Pancreatoscopy guided lithotripsy for difficult pancreatic duct stones: Evidence and treatment selection in chronic pancreatitis

Table 1 Phenotype-driven features that define difficult pancreatic duct stones

Domain	High-yield features	Clinical implication	Preferred action/caveat
Stone phenotype	> 5 mm size, impaction, multiple or chain-like burden, radiolucency, high CT attenuation, poor fluoroscopic target	Predicts failure of simple ERCP extraction and informs selection between intraductal and extracorporeal fragmentation	Classify size, density, location, burden, and radiopacity before ERCP; avoid repeated extraction attempts when mechanical failure is predictable
Duct anatomy	MPD diameter, downstream dominant stricture, tortuosity, angulation, side-branch disease, inflammatory head mass	Determines pancreatoscope passage, fragment clearance, drainage durability, and need for stricture therapy	Treat drainage and stricture control as part of the same obstruction syndrome, not secondary details
Access route	Major papilla, minor papilla, pancreas divisum, surgically reconstructed anatomy, EUS-guided access route	May favor conventional ERCP, pancreatoscopy, ESWL, surgery, or expert-center antegrade salvage	Avoid intraductal lithotripsy when safe access and drainage are not achievable
Pain and patient phenotype	Intermittent vs constant pain, opioid use, admissions, malnutrition, diabetes, exocrine insufficiency, central sensitization	Determines probability that ductal clearance will translate into durable clinical benefit	Assess pain and QoL before committing to repeated endotherapy; involve pain, nutrition, and diabetes care early
System factors	ESWL availability, pancreatoscopy expertise, anesthesia, trained assistants, quality monitoring, pancreatic surgery backup	A technically attractive modality may be locally unsafe, unavailable, or inefficient	Use local capability honestly; refer when required expertise or backup is not available

CT: Computed tomography; ERCP: Endoscopic retrograde cholangiopancreatography; MPD: Main pancreatic duct; EUS: Endoscopic ultrasound; ESWL: Extracorporeal shock wave lithotripsy; QoL: Quality of life.

Table 2 Current cholangiopancreatoscopy/pancreaticobiliary scope platforms relevant to pancreatic duct therapy

Manufacturer	Platform/processor	Reusable or single-use	Typical access route	Approximate outer diameter/working length	Working channel	Diagnostic/therapeutic versions or accessories	Pancreatic relevance/caveat
Boston Scientific	SpyGlass DS/DS II Digital Controller with SpyScope DS II catheter	Single-use digital catheter-based cholangiopancreatoscope	Duodenoscope-assisted transpapillary access	Approximate distal tip 10.5 Fr/3.5 mm; working length approximately 214 cm; requires large duodenoscope channel	Approximately 1.2 mm channel	Diagnostic visualization; compatible with EHL and LL fibers/probes within channel constraints	Most commonly reported modern platform; duct caliber and downstream stricture can limit passage
Boston Scientific	SpyGlass Discover Digital Catheter	Single-use digital catheter designed for surgical/endoscopic pancreaticobiliary use	Short-access or operative access routes depending on setup	Approximate distal tip 10.5 Fr/3.5 mm; working length approximately 65 cm	Approximately 1.2 mm channel	Diagnostic and therapeutic pancreaticobiliary visualization with compatible accessories	May be relevant to altered access or operative settings; pancreatic duct use depends on local indication and equipment
Micro-Tech	eyeMAX cholangiopancreatoscopy platform	Single-use digital scopes in different outer-diameter/channel configurations	Duodenoscope-assisted transpapillary access	Reported configurations include approximately 3.2-3.9 mm outer diameter; working length depends on model	Reported channels approximately 1.2-2.0 mm depending on model	Diagnostic and therapeutic versions/accessory compatibility varies by region	Larger channel may aid accessory passage but may require larger duct/access; verify local regulatory availability
Olympus	CHF-B260/CHF-B290 mother-baby pancreatocholangioscopes	Reusable fiber/video cholangiopancreatoscopes	Mother-baby system through duodenoscope	Approximate outer diameter around 3.4 mm for older systems; working length/model-specific	Approximately 1.2-1.3 mm channel depending on model	Diagnostic visualization and selected therapy with compatible accessories	Reusable mother-baby systems require two operators and are less widely used than single-operator platforms
Olympus	CHF-BP260 ultra-slim pancreatocholangioscope	Reusable ultra-slim fiber/video scope	Mother-baby or special access routes	Approximate outer diameter around 2.8 mm; working length/model-specific	Approximately 0.8 mm channel	Primarily diagnostic or limited therapy due small channel	Smaller diameter may help narrow ducts but restricts lithotripsy accessories
CenterPoint Systems	Dragonfly Pancreaticobiliary Scope and Digital Controller	Single-use digital catheter and controller	Duodenoscope-assisted transpapillary access	FDA-cleared specifications report approximately 3.6 mm outer diameter and 139 cm working length	Working channel approximately 5.1 Fr	Diagnostic and therapeutic pancreaticobiliary endoscopy with compatible accessories	Newer platform; published pancreatic stone outcome data remain limited
Tangent Endoscopy	Tangent Single-Use Digital System	Single-use digital catheter and controller	Pancreaticobiliary endoscopy via compatible endoscope/access route	FDA-cleared specifications report approximately 3.3 mm shaft outer diameter and 650 mm working length	Approximately 1.6 mm channel	Diagnostic and therapeutic pancreaticobiliary use with compatible accessories	Newer platform; real-world pancreatic lithotripsy evidence is limited

Specifications are manufacturer- or regulator-reported approximations and may vary by model, catalog number, region, and date of procurement. This table is intended for clinical orientation and should not substitute for local device verification. EHL: Electrohydraulic lithotripsy; LL: Laser lithotripsy; FDA: United States Food and Drug Administration.

