radio 250 [8] lec 11 introduction to interventional radiology

TOPIC OUTLINE

I. Interventional Radiology Procedures

A. Vascular ProceduresB. Non-vascular Procedures

II. Catheterization

A. Catheters and GuidewiresB. Seldinger Technique

III. Vascular Procedures

A. Angiography and DSAB. EmbolizationC. Angioplasty and StentingD. Transjugular Intrasystemic E. Shunt (TIPS) F. Transarterial Chemoembolization (TACE)

IV. Non-vascular Procedures

A. BiopsyB. Radiofrequency AblationC. Percutaneous DrainageD. Percutaneous CholecystostomyE. Percutaneous Transhepatic Biliary Drainage (PTBD)

Legend:Discussed by sir, not in the powerpointFrom 2016

I. INTERVENTIONAL RADIOLOGY PROCEDURES Diagnostic or therapeutic Vascular or non-vascular

Advantages of Interventional Radiology over Surgeryo Minimally-invasive; no incision, sir’s widest incision is 5mmo Sometimes, general anesthesia is not needed – just IV sedation or

local anesthesiao Most procedures are done inside the catheterization lab

A. VASCULAR PROCEDURES1. Increase Blood Flow Mechanical methodso Dilatation of stenotic arteryo Recanalization of occluded arteryo Removal of embolus

Pharmacologico Increase vasodilators

2. Decrease Blood Flow Mechanical methodso Embolizationo Balloon techniqueso Intravascular electrocoagulation

Pharmacologico Increase vasoconstrictors

3. Miscellaneous Infusion of chemotherapeutic agents Radioembolization Laser angioplasty Vena cava filtering Renin sampling – not just renino Active pancreatic nodule: must be located by the interventional

radiologist; samples of venous blood are collected from head, body and tail of the pancreas stimulate pancreatic cells to secrete insulin by injecting CaGLuc get samples again after 1 minutes graph determine where insulin is highest

B. NON-VASCULAR PROCEDURES Mostly basic procedures done by radiologists Biopsies Abscess drainage Puncture and drainage of cysts Cysts sclerosing by introducing sclerotic agents like tetracyclines,

ethanol. Placement of stents – bile duct, ureter, GI tract, colon Percutaneous transhepatic biliary drainage – drain the biliary system. Endoscopic retrograde cholangiopancreatography – done by GI Sialography Joint aspiration – orhto or rheuma

II. CATHETERIZATION

A. CATHETERIS AND GUIDEWIRES

Figure 1. Interventional CathetersFrom 2016: Top Left (L to R): Neff catheter and pigtail catheter. Both are used for invasive diagnosis with injection of contrast agents through large arteries, so they have a multiperforated distal tip to enable high-flow injection (such as in an aortogram)Top Right (L to R): distal tips of a conventional J-tipped guidewire and a curvedtip hydrophilic guidewireBottom Left (L to R): vertebral catheter, cobra catheter, and type I Simmons catheter (for visceral blood vessels). These catheters all have a preformed distal tip for selective catheterization; the choice of which one to use depends on the procedureBottom Right (T to B): introducer sheath, dilator, and guidewire

B. SELDINGER TECHNIQUE Most procedure are done using this technique By using this technique we can insert big catheter into small vessel To avoid collapsing of vessel Puncture by needle, insert wire to maintain axis, With a series of wire and catheter exchange maneuver we can

access small vessels with big tubes having the least trauma Gradually dilating Ensures atraumatic placement of catheter. Can also be done in non-vessel structures i.e. bile duct, abscesses,

and cysts

Figure 2. Seldinger Technique

IV. VASCULAR PROCEDURES

A. ANGIOGRAPHY OR ANGIOGRAM X-ray exam of arteries and veins to diagnose blockages and other

blood vessel problems Simplest procedure done for the vascular system Purely diagnostic Vessel opacified by contrast medium Catheter introduced using Seldinger technique Uses:

1. For blockage or narrowing in a blood vessel2. Aneurysms – an area of a blood vessel that bulges or balloons out3. Cerebral vascular disease, such as stroke or bleeding in the brain4. Blood vessel malformations, hypervascular tumors

Digital Subtraction Angiography (DSA)o Gold standard in diagnosing vascular lesions; can assess location,

configuration, and hemodynamicso X-ray is taken and used like a mask. The contrast is injected and

then an image is subsequently taken.o The resulting picture is “subtracted” by the mask and the vessels

will be shown

October 20, 2014

#Radio 250 [8]: ICC in Radiology and Nuclear MedicineLec ##: Introduction to Interventional RadiologyJason Catibog, MD, FPCR, FPCVIR, FCTMRISP

