Medical Breakthroughs: High-Tech 'Surgery'

Much easier on a patient and often more effective and less expensive than conventional surgery, revolutionary procedures allow doctors to successfully perform life-saving operations with incisions as small as the point on a pencil.

By Gail McBride

Tiny tubes, wires, balloons, coils, glue, plastic particles–these sound like the pieces of a child's construction kit, not the tools of a rapidly growing branch of medicine. But chances are that one day a doctor will be threading a few of those tools into your blood vessels or, possibly, going right through the skin into one of your organs. And it's likely that that physician will be using those miniature tools to treat you, not just to look to see what's there, although the treatment will be done with the constant guidance of powerful imaging machines, like CT (computerized tomography) scanners, ultrasound scanners, fluoroscopy (X-ray) machines and sometimes MRI (magnetic resonance imaging) scanners, to show the physician exactly where to deploy the tools. The ability to see what you're doing is an absolute necessity when treating radiologists who spend some of their time diagnosing problems in the blood vessels–using magnetic resonance–but the majority of their time treating diseases in blood vessels and other body sites with those tools. They're more like surgeons than anything else and frequently keep surgeons' hours, sometimes doing a procedure in the wee hours because a the interior of someone's body through an opening no larger than a pencil tip and sometimes at considerable distances from that opening.

Although physicians who use such tools to treat the heart and its surroundings usually are specialized cardiologists, those who do so elsewhere in the body are called interventional radiologists (IRs). They are specially trained patient is critically ill or injured. Often, they invent new procedures on the spot to deal with the unexpected. There are also about 150 interventional neuroradiologists in the United States who perform their extremely delicate, incredible procedures only in the brain and spinal cord, treating strokes, aneurysms and other abnormalities, often at the behest of neurosurgeons.

Most of us actually are familiar with interventional radiology, although we may not realize it. That's because balloon angioplasty–the use of a miniature inflated balloon at the end of a long thin tube, or catheter, to open up blocked blood vessels–is one of the procedures done in this field. Angio-plasty is performed on over 400,000 patients each year in the United States. In 1964, that and some other "crazy" ideas were advanced by an American radiologist named Charles Dotter. American physicians weren't particularly interested, but some Europeans were, and a Swiss cardiologist named Andreas Gruentzig actually developed the balloon catheter and the procedure of angioplasty for use in the blood vessels that supply the heart. One of Gruentzig's main achievements was to develop a balloon that, when inflated, assumed the shape of a hot dog rather than a ball so it would conform to the shape of a blood vessel. Now the technique is applied to blocked blood vessels all over the body.

In some ways, however, the field actually began a decade earlier, in the 1950s. That's when a Swedish radiologist named Sven Seldinger had, in his words, "an acute attack of common sense" when trying to do an angiogram–an X-ray of blood vessels made visible by injection of a contrast material into the bloodstream. Seldinger wanted to avoid cutting into blood vessels in order to inject the contrast material, so he tried inserting a hypodermic-type needle into a blood vessel through the skin, much as when blood is drawn. Monitoring his progress with an X-ray machine, he then put a wire through the needle, guided the wire into place in the blood vessel, then removed the needle and slid a long catheter over the wire. Through the catheter he injected contrast material into the blood vessel before looking at it with X-rays. There was the image! To this day those same tools–needle, wire and catheter–are used in interventional radiology. In fact, as in surgery, the design and materials of the catheters, coils and other tools used in interventional radiology are as crucial to the success of the "operation" as the right imaging equipment, a pair of steady hands and a creative mind.

In many cases, interventional radiologists work closely with surgeons of various types to treat patients. Other times, they work on their own, sometimes doing procedures that formerly were performed only by surgeons. This often results in lower cost (because no operating room is necessary), minimal invasion of the body and, thus, a shorter recovery time.

 

Everyday Procedures. So what can interventional radiologists do? The list is long, but among their routine procedures in the blood vessel, or vascular, system are the following:

• Foiling strokes or heart attacks by injection of TPA or other clot-lysing agents into the body to dissolve blood clots in the arteries that bring blood to the brain or heart. Cardiologists usually perform the heart procedures.

• Unblocking clogged arteries anywhere in the body, such as the legs or kidneys, with balloon angioplasty. This may be followed by insertion of a stent–a miniature metallic or plastic device inserted into a blood vessel via catheter which then expands to hold the vessel open.

