Cutting Edge

Minimally invasive procedures mean less pain and faster recovery for many patients.



"Red meat is muscle. Anyone who has ever had a t-bone steak knows how firmly that meat is attached to the bone, and you have to take a knife and carve the meat away."

That's Dr. Kevin T. Foley, a neurosurgeon with Semmes-Murphey Clinic and Methodist University Hospital, and he's not talking about a recent meal. He's discussing the problem that led him and a colleague, Dr. Maurice Smith, to develop the Minimal Exposure Tubular Retractor — METRx for short — a remarkably simple device that allows them to perform minimally invasive spinal surgery.

In the past, surgeries to repair anything from bulging disks to broken vertebrae began by hacking through inches of muscle and tissue. "When we cut the muscle off the bone, it eventually grows back," says Foley, "but it's not the same. The healing process takes a very long time." The METRx not only reduces the muscle damage but offers other, significant benefits as well. It's just one example of the new devices and techniques that allow physicians to treat patients better and faster than in the past.

Here's a look at some cutting-edge technology that almost — but not quite — does away with the scalpel.

BEHIND YOUR BACK

"It's like you've squeezed a jelly doughnut, and some of that jelly comes out through a hole." Foley is using another dramatic food image to convey what happens to patients who have a ruptured disk. When patients are young, fluid-filled disks act as shock absorbers between the bony vertebrae that make up your spine. They compress when you bend, and flex as you twist. As we age, however, that fluid in the "doughnut" dries up, and the disk, says Foley, "can calcify and turn into a rock-like consistency."

Problems occur when small pieces of those "rocks" bulge out or break away entirely and press against the spine and other nerves in your neck and back. The result can be excruciating pain that can radiate down your arms and legs. Sometimes conservative treatments — physical therapy and medication — work, but surgery can be the only answer.

In years past, surgeons made a six-inch incision along the spine, sliced through layers of tissue, and used bulky metal retractors to spread the opening so they could cut away the protruding chunks of disk. The discectomy is a relatively simple procedure in the hands of a skilled surgeon; the main problem is the lengthy recovery time.

"They are still done that way in many places," says Foley. "Patients would remain in the hospital for four to five days, and they would typically be off work for several months." Plus, as with any open surgery, there was the ever-present risk of infection and reliance on pain medications, which can cause addiction and side effects.

About 10 years ago, Foley and Smith realized, "The solution was to make a retractor that was a single unit, and that's where the tube came from, because you can make a tube very thin and small, but make it very strong."

The brilliant simplicity of the METRx system is a series of tubes — plastic, titanium, even carbon fiber depending on the surgery — that fit snugly inside each other ("like those nesting Russian dolls" explains Foley). The procedure begins by making a half-inch slit in the patient's back — the only external cut required here — and then pressing a very small tube down until it reaches the spine. The trick is to insert the tube so that the surgeon is actually pushing aside the muscle fibers, not cutting them. "Needless to say, there's an art to it," says Foley. Another tube is slipped over the first one, then another, and another, until the final tube — which can be 22mm wide for a spinal procedure, or only 14mm for a neck operation — is in place. Then all the inner tubes are pulled out, and the last one serves as a "port" that gives surgeons access to the spine.

"The 'Eureka' moment was when we realized that we could apply the same techniques at the bottom of the tube that we normally used in open surgery," says Foley. "That led to the development of a whole series of specialized tools that allowed us to work through the tube."

After repairing the damaged disk, the surgeon removes the tube, then seals the incision with a few drops of a glue called Dermabond and a Band-Aid. The patient usually goes home that afternoon; in the past, back surgery meant a week in the hospital. Total recovery time is anywhere from one to four weeks, depending on the patient's occupation. An office worker can probably return to work sooner than someone doing construction.

The technique was invented in 1994 and, after the required medical trials, has been used on patients since 1996.

"It has gone from something that was called a niche technique to a procedure that has now been adopted all over the world," says Foley. "This is one of those techniques that, after all these years, has stood the test of time. And it is relatively straightforward. It's technically demanding because you are working in such a confined space, but you don't need a lot of fancy equipment."

