Robot-Assisted, Minimally-Invasive Surgery to Repair Mitral Valve Prolapse (MVP)

I seem to have a badly leaking valve in my heart and need to undergo open-heart surgery to repair the problem. While I don’t seem to exhibit any real symptoms, given another year or so I might have significant and possibly irreversible problems. With a repair, I should be good as new.

Technically I have Mitral Valve Prolapse (MVP). From high school biology, you’ll remember that the left ventricle pumps blood rich in oxygen into the aorta and onward to the rest of the body through a vast system of arteries. The left atrium pulls blood from the lungs, freshly loaded with oxygen. The mitral valve keeps the blood flowing from the left atrium to the left ventricle. When the valve leaks blood back upstream, some of the work of the heart muscle is wasted, diminishing the flow down the arteries. A nice animation of the heart pumping can be viewed at the Links but a good illustration is below.

The heart does whatever is necessary to keep the body fed, so over time the ventricle enlarges to compensate for the lost flow. cutaway illustration of the heart Meantime the upstream atrium is getting more pressure than it should, causing it to also enlarge as a balloon would. Blood can even back up into the lungs in severe cases. These enlargements are the ultimate problem, because beyond some critical point the heart tissue is over-extended and cannot reduce to its original size even if the valve is corrected, leading to long term problems that I don’t know.

Symptoms of the leaky valve include shortness of breath and just plain being short of energy, possibly fainting. But since the body compensates in so many ways, these may not be immediately obvious. Except for the one fainting episode, I never have experienced any of the symptoms. In fact most weekends I ride my bike 25-40 miles or up and down hills on the trails in the 100° heat. This is good since it put me in good aerobic health. The doctors like this.

The mitral valve gets its name from its resemblance to a bishop’s tall hat or miter, and consists of two triangular leaflets. It is sometimes called the bicuspid valve. faulty mitral valve The bad valve is considered to be "prolapsed" or floppy, which can be caused by the two leaflets not meeting neatly, sometimes due to the old rheumatic fever, sometimes you are born with it that way.

Special cords (technically called "chordae" but sometimes thought of as "heart strings") are supposed to hold the valve halves in closed position, the way cords must hold a parachute in place to catch air. A muscle at the other end of the chordae quivers perfectly timed when the heart pumps to aid the process. If too many of the dozen or so chordae break or disease deforms the tissue, the valve is compromised.

The blood leaking severely back through the valve into the left atrium is regurgitating, and makes a rushing sound much like the turbulence of a river going over rapids. This noise is what is called a heart murmur, a pleasant-enough-sounding term that most people wouldn’t worry about. If it’s loud enough, however, a trained physician considers a murmur to be a warning. A nice little brochure given to me by a doctor assures the reader that a heart murmur or mitral valve prolapse is rarely a concern to most people, and less so to men. Apparently my heart hadn’t read that brochure.

Interestingly, around the mitral valve where that backwash occurs in the atrium is a highly oxygen-rich environment, and such patients must be given an antibiotic prior to certain "dirty" procedures from getting your teeth cleaned at the dentist, and even just flossing, to having a colonoscopy. Such procedures open the bloodstream to bacteria- and viral-laden matter that can settle and flourish around the faulty valve where steady flow no longer flushes the area. Here it can take weeks for antibiotics to suppress an infection, rather than a couple of days in more typical locations. Therefore, a person with MVP takes an antibiotic before teeth cleaning and various other procedures – an ounce of prevention. Actually, after surgical treatment for MVP, you still take this antibiotic precaution when you go to the dentist and such.

Fix Me Up, Doc

The corrective action for a severe MVP is pretty serious. Generally it is open-heart surgery, something only available in the last 25 years. While a very common operation now (70,000 done a year), it is not trivial. After all, the valve is inside the heart, a pretty critical organ of the body. Think about it – the heart starts beating before birth and doesn’t stop until death. Repairing this never-resting organ is pretty amazing. There’s nothing simple about any open-heart surgery.

Typically open-heart surgery involves cutting the sternum and lifting the ribs so the surgeon can open up "the hood" and get direct access to the heart. There’s obviously a lot of trauma with that, with some clues evident when they talk about sewing the bones back together with stainless steel "thread". People go through this all the time for all kinds of heart surgery and I’m sure various lung ailments and other treatments, but even a bad day at the office sounds more fun than this.

