Endoscopic ultrasound-assisted transmural cholecystoduodenostomy or cholecystogastrostomy as a bridge for per-oral cholecystoscopy therapy using double-flanged fully covered metal stent

Choledocholithiasis is a common problem that for almost the past 300 years has been treated by surgery [6]. A major step in the treatment of choledocholithiasis was the evolution from laparotomy to laparoscopy, which today remains the standard treatment for gallstones. Long-term follow-up studies have found that cholecystectomy is associated with an increased incidence of dyspepsia, calculus of the common bile duct, and colon carcinoma. There are also serious complications associated with the procedure, including hemorrhage, bile duct injury, bile leakage, and abdominal infection [11‐13]. For these patients whose still have good gallbladder functions, gallbladder-preserving cholecystolithotomy should be considered. Laparoscopic, transcutaneous and endoscopic methods were reported in the previous studies [14‐18]. In our study, EUS-guided trans-GI tract cholecystolithotomy has the advantages of sampler, preciser and less invasive (scarless).

Between 10 and 18 % of patients undergoing laparoscopic cholecystectomy (LC) for gallbladder stones also have concurrent common bile duct (CBD) stones [19]. The most popular approach to treating CBD stones detected prior to LC is with ERCP, followed by LC [20]. This two-stage approach has some disadvantages, including the risk of CBD stone passage taking place between ERCP and LC or during LC due to excessive gallbladder handling. These potential problems can be avoided by using the single-session laparoscopic approach for managing CBD stones during LC by transcystic exploration (TCE) or laparoscopic CBD exploration (LCBDE), which is as safe and effective as the ‘gold standard’ sequential ERCP followed by LC with the nearly same rate of success, length of hospital stay, and rate of complications [10]. In this study, we used a trans-gastrointestinal tract cholecystoscopy technique in treating GB disease without cholecystectomy, which may be superior in reduction of residual scarring and in preserving of gallbladder function. We also combined EST and cholecystolithotomy into a one-session procedure for those patients with both gallstones and common bile duct stones, which may become another popular alternative treatment option besides LC plus LCBDE.

Transgastric gallbladder entry through a cholecystogastric fistula formed as a complication following gallbladder surgery was first described in a case report by Chen et al. However, cholecystoenterostomy may also be a complication of gallstone disease rather than of medical intervention [21]. EUS has the ability to locate abdominal structure sprecisely [22]. In a previous animal study, we evaluated EUS-assisted transmural cholecystolithotomy performed 4 weeks after acholecystogastrostomy procedure in which a novel, fully covered metal stent was inserted in place, guided by EUS [23, 24]. Transmural cholecystogastrostomy using a lumen-apposing metal stent may not only be used to facilitate gallbladder drainage, but it may also be a technically easy method for treating cholelithiasis and polyps. The efficient anastomosis formation that we found in our study could be attributed to the lumen-apposing metal stent, which has 2 large, flared ends that firmly hold the gastric wall against the gallbladder wall. The blunted edges of the flared ends act to prevent further injury to the mucosa. The covered stents were also found to prevent bile leakage. Over the past 3 years reports of several types of lumen-apposing metal stents have been published; these have mainly found application in endoscopic pancreatic fluid collection drainage, gallbladder drainage and common bile duct drainage [25‐31]. EUS-guided transmural cholecystolithotomy by a metal stent has been reported by Itoi et al., with the stone removal performed through a lumen-apposing metal stent in a patient with acute cholecystitis, rather than through a fistula maturely formed by stent or intended to be applied in patients with good gallbladder function [32]. In our case, we used this technique as a bridge to facilitate per-oral cholecystoscopic therapy.

In our clinical study, the EUS-guided cholecystogastrostomies were all successfully performed. 7 patients experienced transient increases in Blood leucocytes and 4 developed mild fever. These incidents may have been caused by limited leakage of bile taking place during the procedure,which however did not develop into peritonitis. Other severe complications such as pneumoperitoneum, hemorrhage and dislocation of the stent, were not observed in the patients in this study, which indicates the safety of this procedure.

The optimal timing of the cholecystoscopic technique following the cholecystogastrostomy depends on the maturity of the fistula formed by the stent. It is safe to allow for 7 days for the fistula dilation, removal of gallstones and polyp resection. The fistulas were expected to completely heal within 24 h after the ENBD was removed. However, there was 1case of delayed healing of the fistula found in our study; this fistula was located at the lesser curvature of the antrum near the pylorus. Since, in this case, food debris always filled the gallbladder, we assumed that the fistula in this location may have interfered with the gastric emptying function. A trans-duodenal path may have less impact than a transgastric path in the gastric emptying function, which could therefore be a better place of puncture. However, this assumption needs further evaluation. An OTSC device was used to help in closing the fistula. According to the literature, the use of OTSC in the closing of a fistula is not very common [33‐35].

It is noteworthy that the ultrasound follow-up evaluation of 20 month showed no gallstone or polyps recurrence and the function of the gallbladder remained satisfactory. Hence this endoscopic gallbladder-preserving cholecystolithotomy or polyp resection may be an option for patients with gallstones or polyps but who still have a well-functioning gallbladder.