Single-Incision Laparoscopic Surgery (SILS) and Natural Orifice Transluminal Endoscopic Surgery (NOTES) Techniques for Cholecystectomy

Introduction

Laparoscopy has blossomed over the last 20 years and is one of the most significant surgical advances of the twentieth century. However, the true birth of laparoscopy can be dated to over 100 years ago when George Kelling from Dresden, Germany introduced a cystoscope into the peritoneal cavity of a living dog and insufflated air to enhance the view. Surgery of the gallbladder has similarly evolved over this same century. As cited by Bittner, Langenbuch performed the first successful cholecystectomy on a 43-year-old man with symptomatic cholelithiasis in 1882. More than a century later (in 1985) German surgeon Eric Muhe applied the technique of laparoscopy to remove a gallbladder using a modified laparoscope, called the galloscope. It was soon thereafter (1987) that the advent of the computer chip television camera allowed Phillipe Mouret to perform the first video-laparoscopic cholecystectomy.
Today, laparoscopic cholecystectomy is the gold standard for gallbladder removal and the most common laparoscopic surgical procedure in the world. Numerous reports have provided overwhelming evidence that laparoscopy provides better cosmetic results, less postoperative pain, and shorter recovery time when compared with open cholecystectomy. However, the quest to develop even more minimally invasive surgical techniques in order to enhance the advantages of laparoscopy remains robust. This quest has led surgeons to seek to minimize the number and the size of incisions, or in the case of natural orifice transluminal endoscopic surgery (NOTES), to eliminate skin incision(s) altogether. The hope of these more minimally invasive procedures is that they will also lead to minimal or no post-procedural pain while improving cost-effectiveness and patient safety.
While totally incisionless surgery remains an impossible idea at present, NOTES, initially performed in animal models, is now a clinically relevant idea with anecdotal procedures having been performed on human subjects worldwide. Reddy and Rao are credited with performing the first transgastric ppendectomy in a human without an external incision, and Marescaux et al. performed the first cholecystectomy via a natural orifice. As a bridge between traditional laparoscopy and NOTES, recent focus has been on the development of single-incision laparoscopic surgery (SILS) to further minimize the invasiveness of laparoscopy by reducing the number of incisions, and hopefully the pain and complication(s) associated with them. SILS was described as early as 1992 by Pelosi and Pelosi who performed a single-puncture laparoscopic appendectomy and in 1997 by Navarra et al. who performed a laparoscopic cholecystectomy via two transumbilical trocars and three transabdominal gallbladder stay sutures. These innovations, either exclusively or in a hybridized fashion, have now been applied to a wide variety of surgical procedures.

A Review of Novel and Innovative Minimally Invasive Cholecystectomies

A large number of individualized techniques for NOTES or SILS for a variety of different operations have been described. The described procedures include appendectomies, gastrostomies and gastrectomies, adrenalectomies, colorectal and bariatric procedures, and urologic procedures including donor nephrectomies. To date, however, cholecystectomy appears to be the most common surgical procedure to which significant efforts have been applied toward the development of technique and equipment for both NOTES and SILS. We will spend the remainder of the article reviewing these novel and innovative techniques that have been described for more minimally invasive cholecystectomy, and provide a discussion of the positives and negatives associated with these innovations

Natural Orifice Transluminal Endoscopic (NOTES) Cholecystectomy Techniques

Bessler et al. have described a transvaginal laparoscopically assisted endoscopic cholecystectomy using a single 5-mm trocar and two 3-mm trocars through the anterior abdominal wall. The sole purpose of the 5-mm trocar was to introduce a clip applier while the 3-mm trocars were used to retract the gallbladder, induce and maintain pneumo-peritoneum, and assist in the creation and dilation of an incision in the posterior fornix of the vagina for gallbladder removal. A double-channel endoscope was introduced transvaginally into the peritoneal cavity to permit dissection, and removal of the gallbladder was completed entirely with a hook knife and a grasper that was inserted through the endoscopic channels. Following removal of the gallbladder, the colpotomy was closed with absorbable sutures. The entire procedure took 3.5 h. A similar technique used by Marescaux et al. required only a single 2-mm transumbilical needle port to create pneumoperitoneum and provide laparoscopic guidance for the colpotomy. Endoscopic scissors, grasper, and a unipolar round-tipped electrode were used to dissect and remove the gallbladder. The entire procedure took 3 h to complete.

