Inclusion Criteria:  Consecutive patients with acute cholechystitis unsuitable for surgery age ≥ 18 years old Written informed consent from patient or guardian who is able to understand the nature and possible consequences of the study  Exclusion Criteria:  Pregnancy Patients unwilling to undergo follow-up assessments Patients with suspected gangrene or perforation of the gallbladder Patients diagnosed with concomitant liver abscess or pancreatitis (defined as elevated serum amylase more than three times the upper limit of normal) Altered anatomy of the upper gastrointestinal tract due to surgery of the esophagus, stomach and duodenum Patients with liver cirrhosis, portal hypertension and/or gastric varices Abnormal coagulation (INR > 1.5 and/or platelets < 50.000/mm3) Contraindication to perform endoscopy