This multicenter, prospective, open-label, randomized controlled trial compares endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) with endoscopic transpapillary gallbladder drainage (EGBS) in poor surgical candidates with acute calculous cholecystitis. Eligible patients will be randomized in a 1:1 ratio to undergo either EUS-GBD using a lumen-apposing metal stent or EGBS using a transpapillary plastic stent. The primary endpoint is clinical success, defined as successful gallbladder drainage with subsequent improvement of acute cholecystitis without the need for additional gallbladder drainage. Secondary endpoints include technical success, adverse events, reintervention rate, procedure time, length of hospital stay, and 30-day mortality. The trial aims to determine whether EUS-GBD provides superior clinical outcomes compared with EGBS in this high-risk population.

Acute calculous cholecystitis is a common condition for which early laparoscopic cholecystectomy is the standard treatment. However, some patients are poor surgical candidates because of advanced age, severe comorbidities, poor performance status, or refusal of surgery. In such cases, gallbladder drainage is required.

Endoscopic gallbladder drainage has become an alternative to percutaneous drainage because it avoids external drainage tubes and may improve patient comfort and quality of life. Endoscopic transpapillary gallbladder drainage (EGBS) is an established endoscopic approach, but it is technically challenging because selective cannulation of the cystic duct is often difficult. Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumen-apposing metal stent (LAMS) has recently emerged as a promising alternative with high technical and clinical success rates. However, prospective randomized evidence directly comparing EUS-GBD with EGBS is lacking.

This study is a multicenter, prospective, parallel-group, open-label randomized controlled trial designed to compare EUS-GBD and EGBS in poor surgical candidates with acute calculous cholecystitis. After written informed consent and confirmation of eligibility, participants will be randomized in a 1:1 ratio to either the EUS-GBD group or the EGBS group using a web-based central registration system. In the EUS-GBD group, gallbladder drainage will be performed under endoscopic ultrasound guidance using a commercially available LAMS. In the EGBS group, gallbladder drainage will be performed by a transpapillary approach with placement of a plastic stent. Procedures will be performed as early as possible after enrollment, preferably within 24 hours.

The primary endpoint is clinical success, defined as successful gallbladder drainage followed by improvement of acute cholecystitis without the need for additional gallbladder drainage. Secondary endpoints include technical success, procedure-related adverse events, reintervention rate, procedure time, length of hospital stay, and 30-day mortality. Long-term follow-up data, including recurrent cholecystitis, late adverse events, reinterventions, and survival, will also be collected.

The study aims to establish high-level evidence regarding the optimal endoscopic gallbladder drainage strategy for poor surgical candidates with acute calculous cholecystitis.

Inclusion Criteria:

• Diagnosed with acute calculous cholecystitis according to the Tokyo Guidelines 2018 diagnostic criteria.
• Poor surgical candidate for cholecystectomy, determined comprehensively based on clinical condition, including advanced age, comorbidities, performance status, anesthetic risk, or patient refusal of surgery.
• Requires gallbladder drainage for treatment of acute cholecystitis.
• Age 18 years or older at the time of consent.
• Provides written informed consent before study enrollment.

Exclusion Criteria:

• No gallstones identified.
• Suspected gallbladder carcinoma.
• Gallbladder perforation.
• No gallbladder distension.
• Surgically altered anatomy.
• Concomitant common bile duct stones.
• Bile duct stricture.
• Massive ascites.
• Gastric or duodenal stenosis.
• Considered unsafe for endoscopic intervention.
• Pregnant or possibly pregnant.
• Judged unsuitable for the study by the investigator.