Interventional radiography

Various Procedures Angioplasty and Vascular Stenting Catheter Angiography Catheter Embolization CT Angiography MR Angiography Cryotherapy Uterine Fibroid Embolization Vertebroplasty

Angioplasty and Vascular Stenting Minimally invasive procedure to improve blood flow

in arteries. Surgeon threads a balloon tipped catheter to the

site. The balloon is inflated in order to open the artery –

deflated and then removed. Vascular stenting also may be done at the same

time. Stent is a permanent device left in the artery Assists the healing of the artery in the open

position after angioplasty.

Common uses Peripheral Vascular Disease.

Renal Vascular Hypertension.

Haemodialysis access maintenance.

Carotid Artery Disease.

Coronary Artery Disease.

How is it performed? Balloon inserted – inflated – deflated –

removed. Stents placed over the catheter- scaffolding for

the artery walls. Drug-coated stents – used in case of coronary

arteries (FDA approval). Stents coated with medication – to prevent

restenosis. Sometimes stent is not necessary.

Benefits Vs Risks Benefits Compared to bypass – much less invasive, low

cost and low risk.

No general anesthetic required.

No surgical cuts or incisions needed.

Patient can return to normal activities after the procedure.

Benefits Vs Risks Risks Catheter insertion can lead to injury of the

artery. Balloon can also cause blood clots or rupture the artery.

Blockages can recur. Heavy bleeding requires special medication or

even blood transfusion. Risk of stroke when performed on carotid

artery. Abrupt vessel closure – emergency bypass also

may be done.(Back)

Catheter Angiography Type of x-ray which is used to visualize the

arteries of heart, brain, kidney etc. Used to determine if arteries are diseased,

enlarge, narrowed or blocked. Nowadays has been replaced by less invasive

methods such as MRA and CT Angiography. Still used in patients undergoing angioplasty or

stenting.

Common uses Show arteriosclerotic disease in carotid artery. Demonstrate intra-cranial aneurysm or other

disorders of blood vessels in the brain. Indicate disease of renal artery. Indicate aneurysm of aorta. Show severity of arteriosclerosis in coronary

artery. Demonstrate a source of bleeding e.g.

Stomach ulcer.

How is it performed? X-rays passed through body. Catheter inserted which injects contrast

material or dye. Gives a detailed picture of the artery from

inside the blood vessel. Imaged are stored in computer or captured in

film (can also be viewed like a movie !!)

Benefits Vs Risks Benefits Presents a clear,accurate and detailed picture

of the blood vessels. “Super selective Angiography” Use of catheter makes it possible to combine

diagnosis and treatment in a single procedure. Similar degree of detail is not possible with

any other non-invasive procedure.

Benefits Vs Risks Risks Allergic reaction to the dye – complications. Blood may form a clot around tip of catheter. Diabetes or kidney disease – kidneys may be

injured when contrast material is eliminated through the urine.

Internal bleeding or causing a block “downstream”. Pregnant women should not undergo this

procedure.

(Back)

Catheter Embolization “Embolization” – way of occluding blood vessels

which are doing more harm than good. Material is passed through the catheter with its

tip lying in or near the blood vessel to be closed. Very useful to control excessive bleeding or cut

off blood supply to a tumor. Therapeutic Embolization serves to eliminate

AVM. Embolus – medication or synthetic material to

occlude the blood vessel.

Common uses Controlling bleeding from injury, tumor or stomach

ulcer. To cut off blood supply to a tumor. Can be used in

conjunction with chemotherapy. To treat benign fibroid tumors of the uterus – an

alternative to hysterectomy. Multiple fibroid tumors can be treated at one time.

Excellent for treatment of AVM (abnormal connection of the artery and the vein like a “short circuit”).

For plugging of an aneurysm in the brain. Treatment of hemangiomas.

How is it performed? The equipment used is same as in Catheter angiography. The first step is angiography (injection of x-ray dye into

an artery or vein) to locate the exact site of bleeding or abnormality

A catheter is introduced and contrast material is injected (normally through femoral artery).

An appropriate embolic material then is chosen and injected through the catheter to lodge at the treatment site

Repeat angiograms are done until bleeding is controlled or there is enough embolic material in a tumor or vascular malformation

Different Embolic materials used Gelfoam - used to control bleeding until the cause

—such as a bone fracture can be identified and fixed, or until it has time to heal on its own.

