Cotton grades of difficulty of endoscopic retrograde cholangiopancreatography (ERCP) procedures7
| Grade | Procedure |
|---|---|
| 1 | Deep cannulation of duct of interest, main papilla or sampling Biliary stent removal or exchange |
| 2 | Biliary stone extraction <10 mm Treatment of biliary leaks Treatment of extrahepatic strictures (benign or malignant) Placement of prophylactic pancreatic stents |
| 3 | Biliary stone extraction >10 mm Minor papilla cannulation in divisum and therapy Removal of internally migrated biliary stents Intraductal imaging, biopsy or fine-needle aspiration Management of acute or recurrent pancreatitis Treatment of pancreatic strictures Removal of pancreatic stones that are mobile and <5 mm Treatment of hilar tumours Treatment of benign biliary strictures, hilum and above Management of sphincter of Oddi dysfunction (with or without mannometry) |
| 4 | Removal of internally migrated pancreatic stents Intraductal image-guided therapy (eg, photodynamic therapy) Removal of intrahepatic stones Pseudocyst drainage or necrosectomy Ampullectomy ERCP after a Whipple procedure or Roux-en-Y bariatric surgery |
One grade should be added (for a maximum grade of 4) for procedures performed after normal working hours, children under 3 years of age, in post-Billroth II gastrectomy patients, or for procedures that have previously failed.