Even so, Foley says the procedure took a while to catch on. "In medicine, what we do is tough enough and risky enough that we are reluctant to change our habits, but this is slowly but surely gaining traction." Twenty years ago, when Foley was in training, he says no back surgeries were minimally invasive. By the year 2000, maybe 25 percent were, but the remaining 75 percent were still performed as open surgeries. Today, he estimates that 90 percent of his spinal surgeries can be performed minimally invasively.

Not only are other surgeons learning the technique, but so are patients. "We get patients from all over the world, and this past year we had a drummer from England," says Foley. "He was an active young man and he wanted to get back to his band, so he came to good ole Memphis to have his back surgery done."

And how did this British rocker learn about the procedure? Foley laughs and says, "He found me on YouTube." One of Methodist Hospital's live "webcasts" of Foley's surgery somehow found its way to YouTube. "It's a small world," says the surgeon. "And he's doing great, by the way."

HARD TO DIGEST

Dr. John Cromwell's 17-year-old patient had suffered for years from ulcerative colitis, and his colon was now so ravaged by the disease that the only cure was to remove it entirely.

"A few years ago, no one would have thought to do that laparoscopically" — operating through small incisions and viewing the work through a video system called a laparoscope — "because it's such an enormous procedure. But it's something we do here now on almost a weekly basis."

Cromwell is chief of colon and rectal surgery at UT Medical Group. Sitting in his office in the Medical Center, he explains that minimally invasive surgery began back in the 1980s with gall bladder removal "because of its location and ease of removal. Even then, it was hard to convince surgeons to take it out that way because they didn't realize the benefits."

After all — and Foley made the same point — just because doctors can do something a certain way doesn't mean they should. Minimally invasive surgery leaves a smaller scar, but if the procedure doesn't work as well as traditional open surgery, then the result might be a better-looking corpse. But over time, doctors began to recognize the benefits of laparoscopic surgery to remove small organs like the gall bladder or appendix: less cutting of tissue and blood vessels, shorter stays in the hospital, and quicker recovery.

"The same thing has now happened with the colon," says Cromwell, "but the colon is much more difficult because it occupies all four quadrants of the abdomen, and it's much more variable in anatomy. It's just kind of swimming around in there with the small intestine."

What that means is that surgery on the five-foot-long organ is never standardized. Even the blood supply can be unique. "There's a blood vessel that goes to the colon and sometimes it's not there, or there's a variant and it comes from several places," says Cromwell. "The surgery is very technically demanding."

Beginning several years ago, surgeons began what Cromwell calls a "hybrid" or "hand-assisted" approach. Some of the colon procedures were done through small incisions in the abdomen, but the main operation was still performed by reaching into a large incision cut into the abdomen.

Since coming to Memphis about two years ago, Cromwell and his partner, Dr. Alexander Mathew, have refined that approach. He switches on a laptop and clicks through images showing the surgery he performed on the 17-year-old boy. The process begins by making several half-inch incisions around the abdomen that will serve as access ports for the instruments, camera, and suction tube.

"We obviously can't take the colon out through an incision this small," he says, "so we make a longer incision at the bikini line, and that's where we can remove the entire colon and rectum."

Next, he inserts a tube that fills the abdomen with carbon-dioxide gas, explaining, "If we didn't have that gas in there, the abdominal wall would collapse on the bowels and we wouldn't have space to work."

A restorative proctocolectomy, as this procedure is called, is extremely complicated. The entire colon and rectum are removed, and a pouch is created from a loop in the small intestine, which is then attached to the anus. Though the patient will have to use the bathroom more often, full bowel function is essentially restored, since the main function of the colon is to hold waste and help in the absorption of water.

"After the colon is removed, patients don't require any nutritional supplementation," says Cromwell. "There is no problem with malabsorption of nutrients."

By looking at large color monitors mounted around the operating table, Cromwell works through the ports in the abdomen and begins to cut the diseased colon away from its various attachments — the muscles, blood vessels, and other membranes. He uses an electric cauterizing scalpel to seal off any bleeding vessels, and closes the end of the small intestine with what is essentially a high-tech staple gun.

Cromwell then reaches into the bikini-line incision and tugs out loop after loop of the diseased colon, explaining, "You can see that the pelvis is completely hollow now." After a few more minutes, he says, "The patient, at this stage, is completely cured of his ulcerative colitis."

