Diagnostic Radiology Interventional Radiology - PDF - PDF

							Integrated Block Teaching Radiology
Interventional Radiology
Department of Diagnostic Radiology The University of Hong Kong and Queen Mary Hospital

Learning objectives
• What is “Interventional Radiology” • Indications, contra-indications and complications of commonly encountered procedures • Percutaneous biopsy • Percutaneous drainages • Transcatheter treatment

Principles of IR
• Non-surgical intervention to provide diagnosis and treatment • Image-guided • Risks attached “intervention”

Principles of IR
• Contraindications - related to the risks of bleeding, infection, trauma to other organs • Post-procedure care - input from clinicians • Requires proactive consent from either patients or their carers

Interventional radiology
Diagnosis (biopsy) • To obtain tissue samples from masses or fluid collections for microbiology, histology and cytology • These tissues or fluid are obtained by percutaneous puncture with a needle of the mass or collection • This is performed using imaging to guide the needle

Interventional radiology
Treatment • Palliative, curative or adjunct (to other forms of treatment) • Drainage of abscesses • Drainage of obstructed systems (benign or malignant causes) • Intravascular transcatheter techniques

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Interventional radiology
Image guided • Fluoroscopy • Ultrasound • Computed tomography • Magnetic resonance imaging

Percutaneous biopsy
What organs or structures can be assessed with percutaneous biopsy?

Percutaneous biopsy
• • • • • • Lung Liver Kidney Thyroid Soft tissue masses Others - lymph node, pancreas, adrenal gland, breast

Fluoroscopy

• X-rays with fluoroscopic image obtained 2 planes (AP and lateral) to localize position of lesion • Traditional method • Superceded by US and CT guided

Lesion A will be biopsied from the anterior approach

Ultrasound guided biopsy

A A B B

Lesion B will be biopsied from the posterior approach

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Ultrasound
• Abdomen - liver, kidney • Neck - thyroid • Breast • extremities These are structures where the organs can easily be visualised using US with no overlying structures such as bone, bowel or lung

• CT uses x-rays and the x-ray tube goes around the patient in 350° • CT presents data in true cross section • No trouble with overlying structures such as bones, bowel or lung

CT guided biopsy:
• Thorax • Abdomen: P pancreas, adrenal gland, bowel, retro peritoneal masses • Neck masses not seen on US Visualised the adrenal and pancreas clearly Not so easy with US due to overlying bowel and fat

• Select a section where the target lesion is found • Place a grid on the section • Helps localise the lesion via markers on the skin • Aids determination of needle entry point

Lung biopsy

Fine needle biopsy
• Positive tissue: 80% - 95% • Complication rate: overall < 2% Mortality rate : 0.006% - 0.031% Overall - SAFE !!

Needle is inserted through the skin into the lesion

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Percutaneous biopsy
What possible complications can be associated with this procedure?

Complications
• Vascular damage - bleed, arteriovenous fistulas, pseudoaneurysm • Infection • Organ injury (pancreatitis 2-3% if normal pancreas punctured) • needle tract tumour seeding (rare, 0.003-0.009%)

Complications
Post renal biopsy
Arteriovenous fistula, which is a communication between the arterial ( ) and venous system ( ) secondary to biopsy

Lung biopsy • Pneumothorax - up to 57%. Chest drain required in 3-20% • Haemoptysis 2-12%, usually mild

Air in pleural space outside the lung

Contra-indications
• Uncorrected bleeding diathesis • platelets less than 50,000/mm3 • INR > 1.5 • Inaccessible lesion e.g. surrounded by bone or vessels without safe path • Uncooperative, confused or unwilling patient

Percutaneous drainages
Principles • Uses image guidance as biopsies • Fluoroscopy, US and CT • Similar precautions and contraindications as biopsies • Similar risks with additional ones relating to organ to be drained

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Percutaneous drainages
Common ones: • PTBD - percutaneous transhepatic biliary drainage • Percutaneous nephrostomy • Percutaneous abscess drainage

PTBD
• It involves identifying dilated bile ducts usually by US • Puncturing the duct through the skin and liver • Injecting contrast material to opacify the ducts using fluoroscopy

Liver

kidney
After bile ducts are opacified, a guidewire is passed through the needle into the bile ducts and maneuvered into the duodenum

Normal liver and kidney

Dilated ducts in liver
Needle puncturing the bile duct - note dilated system

Catheter

When do we do PTBD?
A drainage catheter is passed over the guide wire into the duodenum through the obstruction. Guide wire is then withdrawn

Duodenum

Side holes in catheter

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Acute complictions
• To treat obstructive jaundice (benign or malignant) • To treat biliary sepsis (cholangitis) • Before surgery to decompress the biliary system • Bleeding into biliary system most common • Infection - Septic shock • Pancreatitis - rare • Puncture of other organs - lung, kidney Overall 5-10% PTBDs

