Found this from 2009 April, Emerging Technologies, Issue Archives
Single-incision surgery has been given a panoply of acronyms and names, including single-incision laparoscopic surgery (SILS), single-port access (SPA) surgery, laparoscopic endoscopic single-site surgery (LESSS), single laparoscopic incision transabdominal (SLIT) surgery, one-port umbilical surgery (OPUS), natural orifice transumbilical surgery (NOTUS), and embryonic natural orifice transumbilical endoscopic surgery (E-NOTES). SILS has been described since the late 1990s, beginning with appendectomy and cholecystectomy.[24,29] Since then, the technique has been applied to multiple surgical procedures, including gastric banding, sleeve gastrectomy, splenectomy, nephrectomy, colectomy, and adrenalectomy.[24,28] Studies have shown that smaller incisions, including smaller port size, decrease morbidity in both appendectomy and cholecystectomy patients. In comparing patients undergoing needlescopic versus conventional laparoscopic appendectomy, the needlescopic group had a shorter hospital stay (1.3 days vs. 3.2 days), reduced narcotic requirements, and faster return to work (8 days vs. 17 days) than controls.[30] In a similar study pertaining to cholecystectomy patients, the group with downsized trocars reported less incisional pain in the first postoperative week.[31] Based on the results of these studies, it seems logical that eliminating multiple incisions/port sites would further decrease associated morbidity. However, no prospective, randomized study demonstrating clear advantage over standard laparoscopy has been reported.
The tenet of single-incision laparoscopic surgery is to reduce the number of incisions to one, typically at the umbilicus, for multiple trocar placements. This can be accomplished in several ways: a single umbilical skin incision with skin flaps to insert ports through multiple fascial punctures as described by Curcillo, or the use of newly developed systems, such as the Uni-X™ Single Port System (Pnavel Systems, Inc., Morganville, New Jersey), Surgiquest AnchorPort®, TriPort™ (Advanced Surgical Concepts, Wicklow, Ireland), or GelPort® (Applied Medical, Rancho Santa Margarita, California) requiring a larger but single fascial incision for passage of multiple instruments. The required proximity of the trocars at a fixed position illustrates one of the disadvantages of these techniques. The freedom of the hands is relatively restricted, which causes clashing of the instruments, and the fixed port at the umbilicus potentially creates a long distance to the surgical site. This is somewhat contradictory to the traditional teaching of triangulation of instrumentation in laparoscopy, creating a steep learning curve. Thus, the lack of triangulation, pneumoperitoneum leaks, and instrument clashing have been described as real disadvantages of this procedure.[22] Furthermore, there is no long-term data that has examined morbidity of single-incision laparoscopic surgery. Multiple, closely placed fascial punctures have the potential for hernia, and wide skin flaps created to accommodate multiple trocars may result in seroma formation. Still many surgical procedures have been performed safely using these techniques, and variations have been described. As new instruments are developed to accommodate the new paradigm of SILS, it is likely that technical difficulties will be minimized.
Since SILS procedures are relatively new and in evolution, many techniques have been described but no widely accepted standard exists. SILS was first adapted to cholecystectomy and once the technique was shown to be safe and effective for basic laparoscopic procedures, it was applied to some of the technically simpler bariatric procedures. Laparoscopic gastric banding was one of the obvious transitional procedures since the significant incision required for the adjustment port provides the needed space to place multiple trocars. However, laparoscopic banding was more technically difficult due to the camera angles required for dissection of the retrogastric tunnel, the need for retraction of an often-fatty liver from a longer distance, and the need for suturing. As surgeons gained more experience, the technique became more sophisticated, and cosmesis was improved by placing the incision in the umbilicus. With this change, the distance from incision to the surgical field increased and the angle of dissection became more technically challenging. Some have modified this technique by adding a small, second incision for retraction or using specialized ports. With attempts to overcome these obstacles, multiple techniques and instruments have been developed. Because the primary benefit of SILS seems to be cosmetic, most agree that the umbilicus is the preferred incision site; however, it is at this point that the techniques diverge.