The patient will have a temporary iliestomy, "where we take the small intestine up to the abdominal wall, and he has to wear a [colostomy] bag for four to six weeks. Then we come back in with a smaller operation, hook the ends together and drop them inside, and restore the normal function."

The complete operation takes almost five hours. "It takes a bit longer than open surgery," says Cromwell, "but the small size of the incisions makes it worthwhile."

Such a complex procedure evolved over time.

"We figured out how to take out the right side of the colon," says Cromwell. "It's the easiest, so we learned to do that very well early on. Next we learned how to remove the left side, and then the transverse colon. Then it was just a culmination — learning how to do all those at the same time."

Surgeons are still learning the benefits of this type of surgery. Less cutting means less pain and a faster recovery time. Far more important, says Cromwell, "is the discovery that there is a 40 to 50 percent reduction in wound infection. Infection rates after colon surgery are fairly high anyway because the colon is full of bacteria, but the rates are quite a bit lower, so it saves the patient a lot of medical issues."

The challenge facing doctors is that this is still a very difficult procedure, one that requires a team approach and a specially equipped operating room.

Most colon surgeries around the country are done by general surgeons, who routinely perform 12 colon surgeries every year. Cromwell has done more than 260, "and my guess is that 50 percent of them were minimally invasive. So these procedures have a steep learning curve, and it takes hundreds of them before you really reach a comfort level doing them, but I think people are coming around to seeing the improvements."

WORKING FROM THE INSIDE

Dr. James Klemis reaches into his desk drawer and pulls out a shiny mesh tube. "You can pull it, twist it, and even tie it in a knot, and it won't break," he says, explaining that it's made of a special alloy called nitinol.

Klemis is an interventional cardiologist with the Stern Cardiovascular Center. Although he is board-certified in five areas of cardiology, his particular specialty is stents — the hollow mesh tubes like the one he demonstrates today.

The thousands of blood vessels that carry oxygen throughout the human body have an unfortunate tendency to clog. Fatty deposits called plaque build up on, and within, the walls of arteries and veins. Over time, these form bulges that can block the flow of blood. Even worse is when one of these bulges ruptures, spilling fragments of plaque into the bloodstream. If the particles block an important artery in a lung, heart, or brain, the result is a heart attack, stroke, or death.

Because plaque is embedded in the wall of an artery, devices developed years ago to "nibble away" at blockages didn't work very well. So physicians began to perfect the procedure known as balloon angioplasty. A thin catheter is threaded up through a large artery in the patient's groin, pushed to the area of blockage, and a tiny balloon at the end is inflated, opening up the artery.

There was still a problem: a condition called restenosis. Within a few months — sometimes as quickly as a few hours — the artery might clamp shut again. So physicians began to place stents in the arteries — hollow mesh tubes that would spring open and keep the blood vessels open.

Although the use of stents is still problematic — some patients tend to form dangerous clots on the stent itself — their use is becoming more common.

"We've gotten to the point where we do very well with preventing heart attacks," says Klemis. "But there hasn't been that much progression with strokes, and to me that's an interesting area. I think in the next 10 to 15 years we're going to come up with interesting and innovative ways to prevent strokes."

Many strokes are caused by plaque in the two carotid arteries in your neck. These and the vertebrobasilar arteries in the back of the head are the primary blood supply for the brain.

"Surgery on the carotids is still the gold standard for treating this disease," says Klemis, "but we offer carotid stenting as a very good alternative to surgery."

Klemis switches on a computer and shows a fluoroscopic image — think of it as a moving x-ray — of carotid stenting. Even to a layman, it's easy to see that one of the arteries in this particular patient's neck — which shows up as a dark "river" on the screen — is pinched off where blockage has formed.

Barely visible on the screen, a thin wire moves inside the artery and carefully pushes through the blockage. The balloon is inflated, the artery opens up, and then the stent is pushed into place, compressed inside a plastic sheath. "When you pull the sheath it expands out and traps all that nasty plaque against the wall," says Klemis. It's quick and effective. Blink too long, and you'll miss the entire procedure.

One issue with angioplasty was the danger of clots breaking off as the doctor pushed the balloon or stent into place. A key development was the use of an embolic protection filter — think of it as a tiny mesh umbrella — that is first threaded into the artery and then popped open "downstream," between the blockage and the brain. The filter catches any stray particles that would cause strokes.

