P2120 - Predictors of Success With Extracorporeal Shock Wave Lithotripsy for Chronic Calcific Pancreatitis

Tuesday, October 26, 2021

10:30 AM – 4:00 PM PT

Location: Shoreline Exhibit Hall

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Presenting Author(s)

Ahmed Ouni, MD

Mayo Clinic
Jacksonville, FL, United States

Ahmed Ouni, MD¹, Sheetal Patel, MD², Justin O'Leary, BS¹, Nader Daoud, MD¹, Allie Metcalfe, MD¹, Victoria Gomez, MD¹
¹Mayo Clinic, Jacksonville, FL; ²University of Florida, Gainesville, FL

Introduction: Extracorporeal shock wave lithotripsy (ESWL) is an effective treatment for patients with symptomatic chronic calcific pancreatitis (CCP). However data regarding the association between pancreatic duct (PD) stone characteristics and procedural success remains very limited. Our aim was to investigate the prognostic utility of pre-procedural stone size and density on clinical and technical success after ESWL.

Methods: This was a single-center retrospective study of patients with CCP who underwent ESWL for treatment of dominant, radiopaque PD stones between 2016 and 2021. ESWL was performed using a dedicated lithotripter, delivering up to 5,000 shockwaves in the endoscopy unit. Patient demographics, PD stone size (in mm) and density (in Hounsfield Units, HU); measured by computed tomography, were abstracted. Clinical and radiographic followup were performed to determine clinical and technical success, respectively. Fishers exact, Chi-square, univariate and multivariate logistic regression were conducted to identify the association between stone characteristics and clinical and technical outcomes after ESWL.

Results: Twenty-three patients were included. Median age was 64 (IQR 54-75) years and 17 (74%) were male. Abdominal pain due to CCP was the most common indication for ESWL (18 patients; 78%). Median stone size was 9 mm (IQR 7-12), median stone density was 837 (IQR 678-1102) HU. Twenty three (100%) patients had clinical followup and 20 (87%) had technical followup. Fourteen (61%) patients had technical success and 18 (78%) had clinical success after ESWL. No statistically significant differences were observed between patients with technical success and failure in age (64.5 years vs 60.0 years, p=0.87), median stone size (8mm vs 9mm, p=0.52), or mean stone density (817 HU vs 1029 HU, p=0.20). Narcotic use at the time of ESWL was more prevalent in patients with clinical failure when compared to those with clinical success (80% of patients vs 22% of patients, p=0.03), but no differences were found between the two groups in median stone size (12 mm vs 9 mm, p=0.85) or stone density (824 HU vs 849 HU, p=0.50). On a multivariate analysis, neither stone density nor stone size were associated with clinical or technical success after ESWL (p > 0.05).

Discussion: In this single center study, PD stone size and density were not predictive of clinical or technical success after ESWL in patients with CCP. Larger studies are needed for external validation.

Age (years) Median, IQR	64 (54-75)
Sex (female) (%)	6 (26%)
BMI (kg/m²) Median, IQR	24 (20.7-28)
Etiology of pancreatitis Alcohol N (%) Tobacco N (%) Hypertriglyceridemia N (%) Idiopathic N (%)	12 (52%) 9 (40%) 1 (4%) 8 (35%)
Stone location Head N (%) Body N (%) Tail N (%) Ampulla N (%) Genu N (%)	17 (74%) 1 (4%) 1 (4%) 2 (9%) 2 (9%)
Stone characteristics imaging modality CT N (%) MRI N (%)	18 (78%) 18 (78%)
Stone size (mm) Median, IQR	9 (7-12)
Stone mean density (HU) Median, IQR Mean Min Max	837 (678-1102) 374 (298-484) 1276 (1194- 1671)
Interventions Prior intervention N (%) ESWL indication N (%) Abdominal pain Acute pancreatitis Steatorrhea Weight loss	11 (48%) 18 (78%) 8 (34%) 5 (21%) 6 (26%)
Clinical Follow up with patient after ESWL? N (%)	23 (100%)
Radiologic follow up of stone? N (%)	20 (87%)
Chronic pain issues related to pancreaticolithiasis? N (%)	16 (70%)
On narcotics at time of consultation or ESWL session? N (%)	8 (35%)

Table: Table 1 - Patient demographics and disease characteristics

Disclosures:

Ahmed Ouni indicated no relevant financial relationships.

Sheetal Patel indicated no relevant financial relationships.

Justin O''Leary indicated no relevant financial relationships.

Nader Daoud indicated no relevant financial relationships.

Allie Metcalfe indicated no relevant financial relationships.

Victoria Gomez: Olympus – Consultant.

Ahmed Ouni, MD¹, Sheetal Patel, MD², Justin O'Leary, BS¹, Nader Daoud, MD¹, Allie Metcalfe, MD¹, Victoria Gomez, MD¹. P2120 - Predictors of Success With Extracorporeal Shock Wave Lithotripsy for Chronic Calcific Pancreatitis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.