By Monica J. Smith

San Diego—The use of natural orifice translumenal endoscopic surgery (NOTES) and single-incision laparoscopic surgery (SILS) as techniques in bariatric surgery are still largely experimental and controversial, according to Ricardo Zorron, MD, PhD, director, Innovative Surgery Division, Klinikum Bremerhaven Reinkenheide, Bremerhaven, Germany.

Speaking at a session on innovations in obesity and metabolic surgery at the 2012 meeting of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES), Dr. Zorron said that it is too early to draw comparisons between bariatric SILS and NOTES and more traditional approaches, but the work needs to keep moving forward: “Our aim is to minimize the access. We are trying to do something less [invasive] for our patients, and [evolve] in our surgery,” he said.

Around 2007, Dr. Zorron, along with other surgeons, started using NOTES and SILS for cholecystectomy, among other procedures, and found generally favorable results with few complications. “Now we are starting to do this for bariatric surgery for more complicated patients with more complex disease,” he said. “For now, we are doing more transvaginal and single-port sleeve gastrectomies, a simpler procedure than gastric bypass which will happen later, I think.”

Aside from the pioneering drive of surgeons, it is not clear what is driving the trend toward minimizing bariatric operations. Patient demand, for example, is not particularly high. Morbidly obese patients tend to be more concerned with the risks of surgery than with the cosmetic after- effects of traditional laparoscopic surgery.

“It is not like in the beginning of laparoscopy when we had patients knocking on the door, wanting to do it that way,” Dr. Zorron said.

Bariatric surgery using NOTES and SILS presents a host of technical challenges to surgeons, such as limited motion and visualization. Surgeons can overcome some of these problems with increasingly sophisticated instruments, but the technology itself is evolving and, when available, is often quite expensive. Furthermore, surgeons who are already fully skilled in bariatric surgery would have to undergo additional training in these increasingly minimal approaches, but what could be a detractor for some is an exciting challenge to others:

“It is the natural history of surgeons to try to do better, to get better. In the environment we work in, surgeons want to be on the cutting edge,” said Raul Rosenthal, MD, professor of surgery, Herbert Wertheim School of Medicine, Florida International University, Miami; chairman, Bariatric and Metabolic Institute; section head, Minimally Invasive Surgery, Cleveland Clinic, Weston, Fla.

“Then there is the technology that is made available to us, and the combination of surgeons who want to take advantage of that technology and start doing new things they hope will be better for the patient,” he aid. “However, there hasn’t been any proper scientific work done to validate that [SILS] is superior to other procedures.”

From Dr. Zorron’s point of view, if the work is not done today, there will be nothing to draw from tomorrow. “Laparoscopic surgery has to change because progress is expected. It is not the point to develop instruments or [technology] that can be sold,” he said, noting that he did not have specific industry support during his 20 years of research in Brazil, where he worked until just a few months ago. “I think the most important thing is that we think about how we can make a better surgery that will be referenced in the next 10 to 20 years.”

At present, bariatric NOTES hinges on the development of instrumentation—long staplers in particular. But surgeons have been using SILS to place gastric bands. “This is an operation that is simpler than others, and I’m sure we can do it,” said Dr. Zorron, citing a study that showed, in a group of 22 patients, only one needed conversion to traditional laparoscopy and the results were good overall, with no intra- or postoperative complications (Surg Obes Relat Dis 2010;6:41-45).

One criterion for patient selection—a body mass index (BMI) range of 35 to 45 kg/m2—may have influenced the positive outcome, “but I think this is an approach that makes sense for these types of surgeries,” Dr. Zorron said.

With regard to sleeve gastrectomy, Dr. Zorron reiterated Dr. Rosenthal’s opinion (which he shared at last year’s SAGES meeting) that the procedure is still evolving: Indications for sleeve gastrectomy are still in question; it is unknown whether patients will need a follow-up procedure; and there is a lack of long-term data.

Despite the challenges with exposure and visualization, skilled surgeons can satisfactorily perform sleeve gastrectomy via SILS, according to Dr. Zorron. The first prospective, randomized study comparing patients who received a laparoscopic sleeve gastrectomy with five trocars, with patients who received a sleeve gastrectomy using only one, found more pain in the multiport group in postoperative days 1 and 2 (Obes Surg 2011;21:1664-1670).

Overall, the extent of literature on SILS bariatric surgery is too limited to conclude whether or not there is a future for it. At present, this procedure costs more than traditional laparoscopic surgery; surgeons often have to add ports during a single-port procedure; and no strong data exist to indicate that it will improve patient outcomes.

However, Dr. Zorron supports continued investigation of NOTES and SILS. “We cannot prove anything now. Maybe we can prove it in 10 years, but if we don’t [study] this, we cannot prove anything or change anything,” he said. “I think progress is like this. It’s easy to criticize, and very hard to do.”

At present, he performs the majority of his bariatric procedures using traditional approaches, and offers SILS and NOTES procedures only to a small percentage of carefully selected patients. “I suffer to do this surgery. I take more time, I go home later,” Dr. Zorron said. “But I want to do progress in surgery—that is the point.”

