Complete extraction of main pancreatic duct residual and microstones using an 8-wire basket catheter

<b>Background and study aims</b> Extracorporeal shock wave lithotripsy (ESWL), pancreatoscopy-guided electrohydraulic lithotripsy (EHL), and endoscopic retrograde cholangiopancreatography (ERCP) are primary treatments for symptomatic main pancreatic duct (MPD) stones. However, incomplete clearance of residual/microstones post-treatment may cause symptom recurrence. We hypothesized that the 8-wire biliary basket catheter could be suitable for MPD stone extraction and aimed to analyze its ability to achieve more complete clearance of MPD residual/microstones. <b>Patients and methods</b> Patients suspected of having MPD residual/microstones ≤ 5 mm because of abdominal symptoms, computed tomography examination results, and pancreatography results after previous therapy, including ERCP, EHL, and extracorporeal shock wave lithotripsy, were retrospectively enrolled. Patients with severe MPD stenosis/biliary obstruction requiring ERCP drainage were excluded. Extraction of residual/microstones was attempted using an 8-wire basket that is widely expandable in the narrow pancreatic duct and can capture and sweep stones in the narrow pancreatic duct. Technical success was defined as extraction of residual/microstones. The primary outcome was the technical success rate. Secondary outcomes were therapeutic details of stone extraction using the 8-wire basket catheter, including symptom improvements. <b>Results</b> The technical success rate was 100% for seven patients; 1 to 8 residual/microstones were extracted. An improvement was observed in five patients with symptoms after the previous therapy. Three patients underwent residual stone extraction after extraction using a dedicated basket. No patient experienced symptom recurrence during the 270-day follow-up period. <b>Conclusions</b> The 8-wire basket resulted in successful MPD residual/microstone extraction and pancreatic symptom improvement. This method may prevent symptom recurrence caused by incomplete residual/microstone clearance.