Interventional radiology Ppt
Transcript of Interventional radiology Ppt
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 Nowadays has been replaced by less invasive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