Lozova E. et al., 2025: Stone density can predict the number of ESWL treatments needed in patients with pancreatic duct calculi.
Evgenija Lozova 1, Mia Rainio 1, Marianne Udd 1, Outi Lindström 1, Taija Korpela 1, Antti Kuuliala 2, Arto Mikkola 3, Leena Kylänpää 1
1Department of Abdominal surgery, Helsinki University Hospital, Helsinki, Finland.
2Department of Bacteriology and Immunology, Helsinki University Hospital, Helsinki, Finland.
3Department of Urology, Helsinki University Hospital, Helsinki, Finland.
Abstract
Objectives: Extracorporeal shock wave lithotripsy (ESWL) with endotherapy (ET) is the first-line treatment in patients with chronic pancreatitis (CP) and main pancreatic duct stone (PDS). Our study aimed to evaluate factors that predict the outcome of ESWL in CP patients with PDS.
Methods: We retrospectively analyzed data of 166 patients with CP and radiopaque PDS. Computed tomography (CT) images were evaluated for stone density, stone size, main pancreatic duct (MPD) size, and skin-to-stone distance (SSD). Long-term pain relief results were determined via telephone interview in 100 patients.
Results: Mean stone density (MSD) > 1336 HU predicted the need to perform more than one ESWL session (odds ratio [OR]: 1.002; 95% confidence interval [CI]: 1.001 to 1.003; p = 0.002), cut-off 1336 HU yielding 71% sensitivity and 65% specificity. Denser stones required more ESWL and following ET, with ≥4 ET sessions resulting in better technical success. (OR: 3.222; 95% CI: 1.240 to 8.371; p = 0.016). Overall technical success (complete stone fragmentation in ESWL or placing a stent past the stone in ET) rate was 81.3%. Clinical success (complete or partial pain relief at the end of the treatments) rate was 83.7% and remained at the same level also in the long-term follow-up (median 5.5 years). Stone size, MPD size, or SSD were not associated with any of the study outcomes.
Conclusions: Higher MSD than 1336 HU predicts the need for more than one ESWL and ET sessions to fragment the stone and clear the duct, but when successful the long-term result is favorable.
Scand J Gastroenterol. 2025 Apr;60(4):386-393. doi: 10.1080/00365521.2025.2475084. Epub 2025 Mar 13. PMID: 40079198.
Comments 1
This is the most detailed paper on ESWL treatment of pancreatic duct calculi I remember to have reviewed. And the authors are proud of their study with “excellent clinical outcome”…”Our study is one of the biggest in terms of the sample size, which brings more power to our results.” However, they add: “Limitations of this study arise from its retrospective nature. We collected data over a 16-year period but were unable to obtain all necessary parameters for all patients.” Would be nice to see a prospective study from the authors without selection bias.
Reviewing these publications as a urologist I always wonder how slowly the urological ESWL experience with the causes of success and failure are integrated into gastroenterology: “The effect of SSD on technical outcome has mostly been investigated in conjunction with urinary stones, and pancreatic stone-related studies of this parameter are scarce.”
The only thing constant seems to be the fact that either the tissue itself or the microanatomical structure of pancreas and kidney are differentially susceptible to the ESWL inflicted trauma (1,2): Up to 4 sessions with 12.000 shocks were applied in this and other series. I ma not aware of any research on that hypothesis.
1 Wendt-Nordahl G, Krombach P, Hannak D, Häcker A, Michel MS, Alken P, Knoll T. Prospective evaluation of acute endocrine pancreatic injury as collateral damage of shock-wave lithotripsy for upper urinary tract stones. BJU Int. 2007 Dec;100(6):1339-43. doi: 10.1111/j.1464-410X.2007.07127.x. PMID: 17979932.
2 Deng T, Liao B, Tian Y, Luo D, Liu J, Jin T, Wang K. New-onset diabetes mellitus after shock wave lithotripsy for urinary stone: a systematic review and meta-analysis. Urolithiasis. 2015 Jun;43(3):227-31. doi: 10.1007/s00240-015-0761-9. Epub 2015 Mar 10. PMID: 25753541.
Peter Alken