• Purposely blocking off, or embolizing, blood vessels that are bleeding or that are "feeding" a tumor. This procedure avoids surgery to stop the bleeding: The IR does an angiogram to locate the bleeding vessel, and then threads a catheter to the site of bleeding and blocks the vessel, using occluding materials like coils, foam particles or glues. The procedure can be done on an emergency basis when someone is injured and an organ such as the spleen is bleeding; embolization avoids removal of the entire organ.

When embolization is employed to shrink or kill a tumor, it may be either the sole treatment or an ancillary procedure done before surgery to reduce bleeding during the operation.

• Placing catheters into large veins, usually in the arm or neck, so that drugs or nutritional substances can be continuously infused into the body, sometimes for long periods. This procedure is used for hemodialysis, total parenteral nutrition, cancer treatment or prior to bone-marrow transplantation. These catheters allow medications to be given or blood drawn without repeated needle sticks. Such large veins also can be opened up again by angioplasty if they become damaged by the catheter or the substances being infused. This is commonly done for patients on hemodialysis so dialysis can continue.

• Treating claudication, namely pain that occurs in the legs when walking or exercising. The pain is caused by blood clots or atherosclerotic disease in the leg arteries. As distressing as claudication is, vascular surgeons are reluctant to do risky bypass surgery unless poor circulation actually threatens the whole leg. An interventional radiologist, however, will have the patient undergo angiography to determine the location of the clots or obstruction. Then the IR often can treat the obstruction by balloon angioplasty and/or stenting. Results usually are excellent, and the condition seldom recurs.

Blood clots in leg veins–called deep vein thrombosis–are more difficult to treat. If allowed to persist, the condition can destroy the valves in the veins, leading to chronic pain and severe swelling in the leg. Bypass surgery has poor results because the blood in veins is under low pressure and tends to re-clot. Usually the patient is treated only with anticoagulant drugs, which merely prevent new clots from forming.

Some IRs, however, are now aggressively treating large clots in leg veins with urokinase, a clot-busting drug. This costly treatment may take several days, but results in some patients have been very promising, with patients' leg swelling improving as clots are dissolved. In some cases, stents may be placed in veins where significant narrowing is present.

 

Nonvascular procedures. Many nonvascular procedures are also performed by IRs, although in some places surgeons still do them. These include:

• Draining abscesses. With imaging guidance, interventional radiologists insert a small needle through the skin into the abscess, then a wire and catheter are pushed through the nick in the skin and the fluid and pus are drained out through the catheter. The procedure can be done, for example, to treat an abscess resulting from an infected appendix or for diverticular abscesses, avoiding the temporary colostomy necessary with a strictly surgical approach.

• Inserting feeding tubes (gastrostomy tubes) into the stomachs of patients unable to eat normally.

• Taking biopsy tissue from almost any organ or tissue in the body by inserting a needle directly through the skin into the area to be biopsied. Sometimes a biopsy can be performed by placing a miniature forceps device that is able to remove tiny pieces of tissue for examination through a catheter into a blood vessel leading to the organ. Local anesthesia usually is sufficient.

Many women still undergo surgical biopsy of suspicious breast masses that are seen on mammography but cannot be felt. However, interventional radiologists offer other methods of biopsy that are less traumatic, easier, cheaper and usually just as reliable. One such method is ultrasound-guided core breast biopsy. An ultrasound probe is placed right over the site of the mass and, with the patient under local anesthesia, a cutting needle is placed directly into the mass. It automatically takes up to seven tissue specimens within 20 minutes.

• Enhancing female fertility by opening fallopian tubes that are blocked due to previous infection or adhesions.

• Treating a failing liver. If other treatments are ineffective or are considered too dangerous for a sick patient, a procedure called TIPS (transjugular intrahepatic portosystemic shunt) is performed by an interventional radiologist. In order to improve blood flow and prevent hemorrhage, the IR uses a catheter and then a stent to make a unique connection between two veins in the liver. According to Matthew Mauro, M.D., professor of radiology and surgery, University of North Carolina, Chapel Hill, TIPS is now often used as a bridge to liver transplantation.

As worthwhile as some of the above procedures may sound, one potential problem is that interventional radiologists are not in abundant supply (there are just over 4,000 in the United States). You'll find several in most large academic medical centers and probably one in larger community hospitals. As for smaller hospitals, it's uncertain. Yet, according to Robert Vogelzang, M.D., professor of radiology and chief of vascular and interventional radiology at Northwestern University Medical Center, Chicago, "You can't get modern health care unless there's an interventional radiologist at your hospital who's draining abscesses and doing biopsies and other procedures. I think that's now obvious to the majority of physicians."

