4. What embolic material should be used?

Back 16

1. Variceal hemorrhage and mallory-weiss tears.
2. Endoscopy is helpful in differentiating the two etiologies. Variceal hemorrhage is treated with TIPS and mallory-weiss tears are treated with embolization.
3. Left gastric artery. Even if no active bleeding is found on angiography, empirically coil the left gastric artery.
4. Gelfoam.

Front 17

1. What are the etiologies of bleeding from the GDA?
2. What is the course of the GDA with respect to the 1st portion of the duodenum?
3. How do you embolize a bleeding artery?

Back 17

1. Duodenal ulcers and pancreatitis.
2. GDA runs immediately behind the first part of the duodenum. Therefore, ulcers penetrating its posterior wall can cause life threatening arterial bleeding.
3. Arteries that do not anastomose with other arteries can be embolized proximal to the site of bleeding (renal artery). However, GDA has anastomoses with the epiploic artery (branch of splenic artery) and pancreaticoduodenal arcade (branches of SMA) and thus embolization should be done from distal to proximal to prevent backfilling of the ulcer.

Front 18

1. What are surgical options for portal HTN?
2. What are the complications of these conduits?

Back 18

1. Creation of portacaval shunt (from main portal vein to IVC), a mesocaval shunt (SMV to IVC), splenorenal shunt (splenic vein to left renal vein).
2. Stenosis and occlusion.

Front 19

1. What is the name of the portal- portal collateral that forms with splenic vein thrombosis?

Back 19

1. Arc of Barkow (arises near the spleen, follows the contour of the stomach and drains into the portal vein).

Front 20

1. What is the MELD score?
2. What three things make up the MELD score?

Back 20

1. Used to determine if patient will survive after placement of TIPS.
2. Consists of bilirubin, INR, serum creatinine.

Front 21

What are the two types of G-tubes?

Back 21

1. Pull- vs. Push type

Front 22

Acute mesenteric ischemia:

Back 22

- Typically 2/2 thrombosis at atherosclerotic site or embolic disease (usually from cardiac source)
- Surgical thrombectomy is the treatment of choice. Lytic therapy for mesenteric ischemia very controversial
because you cannot be certain that you are not infusing tPA into infarcted bowel

Front 23

How can you treat choledocholithiasis?

Back 23

- Use an occlusion balloon to push the stone through ampulla of Vater.
- Basket devices can be used to fragment the stone and push pieces into the duodenum.

Front 24

How do you manage abscess drainage catheters?

Back 24

- Monitor drainage, WBC count, temperature
- If symptoms and signs resolve and tubes stops draining, remove tube
- If tube drainage stops but the pt's sxs have not improved, consider tube obstruction and/or repeat CT scan.
- Thick, viscous fluid—consider TPA into cavity
- Continued large drain outputs—consider fistula to bowel or pancreas.

Front 25

Celiac axis stenosis/occlusion

Back 25

ATHEROSCLEROSIS:
-most common cause of narrowing of the mesenteric vessels.
-Management usually involves angioplasty or stent placement over surgery.
THROMBOEMBOLISM
-usually from a cardiac or proximal aortic source.
-Patients with acute mesenteric ischemia are usually treated with surgery (embolectomy)
VASCULITIS
- Takayasu arteritis
-acute diseases treated with steroids
-angioplasty/stent placement can be offered in the fibrotic phase of the disease
MEDIAN ARCUATE LIGAMENT SYNDROME
-typically effects in women between ages of 20 and 40.
-Lateral angiography reveals an indentation along the superior aspect of the celiac axis which is worse during expiration
FIBROMUSCULAR DYSPLASIA
- look for beaded appearance of the vessel.
RADIATION
- usually results in multiple, smooth, long segment regions of vessel narrowing

Front 26

Common causes of lower GI bleeding

Back 26

- Diverticulosis
- Angiodysplasia
- Inflammatory bowel disease
- Carcinoma

Front 27

Non-occlusive mesenteric ischemia

Back 27

- Reversal of cause (hypotension, volume loss, shock, etc)
- TX = Papaverine infusion (test dose of 30 mg slow bolus; repeat angiogram to see if there is a response. Infusion at 1 mg/minute for up to 12 – 24 hours)
- May cause/worsen hypotension due to splanchnic vasodilatation.
- Precipitates with heparin

Front 28

Agents used for chemoembolization of the liver

Back 28

- Doxorubicin, Cisplatin, and Mitomycin C
- These are hard to come by nowadays, so we are using chemotherapeutic beads.

Front 29

Relative contraindications for chemoembolization

Back 29

- > 50% of liver replaced with tumor.
- LDH > 425, AST > 100, t bili > 2
- Extrahepatic metastasis
- Encephalopathy
- Biliary obstruction
- Hepatofugal flow in main portal vein or portal vein thrombosis.

Front 30

Small bowel bleeding

Back 30

1. Vasopressin infusion
2. Embolization
- Microcoils superselectively in branch supplying bleed
- Less effective in SB due to rich collaterals from vasa recta
3. Surgery
- Assisted by selective injection of methylene blue dye to aid with visualization.

Front 31

Portal HTN

Back 31

-Can be divided into presinusoidal, sinusoidal, postsinusoidal.
PRESINUSOIDAL:
- Extrahepatic obstruction: PV thrombosis (most common in US)
- Overcirculation: Art-portal fistula, bowel AVM
- Intrahepatic obstruction (at portal venules): Schistosomiasis, Infiltrative conditions, Congenital hepatic fibrosis, PBC
SINUSOIDAL: Hepatitis, Sickle cell disease.
POST-SINUSOIDAL:
Cirrhosis
Budd-Chiari Syndrome
Constrictive pericarditis
CHF
Veno-occlusive disease of the liver

Front 32

Etiologies of UGI bleeding

Back 32

Ulcers
Gastritis
Esophageal/Gastric varices
Mallory-Weiss tears
Tumors

Front 33

Etiologies of Lower GI bleeding

Back 33

Diverticula
Angiodysplasia
Neoplasm/Polyp
Inflammatory Bowel Disease
Meckel’s Diverticulum