Predictors of persistent pain after extracorporeal shockwave lithotripsy for painful chronic calcific pancreatitis

Background Extracorporeal shockwave lithotripsy (ESWL) and/or endoscopic retrograde cholangiopancreatography (ERCP) are recommended as first-line therapy for painful uncomplicated chronic pancreatitis with obstructed main pancreatic duct (MPD) in the pancreas head/body. However, predictors of pain relief after ESWL are unknown. We evaluated independent predictors of persistent pain in patients who underwent ESWL for chronic pancreatitis. Methods 640 consecutive adult patients with chronic pancreatitis, who underwent successful ESWL with ERCP and pancreatic duct (PD) stent placement, were followed for 12 months. The pain was assessed at baseline and at 12 months using the Izbicki Pain Score, with a score decrease of >50% considered pain relief. Independent predictors of pain relief were derived from logistic regression analysis. Results Of 640 patients (mean age 36.71 [SD 12.19] years; 60.5% men), 436 (68.1%) had pain relief and 204 (31.9%) had persistent pain. On univariate analysis, older age, male sex, alcohol and tobacco intake, longer duration of symptoms, dilated MPD and MPD stricture were associated with persistent pain at 12 months (P<0.05). Consumption of alcohol (odds ratio [OR] 1.93, 95%CI 1.26-2.97), tobacco (OR 4.09, 95%CI 2.43-6.90), duration of symptoms (OR 1.02, 95%CI 1.01-1.04), MPD size (OR 1.22, 95%CI 1.11-1.33), and MPD stricture (OR 8.50, 95%CI 5.01-14.42) were independent predictors of persistent pain. Conclusions Alcohol, tobacco, duration of symptoms, MPD size and stricture were independent predictors of persistent pain after successful ESWL. A multidisciplinary team approach that includes behavioral therapy and surgical options should be considered for such patients.