With all these procedures, and advances on the horizon (see the accompanying sidebars), it may appear that interventional radiologists are trying to take over much of surgery. Not true, they say; it's just that some things can be done better in a different, less invasive way. "Surgery is still a vital and vibrant field," says Vogelzang. "We don't remove organs or do large resections or replace joints. We're nibbling at the edges, and we make a difference."

"A nice thing about minimally invasive therapy is that you usually don't burn bridges," says Michael Soulen, M.D., associate professor of radiology and surgery, University of Pennsylvania, Philadelphia. "If the procedure doesn't work well," Soulen says, "we can fall back on a more invasive, surgical approach. For example, if leg angioplasty fails due to reclosure, you can still have bypass surgery." Adds Mauro, "There's no question about the value of open surgical procedures. The main point is to choose the best procedure for a particular patient."

If you're curious about whether a minimally invasive approach might work for your problem, ask your physician. "Things change so rapidly in medicine that it's hard for any physician to keep up," says Anne C. Roberts, M.D., professor of radiology and chief of vascular and interventional radiology at the University of California, San Diego. "But if you are facing major surgery or some other major procedure like systemic chemotherapy for cancer, it's always wise to ask if there are other options or if a less aggressive approach could be tried. Good doctors will be receptive to these questions."

In the near future, we may see vascular centers or centers for minimally invasive treatment adding to the medical landscape. At such centers, patients with a vascular or other problem would be seen by several specialists who would jointly decide on the best treatment for the patient. Such collaboration could go a long way in giving patients more and better treatment options than ever.

 

(Non)Cutting-Edge IR Treatments. Some interventional radiology procedures are new or in the developmental stage. Not all have been proven in terms of benefit. The following are some of the newer procedures:

• Uterine artery embolization (UAE) for fibroids. Probably the most exciting new procedure being performed by interventional radiologists, UAE involves the embolization (blocking) of both uterine arteries (which carry blood to the fibroids) by particles. The result is marked shrinkage of the fibroids and disappearance of symptoms such as bleeding and pelvic pressure. For many women, the procedure may replace hysterectomy, myomectomy (removal of the fibroids) and other procedures as a treatment for fibroids. Recovery time is only about a week, and women who underwent the procedure at least five years ago in Europe and the United States have had relatively few problems and no recurrences.

• Stent-grafts for aortic aneurysms. A variety of these experimental devices are being placed in patients with aneurysms of the aorta–the huge blood vessel that carries blood from the heart to the rest of the body. The aneurysms (places where the blood vessel wall has weakened and, filled with blood, bulges out, threatening to burst) may occur in the chest or abdomen area. If they burst, surgery must be performed immediately, or the patient will die. If aneurysms are caught before they burst, surgeons generally remove the weak portion of the aorta and put a Dacron graft in its place. While quite effective, however, such major surgery is not suitable for all patients, especially those with preexisting heart or lung disease. In addition, recovery time is around two months.

Now interventional radiologists, working with vascular surgeons, are doing a new procedure in which the surgeon opens up an artery at the hip and the IR places a stent-graft–a large stent covered with a plastic material–through that artery into the aorta and into the area of the aneurysm, excluding it from the blood circulation. Stent-grafts appear to work well in the short term, but long-term results are not yet known. It may be that surgery will be the better option for younger, healthier patients and stent-grafts the better choice for older patients who have heart or lung disease.

• Angioplasty and stenting of the carotid arteries. Blocked carotid arteries–the main arteries that carry blood from the heart to the brain–are responsible for 20 percent to 30 percent of strokes. Vascular surgeons routinely perform a procedure called carotid endarterectomy in which, with the patient under general anesthesia, they open the carotid arteries and clean them out. More recently, interventional radiologists and cardiologists have begun to do balloon angioplasty and stenting in these arteries while the patient is under sedation. The main risk with both procedures is dislodging a bit of plaque that travels into the brain and causes a stroke. Whether angioplasty and stenting is better or worse than surgery is unclear, and the procedure is controversial. Again, the new procedure may be better suited to some patients–such as those whose blockages occur too far into the brain for surgeons to reach or who have had radiation therapy to the neck–than others.

• Treating chronic pelvic pain (pelvic congestion syndrome) in women. In about half of women who suffer such pain, the culprit is faulty valves in the ovarian veins, resulting in pooling of blood in pelvic-area veins, causing them to swell and become painful–essentially varicose veins in the pelvis. The condition is difficult to diagnose, but when it is suspected, an IR can perform a test to diagnose and treat the problem. Embolization of the abnormal veins with stainless-steel coils is performed, using a catheter placed in another nearby vein. About 80 percent of women who undergo the outpatient procedure have immediate or gradual cessation of their pain.