Permanent particulate agents - These agents are used to occlude small blood vessels permanently. They are used to stop bleeding or block arteries to a tumor when the underlying lesion is not likely to heal. They are the materials used most often to embolize uterine fibroid tumors. Eg : Polyvinyl alcohol (PVA).

Different Embolic materials used Metal coils made of stainless steel or

platinum may be used to occlude large arteries. They come in a range of sizes.

Liquid sclerosing agents such as alcohols are used to purposely destroy tissue. This might be desired to treat a large malformation of veins by filling it with the liquid to induce clotting and damage the inner lining of the veins

Benefits vs Risks Very effective way of controlling bleeding

especially in emergency. Used to treat tumors and vascular

malformations. It is much less invasive than conventional

open surgery. When embolization is used to treat an

intracranial arteriovenous malformation (AVM), injection of a small amount of material minimizes the risk of serious brain dysfunction.

Benefits vs Risks Embolus can lodge in the wrong place and

deprive normal tissue of its oxygen supply. Risk of infection after embolization, even if

an antibiotic has been given. Because angiography is part of the

procedure, there is a risk of an allergic reaction to contrast material and also there is a risk of kidney damage in patients with diabetes or other pre-existing kidney disease.

(Back)

Cryotherapy Cryotherapy, also called

cryosurgery, cryoablation or targeted cryoablation therapy, refers to the application of extreme cold to destroy diseased tissue, including cancer cells.

Common Uses Used to destroy skin tumors, pre-cancerous

skin moles, nodules, skin tags or unsightly freckles.

Used to destroy Retinoblastomas. Physicians have begun to perform

cryotherapy for prostate, liver and cervical cancer, especially if surgery is not possible.

Current research on cryotherapy for tumors of the bone, brain, kidney, lung and spine.

How is it performed? Carried out using cryoprobe (attached

via tubing to a source of N or Ar). For external masses, liquid N is applied

directly with a cotton swab or spray device.

For internal tumors, liquid N or Ar gas is circulated through the cryoprobe, which comes into contact with the diseased tissue.

How is it performed? (contd.) More advanced forms of cryotherapy, such

as for treatment of liver cancer, involve the insertion of the probe through an incision or threaded through the skin. Then using imaging device the physician targets and freezes the tumors.

Likewise, for prostate cancer, six to eight needle probes can be inserted through the perineum (the tissue between the rectum and the scrotum/penis) and ultrasonically guided to freeze the cancer.

Benefits vs Risks For intraoperative cryotherapy recovery

time is much less than for major surgical removal of the tumor.

Percutaneous cryotherapy has great potential to evolve into an outpatient procedure.

Less traumatic than open surgery since only a small incision is needed.

It causes minimal scar tissue and apparently no calcifications.

Benefits vs Risks (contd.) Treatment of the liver can damage bile ducts or

cause heavy bleeding Treatment of the kidney can damage the urine-

collecting systems or cause heavy bleeding. Treatment of lung tumors can cause the lung to

collapse and fluid to accumulate around the lung. Care must be taken anywhere nerves are near

the tumor. Completely frozen nerves can cause motor weakness or numbness in the area supplied by the nerves.

(Back)

CT Angiography CTA uses X-rays to visualize arterial

and venous vessels throughout the body.

CT combines use of x-rays with computerised analyzis of the image.

CTA is much less invasive and more patient friendly than catheter angiography.

Common uses To examine pulmonary arteries to rule out

pulmonary embolism. Visualize blood flow in the renal arteries in

patients with high blood pressure and those suspected of having kidney disorders. Also done in kidney donors.

Identify aneurysms in the aorta or in other major blood vessels.

Detect atherosclerosis disease that has narrowed the arteries to the legs.

Detect thrombosis (clots) in veins, for example large veins in the pelvis and legs.

How is it performed? Before the actual exam a contrast agent is

injected into a vein. During the examination, the rotating device spins

around the patient, creating a fan-shaped beam of x-rays, and the detector takes snapshots of the beam after it passes through the patient.

As many as one thousand of these pictures may be recorded in one turn of the detector.

Then reconstruction techniques are used to view images as desired.

Benefits vs Risks CTA can be used to examine blood

vessels in most parts of the body. More precise than MR Angiography

and Ultrasound Useful way of screening arterial

blood vessels because it is safer and less time consuming than Catheter Angiography.

Risks Risk of allergic reactions because

of contrast agents like iodine. Dangerous for patients with kidney

disorders and diabetes. Skin damage may occur because

of excess contrast agent.(Back)

MR Angiography MRI produces images of the body without

the use of X-rays. The electromagnetic energy that is

released when exposing a patient to radiofrequency waves in a strong magnetic field is measured and analyzed by a computer

MRA is MRI study of the blood vessels. Provides detailed images of the images

without using contrast agents.