This in itself can be risky, since too many trapped particles can block the blood flow. "One of the things you look at is how long that filter stays in there," says Klemis. "It's recommended that you do this in eight minutes, 10 minutes at the most, and we routinely do it in five. In this kind of thing, the more effectively and quickly you can do a procedure, the better."

So if stents work so well, and the procedure can be done without open surgery, why isn't it done all the time? Well, because of the way their blood vessels may be formed, not every patient is a candidate for stenting.

"There are patients who do well, and certain patients who don't do well," says Klemis. "If you don't select the right patient and you are trying to advance the medical tubes through bends and narrowings that aren't suited for it, you'll cause the plaque to dislodge and cause a stroke."

He shows a detailed angiogram of a patient with a twisting of an area above the heart called the aortic arch, where the major blood vessels branch off to the brain, lungs, and limbs. In angioplasty, the wire holding the balloon, stent, and filter is threaded up through the beating heart, past the valves, and then up into the carotid arteries.

Not in this case. "You would have difficulty getting the devices past here," he says, pointing to a sharp turn in one of the vessels. "This is someone who would not be a good candidate because I would have to push and turn, and this is an aorta with plaque. So I would tell this patient ahead of time that surgery is a better option."

Just this morning, he had to turn a woman down for stenting. "She was upset, but I told her this is just not right. You have to determine what is best for the patient, and her best option is surgery. I have probably sent as many patients for surgery as I have for stenting. The benefit is to give the patient an option if it can be done safely."

Klemis shows other cardiac procedures that can be performed by working inside the arteries, including a remarkable device called a CardioSEAL occluder that can close a hole in the wall of your heart.

"Some 20 percent of the general population are born with a hole in their heart. Some close with time, some stay open, but if the hole remains open a blood clot can form and pass from one side to another. It's still very controversial whether we should even try to fix this, but in the past your only option was open-heart surgery."

Not today. "Now we can go inside the beating heart," says Klemis, who shows a video of the device threaded into the heart and through the hole. A tiny spring-loaded circular disk pops open, sealing one side of the opening. As he slowly pulls the catheter out, another disk pops open on the other side, and the catheter is then completely removed. The whole process takes just a few seconds. "The skin eventually grows completely over it. This has replaced cracking your chest open."

Although watching these procedures usually elicits a "Wow!" from the viewer, Klemis downplays some of the gadgetry involved. "If you can operate your VCR, you can do most of the stuff that we do," he says. "But it's not just the technique, it's the proper selection of the technique, and making sure it's right for that patient."

THE HEART OF THE MATTER

It was originally developed by NASA and then refined for military use, but today the da Vinci Surgical System — usually referred to as the "robot" — is used at Baptist Memorial Hospital and Methodist University Hospital to help surgeons perform an astonishing range of complex procedures — from removing diseased prostate glands to repairing damaged heart valves.

In the special da Vinci operating room, the surgeon sits at a computer console, peers through binocular viewers that provide a clear, three-dimensional view, and with hand controls and foot pedals guides remote-controlled arms that are inserted into the patient through small incisions. Other members of the operating team switch out different "arms" on the robot and monitor the patient.

"The robot is particularly well-suited to repairing the mitral valve," says Dr. Edward Garrett, a cardiovascular surgeon with Baptist Hospital. "It not only gives you magnification, but its range of motion is greater than the range of motion of your wrist. It is probably easier to repair the mitral valve with the robot than with an open procedure because the technology gives you better dexterity and better visualization."

The only thing lacking with the robot is a sense of touch, and Garrett explains, "Part of the learning curve is to learn the visual cues for tension" — when making stitches, for example — "because you don't have that feel. But every other aspect of it is superior."

The mitral valve is a complex structure that separates the top and bottom chambers of your heart. The valve, composed of overlapping leaflets held in place with fibrous cords, can become damaged by disease, stretched with age, or hardened with atherosclerosis. In the past, the only solution was replacing it with an artificial valve, which required patients to take blood thinners for the rest of their lives because clots tended to form on the new valve.

