NOTES: because we can or because we should?
Authors: Manish Chand, Guy F Nash
Journal: Journal of the Royal Society of Medicine (2008)

The demands of surgical evolution necessitate constant improvement, but may some technological advances be ultimately detrimental to what we set out to achieve? Natural Orifice Transendoluminal Surgery (NOTES) is a novel surgical technique which shatters the traditional boundaries of minimally-invasive surgery. Potentially the most exciting surgical innovation since the inception of laparoscopic surgery, encouraging reports of NOTES procedures have been seen in animal models, ranging from diagnostic biopsies to cholecystectomies. But with reports of the first human trials recently published – the operation Anubis – there is a danger that such technological advances, rather than benefit patients, may present safety risks similar to those experienced early in the history of laparoscopic surgery.

Since the introduction of laparoscopic surgery, many traditional open procedures have been largely replaced by more minimally invasive techniques. This is particularly so in the case of gallbladder surgery, where the majority of today's trainee surgeons have not been exposed to elective open cholecystectomies. Such a transition in the surgical approach for cholecystectomy has occurred in less than 20 years, confirming the acceptance of the laparoscope. There is plenty of evidence supporting the advantages of laparoscopy, including faster recovery, less postoperative pain, better cosmesis, improved pulmonary function and a decreased inflammatory response.1–3 These benefits are largely attributed to smaller incision sizes. By extrapolating this argument, one may hypothesize that by removing the need for skin incisions, one would maximize such benefits. At the same time, endoscopy has evolved so that many gastrointestinal conditions are now managed without the need for surgical intervention. This has been successfully demonstrated in the case of therapeutic gastroscopy, which has reduced the role of upper gastrointestinal haemostatic surgery. These advances have no doubt had a beneficial effect on patients, with a reduction in patient morbidity and mortality.

In theory at least, NOTES is the ultimate in surgery, avoiding unnecessary incisions by using the available orifices of the human body. It has combined the advances in therapeutic endoscopy and laparoscopic surgery to create a new hybrid form of surgery. This proposes to be the extreme of minimal invasive surgery; a truly scar-less operation. Allowing the surgeon to use orifices to access the body cavity, target organs can be reached without the need to create surgical access ( Figure 1). The operating instruments are housed within the channels of a flexible endoscope which perforate the stomach, bladder or colon to provide access to the abdominal and thoracic cavities. These are then insufflated with carbon dioxide, as in a laparoscopic procedure, allowing visualization of the object organs. The scope is withdrawn at the end of the procedure and the hollow organ perforation is repaired. In addition to the benefits of minimally-invasive surgery already described, the access may in fact be improved compared with both traditional open and laparoscopic procedures.4 It is notable that the first reported laparoscopic and NOTES procedures were cholecystectomies performed by French surgeons.



Figure 1

Example of NOTES: transrectal cholecystectomy



New surgical techniques have historically been met with some scepticism and NOTES is no different. Some surgeons still refute the laparoscope and one must appreciate that pioneering surgical techniques may bring about new complications. Using endoscopy to directly access intraluminal pathology may be seen as advantageous over other approaches. In the mind of some surgeons, however, breaching a contaminated cavity to access a sterile one seems foolhardy. One must remember that iatrogenic perforation of the gastrointestinal tract is a potentially fatal complication of endoscopy.

Consider TEMS (Trans-anal Endoscopic Microsurgery), which may be thought of as a more basic form of surgery than NOTES. A quarter of a century after TEMS was introduced by Buess, its role is largely restricted to small, early stage rectal lesions and it has yet to find an accepted place in many surgical practices. Buess himself questions the motives of surgeons who may be keener to break new ground than preserve common sense.5 Pioneering work in surgery must be encouraged, but this must be tempered with reality. Surgeons must not pursue advancement of new techniques without a true realization of the cost.

For any new technique to become widespread, it must be deemed safe, efficient, cost-effective and, if it does not improve on previous techniques, at least compliment the repertoire of treatments available at the time. If this new technique aims to challenge laparoscopic appendectomy or cholecystectomy with transgastric or even transcolonic surgery, it must have truly impressive results. These will only be likely after the learning curve is passed, though this may be both long and steep. Furthermore, it is unlikely that published reports will include such learning-curve failures. Current laparoscopic procedures cause minimal postoperative pain, are associated with few complications, cause little or no contamination and are often day-case procedures. How can NOTES supersede these well-accepted techniques? There are no external scars, assuming conversion is not required, which initially at least will confuse patients and doctors who may not know which organs have undergone surgery. We wonder whether all the additional risks of such an approach will outweigh the seemingly slim advantages of avoiding incision complications.

It is important to appreciate that NOTES is not yet in its infancy, and there are scarce published reports of operations performed via this route in humans. Most work has been conducted using porcine models and relatively simple operations such as biopsies, cholecystectomy and tubal ligation.6–8 The results show future promise, but even at this early stage there are many key issues which will need to be addressed to avoid this promise remaining tantalisingly out of reach. Initial problems will include safely gaining optimal access (i.e. transgastric, transvaginal, transurethral or transcolonic). This will no doubt depend on the target organ and certainly the sex of the patient. Other issues are potential sepsis, closure of the visceral perforation and training issues.9 The operator will not only be required to be an experienced laparoscopist but also a highly-skilled endoscopist. Currently, laparoscopy is increasingly being used by all types of surgeons whereas endoscopy is predominantly practised by surgeons concerned with either upper or lower gastrointestinal surgery. Yet NOTES will not be exclusive to gastrointestinal procedures and it is surgeons within fields such as gynaecology and thoracic surgery who will be required to become proficient in endoscopy. Alternatively, surgical procedures within specific branches of surgery may be limited to forms of access which are familiar to them. For example, a gynaecologist may be restricted to using hysteroscopy while a thoracic surgeon is restricted to bronchoscopy. This in itself is an interesting evolutionary point and may well lead to a new breed of surgeon who will be required to demonstrate competency in both general laparoscopic and generic endoscopic skills, regardless of the access route. It seems likely and indeed sensible to share both the responsibility and acclaim between at least two senior surgeons during the inevitable learning curve. Both early and late complications must carefully be audited and it behoves the surgeon to accept external inspection of results.

With this is mind, it is appropriate that the Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) has been created to oversee the development of this branch of surgery. A website has been established allowing researchers to join the debate and provide accounts of their experiences (http://www.noscar.org). There is little doubt that NOTES does provide an exciting and potentially revolutionary direction for surgery in the 21st century – some have even gone as far as touting it as evidence that there are no limits to how human ingenuity and technology can reduce the physical and emotional trauma related to surgery – but we offer a note of caution in light of the lessons learned with the advent of laparoscopic surgery. There is a fine line between what we can do and what we should do.