• Treatment of urethral strictures in men. Some men have a narrowing in the urethra, the long tube leading from the bladder through which they urinate. It's caused by injury, previous surgery, infection or, in older men, enlargement of the prostate gland. Neither surgery nor insertion of a permanent stent to hold the urethra open works well, and usually affected men must have a urologist stretch or dilate the urethra every few months, an unpleasant procedure. Now, a few interventional radiologists are inserting a new temporary stent to relieve the condition. It's intended to be removed every six months and a new one inserted. Results have been encouraging.

• Cancer therapy. Before their surgical removal, colon or other gastrointestinal tract tumors may seed the liver with tumor cells. Surgery may not be a good option for removing these metastases, and systemic chemotherapy often is not effective. However, interventional radiologists can perform "chemoembolization" to treat the tumor, injecting tiny polyvinyl alcohol particles together with an anticancer drug into the blood vessel feeding the tumor. The particles block off the blood vessel and keep the drug concentrated in the tumor. Or, they may inject only the drug into the appropriate artery. Other approaches involve inserting a radiofrequency probe or a laser to "cook" the tumor, or injecting alcohol directly into the tumor to destroy it. With small lesions, cures may result. With more extensive tumors, there may be relief of symptoms and increased survival but no cure.

Such methods are also being used on liver cancers (hepatomas), and to some extent on brain cancers (such as gliomas) or head and neck cancers, where surgery and radiotherapy may have limited benefit and present other problems. In addition, stents may be coated with anti-cancer drugs. According to Lindsay Machan, M.D., of the University of British Columbia, Vancouver, this has helped people with late-stage esophageal cancer continue to eat and swallow. Finally, there is the prospect of using these techniques to directly inject genes into a cancer that will change its course by shutting down blood vessels that feed the tumor.

 

On The Horizon For Men And Women. Among the breakthrough announcements at the recent 84th Scientific Assembly and Annual Meeting of the Radiological Society of North America, two developments in particular offer hope to countless Americans.

• Breast cancers may be treated without surgery. Using magnetic resonance imaging (MRI) to guide a laser, doctors may be able to destroy breast tumors in an outpatient procedure, without an incision of any kind. Although this treatment is in early testing and not yet available, it holds tremendous promise for avoiding disfiguring surgery to treat breast cancer. What's unique in this treatment is "interactive" MRI, which enables doctors to see the edges of a tumor in soft breast tissue. A doctor simply inserts a needle into the tumor, threads a fiber-optic wire through the needle, and ablates the tumor–applies laser heat for about 10 minutes. This destroys the tumor. The procedure was tested by Steven Harms, M.D., professor of radiology and director of imaging research, University of Arkansas for Medical Sciences, and chief of radiology for the Central Arkansas Veterans Healthcare System in Little Rock. All the patients who received the MR-assisted ablation then received conventional treatment, and lumpectomies revealed that the tumors had been entirely destroyed.

• A new treatment for prostate cancer. A technique called Intensity Modulated Radiation Therapy (IMRT) decreases the side effects of traditional therapy and may improve cure rates for prostate cancer, which currently kills some 39,000 men each year. Available in more than 30 medical centers around the country, IMRT uses a sophisticated computer program to accurately pinpoint the cancer and precisely target the radiation treatment without affecting healthy tissue in the bladder and rectum. Two features of the new treatment are key: faster computers and the ability to immobilize patients in a partial "vacuum" box. Computed tomography is used to create a three-dimensional reconstruction of the bladder, rectum and prostate gland. Because the patient is immobilized, a radiation therapist can direct the computer to deliver radiation only to the prostate, meaning higher dosages can be used with fewer side effects than traditional radiation therapy.

• A Web site maintained by the Society of Interventional Radiology (SIR) is a good place to obtain further background information. You can use the site to conduct a search for an interventional radiologist in your area, as well as access a number of online brochures, including one which describes pediatric interventional radiology procedures. Information can be obtained by calling SIR at (800) 488-7284 or contacting them online.

Award-winning science and medical writer Gail McBride was for many years editor of the medical news section of the Journal of the American Medical Association.

This article appeared in the January/February 1999 issue of Consumers Digest Magazine, www.consumersdigest.com, and is reprinted with permission.