Once inside, the doctors completely stop the heart (with great cold and some potassium-rich drug) during the crucial work and you are on a heart-lung machine that oxygenates and circulates your blood while the heart is "out of the circuit" being worked on. This is very critical, and one of the measures of such a surgery is the "pump time" – how long the heart-lung machine is keeping you alive.

The surgeon must go through the heart wall to get to the valve, trim up the tissue so the two halves mate well, and reattach or reallocate broken chordae. This is the art of surgery and requires tremendous knowledge, care, and skill. The final configuration is tested to assure the valve isn’t still leaking before they stitch up the heart wall, and a few minutes later they restart the heart to beat endlessly for the rest of your life – no time for things to heal before they have to work full-strength again. I think it’s kind of funny that they lay down some pacemaker wires as they’re closing you up – though I think these are removed a few days later – I imagine them bringing in a car battery to jump-start you again.

Again, this stuff is pretty involved, although it is done every day by well-trained surgeons. However, my wife Jan had scrounged around the web and found that there are maybe 4 levels of alternatives available with regards to accessing the heart. The full sternotomy is where they cut through most of your sternum with an 8-10" cut and go in.

There’s a smaller technique where they can maybe cut four ribs and get adequate access. Then there is a minimally invasive approach where they go in with endoscopic utensils and optics through very small holes between the ribs and do the work. The most exotic approach is robotically-assisted minimally invasive where the surgeon’s hands aren’t even near your body. I am intending to make use of this last approach.

Robotically-Assisted Minimally Invasive Surgery (MIS)

In this most advanced procedure, the surgeon sits at a console directing a robotic machine while intently watching in 3-D with a camera in the drained heart. The machine mimics his hand motions on a much smaller scale (as much as 8:1 reduction), some distance away, inside your body, manipulating tiny tools on the endoscopic arms.

While I expect to be able to take advantage of the most advanced techniques, should the doctor need to back away and go with a more traditional approach, I figure Dr. Chitwood has the experience to do that as well, evaluating all of the trade-offs. If I come out with a zipper from stem to sternum, I want to know they tried their best to do the job with the tiny cuts first. But I also want to know he is well-practiced in the fallback procedure, too.

To provide a reference point, Dr. Chitwood had performed about 85 of these robotically-assisted MVP surgeries (at the time of mine), 350 minimally-invasive procedures before this machine was available or where it isn't appropriate, and numerous full sternotomies where those were required. Apparently he needed a full sternotomy himself so he knows both sides of that procedure. Maybe a dozen surgeons in the world perform this advanced robotically-assisted version of the surgery, pioneered by Dr. Chitwood.

Dr. Chitwood led the clinical trials for FDA approval of the da Vinci® machine made by Intuitive Surgical for use in mitral valve repair. Dr. Chitwood has performed more robotic-assisted MVP repairs himself than anyone else. It seems if you want to perform this surgery with the robotic assist, you get the machine from Intuitive Surgical as well as the baseline training on how to use the instrument. Then you get specific training for the surgical procedure you want to perform from a specialist in that field. Dr. Chitwood trains all the other surgeons on how to perform mitral valve repair using the da Vinci equipment. More on that later.

Though he has demonstrated to a couple surgeons in Texas, so far nobody in the state performs the minimally invasive, let alone the robot-assisted surgery. I think some of the doctors I’ve talked to think I’m a little nuts. But they know of Chitwood and his work.

Even an endoscopic hand surgeon that fixed up my wife’s broken finger was glad to hear I was going to try a endoscopic approach because he struggles convincing other doctors and patients that the smaller instruments and cuts allow just as good a work to be done. The tried and true seems to dominate the thought processes in the medical world. Generally, that’s good, mind you. But I’m fairly confident that there is minimal additional risk and significant greater comfort in the minimally invasive technique.

Got a Map?

Before the MVP repair work, the surgeon needs a mapping of what he’s getting into. Everybody (every_body) is different, and you don’t want to get surprised if you can avoid it. Also, like with an automobile, if you’re going deep to repair something, if you can fix up a couple of other things while you’re in there, you might as well optimize your time. So a cardiac catheterization is requested before the MVP surgery.

I don’t know if it’s less squeamish than the more familiar kind of catheter, but here they run a tiny plastic tube (the catheter) in an artery (and another in a vein) and run it up to your heart. my "cath"
This is an amazing process in itself. I can hardly fish telephone wire up the wall from between the studs. And speaking of studs, they start this catheter where the arteries are handy, down at the groin, so they’re pushing 3 feet of tube to reach the heart!