According to Dr. Rosenthal, no one should be performing NOTES or SILS bariatric procedures outside a randomized controlled trial with an institutional review board (IRB) protocol, and he suggested that the industry might be pressuring surgeons to move into territories as yet unproven and unsafe.

“[There is the] perception that you’re missing something, that if you guys don’t do single incision, NOTES or [robotic surgery], you’re not going to be leading-edge. In five years, you’re not going to have a job,” he said.

Dr. Rosenthal also said that, without industry support, it is unlikely that anyone would experiment with approaches that are more challenging and expensive, offer no proven benefits in pain reduction or improved cosmesis, and that fly well under the radar of patients still impressed by traditional laparoscopy.

Furthermore, the challenges brought about by reducing the number of port sites to a single port, flouts one of the most important tenets of surgery—safety—starting with the compromised visibility and potential crossing of instruments. Dr. Rosenthal said, “The principles of safe surgery are traction and counter-traction, triangulation, dissection, critical view, control of critical structures, but with the exposure allowed by SILS, you can barely see anything. The principles of safe surgery, all basic principles, are gone with SILS.”

The additional length of time it takes to perform SILS procedure is another safety issue that results in patients spending more time under anesthesia, Dr. Rosenthal said. “All these references tell you very clearly, the longer you’re under anesthesia, the more complications you can have.” More time on the operating table means greater cost, especially in the United States, and that cost is further driven by the expense of new technology.

“The little [scientific research] that has been done shows that [SILS] is of no benefit for the patient, could be detrimental, is more costly; and to some degree I believe that we should not be doing it until we have prospective, randomized controlled studies that show the reasons we should be doing it and when we should be doing it,” said Dr. Rosenthal.

This leads to the question of whether there is any point in investigating SILS procedures even within prospective randomized trials.

“That is a good question,” Dr. Rosenthal said. “I think we have to be fair to the scientific process. Personally, I might be a little biased; I don’t see any benefit. But at this point, it would be unfair to any hypothesis to say, ‘this should not even be done in a randomized controlled trial.’ I would not take that away from any new approach.”

Eric DeMaria, MD, WakeMed Health and Hospital System, Raleigh, N.C., sides with the skeptic’s view when it comes to the pursuit of NOTES and SILS in bariatric procedures. “What we’re doing is really not tried, tested, vetted or endorsed as the appropriate standard of care,” he said, and the discussion raises more overarching questions.

“I’m really concerned about how we always seem to be innovating in bariatric surgery but never really seem to find the appropriate thing to do and stick with it,” he said. “Laparoscopic cholecystectomy was introduced, and created a dramatic change in our approach to cholecystectomy about 20 years ago, but it hasn’t changed very dramatically since then. In contrast, bariatric interventions seem to be continuously evolving and changing and never quite reach the point of standardization.”

Dr. DeMaria agrees with the notion that surgeons are innovators by nature, always problem solving and trying to figure out a modification that will improve outcomes or cut down on length of procedure, but this comes down to a matter of degree.

“I don’t think it’s such an issue if you’re looking at a question of, say, changing what suture material you use or how you perform the suturing,” he said. “Tremendous variability occurs in surgery because you can’t always do things the same way. Unfortunately, in bariatrics, we also seem to regularly come across novel procedures, or access concepts that many people begin to apply without proving those concepts with any sort of prospective research approach.”

In some cases, this approach begins to blur the fine line between innovation and human experimentation, Dr. DeMaria said. “That may seem strong language, but at some point in the continuum you go from modification to innovation to human experimentation. Human experimentation has led to tremendous advances, but it has also caused harm.”

Bariatric SILS has not been proven to demonstrate desired outcomes, but there may be some subtle benefits, said Dr. DeMaria. “One that I often hear argued is that the reduced invasiveness of single incision encourages patients to come forward for surgical treatment who might not have been comfortable with it before.”

Additionally, there is no schematic for location and number of incisions that laparoscopic surgeons place. For years, Dr. DeMaria has placed fewer incisions for laparoscopic procedures when the individual case has warranted doing so. “The question is can you push from four to six incisions to a single incision safely and talk about this being advantageous when you don’t have the data to back that up?” he said.

A greater criticism of the field of surgery, however, is that there is no standard system for adopting new approaches, even if they have been tested and found beneficial.

“I’ve lived through two eras in surgery where I know for a fact that patients were injured by the lack of an appropriate, careful system for introducing new concepts in surgery,” said Dr. DeMaria.

The first era was the introduction of laparoscopic cholecystectomy, and the second was the beginning of laparoscopic gastric bypass.

“Bariatric surgery took such a black eye from highly publicized complications that it almost fell into disfavor and may not have existed if things had continued for another couple of years in the same direction,” Dr. DeMaria said. “It’s really about time that we in minimally invasive surgery, and bariatrics in particular, figure out a way to offer and train surgeons well, to perform standard procedures and not be so tolerant of disruptive innovation,” he said.

“Our bariatric population is so vulnerable to being misled and convinced that a ‘great’ new concept could save them from their disease. We have to be more responsible because we have a population that’s willing to sign up for anything that will help.”