Introduction

Surgical procedures have been performed since Neolithic times with advances in the field marked by key events.¹ In 1809, McDowell completed the first successful abdominal operation without the use of general anesthetic.² The invention and use of inhaled ether as a form of general anesthetic marks the first great advance in surgical therapy (Fig. 55.1), followed by the introduction of antisepsis by Lister.³ In the centuries that followed, large abdominal incisions were required to permit the surgeon’s hands and instruments access to the disease process. More recently, disease processes have been accessed with smaller incisions (as in laparoscopy) or by a different route entirely (endoscopy or endovascular), decreasing the pain and infection risk of the abdominal incision and improving patient outcomes.

Fig. 55.1 Artist’s conception of Dr. Crawford Long demonstrating for the first time the use of ether as an inhaled anesthetic on March 30, 1842.

(From Boland F: The first anesthetic: The story of Crawford Long, Athens, 1950, University of Georgia Press.)

Natural orifice transluminal endoscopic surgery (NOTES) is an experimental surgical technique whereby scarless abdominal operations can be performed with an endoscope passed through a natural orifice (mouth, anus, vagina, or urethra) and then through an internal incision in the stomach, colon, posterior vaginal fornix, or bladder, avoiding any external incisions or scars (Fig. 55.2). Similar to the introduction of laparoscopy, surgical opinions of this new approach vary widely. This chapter briefly reviews NOTES and examines current surgical opinions.

Fig. 55.2 A–C, Renderings of natural orifice access through transgastric (A), transcolonic (B), and transvaginal (C) routes.

(From Bessler M, Stevens P, Milone L, et al: Transvaginal laparoscopically assisted endoscopic cholecystectomy: A hybrid approach to natural orifice surgery. Gastrointest Endosc 66:1243–1245, 2007.)

History of Minimally Invasive Surgery

The advent of minimally invasive surgery brought with it an opportunity to decrease postoperative pain with resultant shorter hospital stays and quicker returns to normal activity and to shrink surgical scars, providing a more pleasing cosmetic outcome.⁴ The minimally invasive surgery concept influenced the next paradigm shift in intervention, NOTES, which may eliminate the anterior abdominal wall approach altogether (Fig. 55.3).

Fig. 55.3 Depiction of the transfer of advances in technology between specialties leading to decreased invasiveness.

History of Natural Orifice Transluminal Endoscopic Surgery

The history of NOTES begins in 1901, when Ott performed the first endoscopic examination of the peritoneal cavity through the vagina.⁵ He termed the procedure ventroscopy and became the pioneer of natural orifice access. The feasibility of a peroral transgastric flexible endoscopic approach to the peritoneal cavity with long-term survival in a porcine model was reported by the Apollo Group in 2004 (Fig. 55.4).⁴ Since this publication, NOTES has continued to evolve. Success in early animal studies led to the initiation of human trials.^6–11 Rao and Reddy performed the first flexible endoscopic transgastric appendectomy in humans in Hyderabad, India; although this report remains unpublished, a description of their technique and videos have become widely dispersed throughout the research community.^12,13 Since that time, this group has successfully attempted the transluminal approach for 17 cases, including appendectomy, liver biopsy, and tubal ligation.¹⁴ Multiple transvaginal and transgastric NOTES procedures have been published by other NOTES teams, including transgastric appendectomy, cholecystectomy, fallopian tube ligation, and transvaginal cholecystectomy with active clinical trials ongoing.^15–20 Currently, the number of successful NOTES procedures (with or without laparoscopic assistance) around the world is greater than 3000 cases.

Fig. 55.4 Timeline for the development of natural orifice transluminal endoscopic surgery (NOTES) from the first feasibility studies to more advanced animal studies.