"There are now four to five repair techniques that are known to be durable," says Garrett, "and repairing the valve is much better because it doesn't require opening the chest." Using the robot, mitral valve surgery is performed through a small incision made in the side of the rib cage. "In open surgery, where we open the chest, it usually takes about three months for the bone to heal, with restricted activity after that. Minimally invasive cardiac procedures often allow an immediate return to normal activity."

Other minimally invasive heart procedures are being developed, but the American Heart Association recently issued an alert, advising that two bypass procedures — one called a PortCAB, the other a MIDCAB — "appear promising but need more study to examine the short- and long-term benefits." The AHA concluded, "Neither procedure can be given an unqualified endorsement at this time."

"There are other heart surgeons around the country who are attempting to do coronary bypass robotically," says Garrett. "But we don't do them here. I think it will happen someday, but I would consider it experimental at this point."

Garrett and other surgeons at Baptist and Methodist also have used the da Vinci device to perform minimally invasive major surgeries on lungs, including lobectomies — the complete removal of one of the five lobes of the lungs.

"Taking the lung out for cancer is a well-suited procedure," says Garrett. "The chest, since it's a rigid structure, gives you space for the robot to work well. And instead of working with long laparoscopic instruments, with the robot it is like miniaturizing your hand and putting it in there."

Garrett says that surgeons at Baptist have performed more than 50 lobectomies and 35 mitral valve repairs since acquiring the da Vinci machine in 2004. Other minimally invasive procedures are being perfected, including bypass surgery for the femoral arteries that branch off from the aorta to feed blood to the legs.

"It's amazing what has happened so far," he says, "and we can look for it to continue to progress."

SUPER POWERS

Some medical procedures don't require a scalpel at all.

Dr. Michael Farmer, a radiation oncologist with Methodist Hospital, recently removed a large spinal tumor from a patient using a process called "stereotactic body radiation."

Stereotactic simply means that "we register the patient to the table very precisely in three-dimensional space." The patient lies on a vacuum-operated "bean bag" that keeps him or her completely immobile during the procedure. For radiation therapy involving the head or neck, a mask of coated nylon mesh is draped over the patient's face. The mesh hardens and is then clamped to the table; because the patient can see through it, there's no sense of claustrophobia.

Immobility is very important because "zapping" a spinal tumor with radiation requires extremely close tolerances. "The accuracy is down to the width of three sheets of paper," says Farmer, so there's little margin for error. "It depends on what is in the way. If I kill a couple of centimeters of normal lung, you'll never know it. But if I kill a quarter-centimeter of spinal tissue, well, you're going to be pretty mad at me."

Farmer uses a Siemens linear accelerator to blast tumors with extremely high doses of radiation. "It's sort of like the microwave you have at home," he says, "except that might be 3,000 kilovolts, and this is more like 30 million."

Because of the immense power of the equipment, the protocol for radiation treatment is changing. "Before, the standard was 35 treatments of two 'grey' — that's a term that refers to the amount of absorbed radiation. But the stereotactic treatment is just three treatments of 20 grey — about ten times the regular dose."

Advanced computer equipment also allows Farmer to aim the rays precisely, avoid adjacent organs, and even bend them around corners. He shows an MRI scan of a patient with a massive tumor on the front of his spine. In the past, this might have been a hopeless case. "Taking this out would have required a posterior and an anterior approach," he says. "There's the heart right there, and you'd have to move that out of the way. No one would ever do that; it's just too much surgery."

The new approach allowed him to reach the tumor with radiation.

Contrary to popular belief, radiation doesn't kill tumors. "It damages the DNA of cancer cells," Farmer says. "Cancer cells have a diminished capacity to repair any damage, compared to normal tissue. So they eventually die away, and the tumor is absorbed by the body's own immune system."

Planning is everything in radiation treatment. Farmer uses multiple scans to determine the exact location of a tumor — whether it's on the spine, kidney, lung, or any organ — and then uses a sophisticated computer program to aim the Siemens device. Once the patient is locked into place, "I use the computer to make sure that what I think I'm doing is exactly what I am doing. The planning scan and the actual scan must overlap."

The stereotactic procedure is gaining popularity within the medical field. "In the last year, the number of these procedures has increased 300 percent," says Farmer, "and I expect that number to rise." Looking around the large operating room, tucked away behind foot-thick doors in the basement of Methodist University Hospital to confine the radiation, he sums it up: "It's pretty amazing, really." 

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