Single-incision Laparoscopic (SILS) Cholecystectomy

Techniques Navarra et al. performed the first SILS cholecystectomy in 1997 using two 10-mm trocars and three transabdominal stay sutures to aid in gallbladder retraction. Piskun and Rajpal described the use of two 5-mm trocars and two stay sutures in 1999. In both these methods, the two trocars were inserted through the umbilicus, with a bridge of fascia between them, and were used for a camera and a working instrument, respectively. The two umbilical fascial incisions were united by cutting the bridge between them to allow retrieval of the gallbladder following its removal. In place of sutures, Cuesta et al. have described a technique in which a percutaneous Kirschner wire is introduced subcostally and modified into a hook intra-peritoneally. This wire hook was used to provide exposure of Calot’s triangle. The authors used this technique to successfully treat ten female patients with cholelithiasis, with an average operative time of 70 min.

Discussion

NOTES and SILS mark the beginning of a new era in the field of surgery. Endoscopic surgery via natural orifices is essentially surgery without a visible scar, and marks a prominent evolutionary leap in medicine. Single-incision laparoscopy purports to offer better cosmesis and avoidance of extra incisions, with an added benefit of the option to convert to multiport laparoscopy if necessary. It has further been suggested that both NOTES and SILS may be associated with reduced post-procedural pain when compared to traditional laparoscopy. While some of the aforementioned reports suggest a promising future for these innovative techniques, the promise currently remains unfulfilled as significant ethical, procedural, and technological questions remain.
Natural orifice endoscopic procedures are performed with flexible endoscopy and at present most surgeons have little, or more commonly no experience with their use in the abdominal cavity (or elsewhere). In transgastric or transcolonic NOTES, the lack of sterilization and secure closure of the gastric or colonic wall remains the greatest challenge since the development of gastrointestinal leaks would represent a catastrophic complication which rarely follows routine laparoscopic cholecystectomies and appendectomies. In our opinion, until improved technology and training is available and a robust discussion of the ethics of NOTES is held, the purported benefits of better cosmesis in no way outweigh the risks posed by potential intra-abdominal injuries. Though no meaningful data regarding complication of NOTES procedures are available in any form, it would appear that the paucity of infections or hernia following transvaginal pelvic surgery, even when the colpotomy is not routinely closed, makes the transvaginal route a preferred option over transgastric or transcolonic methods. However, it is important to note that no information on the impact of the transvaginal approach on subsequent fertility and the potential for discomfort during sexual intercourse exists.
In our practice, an attending surgeon, a surgical resident and an assistant (usually a medical student) in addition to the nursing staff makes up the laparoscopic cholecystectomy operative team. We performed the last 100 laparoscopic cholecystectomies in an average time of 51 min. Most of the reported NOTES were carried out by a team of surgeons, gynecologists, and gastroenterologists in various combinations. This not only signifies the complexity of this technique, but also suggests that the reported operative times alone do not precisely reflect the cumulative manhours invested by specialists in the performance of these procedures.
Varadarajulu et al. surveyed 100 patients who were undergoing endoscopic ultrasound (EUS) or an ERCP for evaluation of abdominal pain, pancreatitis, or suspected choledocholithiasis. All patients were given information on the technique, complication rates, and benefits of laparoscopic cholecystectomy. In addition, the concept of NOTES, as an evolving less-minimally invasive technique, for gallbladder removal was described simultaneously. Patients were then queried regarding the cholecystectomy technique (laparoscopic versus NOTES) they preferred, reason(s) for their choice and the amount of risk that they were willing to assume if they selected NOTES. Seventyeight percent of these patients expressed preference toward NOTES over laparoscopic cholecystectomy if the complication rates of the procedures in question were comparable. The most common reason given for preferring NOTES was to avoid incisional pain and scarring. This raises two important questions: what is the complication rate associated with NOTES and SILS cholecystectomy, and is the post-procedural pain following either NOTES or SILS cholecystectomy any different from that reported after traditional laparoscopy? We know that the incidence rate of major complications (common bile duct and major vessel injury) following three or four-trocar laparoscopic cholecystectomy is well documented at <1% with an overall complication rate of≤3%. Post-laparoscopic cholecystectomy pain and recovery time is also significantly lower when compared to the alternative open procedure. Whether there is less postoperative pain associated with NOTES or SILS is so far a subjective conclusion and systematic objective assessments of post-procedural pain, as well as procedure-related complication rates, are lacking. Interestingly, among the patients surveyed by Varadarajulu et al., 82% (18/22) of those who preferred laparoscopic cholecystectomy over NOTES, irrespective of incisional pain and scarring, stated they considered the risk of complications and the proven safety and efficacy of the procedure as the most important variable. Even among those patients initially preferring NOTES to avoid pain and scarring, the interest decreased to less than 15% when the complication rates of NOTES were stated as higher than that oftraditional laparoscopic cholecystectomy.