So why all the fishing around? With some sonic imaging type of machine watching, they can tell when they’ve got the catheter poised at the exit of the heart. Then they pump the slightest bit of iodine into the tube. The iodine is pretty dense so as it comes out the end of the tube they can see it disperse. They kindly refer to the iodine as "color" since they don’t like to use the word "dye" (die) when discussing patient’s hearts.

One thing they are doing is mapping the arteries that feed blood to they heart muscle itself. You don’t want to cut into one of these just because it isn’t where you think it should be. Also, these are the arteries that cause a heart attack if they can’t provide enough blood to the heart and the muscle starves out for oxygen. So they want to know that the arteries are clear. They can tap a little iodine into the arteries on the heart surface to see where they all are. They can also see if there are restrictions in these arteries to heart – the evil plaque build up due to all that chocolate, fried chicken, and butter. If you’ve got clogged arteries of the heart they had better prepare to clean those out while they’re in there. Mine were just fine, I’m happy to say, so pass me the Ben & Jerry’s.

They are also able to push the catheter a little farther, into my heart and show that the iodine was backwashing into the left atrium through the mitral valve. Rats. More confirmation. However, while in there they can also get highly precise measurements of the pressure in the heart chambers – none of this cuff on the arm 12" away stuff – we’re talking live, dead-center of the heart millimeters of mercury! By the way, the whole time this was taking place, I was awake and alert, watching it all on the monitor with the doctor, discussing what was going on (and chatting about the bicycle rides he also takes!)

What Next?

So, I’m all set up now. I have great labs (blood tests show right-on normal), clean arteries, great blood pressure and pulse and circulation, and in great health. I just happen to have this sloppy valve and a heart that’s 50% too big (contrary to popular opinion). But I’m a great candidate for this fancy surgery to fix things.

North Carolina is farther to drive than I’d like, but airplanes get within 100 miles. The average stay at the hospital is a little over 3 days (!), which makes the insurance people happy, but the heck with them, I think it’ll make me happy. If you’re still OK a week later, then you can wander on home for final healing. Your wife has to tend to you and put up with you more than she’d like but she may see some benefit to having you around a few years longer too.

From what I can tell, there’s a good chance this is the only surgery like this that I’ll ever need. While, frankly, there isn’t enough data to go on for the robot-assisted, minimally-invasive MVP surgery, it isn’t terribly different from the traditional approach, and they haven’t lost anyone from it yet. Some clotting could cause a stroke but that isn’t much different from any open-heart surgery.

Anesthesia is always risky, but you’re hopefully cutting down dramatically on exposure to the ugly environment with the smaller cuts, and less trauma to muscle, tissue and bones. Less than 20% of the time do patients require transfusion to top up for blood loss. I’m as healthy as they get so it’s far better to do this now than when I’m 10 years older. I’ll have to spend my 49th birthday in the Intensive Care Unit, but if you were a betting mathematician, you’d know that 7 x 7 = 49 so I’ll have a multitude of luck going my way.

But you have to remember, all these guys can do is put me back where I was. They may fix my heart back to being the fine machine it once was. And you know how kind, generous, and loving I am. They can’t improve that mythical aspect of the heart, so I’m not likely to come out like Mother Teresa. So don’t get your hopes too high.

Cheers for now, Tom

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The surgeon has better dexterity than large fingers normally could manage (though I think these guys thread needles with garden twine in their sleep) giving him much more precise control of his work (her too). I liken the robotic-assisted part to the earlier remote rear-view mirror adjuster on the car where there was a packet of cables snaking to the outside, vs. the new electric motor-controlled ones.

Robotic minimally-invasive surgery is performed without disturbing the rib cage, utilizing only three small (1 cm, ½") holes ("ports") and one larger (5 cm, 2") incision between the ribs, where the surgeon’s instruments snake in, plus the camera and the heart-lung machine connections. That sounds a whole lot easier on me. Indeed, this robotically-assisted minimally-invasive surgery is hardest on the surgeon with more time taken feeding instruments down these tubes rather than just laying them in an open rib cage, although his vision of what he’s doing is enhanced using the computer-based system. So, there appears to be a longer "pump time" on this type of surgery and the surgeon has longer concentration to deal with.