Table 3 Primary pancreatoscopy guided lithotripsy studies and clinically relevant quantitative endpoints

Ref.	Design/population	Sample size	Lithotripsy modality	Technical/clearance result	Clinical result	AEs/follow-up	Major limitation/practical inference
Attwell et al[19], 2015	Multicenter United States retrospective/prospective follow-up experience in calcific CP	28	LL	Successful stone fragmentation/clearance in most patients; early evidence that LL could be performed during ERCP with POP	Pain improvement reported during follow-up	AEs occurred but were generally manageable; follow-up heterogeneous	Small nonrandomized cohort; older platforms; limited phenotype stratification
Brewer Gutierrez et al[18], 2019	International multicenter retrospective study at 17 tertiary centers	109	EHL 59; LL 50	Complete ductal clearance 899%; single-session success 73.5%; > 3 stones predicted repeat sessions	Clinical endpoints less standardized than technical endpoints	AEs 10.1%; median follow-up 210 days	Expert-center retrospective design; no randomized comparator
van der Wiel et al[20], 2022	Prospective single-center consecutive case series of first-line EHL in obstructive CP stones > 5 mm	34 included; 26 with successful duct cannulation	EHL	Complete or partial clearance in 24/34; technical success after duct cannulation 92.3%; complete clearance 80% of treated patients	Izbicki pain score improved from 62.3 to 27.5 at 6 months	Acute pancreatitis in 7 patients, all mild; median 2 ERP and 1 EHL procedure	Duct cannulation failure excluded from technical denominator; single-center expertise
Bick et al[21], 2022	Comparative retrospective cohort: Single-operator pancreatoscopy-guided intraductal lithotripsy vs ESWL	18 POP; 240 ESWL	EHL/LL	Clearance 889% vs 86.7% with ESWL	Clinical response not uniformly patient-reported	Complications 5.6% vs 6.3%; fewer total procedures and shorter cumulative procedure time with POP	Selection bias; small POP group; historical/Local practice effects
Gerges et al[22], 2023	Prospective multicenter cohort of digital single-operator pancreatoscopy for symptomatic pancreatic duct stones	40 enrolled	EHL and/or LL	High complete clearance in selected patients with limited head/body stone burden	Overall pain relief reported in most evaluable patients at 6 months	Serious AEs 12.5%, conservatively managed	Highly selected anatomy; moderate sample size; no randomized comparator
de Rijk et al[23], 2023	Long-term observational follow-up of first-line EHL compared with historical ESWL cohort	19 EHL; 18 ESWL	EHL	Long-term treatment success at least comparable to historical ESWL; recurrence 37% vs 61%	Sustained clinical success 58% in EHL group	Median follow-up 35.0 months EHL and 76.5 months ESWL; QoL not significantly different	Historical comparison; small cohorts; follow-up duration imbalance
Iwata et al[24], 2024	Multicenter retrospective cohort: Disposable POP-guided lithotripsy vs ESWL	19 POP; 47 ESWL	EHL 13; LL 4; mixed or failed in some	Treatment success 78.9% vs 70.2%; median sessions 1 vs 5	Clinical symptoms heterogeneous	Complications 21.0% vs 6.3%; POP complications included hyperamylasemia and MPD perforation	Small POP group; nonrandomized treatment assignment; era and technology effects
Conrad et al[25], 2025	Retrospective multicenter long-term study after successful digital single-operator video pancreatoscopy-guided lithotripsy	58	EHL	Sustained ductal and clinical outcomes in selected patients with initial success	Pain relief 70.7% at month 3, persisting through 24 months; QoL not consistently improved	AEs 26%, mostly mild/moderate pancreatitis	Enriched for initial technical/clinical success; limited generalizability
Yoshida et al[26], 2026	Retrospective predictor study of POP-guided EHL without ESWL	Noted in article; cohort focused on pancreatic duct stones treated with EHL	EHL	CT attenuation > 2050 HU and diameter > 12.8 mm predicted incomplete EHL	Clinical outcomes linked to clearance predictors	AE details center-specific	Thresholds require external validation before universal use

CP: Chronic pancreatitis; LL: Laser lithotripsy; ERCP: Endoscopic retrograde cholangiopancreatography; POP: Per-oral pancreatoscopy; AE: Adverse event; EHL: Electrohydraulic lithotripsy; ERP: Endoscopic retrograde pancreatography; ESWL: Extracorporeal shock wave lithotripsy; QoL: Quality of life; MPD: Main pancreatic duct; CT: Computed tomography; HU: Hounsfield units.

