Table 3.

AAST EGS grade descriptions of acute cholecystitis severity.

Grade	Description	Imaging	Operative	Management
Grade I	Localized gallbladder inflammation	Wall thickening, pericholecystic fluid, nonvisualization of the gallbladder	Localized inflammatory changes	Laparoscopic cholecystectomy with low risk of conversion to open.
Grade II	Distended gallbladder with purulence or hydrops, necrosis/gangrene of wall noted without iatrogenic perforation	Above plus air in the gallbladder lumen, wall or biliary tree	Distended gallbladder with pus/hydrops, nonperforated wall necrosis/gangrene	Laparoscopic cholecystectomy with low risk of conversion to open.
Grade III	Noniatrogenic perforation with bile located to RUQ	Extraluminal fluid collection limited to RUQ	Noniatrogenic gallbladder wall perforation with bile limited to RUQ	Laparoscopic cholecystectomy with risk of conversion to open. Consider percutaneous, cholecystostomy, if severe comorbidities.
Grade IV	Pericholecystic abscess, bilioenteric fistula, gallstone ileus	RUQ abscess, bilioenteric fistula, gallstone ileus	Pericholecystic abscess, bilioenteric fistula, gallstone ileus	Laparoscopic cholecystectomy with high probability of conversion to open. Consider open cholecystectomy initially. Consider percutaneous cholecystostomy if severe comorbidities.
Grade V	Grade IV disease but with generalized peritonitis	Free intraperitoneal fluid	Above with generalized peritonitis	Laparoscopic cholecystectomy with high probability of conversion to open. Consider open cholecystectomy initially. Consider percutaneous cholecystostomy if severe comorbidities.