The ASGE ERCP (Endoscopic retrograde cholangiopancreatography) grading scale indicates the procedure complexity and predicts the chance of complictions.

The ERCP grading scale:

Grade 1
-Deep cannulation of duct of interest, main papilla, sampling
-Biliary stent removal/exchange

Grade 2
Biliary stone extraction < 10 mm
Treat biliary leaks
Treat extrahepatic benign and malignant strictures
-Place prophylactic pancreatic stents

Grade 3
-Biliary stone extraction > 10 mm
-Minor papilla cannulation in divisum, and therapy
-Removal of internally migrated biliary stents
-Intraductal imaging, biopsy, FNA
-Management of acute or recurrent pancreatitis
-Treat pancreatic strictures
-Remove pancreatic stones mobile and < 5 mm
-Treat hilar tumors
-Treat benign biliary strictures, hilum, and above
-Manage suspected sphincter of Oddi dysfunction (with or without manometry)

Grade 4
-Remove internally migrated pancreatic stents
-Intraductal image-guided therapy
-Pancreatic stones impacted and/or > 5 mm
-Intrahepatic stones
-Pseudocyst drainage, necrosectomy
-Papillectomy
-ERCP after Whipple or Roux-en-Y bariatric surgery

Increase 1 level (to a maximum of 4) when the patient has had Billroth II gastrectomy

ERCP adverse event rates

References:

Cotton PB, Eisen G, Romagnuolo J, et al. Grading the complexity of endoscopic procedures: results of an ASGE working party. Gastrointest Endosc. 2011;73(5):868‐874. doi:10.1016/j.gie.2010.12.036

Sahar N, La Selva D, Gluck M, et al. The ASGE grading system for ERCP can predict success and complication rates in a tertiary referral hospital. Surg Endosc. 2019;33(2):448‐453. doi:10.1007/s00464-018-6317-7