Domo Arigato, Mr. Roboto?

Everything old is new again. However, what do you do when what’s new again is a surgery that most patients really, really, really want to avoid?

The “old”—coronary artery bypass graft surgery (CABG)—has remained the gold standard for three-vessel or left main coronary artery disease. Now it may be reasserting its authority for multivessel disease period, according to the ASCERT trial.

Recently, investigators conducted an analysis of health outcomes for about 190,000 patients across the United States using a large PCI registry and a large CABG registry with all data linked to Medicare claims records. In patients with multivessel disease that could be managed on a non-emergency basis, CABG surgery was associated with better long-term survival than PCI. Specifically, among Medicare patients 65 years of age or older, there was no significant difference in short-term mortality, but at 4 years mortality was significantly lower in the CABG group (16.4% vs. 20.8% in the PCI group; risk ratio = 0.79). The results were similar in all subgroups and survival was better following CABG, even among patients whose propensity scores were most consistent with selection for PCI.

Data certainly suggest long-term benefits associated with CABG. One teensy little problem: patients don’t like having their chest cracked open. Consequently, many patients with severe multivessel disease will choose PCI over what marketing tries to avoid calling open-heart surgery. Wouldn’t it be better if there was a way to gain the benefits of bypass surgery with the advantages of NOT having to separate the sternum and ribcage, stop the heart, or use a heart-lung machine?

This future is now, thanks to robotic technology and hybrid operating rooms. However, unlike other areas of medicine, robots have had a harder time getting a foothold in cardiology. It’s kind of like those personal jet-packs promised as our main mode of transportation back in the 1960s for use—oh, right about now—or those flying cars from “The Jetsons:” gee whiz, why doesn’t everybody have one?
Although robotic procedures in cardiac revascularization have been slow to catch on for various reasons, including longer procedure time, demanding training, and high learning curve, robotics are definitely making inroads in the cardiac arena. Although the jury may still be out on the ultimate fate of robotics, more and more procedures are testing their use including minimally invasive direct coronary artery bypass (MIDCAB), totally endoscopic coronary artery bypass (TECAB), and now, the use of robotics to assist in PCI.

CardioSource WorldNews jumped on a hoverboard to find out where things stand now, and what the future holds for robotic systems in the cardiac operating room.

Totally Endoscopic, Dude

Similar to the Hippocratic oath of “first, do no harm,” the first of the three laws of robots says a robot may not injure a human being or allow him to come to harm through inaction. The incorporation of robotics into cardiac surgery is attempting to do just that, minimize harm while maximizing benefit.

At its most basic level, one of the main appeals of MIDCAB is avoiding having to perform a median sternotomy to access the heart, meaning no 6-inch scar for the patient. Instead, in these procedures, a lateral incision is made for a robot to harvest the left interior mammary artery (LIMA). However, the remainder of the surgery, tying the LIMA to the left anterior descending (LAD) coronary artery, is still performed by good old-fashioned hands.

MIDCAB is an appropriate name, with almost a visual reminder that the procedure is ‘mid’-way between the traditional open-heart CABG and the state-of-the art totally endoscopic coronary artery bypass, more commonly referred to as TECAB. Now about 10 years old, TECAB started in single bypass procedures, but, as a tween, has evolved to include double bypass and multivessel disease. The procedure is accomplished with the aid of what can only be described as a somewhat frightening, multi-armed spider-like robot controlled by the surgeon sitting in a console that rivals those seen in The Matrix.

“Among the main advantages of TECAB is that the operation is performed through tiny portholes, which keep the breast bone completely intact,” said Johannes Bonatti, MD, chairman, thoracic and cardiovascular surgery, Cleveland Clinic Abu Dhabi, United Arab Emirates. In the alternate universe of TECAB—almost like a scene from Innerspace—surgeons plunge themselves into the surgical field via
3D binoculars on the surgical console. “I am completely immersed into the operative field and have up to 10-fold magnification. I can see details that I could not appreciate with regular loop magnification.”

In addition, TECAB can be particularly advantageous in morbidly obese patients as some surgeons hesitate to use two internal mammary arteries during sternotomy because of wound healing problems, according to Dr. Bonatti, who is among the more experienced surgeons in cardiac robotic techniques having completed more than 500 robotic CABG procedures. The reduction in surgical trauma also allows earlier return to normal activities.

