Commentary on “Feasibility and Safety of Functional Cholecystectomy by Pure NOTES: A Pilot Animal Study”

Liu et al. ¹ detail their experience with natural orifice translumenal endoscopic surgery (NOTES) along with a unique approach to treat cholelithiasis. Using a standard gastroscope, these investigators utilized a transvaginal portal to access the peritoneal cavity in 8 pigs. Subsequently, the cystic duct was clipped, and the gallbladder was entered using an injection needle to suction the bile. The gallbladder wall was then incised for 2 cm, and the mucosa of the gallbladder was examined. The gallbladder wall was closed with clips in 4 animals and left open in the other 4 animals. The endoscope was then retrieved, and the vaginal wall was closed with clips as well. Postoperatively, all animals survived and resumed a regular diet. Four weeks later, the animals were euthanized. When the researchers examined the abdomen, there was no evidence of bile, blood, mucin, or enteric contents. The gallbladder specimens were extracted en bloc. The clips were intact on the cystic duct, and the re-approximated gallbladder wall was well healed without evidence of bile leakage.

Initially, this article might engender the quote that “Two wrongs don't make a right” as the investigators from China bring two provocative modalities to the table. First, the authors promote a NOTES approach to the gallbladder to garner access to the biliary system. Their operative technique is based on previous work that has appeared in numerous journals since 2007. ² These previous studies were accomplished after animate and inanimate work at various institutions and then performed clinically in humans with a multidisciplinary team.^3,4 To date, this initial interest in NOTES has only engendered a small blip on the evolutionary timeline of surgery. A few centers have truly embraced the technology and incorporated these endoscopic techniques into their daily algorithms for patient care. However, NOTES continues to evolve and has spawned innovative procedures such as peroral endoscopic myotomy (POEM). ⁵

POEM has nestled quite comfortably among surgeons and gastroenterologists. This modality has not only gained traction at highly specialized centers but seems to be traversing along the “early majority” aspect of the consumer curve. The procedure itself does not alter the long-standing principles that Heller established a century ago. All of the surgical steps within POEM follow a seamless progression, and the violated lumens are closed easily under direct vision. This new technique requires a degree of finesse and uses a skill set that most surgeons have placed on the shelf. Clearly, anyone who gasped and squawked at the appendectomy by Reddy and Rao ⁶ in 2004 should now appreciate the offspring of that initial NOTES procedure. Therefore, the approach of Liu et al. ¹ to the gallbladder should not be admonished.

The second provocative aspect from this article entails the use of cholecystolithotomy via cholangioscopy. Presently, the standard of care in the Western hemisphere is a cholecystectomy for cholecystitis. Depending on patient presentation and co-morbidities, other modalities may be indicated, including a cholecystostomy tube that is placed via interventional radiology, laparoscopy, or laparotomy. As well, subtotal cholecystectomies have been utilized secondary to difficult anatomy or varices associated with portal hypertension. Although cholecystolithotomy has appeared in the literature, ⁷ it has not gained traction clinically because of the likely recurrence rate associated with this technique. Liu et al. ¹ attempt to sidestep the potential recurrence rate by clipping the cystic duct and depriving the gallbladder of precious bile. The authors rationalize this approach by noting that the proposed procedure avoids difficult anatomy, removes the offending gallstones, and circumvents the dissection along the hepatic fossa.

However, the proposed procedure still requires clipping of the cystic duct. From a procedural standpoint, it is unclear how many bile duct injuries would be averted by simply clipping the duct as opposed to clipping and dividing the cystic duct. Theoretically, this might avoid converting a few minor ductal injuries into major injuries. Regardless, the simple act of placing a clip may engender a ductal injury as the dissection still requires isolation and clipping of the duct. The proposed procedure would then remove the offending gallstones followed by closure of the gallbladder incision. However, the organ would be obstructed against a clipped duct. The authors state that the absorptive capacity of the gallbladder is greater than its secretory capacity and that hydrops would be averted. This may be true pathophysiologically in animal models, but this has not been validated in human applications. From a clinical standpoint, most surgeons have encountered a solitary stone wedged in the gallbladder neck associated with hydrops. A clip placed on the cystic duct would only replicate this clinical scenario. The authors combat this situation by leaving the gallbladder wall patent to drain mucin into the peritoneal cavity. Again, this scenario is not clinically appealing based on the body of literature regarding intraperitoneal mucin secreted from the appendix and ovary. These relatively benign secretions have devastating results with poor long-term outcomes. Moreover, an incision in the gallbladder risks soiling the peritoneal cavity with purulent material and spilling multiple stones. Finally, the risk of seeding the peritoneal cavity with an incidental gallbladder cancer is unknown but is certainly not appealing from an oncologic standpoint.

At this time, it would be difficult for a surgeon to adopt and perform a cholecystolithotomy. Quite simply, if a patient tolerates general anesthesia and the cystic duct has been safely and successfully clipped, then the gallbladder should be removed because the majority of the potential morbidity has been averted. Overall, the authors seem to provide two hammers seeking the proper nail. NOTES has certainly found a home with POEM, and further technological advances may propel the platform forward to address a host of other diseases. Similarly, NOTES drainage with and without closure of an intra-abdominal organ, as proposed by Liu et al., ¹ may be applicable for other pathologic entities such as ovarian cysts, foreign bodies, lymphoceles, occult gastrointestinal bleeding, and possibly gastrointestinal stromal tumors. Currently, it would be difficult to advocate a surgical cholecystolithotomy without more data. It is hoped that further work from Liu and colleagues will clarify some of these major issues. Regardless, their work should remind other investigators about the limitless potential of NOTES.