WSES guidelines on acute calculous cholecystitis The learning curve of single-port laparoscopic appendectomy performed by emergent operation Laparoscopic versus open appendectomy: a retrospective cohort study assessing outcomes and cost-effectiveness Laparoscopic lavage versus resection in perforated diverticulitis with purulent peritonitis: a meta-analysis of randomized controlled trials Laparoscopic cholecystectomy for acute calculous cholecystitis: a retrospective study assessing risk factors for conversion and complications WSES guidelines on colon and rectal cancer emergencies: obstruction and perforation