Common uses Used in checking patients for

diseased intracranial (in the head) arteries.

Used to detect disease in the aorta and in blood vessels supplying the kidneys, lungs and legs.

Used for confirmation of carotid artery stenosis.

How is it performed? Traditional MRI units are used. Patient is placed in the MRI unit. Exposing the patient to radio waves in a

strong magnetic field generates data that are used by a computer to create images of tissue slices that may be viewed in any plane or from any direction.

Contrast material used is Gadolinium. It is given by IV injection during one of the imaging sequences.

Benefits Vs Risks Benefits Procedure time and time to recover is

relatively small. Cost-effective procedure. No exposure to x-rays. Very useful for patients having allergic

reactions to contrast material. Possible to defer surgery.

Benefits Vs Risks Risks In case of implants being present, it is difficult

to get a good quality image. Pregnant women cannot be allowed for this

procedure.(Back)

Uterine Fibroid Embolization New way of treating fibroid tumors. Also called as myomas, fibroid tumors are

masses of fibrous and muscle tissue in the uterine wall which are benign but can cause heavy bleeding, pain in the pelvic region or pressure on the bladder and the bowel.

Much less invasive than open surgery. UFE was first used to limit blood loss during

surgical removal of fibroid tumors. Now it is a stand-alone treatment for women

who have symptoms of uterine fibroid tumors.

Common uses Obviously for fibroid tumors.

Otherwise, also to limit the bleeding after child birth or caused by malignant gynecological tumors.

How is the procedure performed? Carried out in an angiography suite with x-ray

equipment and vital signs being monitored. Nick in the groin area. Catheter is introduced via the femoral artery. Catheter threaded to the uterine arteries. X-ray guidance and periodic injection of radiographic

contrast material is done to map the blood vessels. Embolization particles are injected till the uterine

arteries are not completely blocked. Both arteries can be blocked in a single procedure. Site of skin is then cleaned and bandaged.

Benefits Vs Risks Benefits Minimally invasive, patient can resume normal activities

weeks earlier than compared with hysterectomy, minimal blood loss, general anesthesia is not required.

85% of women experienced significant reduction in pain or complete resolution of their symptoms.Overall, fibroid size becomes half in about 6 months after UFE.

More permanent solution as even small fibroid tumors are eliminated. No regrowth occurs.

Better procedure compared to hormone therapy. Regrowth is also a problem with laser treatment of

these fibroids.

Benefits Vs Risks Risks Catheter related risks Allergic reactions to the contrast material. 2-3% of women may have to undergo D&C to

ensure there is no bleeding and infection. Menopause occurs immediately in about 1-5%

of women undergoing this procedure. Future fertility..??

(Back)

Vertebroplasty Image-guided, minimally invasive, non-surgical

therapy. Mainly to strengthen a broken vertebra that

has been weakened by osteoporosis or cancer. Successful at alleviating the pain caused by

compression fracture. Is accomplished by injecting an orthopedic

cement mixture by means of a needle into the fractured bone.

Common uses To treat pain caused by osteoporotic

compression fractures. Often performed on patients too elderly or frail

to tolerate open spinal surgery, or with bones too weak for surgical spinal repair.

Usually recommended after simpler treatments.

How is it performed? Usually performed in the morning – the patient is

sedated and local anesthetic is used along with intravenous antibiotics.

With the help of a fluoroscope, a hollow needle is passed through the spinal muscles till its tip is positioned within the fractured vertebra.

After the position is confirmed (introsseous venography), the orthopedic cement is injected into the fracture.

Cement hardens in about 10 to 20 minutes. Entire procedure takes less than 2 hours

(provided only one site is being treated)

Benefits Vs Risks Benefits Patients feel significant relief almost

immediately. About 75 percent of patients regain lost

mobility and become more active, which helps combat osteoporosis.

Increased activity builds more muscle strength, further encouraging mobility.

Benefits Vs Risks Risks Small amount of orthopedic cement can leak

out of the vertebral body. This does not usually cause a serious problem, unless the leakage moves into a potentially dangerous location such as the spinal canal.

Possible complications include infection, bleeding, increased back pain and neurological symptoms such as numbness or tingling. Paralysis is extremely rare.

References www.radiologyinfo.com

www.pubmed.com

www.wikipedia.org