Acute cholecystitis (AC) is defined as an acute inflammatory disease of the gallbladder consequently to the presence of sludge or stones. AC accounts for 3-10% of all cases of abdominal pain. Cholecystolithiasis accounts for 90-95% of all causes of acute cholecystitis, while acalculous cholecystitis accounts for the remaining 5-10% of the cases. Laparoscopic cholecystectomy is actually the gold standard treatment for acute cholecystitis (AC) although it is always not suitable for patients who are poor candidates for surgery [ ]. In 2001 Giovannini et al. described the first EUS-guided biliary drainage (EUS-BD) through a transduodenal access with a needle knife. Subsequently, EUS-BD has considerably evolved thanks to the development of dedicated devices such as lumen apposing metal stents (LAMS), specifically designed for endoscopic ultrasound procedures. LAMS are made up of braided nitinol, that is fully covered with silicone to prevent tissue ingrowth, with wide flanges on both ends to provide anchorage.

Recently, LAMS have been incorporated into a delivery system with an electrocautery mounted on the tip which allows the device to be used directly to penetrate the target structure without the need to utilize a 19G needle, a guidewire, and a cystotome for prior dilation. Different are actually the indication of the LAMS for different disease and its use has been described for drainage of peri-pancreatic fluid collections, common bile duct (CBD), gallbladder, and for creation of gastro-jejuno anastomosis.

Recently, endoscopic gallbladder (GB) drainage was found to be a potentially revolutionary alternative for cholecystectomy for the control of symptoms, definitive treatment, or bridging therapy until surgery is possible.

Before the advent of LAMS, the standard of care of acute cholecystitis (AC) was the percutaneous drainage (PTC) and after the advent of these new stents, different series showed the higher technical and clinical success of the EUS-gallbladder drainage (EUS-GB) for acute cholecystitis, with a lower recurrence rate, than PTC. The superiority of this technique was assessed in terms of technical and clinical success, AEs and AC recurrence if compared to the endoscopic drainage. This could be explained with the use of larger caliber stents, allowing an effective drainage, with low risk of stent occlusion. Finally, a recent study with a long-term follow-up showed as the outcomes of EUS-GBD for AC were comparable with LC with acceptable rates of recurrent acute cholecystitis.

Inclusion Criteria:

• Age ≥18 years
• Patients arrived to the ER for AC with clinical and radiological evidence of AC (such as abdominal ultrasound, computed tomography or magnetic resonance)
• EUS gallbladder accessibility from the duodenum or from the stomach for the drainage
• Agree to receive follow up phone calls
• Able to provide written informed consent

Exclusion Criteria:

• Coagulation and/or platelets hereditary disorders and/or INR>1.5, PLT<50,000
• Use of anticoagulants that cannot be discontinued
• Pregnant women
• Inability to sign the informed consent

This is an observational multicentric prospective study. Data from consecutive patients with AC will be evaluated and, if eligible and agreed to participate, will be recorded in an electronic register. Patients will be followed until death or for at least 1 year after stent removal.