More Tea, Cabbage; Less Red Meat

Although the differing opinions about the use of robotics in cardiac surgery have not quite reached the level of the war between man and machine depicted in science fiction, there is definitely a split in the field. Unfortunately, we currently lack enough data to draw any direct comparisons between TECAB and traditional procedures, but that is not the goal of surgeons performing the procedure. At least for now, outcomes that are equivalent to traditional CABG, with the addition of improved recovery time, are enough to keep people interested in seeing the procedure gain increased attention.

Although Dr. Bonatti estimates only about 10 to 15 centers do the procedure, interest is growing. At a master TECAB class at the last meeting of the International Society for Minimally Invasive Cardiothoracic Surgery, approximately 100 people packed the room to learn about the procedure.

As interest grows, training of young “grasshoppers” becomes a priority. In 2009, Dr. Bonatti was part of a study published in the Annals of Thoracic Surgery that assessed surgical trainees’ performance in a stepwise introduction to TECAB procedures. The study evaluated two surgeons who performed portions of TECAB operations including LIMA and right interior mammary anterior (RIMA) harvesting, lipectomy, pericardiotomy, and internal mammary artery to LAD anastomotic suturing.

Although results showed that trainees were initially significantly slower in the performance of most of these steps compared with their trainers, by the time the trainees were senior surgeons performing the procedures independently, their timing was within the limits expected for the procedure.

Best of Both Worlds

Although not yet equipped with floating operating tables or Star Trek’s tricorders, these hybrids combine the technology and equipment of operating rooms and cath labs into one all-inclusive suite, enabling patients to undergo procedures that combine traditional, keyhole, or robotically-assisted surgeries with coronary stenting (see SIDEBAR). These hybrid procedures seem especially beneficial in patients with multivessel disease.

“They have found that the longevity of bypass is totally written on how well the LIMA to LAD does, and we would often, 10 years later, get patients back and all the vein grafts are closed but the LIMA is still going strong,” said Molly Szerlip, MD, an interventional cardiologist with the University of Arizona, who is familiar with working in a hybrid operating room environment. “Similarly, we found that, over time, stents would get occluded and people would need to have repeat procedures.”

Instead, hybrid approaches combine the best of both worlds so patients can get the LIMA to the LAD in a minimally invasive approach, and receive stents where traditionally they might have received vein grafts.

Dr. Szerlip was part of a group of researchers who presented data discussing hybrid robotic coronary revascularization in the treatment of multivessel disease in May at The Society for Cardiovascular Angiography and Interventions (SCAI) 2012 Scientific Session in Las Vegas. In the study, researchers followed 32 patients for 1 year after undergoing a hybrid revascularization procedure using robotic assistance for LIMA harvesting and mini-thoracotomy for distal anastomosis.

Results indicated that after 1 year, patients who underwent these procedures were 16% less likely to die or experience major complications when compared with outcomes expected in patients who had undergone conventional sternotomy. By 1 month post-procedure, patients were back to pre-surgical activity levels.

Lending a Third Hand

Hybrid procedures could have another arm added to their armamentarium in coming years with the advent of robotically-assisted PCI procedures. Although not commercially available, clinical trials are currently testing the use of robotics in the cath lab.

Unlike robotics in coronary artery bypass procedures, the robotics being tested in PCI change little about the procedure, but instead allow physicians to more efficiently deliver guide wires and devices down the coronary artery, according to George Vetrovec, MD, professor of medicine and director of the adult cardiac catheterization laboratory at Virginia Commonwealth University.

Dr. Vetrovec has been involved in evaluating the Corindus CorPath 200 robotic system, which has a robotic arm mounted to the patient’s bed, controlled by the interventional cardiologist several feet away in a cockpit where they manipulate the arm during stent or balloon placement. Similar to R2D2 navigating for Luke Skywalker, the robotic arm controls the guide wire during the procedure, virtually eliminating movement of the wire mid-procedure.

“The concept is that the robot can make the procedure quicker and safer for the patient, possibly saving on contrast dye and reducing the amount of radiation to the patient,” Dr. Vetrovec said. “For the operator, you can markedly reduce radiation exposure by being shielded in the cockpit and reduce back strain by not wearing lead.”

The results of the first large clinical trial testing the CorPath, the PRECISE (CorPath Percutaneous Robotically-Enhance Coronary Intervention Study) study, were presented at SCAI in May. The study looked at the use of robotically enhanced PCI in 164 patients across nine test sites. In 98.8% of cases, the PCI was successfully completed without bailout to manual procedures. In addition, results indicated that physician exposure to radiation was reduced by 98.2%.

