The sedated patient is wheeled into the operating room. The gastroenterologist inserts a flexible transport tube down the patient’s throat, making it rigid when it is in place. He then threads an endoscope and surgical instruments down the stable platform. The team checks to make sure the video feed is operating properly, and then the surgeon takes over, making a small incision remotely in the stomach. Over the next few minutes, the surgeon carefully cuts away the gallbladder, pulling it through the patient’s throat and out of their mouth. Once the sedation wears off, the patient goes home and returns to work in a day or so, all the while experiencing no pain or discomfort from the surgery.

While the scenario has yet to become routine, surgeons at Northwestern Memorial Hospital in Chicago and the Legacy Health System in Portland, Ore, have taken the first steps to make this type of surgery a reality instead of speculative fiction.

The procedure, natural orifice translumenal endoscopic surgery, nicknamed NOTES, has been performed about 25 times throughout the world.

Like any “new” procedure, the theory behind NOTES has been around for nearly a decade. “It was pretty inevitable that surgery would come to this,” said Lee Swanstrom, MD, director of minimally invasive surgery at Legacy Health System, Portland, Ore. “Surgeons noticed that with smaller incisions, the patients did better.”

What followed was the inevitable question: “What if we could get rid of the incision?” said Swanstrom, who developed the NOTES approach being used at Legacy and Northwestern. Swanstrom has performed five NOTES procedures (as of this writing) since April 2007. He has been investigating natural orifice surgery for the last 5 to 6 years.

“Imaging technology was crucial in the development of NOTES. It really is revolutionizing surgery.” ?Eric Hungness, MD

The current research has identified three natural orifice options available to surgeons: the mouth, the rectum, and the vagina. Nathaniel Soper, MD, the Loyal and Edith Professor and Chair of Surgery at Northwestern University’s Feinberg School of Medicine, said that the vagina and rectum have certain limitations for gallbladder surgery. The vaginal approach would limit natural orifice surgery only to women, and the rectum has hazards due to bacterial infection. “It makes the most sense to go through the abdomen,” he said. The benefits of NOTES include less chance for infection and less chance for a later development of a hernia.

Obviously, the biggest difference between traditional surgery and natural orifice surgery is that the surgeon is not viewing the site with his or her own eyes, and must rely on the endoscope to do so.

Swanstrom credits the advances of endoscopic technology moving it from a diagnostic tool to an almost surgical one as the convergence point to allow NOTES to become a reality. “We’re using a specially designed endoscope,” he said. “It’s a micro-Olympus 6 mm scope. Originally, we were concerned that it would give enough light or have good image quality.” However, in practice, the endoscope has proven to provide the kind of imaging crucial to success.

But while all of the pieces are in place, the procedure is still far from an everyday reality.

The Approach

The physician team at Northwestern—Soper; surgeon Eric Hungness, MD; and interventional endoscopist John A. Martin, MD—have been researching the effectiveness of natural orifice surgery for the last few years. Before performing their first surgery in late 2007, the team performed the procedure on animals and human cadavers.

“…in my opinion, because of NOTES, laparoscopy won’t be the same.” ?John A. Martin, MD

After getting the approval of the hospital, the team approached a patient who had to have his gallbladder removed. Currently, the procedure is only performed on nonemergent cases.

Preoperative preparation is the same as with the laparoscopic approach, with diagnostic imaging procedures performed prior to the procedure.

While the primary characteristic of NOTES is the use of a natural orifice (in this case, the mouth) as an entry point, since it is a new procedure, a laparoscopic camera was also used, and the patient was under general anesthesia. The patient’s abdomen was also filled with gas, as in a laparoscopic procedure.

The first Northwestern procedure itself was uneventful, with the patient staying overnight in the hospital for observation and then going home the next day. A second patient was also successfully operated on a few weeks later, and, according to Soper, would not have needed any pain medication except for some pain she developed in her elbow—probably due to the blood-pressure cuff.

Though a success, Martin notes that a level of “refinement” needs to take place. “The instruments and techniques are evolving,” he said. “With that we will be able to cut down on the time it takes and the maneuvers that are needed. In comparison with laparoscopic techniques, NOTES takes between one third and one half times longer to perform. There is some degree of a learning curve. But, in my opinion, because of NOTES, laparoscopy won’t be the same.”

Swanstrom, who helped develop the technique used at Northwestern, said that the surgery is very different because of the endoscope. “It’s almost like robotic surgery,” he said. “It’s a little disconcerting when you’re first doing it.”

Hungness, the Northwestern surgeon, adds, “Imaging technology was crucial in the development of NOTES. It really is revolutionizing surgery.”

It is probable that without the endoscope, NOTES would still be in the dreams of researchers and science fiction authors alike.

Endoscopic Revolution

The Northwestern and Portland teams use an Olympus endoscope for their procedures. The Northwestern team specifically uses the N-180, a slim 4.9-mm scope that has 1,100 mm of working length and two-way angulation. Hungness found the full-color image quality to be more than adequate. “The visualization was great and the magnification was terrific,” he said. “It’s a smaller scope, so the image size is smaller.”

And while the imaging was good, Hungness did run into a few problems. “The end can get smeared, so you have to clean it,” Hungness said.

