Effect of periampullary diverticulum morphology on ERCP cannulation and clinical results

Periampullary diverticulum (PAD) is a common anatomical variant that can potentially impact the technical difficulty and outcomes of endoscopic retrograde cholangiopancreatography (ERCP), necessitating a comprehensive understanding of its effects on the procedure. To evaluate the effect of PAD subtypes and diameter on ERCP cannulation success and clinical outcomes.

The study included patients with PAD and papilla-naïve patients undergoing ERCP for suspected common bile duct stones or distal benign strictures (due to PAD compression). PAD subtyping was based on Lobo and Li-Tanaka classifications. Diverticulum size was categorized as small (<1 cm), medium (1-2 cm), and giant (≥2 cm).

Of the 907 patients analyzed, 164 (18%) had PAD with a median age of 63 years. PAD patients were significantly older than non-PAD patients and had more comorbidities. The most frequent PAD type was 2B (34.1%) based on the Li-Tanaka classification. Subgroup analysis of PAD types 1, 2, 3, and 4 showed no statistically significant differences in cannulation time, success, total procedure time, or adverse events (AEs). Overall cannulation success rates were similar between PAD and non-PAD groups (99.4% vs 99.6%). Analysis based on diverticulum size revealed higher probabilities of giant stones and procedure-related AEs in giant diverticula. The risk of post-ERCP pancreatitis was notably low at 1.8% in the PAD group.

Diverticulum size, rather than PAD subtype, may be more closely associated with cannulation success and procedure-related AEs in ERCP. Individualized management considering diverticulum size may improve outcomes in PAD patients undergoing ERCP.