Predictive Factors Correlated with Successful Early Endoscopic Removal of Pancreaticolithiasis in Chronic Pancreatitis after Extracorporeal Shock Wave Lithotripsy

Abstract

Background: The treatment of chronic pancreatitis (CP) and symptomatic pancreatic duct (PD) calculi often involves techniques like endoscopic retrograde cholangiopancreatography (ERCP), extracorporeal shock wave lithotripsy (ESWL), or a combination of both. However, identifying predictive factors for the successful removal of these calculi remains variable. This study aimed to determine the factors predicting successful ESWL and endoscopic removal in CP and PD calculi patients.

Methods: We examined data from CP patients who underwent complete PD calculi removal via ESWL combined with ERCP between July 2012 and 2022, and assessed baseline characteristics, imaging findings, and treatment details. Patients were categorized into early- and late-endoscopic complete removal groups (EER and LER groups, respectively).

Results: Of the 27 patients analyzed, 74.1% were male with an average age of 44 ± 9.6 years. EER was achieved in 74% of the patients. Patients in the EER group exhibited smaller PD calculi diameter (8.5 vs. 19 mm, p = 0.012) and lower calculus density (964.6 vs. 1313.3 HU, p = 0.041) compared to the LER group. Notably, PD stricture and the rate of PD stent insertion were not different between the groups. A calculus density threshold of 1300 HU on non-contrast CT demonstrated 71% sensitivity and 80% specificity in predicting EER.

Conclusions: Smaller and low-density PD calculi may serve as predictors for successful EER, potentially aiding in the management of CP patients with PD calculi.

Keywords: Pancreaticolithiasis; chronic pancreatitis; endoscopic clearance; endoscopic retrograde cholangiopancreatography; extracorporeal shockwave lithotripsy; pancreatic calculi; pancreatic stone density; predictive factors.

Scheme 1

Flowchart of patient selection for data analysis. ESWL: Extracorporeal Shock Wave Lithotripsy; ERCP: endoscopic retrograde cholangiopancreatography; PD: Pancreatic duct.

Figure 1

Extracorporeal shock wave lithotripsy is conducted with fluoroscopic guidance, using the tip of the pancreatic duct stent as a reference point to locate the calculus (as denoted by the yellow arrow).

Figure 2

Endoscopic retrograde cholangiopancreatography is performed using a therapeutic side-viewing duodenoscope (Olympus, Exera TJF 190, Tokyo, Japan). (a) A pancreatogram reveals obstructive filling defect from the head to the body of MPD (as indicated by the blue arrow). (b) Retrieval of the pancreatic duct (PD) calculus using a Trapezoid Basket (Boston Scientific, MA, USA) is depicted. (c) Retrieval of the PD calculus is attempted using balloon extraction (Olympus, Medical Systems, Tokyo, Japan). (d) A pancreatogram reveals complete clearance of the calculus from body and tail of pancreas.

Figure 3

Receiver operating characteristic curve analysis for pancreatic duct calculus density reveals an area under the curve of 0.757. A density of 1300 Hounsfield units represents the most sensitive (71.42) and specific (80%) point on the curve (as indicated by the black arrow).