Other advantages of using the computer-controlled machine are a close-up 3-dimensional view of the operation. Additionally, the surgeon’s motions are translated to a much smaller scale (8:1) adding greatly to precision. Digital signal processors even remove the natural tremor (maybe 8 Hz) from the surgeon’s hand, inherent in the human central nervous system. The computer can remember both specific positions and hold them as well as paths to move from position A to position B.

By pure odd coincidence, earlier this year I ran into a design engineer from the company (Intuitive Surgical) that makes the robotic surgery machine at an electronics conference and I talked his ear off to get comfortable with the technology.

What’s with the Beard?

And how did all of this come about? One weekend at the end of March I was feeling poorly so I took a nap, ate lunch, and took a shower. S Scruffy Face omehow I fell and cut my chin. I made Jan take me to get stitches (after all, this was my pretty face we’re talking about). At the emergency room they weren’t at all concerned about my split chin, but focused on why I fell.

My pulse and blood pressure were right on, but they didn’t like the murmur, so when I couldn’t come up with a reason for falling, they figured I had fainted, if ever so briefly (the pain in my chin quickly brought me around). They hooked me up for an EKG and sent me to a cardiologist. They did finally stitch the cut in my chin closed.

So now with these stitches in my chin, my shaving had to take a back seat. A couple weeks into this, Jan actually looked at me (after 20 years of marriage, I wonder if she ever still looks at me) and said "hey, that beard looks kind of neat!" and she had that special look in her eye. So, like a schoolboy hoping to get a little extra attention from a girl, that was all the encouragement I needed. Even though Jan had never before liked facial hair on me and it’s a real nuisance to trim up, I thought I’d keep the Van Dyke. I guess the beard became the badge of my defect. Since my "getting lucky" didn’t live up to its promise, I decided to lose the beard once I got myself fixed – that is, got my heart fixed.

Draw me a Picture

The cardiologist asked for a sonogram, just like they do when you’re pregnant (you, not me). Watching my heart on this, they figured I had this leaky valve. It’s pretty cool to see your own heart beat in real-time, watching all the parts pulse and flap. For a better look they later give you a TransEsophageal Echocardiogram (TEE), an "echo", where they put a sonic imager down your throat and beam it toward the heart. Apparently your heart is right next to your esophagus and they can get a clear picture of the heart in action without all the dense bones and stuff in the way.

You end up with a Doppler picture that shows with color how much flow you have in all the chambers. It is kind of like the weather radar (upper image, with lots of green) but instead of density of moisture, the color shows flow. In my case (lower image, dark kidney shape is the left ventricle) the colors highlight the backwash into the atrium when the heavy pumping is going on in the ventricle, and that’s what’s wrong. stormy atrium The TEE is the definitive tool for confirming the faulty valve. I suppose the proximity of the heart to the esophagus explains your feeling "heart-burn" when acid from your stomach backs up into your esophagus a bit – it’s right in the same spot.

There are three options for a bad valve. The best is repairing the original valve. Fix what you have. This is part of your body and while not perfect, it is native tissue. Should the original valve not be repairable, then a substitute made of pig or cow tissue can be used. Since that would be non-native organic material, the patient has to take drugs to suppress rejection of the foreign material the rest of his life.

The other choice is to use a mechanical valve, something like a ball in a cage and other designs (probably a million of these have been implanted over the years). Blood thinners (anticoagulants – coumadin) are needed to keep man-made valves from accumulating crud (not a technical term) the rest of your life, the mechanical clicking can be heard every time the valve shuts, and the sharpness with which the mechanical valve shuts will be very different from nature’s valve closing. Generally, you want to try to use your original parts as much as possible. There’s no reason to think that my tissue is particularly bad but there are a number of the chordae that will need to be reattached. Other people may not be so lucky.

Decisions. Size Matters

I was quickly fascinated by the minimally-invasive procedures, especially the robot-assisted version. I discussed options with a number of cardiologists, most of whom virtually say "I’d just go with the sternotomy – it’s very routine and very successful." Jan found this robotically-assisted procedure by browsing the web. After much searching it became clear that there was one surgeon driving this approach.

Numerous discussions of minimally-invasive mitral valve repair eventually refer to the work of Dr. Randolph Chitwood. He is the outstanding surgeon in this field. Advancing the surgical procedures and becoming proficient in the use of the machinery for this exact repair is what put him on my target list.