One of the major challenges posed by both NOTES and SILS is the difficulty to attain similar critical views of tissue dissection with more limited instrumentation and field of view. SILS limits the number of ports that can be used through a single incision, and a single port with multiple instruments restricts their degrees of movement. Proximity of instruments when used through a single port often results in inadequate retracting abilities and loss of triangulation, which may lead to suboptimal exposure of Calot’s triangle. The avoidance of clashing the operative instruments with each other and the scope, while maintaining pneumoperitoneum, may actually increase the complexity and technical challenges of the operation rather than decrease them. Most laparoscopic surgeons are familiar with rigid instruments and the suggestion made by Zhu et al. to use semirigid instruments that may “bend”, while potentially ingenious, requires education and training and may make tissue dissection and grasping initially more difficult. Dislodgement of single large tri-ports or multiple small ports through a single incision is another potential problem that may cause loss or leakage of pneumoperitoneum, thereby risking mishap. Also, smoke created by use of a monopolar electrocautery which would have no route for evacuation with a single port in place, is a further challenge to the operating surgeon’s field of view. Improved instrumentation and the use of crossed-over articulating graspers and dissectors may achieve triangulation, but their use requires adjustments which may translate into longer operative time to perform safe and precise dissection. The potential added costs for advanced instrumentation are unknown, but without significant demonstrable benefit to the procedure warrant investigation.
Purposeful percutaneous puncture of the gallbladder for drainage or introduction of suspension hooks which has been suggested by some authors for better visualization of the Calot’s triangle may inadvertently increase the chances of bactobilia. Such maneuvers may also cause perforation of the gallbladder leading to increased risk of bile peritonitis, particularly in the setting of acute cholecystitis. The development of skin flaps circumferentially to accommodate a single large or multiple small ports is necessary with either a single large incision or multiple fascial incisions. Exertion of pressure by a single large port or multiple ports at a single site may potentially weaken the fascia thereby increasing the risk of hernias, especially on intentional creation of a “Swiss cheese” defect. The creation of skin flaps also raises the possibility of forming subcutaneous seromas or hematomas that would contradict the claimed intention of SILS to offer less bodily trauma as compared to conventional techniques. Moreover, if SILS is associated with a higher rate of seroma or hematoma formation, these complications could jeopardize the cosmetic benefits that the procedure attempts to exploit.
Navarra et al. have reported the largest series of 30 consecutive single-incision laparoscopic cholecystectomies. In their own unpublished prospective randomization of SILS versus a conventional four-trocar approach, no significant cosmetic advantages, cost-effectiveness, or difference in postoperative pain between the two techniques were observed. In addition, they noted that the average procedure time was considerably longer, and suggest that the single large umbilical incision may have resulted in a higher incidence of umbilical hernias among their patients. SILS operative times in some series were reported to be at par with conventional laparoscopy, but a majority of the procedures were lengthy which may only be justified in patients who have special cosmetic interest.

Conclusion

NOTES and SILS are promising techniques in the field of minimally invasive surgery. Clinical data in the area of NOTES and SILS are too preliminary to draw any meaningful conclusions. Low success rates and avoidable complications as reported in some published studies raise doubts as to the future of both techniques using current technology. However, we are only at the beginning of a new minimally invasive revolution and modifications in the technological aspects of these procedures will likely yield better outcomes. Randomized studies comparing natural orifice endoscopic surgery and single-incision laparoscopy with traditional laparoscopy are necessary to evaluate the safety, efficacy, complication rates, and potential benefits, if any, that these innovative techniques may provide.

Reference:

Chamberlin R, Sakpal S, “A comprehensive review of Single Incision Laparoscopic Surgery (SILS) and Natural Orifice Transluminal Endoscopic Cholecystectomy (NOTES) techniques for cholecystectomy”, Gastrointestinal Surg., vol. 13, pp. 1733-1740, 2009.