Table 4 Extracorporeal shock wave lithotripsy centered therapy vs pancreatoscopy guided lithotripsy

Domain	ESWL-centered therapy	Pancreatoscopy-guided lithotripsy	Clinical interpretation
Evidence maturity	Longer experience base, guideline-supported for radiopaque obstructive MPD stones ≥ 5 mm in pancreatic head/body	Growing evidence base with prospective and multicenter cohorts but fewer randomized data	Treat as complementary modalities; avoid claims of routine replacement
Best-fit stone phenotype	Large, dense, multiple, chain-like, radiopaque, or diffuse burden; favorable radiographic targeting	Limited stone burden; impacted or radiolucent/poorly fluoroscopic target; favorable duct access; realistic same-session clearance	Stone size alone is insufficient; CT attenuation, radiopacity, duct caliber, and strictures matter
Procedure burden	Often staged; may require multiple ESWL and ERCP sessions	May reduce total sessions in selected cohorts but can increase single-session complexity	Discuss expected session burden and anesthesia exposure before treatment
Advantages	Nonintraductal fragmentation; broad historical evidence; useful for large radiopaque burdens	Direct visualization, targeted fragmentation, immediate reassessment of fragments/strictures, potential same-session clearance	Choose by phenotype and local capability
Limitations	Availability, targeting of radiolucent stones, multiple sessions, modest link between clearance and durable pain benefit	Requires advanced pancreatic ERCP, adequate duct caliber/access, irrigation control, expertise, device cost, AE monitoring	Referral is preferable to low-volume improvisation
Safety profile	Pancreatitis, bleeding, pain flare, steinstrasse/fragment obstruction, need for staged ERCP; pooled AE rates generally around 10% in meta-analyses	PEP, hyperamylasemia, bleeding, infection, ductal trauma/perforation, stent-related events; cohort AE rates range from below 10% to > 20% depending on definitions and follow-up	Use standardized AE definitions and PEP prevention bundle
Patient-centered endpoints	Pain relief may occur but sham-controlled data show only modest short-term benefit in some populations	Pain improvement reported in selected cohorts; QoL improvement inconsistent	Clearance is a technical endpoint; pain, QoL, opioids, admissions, nutrition, and later surgery must be tracked
When surgery should enter	Early when head-dominant inflammatory disease, complex strictures, repeated ESWL/ERCP failure, opioid escalation, or low chance of durable drainage	Early when POP would require repeated high-risk sessions, access is unsafe, or ductal clearance is unlikely to reverse pain biology	Surgery should be parallel-consulted in red-flag phenotypes, not delayed until all endoscopy fails

ESWL: Extracorporeal shock wave lithotripsy; MPD: Main pancreatic duct; CT: Computed tomography; ERCP: Endoscopic retrograde cholangiopancreatography; AE: Adverse event; PEP: Post-endoscopic retrograde cholangiopancreatography pancreatitis; QoL: Quality of life.

Table 5 Scenario-based treatment selection

Clinical scenario	Preferred initial strategy	Rationale	Caveat
Small, mobile stone(s) without major downstream stricture	Conventional ERCP extraction	Fragmentation may be unnecessary when balloon or basket extraction is likely to succeed	Proceed if duct access is safe and drainage is achievable; avoid over-escalation
Limited 5-10 mm burden, favorable duct caliber, impacted or poorly fluoroscopic/radiolucent stone	Selective upfront POP-guided EHL or LL	Direct visualization can reduce targeting uncertainty and allow same-session reassessment	Best in expert centers with clear stopping rules and stent/drainage plan
Very large, high-density, radiopaque, multiple, chain-like, or diffuse burden	ESWL-centered pathway plus ERCP	Extracorporeal fragmentation may be more efficient than prolonged intraductal therapy	Consider CT attenuation and expected sessions; POP can be adjunct or rescue
Dominant downstream stricture with obstructing stone	Stricture-focused drainage strategy with dilation/stenting plus definitive fragmentation	Fragmentation without outflow correction often fails clinically	Stage therapy if necessary; reassess duct caliber and fragment clearance before repeating lithotripsy
Inflammatory head-dominant disease, complex strictures, repeated failed endotherapy, persistent opioid escalation	Early pancreatic surgery consultation	Randomized and health-economic evidence supports early surgery in selected painful obstructive CP	Do not use pancreatoscopy to postpone indicated surgery
Minor papilla access, postsurgical reconstruction, failed transpapillary access, or EUS-guided antegrade route	Individualized expert-center salvage strategy	Alternative access may enable therapy but evidence is limited and AE risk is meaningful	Reserve for high-volume centers with multidisciplinary backup

ERCP: Endoscopic retrograde cholangiopancreatography; POP: Per-oral pancreatoscopy; EHL: Electrohydraulic lithotripsy; LL: Laser lithotripsy; ESWL: Extracorporeal shock wave lithotripsy; CT: Computed tomography; CP: Chronic pancreatitis; AE: Adverse event; EUS: Endoscopic ultrasound.