TANGCO & TURALDE / 4

Introduction to Interventional Radiology Radio 250

Figure 3. Digital Subtraction Angiogram of the Cerebral vesselsLeft: Actual angiogram, Right: Digitally subtracted image, Top: Arterial phase, Bottom: Venous phase

Figure 4. A DSA of an stenosed MCA showing collateral vessels to maintain perfusion

B. EMBOLIZATION

Aneurysm Coiling From 2016:o Use of microcatheter <1mmo Pack aneurysm with coils (made of alloy/Platinum)

o Coils can have thrombogenic material like cotton, polyvinyl alcohol, glue, or even blood clots

o Coils protect dome of aneurysm from rupturing

Figure 5. Embolization of an Aneurysm (Top left: endovascular coil, Top right: process diagram of ambolization, Bottom: actual angiogram

during embolization)Examples of Using Embolization

Uterine AVMo Common History: A young primigravid female with ahyaditiform

mole. She underwent chemotheryapy and as a complication, AVM developed.

o The feeding arteries appeared hypertrophied due to increase demand of the nidus

o Process: The feeding artery to a lesion is identified by angiography and subsequently occluded to shrink the aneurysm by means of a catheter and embolizing material.

Preoperative Embolismo Before the tumor is resected, the blood vessels are occluded. Once

the blood vessel is occluded it creates edema on the affected tissue. This somehow makes the differentiation of normal tissue from edematous tumor during resection.

o It results to lesser blood loss during surgery and easier identification of tumor parts due to surrounding edema.

C. ANGIOPLASTY AND STENTING ANGIOPLASTY- a process to widen a narrowed blood vessel In angioplasty, deliberate trauma is induced to the intima of the vessel

leading to healing with a systematic scar Disadvantage of angioplasty is that stenosis may recur STENTING- a balloon is inserted to a “stubborn” blood vesselso Can be introduced after angioplastyo Some stents slowly release thrombolytic agents (esp. coronary

angioplasty) Among interventional radiologists and interventional cardiologists, the

area of specialty is delineated by the aortic root. Example : Patients may present with hypertension due to renal artery

stenosis

Figure 6. Angioplasty and Stenting A. Aortogram in a patient with hypertension shows pronounced R renal artery stenosis (arrow). B. Following placement of a balloon-expandable stent shows an excellent radiographic result. (Images from Brant and Helms, 2007)

D. TRANSJUGULAR INTRAHEPATIC SHUNT (TIPS) The catheter goes through the jugular and this creates a shunt

between the portal circulation and the systemic circulation. Clinical Application: Patient presents with massive hematemesis due

to esophageal varices from severe portal hypertension. In this case, the pressure must be relieved in the portal circulation.

Procedure: The catheter is passed through the internal jugular vein to the SVC -RA- IVC- hepatic vein then “we drill a hole” connecting the hepatic vein and the portal vein and secure this communication using a stent.

Figure 7. TIPS Diagram (L), actual angiogram (R)

E. TRANSARTERIAL CHEMOEMBOLIZATION (TACE) The vascular supply of the tumor is identified and isolated and the

chemotherapeutic agents are inserted directly into the tumor. This results to lesser side effects since the chemicals are injected

directly into the tumor and the systemic circulation is bypassed. The procedure is repeated until the tumor is reduced to a manageable

size and can be resected. Constant monitoring is important. Clinical Scenrio: Hepatocellular CA- The catheter passes through the

femoral artery-aorta-celiac artery- hepatic artery (identify and isolate)



then the hepatic artery is fed with chemotherapeutic agents as microspheres

Liver has dual blood supply – hepatic artery and portal vein. In hepatocellular carcinoma, where the tumor environment has decreased O2 tension secondary to continued tumor metabolism. Hepatic artery is more reactive than portal vein in increasing blood supply to the tumor.

Procedure:o Access aorta and then celiac trunko Look for feeders at the branches of the hepatic arteryo Deliberately push chemotherapeutic agents to feedero Occlude the feeding artery tumor involutes (poison

[chemotherapeutic agent] and starving [occlusion])

Figure 8. TACE Diagram (Top), actual angiogram (Bottom)

Advantages of the procedure:o Increase concentration of agent at tumors, lowers systemic doseo Longer dwelling time of chemo agent at tumoro Lower probability of recurrence and metastatic disseminationo Chemo agent can be emulsified with lipiodol to minimize

collateral damage (normal hepatocytes have lipases that can digest lipiodol normal hepatocytes spared from chemo)

Indicationso Surgically-unresectable tumoro Tumor confined at livero Liver disease as dominant source of morbidityo Liver-only or liver-dominant metastasis

