Patients
Patients who underwent EUS transluminal cholecystolithotomy (assisted by a guidewire or retrievable puncture anchor) in Shengjing Hospital from Jan 2017 to Dec 2018 were reviewed. The inclusion criteria were as follows: 1. patients with gallstones and recurrent cholecystitis; 2. patients refusing cholecystectomy; and 3. the GB still having satisfactory function (the GB showing satisfactory function by US with an estimated GB ejection fraction greater than 30% or at stage I or II). The exclusion criteria were as follows: 1. GB atrophy and; 2. coagulopathy or other sever comorbidity. The protocol for this retrospective review of the cases was approved by the Medical Ethics Committee. All patients provided informed consent before undergoing the procedure.
Main outcome measurement
The main outcome measures for the EUS-GBD procedure were technical success, clinical effectiveness, and adverse events, which were also compared between the guided assisted group and the RA-assisted group. The main outcome measures for the tansmural cholecystoscopic therapy were the stent indwelling time, clinical success, and adverse events.
Study device
The device used in this study was a through-the-scope LAMS with an electrocautery delivery system (12 mm/25 mm, 16 mm/35 mm; Micro-Tech/Nan Jing Co, Ltd). The stent has wide flanges on both ends, which provide anchoring within the GB. The stent is delivered through a 9F-10.5F catheter. In some patients, the retrievable puncture anchor (Figure 1) (Vedkang Inc., Changzhou, China) was applied to anchor within the GB during ECE-LAMS puncturing.
Procedure
The treatment for GB stones has two parts: first, EUS-guided GBD is performed, followed by cholecystolithotomy or polypectomy when a fistula is formed between the duodenum (stomach) and the GB. The operation was performed with all the patients under general anesthesia and in the supine position. After the cholecystolithotomy procedure, the protocol for minimally invasive endoscopic GB preserving cholecystolithotomy guideline in China (2015) was followed for the patients and they were suggested periodic US follow-up and regular ursodeoxycholic acid oral intake for at least 6 months.
Gallbladder puncture with a needle
A longitudinal echoendoscope (Pentax EG-3870-UT) with a working channel of 3.8 mm was introduced into the duodenal cavity to scan for the GB and mark the puncture point. The contact zone (i.e., the region of the duodenal wall representing the shortest distance from the GB walls) was identified. Color Doppler was then used to identify interposing vessels in order to avoid them during puncture. An EchoTip Ultra endoscopic ultrasound needle (19-gauge, Boston Scientific Corp, Marlborough, Mass, USA) was introduced via the working channel of the echoendoscope, and the GB was punctured under EUS guidance. A sample was aspirated to confirm that the punctured structure was the GB. The GB juice was emptied and the GB refilled with saline and the contrast agent for cholecystography.
Guidewire-guided stent deployment group
After the needle puncture, several loops of a guidewire (0.035 inch/480 mm; Boston Scientific, Bloomington, Ind, USA) were inserted into the GB, and then the needle was removed. Under EUS and fluoroscopic guidance, the stent was slowly deployed. When the distal end of the stent contacted the duodenal wall, the electrocautery was started and the stent was gently pushed through the duodenal wall and then the GB wall.
Under fluoroscopic surveillance, the stent was released until the distal flanges completely opened. Gentle traction was applied to pull the GB wall close to the gastric wall. Then, under endoscopic surveillance, the remainder of the stent was deployed (or the remainder stent was just released within the endoscope). EUS was used to confirm the position of the stent and rule out leakage.
Anchor-assisted stent deployment group
After the needle puncture, the RA was passed along the needle into the GB and engaged to anchor the GB. After needle withdrawal, the GB was pulled with the anchor (Figure 2) when the GB was punctured and drained using ECE-LAMS. After the procedure, the retrieval cord was pulled with a pair of forceps, so that the direction of the anchor was changed and it could be easily removed (Figure 3).
Per-oral transgastric cholecystoscopic therapy (cholecystolithotomy or GB polyp resection)
When a fistula is formed between the GI tract and the GB after cholecystostomy with ECE-LAMS, per-oral cholecystoscopy could be performed.
CT or X-ray was used to determine if the stent remained in place. The endoscope was advanced into the GB via the fistula formed by the stent. A stone basket was inserted into the GB to retrieve the stones. The basket was withdrawn from the GB, and the stones were discharged into the GI tract. After several deployments of the basket to remove stones, an endoscope was introduced into the GB to check for any remaining stones. For the polyp resection, a snare or APC can be used. The stent could be removed after the procedure or before the stone removal (Figure 4). The normal diet should be resumed 48 hours after stent removal.
Follow-up
Regular US examination should be performed at 1, 3, 6, and 12 months after the treatment in the first year and every 12 months thereafter.
Data analysis
Statistical analyses were performed using SPSS version 23.0 (SPSS Inc., Chicago, Ill,USA). Frequencies, percentages, means (±standard deviation), and medians (range) were used, as appropriate, for descriptive analysis. For categorical variables, comparisons between groups were performed with the Fisher exact test(small sample less than 40). Continuous variables with normal distribution were analyzed with the Student t test, whereas those with abnormal distribution were analyzed with the Mann-Whitney U test. All statistical testing was 2-sided.