While the system’s cost is still unknown, Dr. Vetrovec believes that potential cost savings will be apparent with the use of less contrast and, potentially, fewer hospital stays due to kidney damage. More accurate procedures may lead to a cost savings on stents, as well.

“When you look at a flat picture of curvy arteries you can misjudge how long of a stent you need and put in a stent that is too short, forcing you to use a second stent,” he said. “That adds time and there is some evidence that there is a chance that the blockage can come back because you have to overlap the stents.”

The robotic system can give the operator information that human operators cannot get just by looking. For example, Dr. Vetrovec noted that if “the guide wire starts to come out and cross the blockage, you can push a button that marks point zero and it tracks the distance that the wire traverses so that when you get past the blockage you click again and it tells you the exact length of the stent that you need.”

In fact, this additional assistance means that the system could be employed by low-volume PCI hospitals and interventional cardiologists, potentially improving outcomes where a lack of experience due to volume may exist.

Deus Ex Machina?

The final answer of whether robotics will continue to have a role in cardiac revascularization procedures may come with time as more trials are conducted to analyze outcomes of the procedures alone and compared to traditional procedures. Knowledge about what gives the best results for patients will ultimately guide practice.

“If you have two procedures that give equal results, the patient will choose quicker recovery and less discomfort,” stressed James B. McClurken, MD, professor of surgery and director of cardiothoracic perioperative services at Temple University School of Medicine in Philadelphia. “But it is important to remember that for many subsets of patients, especially younger patients who may have a long life otherwise, it is not a minor issue to think about repeat revascularization issues.”

Questions about viability and longevity of stents and grafts will continue to come into play as the cardiac community begins to answer questions about the variety of revascularization procedures, robotic or otherwise. However, Dr. McClurken doubts that robotics will become a victim of the Wayback Machine as another interesting fad, like other “innovations.” Slowly, a learning curve and benchmarking for robotic procedures are being established, helping new technicians to know if they are on the curve or off it, and whether additional training and simulation practice is needed. This will only help to legitimize these procedures moving forward.

“As we progress more and more to less invasive everything in medicine, I think robotic surgery will continue to become a durable option for certain subsets of coronary artery disease and certain types of patients,” Dr. McClurken said.

Dr. Bonatti agreed, pointing out that almost all surgical disciplines have successfully developed endoscopic procedures. “If you look at the success of robotic surgery in urology and gynecology, where these procedures are booming, I see no reason why heart surgeons, with time, should not develop the same level of application of robotic techniques,” he said.—by Leah Lawrence

References

  • Weintraub WS, et al. N Engl J Med. 2012;366:1467-76.
  • Bhatnagar S, et al. Presented at: Society for Cardiovascular Angiography and Intervention 2012 Scientific Sessions; May 10, 2012; Las Vegas, NV.
  • Corindus Vascular Robots. http://www.corindus.com/Default.aspx. Accessed July 14, 2012.
  • Hillis LD, et al. J Am Coll Cardiol. 2011; doi: 10.1016/j.jacc.2011.08.009.
  • Levine GN, et al. J Am Coll Cardiol. 2011; doi:10.1016/j.jacc.2011.08.007.
  • Schachner T, et al. Ann Thorac Surg. 2009;88;523-8.
  • Society of Coronary Angiography and Intervention. Hybrid procedure offers heart patients best of both worlds [press release]. May 10, 2012. http://www.scai.org/Press/detail.aspx?cid=48d3cfeb-fa7e-4083-bde1-fd3326576395. Accessed July 14, 2012.
  • Society of Coronary Angiography and Intervention. Study shows robotically enhanced PCI is safe and feasible for many patients [press release]. May 10, 2012. http://www.scai.org/Press/detail.aspx?cid=fb016ba1-2b7c-4c9d-a40f-d6087dc622ff. Accessed July 14, 2012.
  • Weisz G. Presented at: Society for Cardiovascular Angiography and Intervention 2012 Scientific Sessions; May 10, 2012; Las Vegas, NV.

SIDEBAR

Pimp My OR: Hybrid OR Suites Combine the Latest and Greatest Technologies
Hybrid OR suites “beam up” patients from the OR to the cath lab and vice versa

It seems so obvious now that hospitals have them, but pioneering inventions always appear that way in hindsight. A relatively simple idea, the hybrid operating suite combines the tools and technology of the operating room and the cath lab into an all-in-one, do-all-your-patient’s-procedures-at-once suite.

