Meadows and Chamberlain
numerous and only beginning to be addressed.7 To date, there have been only three case series of NOTES transgastric cholecystectomy reported, and all were “hybrid” in nature. The most pressing technical challenges for transgastric NOTES procedures include: (1) the lack of reliable flexible endoscopic platforms that can be used to gain safe transgas- tric entry, (2) concerns surrounding the risk of peritoneal contamination, (3) lack of current flexible instruments for retraction and dissection, and (4) development of a reliable method for gastric closure.26
Asakuma et al have reported the largest human trans- gastric “hybrid” NOTES cholecystectomy series, which involved 6 patients.45 All 6 patients underwent the procedure successfully. There were no laparoscopic or open conver- sions, and there were no postoperative complications. Mean operative time for all 6 transgastric cases was 138 minutes (range 120–180). The patients were positioned in the supine position and a 5-mm trocar was placed through the umbilicus for insufflation. A 5-mm laparoscopic scope was placed through the umbilical trocar and a gastrotomy was made anteriorly in the mid-body of the stomach under direct visualization. Transcutaneous suspension of the falciform ligament with surgical tape was used to better expose the anatomy and an additional port was placed in the right hypochondrium if needed during dissection or as an addi- tional port for retraction. All dissection, clipping, control of pneumoperitoneum, and closure of the gastric incision was performed via the umbilical trocar. The gallbladder was removed via the mouth.
Dallemagne et al have also reported on a modified “hybrid” transgastric NOTES technique in five patients.44 No peri-or postoperative complications were reported and the mean operative time was 150 minutes (range 120–180). This technique involved placing a 5-mm umbilical trocar, which was used for visualization of the gastrotomy, insufflation, monitoring of the pneumoperitoneum, and introduction of a 5-mm laparoscopic clip applier. An endoscopic monopolar needle-knife was used to create a 0.5-cm gastrotomy anteriorly in the mid-body of the stomach. Expansion of the gastrotomy was accomplished by an 18-mm balloon dilator and allowed for delivery of a 12-mm gastroscope into the peritoneal cavity. Skeletonization of Calot’s triangle was done using a flexible endoscopic blunt-tipped electrode. The cystic duct and artery were clipped using a laparoscopic clip applicator from the umbilical port. The gallbladder was separated from the liver fossa by use of blunt-tipped electrode, hook diathery, and traction achieved through the flexible endoscopic instruments. The gallbladder was pierced and drained of its contents under
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laparoscopic visualization, followed by its removal through the gastrotomy. Subsequent closure was completed using interrupted absorbable thread via a 2-mm laparoscope and a 3-mm needle holder inserted side by side into the 5-mm umbilical port. Confirmation of a tight seal was made by observing the insufflation of air into the stomach.
Transcolonic/transanal approach to NOTeS cholecystectomy
At present there have been no reported cases of a human transcolonic NOTES cholecystectomy. Similar to the trans- vaginal approach, the transcolonic approaches offers more practicality than a transgastric approach since the distance from the incision to the target region is much shorter and the abdominal cavity can be explored under conditions of optical correctness.26 That said, the curvature of the pelvis may pose a substantial obstacle when operating in the upper abdomen. Working in a skeleton model, Fiolka et al have developed a trocar with 60º curvature to avoid impact with the sacral promontorium though this instrument has not been explored in vivo.26 Although Auyang et al have described the feasibility of obtaining the critical view of safety required for performing a cholecystectomy via a transcolonic route in a cadaveric porcine model, no human validation of this approach has occurred.2
Despite the noted potential advantages of a transcolonic NOTES approach, concerns surrounding peritoneal con- tamination and leak associated with a transcolonic approach have limited its applicability and development.63 Interest- ingly, some authors have suggested that a more distal rectal approach using a modified transanal endoscopic microsurgery (TEM) technique may obviate many current concerns surrounding transcolonic NOTES. A transrectal endoscopic retrorectal access (TERA) approach has been described by Ramamoorthy et al.14 Using a porcine model, the investigators made a posterior rectotomy directly above the dentate line, and found that a flexible endoscope could be placed in the retrorectal space allowing for safe balloon dilatation and access to the retrorectal plane. Entry to the peritoneal cavity was accomplished by utilization of a needle knife. No neighboring structures were damaged during this procedure. Although this rectal entry point shows promise, numerous concerns surrounding sterility, efficacy, and potential complications remain unknown. Without sub- stantial research into colonic preparations, risk of luminal sterilization, incision site management, and development of “ideal” closure techniques, the future of transcolonic NOTES approach remains dubious in our estimation.
Open Access Surgery 2010:3