Delayed complictions
• Biliary sepsis (cholangitis) • Catheter migration • Bile leak • Metastatic seeding • Skin infection
45-50% of all PTBDs

Percutaneous nephrostomy
• It involves identifying dilated pelvicalyceal system with US • Puncturing the calyx through the skin • Injecting contrast material to opacify the collecting system using fluoroscopy

needle

After opacification, a guidewire is passed through the needle into the ureter

catheter

Normal kidney

Dilated kidney (Hydronephrosis)

The drainage catheter is passed over the guide wire and placed into the ureter or renal pelvis

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Percutaneous nephrostomy
Indications • When a kidney is obstructed (hydronephrosis) • When there is urine leakage secondary to trauma, infection or neoplasm • Prior to instrumentation such as stone extraction, stricture dilatation and ureteral stenting

When would you request for PCN?

Stone extraction

Percutaneous nephrostomy
• Minor complications (10%) hemorrhage, pain, catheter malfunction • Serious Complications (4-5%) haemorrhage or sepsis pneumothorax, peritonitis, urinoma (rare) • Death : 0.2%

stones

PCN is also performed to create a tract to allow stone extraction during lithotripsy

Percutaneous abscess drainage
PCNL catheters

Definition The systematic withdrawal of fluids and discharges from a wound, sore and cavity

Dorland’s Illustrated Medical Dictionary, 1988 Post PCNL bleeding

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Percutaneous abscess drainage
Principles • Usually ultrasound or CT guided • Same risks and contraindication applies generally • Safest route - avoid overlying blood vessels, viscera, pleura • Hydatid cyst cannot be drained anaphylactic shock G

Anterior

Posterior

Posterior

Anterior

• Contrast CT shows gas containing complex cystic mass in the pelvis • Posterior approach chosen - easiest route

• Prone position • Needle inserted through the gluteal muscle

Ultrasound guided

Still in prone position Catheter inserted over guidewire and placed into abscess cavity

PA film shows position of catheter in the pelvis

Catheter in liver abscess

Percutaneous abscess drainage
Complications
• Sepsis • Haemorrhage • Death (2o to sepsis or haemorrhage)

Intravascular transcatheter techniques
• Transcatheter treatment of cancers TOCE Regional chemotherapy • Transcatheter embolisation of bleeding sites Lacerated vessels Bleeding viscera

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Transcatheter oily chemoembolisation TOCE
• Treatment of inoperable hepatocellular cell carcinoma • Femoral artery punctured and a catheter placed into the coeliac artery • Injection of mixture of iodized oil (lipiodol ultrafluid) and cytotoxic agent (Cisplatin) into hepatic artery, followed by injection of Gelfoam particles

TOCE
Principle • HCC is a vascular tumour supplied almost solely by the hepatic artery • Iodized oil is selectively taken up by HCC cells • Cytotoxic mixed into an emulsion with lipiodol will thus be carried to the tumour cells in high concentration to be released slowly • Gelfoam particles block the washout by the arterial flow and “locks” in the cytotoxic within the tumour cells

Plain CT - HCC

Contrast CT HCC

• Large right lobe HCC • central area of necrosis • Vascular
Normal

• Arteriogram shows vascularity of the HCC • Illustrates arterial anatomy

TOCE
Complications • Post-embolization syndrome (common) nausea, vomiting, abdominal pain, loss of appetite, fever • Others (Uncommon) - Cholecystitis, upper GI bleeding, gastric/duodenal necrosis, acute pancreatitis, hepatic abscess, rupture

Pre-TOCE

Post-TOCE Uptake of lipiodol by tumour cells

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TOCE
Contraindications • Main portal vein tumour thrombosis embolisation of hepatic artery may cause complete occlusion and total ischaemia to the liver • Extrahepatic metastases • Poor liver function procedure induces ischaemia & liver damage

Other transcatheter techniques
Regional chemotherapy • Catheter placed in the artery supplying the tumour to optimize drug delivery • Reduces systemic circulation of the cytotoxic • Smaller doses used • Stomach cancer at QMH

Other transcatheter techniques
Embolisation of lacerated arteries or bleeding viscera • Selective catheterization of artery that is lacerated or bleeding • Particulate matter is injected - gelfoam, coils • Trauma, gastrointestinal bleeding Post PCNL bleed After embolisation

Interventional Radiology
• Non-surgical management of patient to provide diagnosis and treatment • Involves procedures that are associated with risk factors • Weigh need versus risk • Consent from patients or carers

Interventional Radiology
• Requires inpatient aftercare and therefore clinician input • Know your patients - to avoid preventable complications such as haemorrhage (bleeding diasthesis)

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