Although a relatively new concept in the cardiology field, a hybrid operating suite could have been built 25 or 30 years ago, according to John G. Byrne, MD, chairman, department of cardiac surgery at Vanderbilt University Medical Center. “All you are doing is putting a cath lab camera in an OR, or an OR in a cath lab,” Dr. Byrne said. “It could have been done in 1982.”

Instead, in 2005, Vanderbilt University Medical Center was among the first medical centers in the United States to build a hybrid operating suite. Today, moving beyond a mere mash-up of cath labs and ORs, these suites can range in cost from $3 million to $9 million, depending on whether or not the room incorporates robotics and the variety of equipment included when all is said and done.

A Tech Store on Steroids

The health care professionals using these suites must move as if performing a choreographed dance. With a team that includes surgeons, nurses, anesthesiologists, interventional cardiologists, and technicians, these suites must be large, easy-to-use, and adaptable to the changing conditions of each patient’s case. Industry leaders such as Philips, Siemens, and GE Healthcare are all re-thinking their medical technology to create new and advanced equipment for use in these innovative spaces. The equipment that can be incorporated into these suites includes basic items that have existed for a few years, like the da Vinci SI HD surgical system, and new equipment that is stretching designers’ imaginations.

Among the latest systems are GE’s newest imaging system, the Discovery IGS 730, which incorporates sterile surgical draping and has a “one-touch” back-out system so that surgeons can get in place quickly in the case of an emergency, or Artis Zeego from Siemens, a multi-axis imaging system that, among other things, adjusts to the operator’s ideal height and has a compact park position, reducing its footprint in operating suites.

However, all this new equipment comes with a price tag; a price tag with a lot of numbers on it. Although hospitals installing these new suites range from world renowned, large research institutions like Brigham and Women’s Hospital in Boston to smaller regional institutions like Cooper University Hospital in Camden, New Jersey, many of them depend on grants or donations to fund the installation of hybrid ORs. Although they have a large upfront investment, ultimately, hospitals believe the investment will pay dividends for patients and hospitals.

Growing in Popularity

About 100 US hospitals have hybrid operating suites, according to the ECRI Institute, an independent nonprofit that researches the best approaches to improving patient care. In coming years, experts expect this number to rise.

Although the use of these suites has many advantages, they are not without drawbacks to the hospitals that install them. One of the major drawbacks of hybrid ORs, according to the University of Arizona’s Molly Szerlip, MD, is putting one in your hospital and never using it.

“Hospitals are installing these suites with the idea that they are going to hire somebody that will take advantage of it by performing hybrid revascularizations and other complex procedures,” Dr. Szerlip said. “The best situation is to have a staff already doing these complex procedures and the hybrid suite is installed to make them even more efficient.”

One-Stop Shop

Despite any drawbacks, Dr. Byrne and Dr. Szerlip agreed that these one-stop shops are the wave of the future for cardiac procedures, bringing with them the all-important twofold value of benefiting both patient and hospital.

Dr. Szerlip noted that with a hybrid OR, a surgeon can immediately follow a bypass with angiography of the graft to make sure there are no problems. “Then immediately after, the interventional cardiologist can do stenting, all in the same place.”

This one-stop shopping means that patients stay in the sterile environment and avoid being transported between two different suites. In addition, patients procedures are typically shorter, and may be safer, reducing the stress of being put under anesthesia a second time or even having to wait to schedule a second procedure.

The second major value is the change within an organization that happens when physicians are open to working together in a hybrid suite. If hospitals want to survive and be successful in cardiovascular care in the future, they are going to have to begin to adopt an integrated model where surgeons and interventional cardiologists work together, according to Dr. Byrne.

Given that the ACCF and the American Heart Association released updated guidelines in November 2011 recommending a team approach to coronary revascularization procedures, even a magic 8-ball can predict that when it comes to the use of hybrid procedures in the future, “all signs point to yes.”

“The technology in the hybrid OR will come and go,” Dr. Byrne said. “There will be new cameras, new devices, new imaging equipment, but what is really valuable and transformational, in my view, is the hybrid organization because without it, the hybrid OR will be empty.”

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Pericardial Disease, Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Patient Care, Sternotomy, Robotics, Longevity, Endoscopy, Brassica, Registries, Pericardiectomy, Thoracotomy, Sternum, Cicatrix, Tea, Obesity, Morbid, Medicare, United States, Odds Ratio, Propensity Score, Hippocratic Oath, Cardiac Catheterization, Heart-Lung Machine, Stents, Lipectomy, Mammary Arteries, Coronary Artery Bypass, Nurses


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