The scope does have an air/water nozzle that allows it to be washed during the procedure. Swanstrom attributes the problem Hungness experienced to the length of the procedure. “Once we get the procedure down to an hour or less, smearing won’t be an issue,” he said.

Martin sees the use of the endoscope as being a catalyst for change outside the operating suite as well. “The way NOTES works, there is a melding of cultures. We have different skills that we have combined, and we have taught each other those skills,” Martin said. “We’re creating a new kind of clinician with new skill sets.”

But the endoscope alone did not make NOTES possible. It took a peripheral piece of equipment—the transport tube—to give the endoscope and the surgical instruments a solid working base.

The Transport Tube

The need for a multitasking work platform through which to perform NOTES procedures was first identified by the American Society for Gastrointestinal Endoscopy and the Society of American Gastrointestinal and Endoscopic Surgeons (ASGE/SAGES) Working Group on Natural Orifice Translumenal Endoscopic Surgery. (The group has created a cooperative sub-group, NOSCAR, specifically to study issues surrounding natural orifice surgery.)

In an October 2005 white paper by the group, it stated that: “However, for NOTES to develop further, a multitasking platform is critical. Many important maneuvers for manipulating tissue are difficult to perform, even with a two-channel endoscope. ? The flexibility of the endoscope, which provides a great advantage for traversing the gut lumen, is a disadvantage when applying force to tissue because it is very difficult to both push and pull at the same time. Fixation and stiffening the endoscope will be essential for translumenal procedures. Because these procedures will require a team to manipulate instruments, devices with multiple ports are likely to be important.”

Ironically, at the same time, USGI Medical was developing the TransPort, a multichannel device designed for use in endoscopic procedures. The Northwestern and Legacy Health teams both use the TransPort. “The endoscope passes through the TransPort, which has four ports,” Martin said. “It’s a 22-mm flexible tube that has a wheel-and-pulley mechanism that allows the instruments to be manipulated.”

As John Cox, vice president of sales and marketing for USGI Medical, explains, when the TransPort is inserted into the patient, it is a flexible tube. Once it is in place, it can be made rigid and stable, giving the surgeons a platform from which to work.

While the initial design of the equipment and the methodology has proven to be successful, there are still improvements that can be made, and this may give imaging a still larger role in the procedure.

Improvements Needed

“Being on the cutting edge feels good. I’m hooked on that feeling you get when you make a major impact.” ?Nathaniel Soper, MD

Swanstrom, the NOTES innovator, said that “a lot” of technology still needs to be designed for the surgery to become safe and routine. An important piece of equipment that needs to be designed is one that will tell surgeons exactly where the endoscope is in the body, a sort of body global positioning system. “I think [whatever it is], it’s going to be some sort of radiologic solution [such as a CAT scan or ultrasound],” Swanstrom said. He foresees that it could result either in an overlay or picture-in-picture concept.

In terms of endoscopic imaging, Swanstrom said it is “fairly good, but we need better controls and ways to guide it. In the new endoscopes we need arms that move independently, and that will make a big difference.”

Echoing Swanstrom, Soper sees a drawback to the way the endoscope is used in the current iteration of NOTES. “The access of the optics is [on the same line] as the instruments. This can be improved [for instance] by changing the angle of the optics and triangulating them with the instruments,” he said.

Hungness hopes to see endoscopes with higher picture definition and a wider field of vision. He also expects that radiology will be involved just prior to the procedure, doing ultrasound scans for stones in the bile duct.

Even with the needed improvements, the US teams are seeing success with NOTES.

On the Cutting Edge

Swanstrom is a bit further along in the process of making NOTES a truly natural orifice surgery, instead of the hybrid one that it is now. The health system is doing a 25-patient study and needs to meet certain benchmarks before it can move to the next step. After 10 surgeries, he can eliminate the laparoscopic incision.

For the researcher/surgeons at Northwestern, being on the frontier of a new type of surgery is exciting, particularly with their early successes. The three men meet every Thursday in the lab to compare notes and continue their research. “It’s very exciting to be on the ground floor,” Hungness said. “But I’m not so excited that I’m running willy nilly. I’m cautiously excited.”

Martin is a bit overwhelmed about being at the epicenter of the new procedure. “At once it’s fascinating, exciting, humbling, and kind of unbelievable,” he said.

This is the second time Soper has been at the forefront of a medical advance. He was a pioneer in laparoscopic surgery in the late 1980s. But there is nothing jaded about his enthusiasm. “Being on the cutting edge feels good,” he said. “I’m hooked on that feeling you get when you make a major impact.”

But with improvements, the surgeons who are on the literal cutting edge of this procedure see even more possibilities for NOTES. Swanstrom foresees gallbladder surgery as only one of a menu of abdominal procedures available to NOTES practitioners. For instance, it could be used in kidney surgeries. With the success of NOTES, other natural orifice surgeries may become common. It may also be worthwhile to do trans-vaginal surgeries for gynecological ailments and trans-rectal surgeries specifically for colon resections. “It’s kind of an open field. It depends on what the patients want and the benefit of doing surgery this way,” Swanstrom said.

C.A. Wolski is a contributing writer for Medical Imaging. For more information, contact .