Advantages of Natural Orifice Transluminal Endoscopic Surgery

Abdominal incisions elicit a pain reaction that results in a stress response from the body, initiated through the inflammatory cytokine cascade. Theoretical advantages of NOTES include the avoidance of this pain reaction and stress response. A possible development can be imagined with procedures under conscious sedation rather than general anesthesia. This development has already occurred for several procedures that used to be the domain of open surgery, such as endoscopic retrograde cholangiopancreatography for choledocholithiasis or pancreatic pseudocyst drainage. As is shown with the percutaneous endoscopic gastrostomy rescue report by Marks and colleagues,²¹ transluminal procedures may avoid additional insults to ill patients. In addition to the esthetic improvements offered by incisionless surgery, NOTES would also decrease the risk of wound infection and postoperative incisional hernias. NOTES may be ideally suited for patients who have conditions that preclude an open or laparoscopic procedure, such as patients with large areas of burn, scar, or infection of the anterior abdominal wall. Additionally, the NOTES team and equipment are portable allowing procedures to be done in an intensive care unit, multipurpose procedure room, outpatient setting, and battlefield.

These potential advantages, if realized, would have a significant economic impact in health care. These advantages are also appealing to developing countries where complex laparoscopic equipment and sterile operating environments may not be consistently available. There is also the potential for decreased length of hospital stay, faster return of bowel function, and increase in overall patient satisfaction. Perhaps the biggest advantage of NOTES would be the improvements in laparoscopic and endoscopic surgery, including the tool sets used in each and the skills of the surgeons involved.

Disadvantages of Natural Orifice Transluminal Endoscopic Surgery

Not all surgeons support the concept of NOTES. Although studies have shown the feasibility of a NOTES approach, significant constraints also have been identified with the use of a flexible endoscopy platform, including a relative inability to apply off-axis forces, mechanical stability, inadequate triangulation, and limits in passing multiple instruments simultaneously into the peritoneal cavity. Surgeons have also expressed concerns for the risk of postoperative leak and infection. Data from pilot clinical trials have not supported these concerns. Surgeons have also stated that although there is significant research work focused on intestinal closure systems for NOTES access sites, it is doubtful that 100% safety can be achieved. Many current procedures involve the vagina, which avoids the need for intestinal or bladder closure. There is concern that current instrumentation for grasping, dissection, and suction are substandard compared with laparoscopy. Additionally, concerns have surfaced that the operative near-field view using an endoscope is more limited than with a laparoscope, and steering of the endoscopic instrumentation by endoscopic movement leads to poor visualization of the instrument tip.

Industry developments have answered many of these concerns with the design of new operative endoscopes that permit independent instrument and optical movement and development of grasping, dissecting, and closure tools. Many of these tools are expected to evolve over time much as open and laparoscopic instrumentation has evolved from first introduction. One of the greatest challenges faced by NOTES is changing the view of currently practicing surgeons whose training and practice decreed not to perforate otherwise healthy hollow viscus organs. Changes in surgery and health care require surgeons to look at patient care in a new way.

Training Surgeons in Natural Orifice Transluminal Endoscopic Surgery and Incorporating Natural Orifice Transluminal Endoscopic Surgery into a Surgical Practice

As with any new technique, training is important for the clinical incorporation of NOTES. Because of the unique equipment used and the operative view obtained in NOTES procedures, a NOTES surgeon requires specialty training similar to other surgical fellowships and specialties. Although no formal programs have been designed, it is likely that a NOTES surgeon would require an education in general surgery concepts and advanced endoscopic training (Fig. 55.5). Several procedures in the vascular environment are now performed by either vascular surgeons or radiologists and training for both types of specialists has evolved to combine more of both specialties. A similar training model could be applied for training of NOTES surgeons.

Fig. 55.5 Depiction of the training for a surgeon in natural orifice transluminal endoscopic surgery (NOTES), which requires both general surgery and interventional endoscopic training.

Conclusion

The prospects of evolution of NOTES and the international research effort associated with NOTES are exciting. Not since the introduction of laparoscopy has the development of a new surgical technique generated as much enthusiasm and criticism as NOTES. Surgeons must be aware of the developmental nature of these techniques and proceed with appropriate caution in the setting of institutional review board–approved studies. NOTES also needs to be assessed in larger multicenter trials. Regardless of the surgeon’s opinion of NOTES, it is crucial to be informed of advances in surgical disease management.