Contraindicationso Portal vein thrombosis (because you occluded the hepatic

artery, hepatocytes now rely on portal vein for blood supply)o Uncorrectable coagulopathyo Presence of hepatic encephalopathyo Tumor > 50% of livero Biliary obstruction (increase pressure of sinusoids increases

portal pressure which decrease blood flow to liver parenchyma)o Child Pugh C

Figure 9. Child Pugh Classification. Class A – TACE can be performed; Class B – TACE can be done but with precaution; Class C –

TACE is contraindicated

Complications

o Non-targeted embolization to other organso Contrast-related complicationso Hematoma

Post-embolic symptoms (usually less than 1 wk duration)o Fevero Paino Nauseao Vomitingo Fatigue

Selective Internal Radiotherapy In 20-25 grays, normal liver tissue dies; however, need 80-

100 to kill tumors. SIRT allows targeted delivery of radiation while sparing normal hepatocytes

Uses yttrium 90 that emits B radiation; usually 2-3 mm relatively safe for normal hepatocytes which are radiosensitive

IV. NON-VASCULAR PROCEDURES

A. BIOPSY Minimally invasive way to diagnose benign and malignant diseases Small diameter needles— 22 gauge to 18 gauge Aspiration needles versus cutting needles Ultrasound, fluoroscopy, CT or MRI as guide If we see something and we have the proper needle to access that

there’s no reason for us not to puncture, whether lung, retroperitoneum, or liver.

Figure 10. Guided Biopsies, CT-guided lung mass biopsy (L), UTZ-guided breast mass biopsy (R)

B. RADIOFREQUENCY ABLATION Instead of puncturing the mass with just a needle, uses an electrode

connected to a radiofrequency generator. Produce heat like a microwave. Effectively “cooking” the tumor. On the way out the RF generator is still active so the needle track is

ablated and so there is no issue of bleeding or hemostasis. They are effectively cauterized.

Figure 10. Radiofrequency Ablation. Showing the RF ablation probe and the grounding pads on each thigh

Criteria for RF Ablationo Liver-dominant diseaseo Focal rather than diffused infiltrationo 3-5 lesions, < 6cm each if the location is feasbile

C. PERCUTANEOUS DRAINAGE OF ABSCESS For drainage of fluid collections, including nephrostomy, abscess,

biliary gallbladder, pleural fluid, ascites, and lymphoceles For Liver abscess. Treating it with antibiotics is not enough. We need

to remove the pus through sound guidance and a catheter



Figure 11. Percutaneous Liver Abscess drainage, CT Radiographs

D. PERCUTANEOUS CHOLECYSTOSTOMY Drainage of the biliary system For cholesystitis, when the patient is in sepsis and there’s

coagulopathy the patient is surgically unstable and can’t be operated on they can’t just take the gall bladder out.

Insert a catheter and drain the pus inside and when the patient is stable, operate.

Figure 12. Percutaneous Cholcystostomy diagram (UL), radiograph (UR), Sonogram guidance (bottom) showing a stent through the gall

bladder

FROM 2016: E. PERCUTANEOUS TRANSHEPATIC BILIARY DRAINAGE (PTBD)

When the patient has obstructive biliary pathologies and the bile becomes stagnant, he becomes prone to developing infection, which can lead to sepsis, then shock, or even death.

To avoid ascending cholangitis we can put a tube to drain the biliary tree so the bile is free flowing and decreases the chance of sepsis.

Needle is placed into liver and bile duct Guide wire is inserted through the needle and down into the bile duct Needle is removed and the catheter is passed over the guide wire

and into the bile ducts.

Figure 13. Percutaneous transhepatic biliary drainage, TOP: Needle placed into liver and bile duct (A), a guidewire is passed through the needle and down into the bile ducts(B), the needle will be removed from the bile ducts and liver through the guide wire (C), the soft plastic biliary

tube catheter will be passed over the guidewire and into the bile ducts (D), BOTTOM (L to R): The percutaneous catheter is pushed through the stenosed common bile duct, so that bile is advanced inside the catheter towards the bowel loops; Metallic Stent is placed into the common bile duct, keeping the stenosed area patent. Now the percutaneous catheter can be taken out.

_________________________________________________________END OF TRANSCRIPTION

TANGCO: RADIOLOGY! RAD-YOLO-GY! LIKE FORT LIU! HAZZA!

TURALDE: THANK YOU ANDREW FOR THE 3-5 CM LESION <6CM IF LOCATION IS FEASIBLE

TY: HEY BITCHES!! EXTRA HEY HEY HEYLALOO SA STAREXXX!! AT SIYEMPRE HETO NANAMAN KAMI NI HUBBY KO MEHUEHUEHUE PAKYU SA HATERZZZ…


radio 250 [8] lec 11 introduction to interventional radiology

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