Here is the design of a clinical trial:

Official Title: A Randomized, Single-blinded, Single-center, Parallel-group, Sham-controlled, Prospective Trial of Combined Extracorporeal Shock Wave Lithotripsy and Endotherapy for Pain in Chronic Pancreatitis

Included conditions:
- Chronic Pancreatitis
- Chronic Pain

Study Armgroups:
- {'label': 'ESWL followed by ERCP', 'type': 'ACTIVE_COMPARATOR', 'description': 'Patients enrolled in the active treatment group will be subjected to ESWL followed by ERCP and pancreatic duct stenting.', 'interventionNames': ['Procedure: ESWL', 'Procedure: ERCP']}
- {'label': 'Sham ESWL followed by sham ERCP', 'type': 'SHAM_COMPARATOR', 'description': 'Patients enrolled in the sham treatment group will be subjected to sham ESWL followed by sham ERCP with no pancreatic duct intervention.', 'interventionNames': ['Procedure: Sham ESWL', 'Procedure: Sham ERCP']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'ESWL', 'description': "ESWL will be conducted under epidural anesthesia. For epidural anesthesia, bupivacaine will be used to block the T6-T12 spinal segments. The patient's eyes will be lightly covered all along the procedure. Once epidural anesthesia is achieved, the patient will be given a light sedation and ESWL will be performed using a Dornier dual focus lithotripsy system providing a maximum of 5000 at the rate of 90 shocks per minute in over 1-2 days.", 'armGroupLabels': ['ESWL followed by ERCP']}
- {'type': 'PROCEDURE', 'name': 'ERCP', 'description': 'Once ESWL is over, an endoscopic pancreatic sphincterotomy will be performed and complete stone removal will be attempted with subsequent stenting of the pancreatic duct in the presence of a pancreatic stricture (not detected on MRCP prior to enrolment) or in case of incomplete stone removal', 'armGroupLabels': ['ESWL followed by ERCP']}
- {'type': 'PROCEDURE', 'name': 'Sham ESWL', 'description': 'In the sham/control group, patients will be given a transient superficial pin-prick sensation to give the feel of epidural anesthesia. After that the lithotripsy machine the will be switched on, without establishing any form of contact with the patients body.', 'armGroupLabels': ['Sham ESWL followed by sham ERCP']}
- {'type': 'PROCEDURE', 'name': 'Sham ERCP', 'description': 'Following sham ESWL patientswill be subjected to sham ERCP to examine the papillary area, but no pancreatic ductal intervention will be performed.', 'armGroupLabels': ['Sham ESWL followed by sham ERCP']}

Primary Outcomes:
- {'measure': 'Change from baseline pain score at 3 months', 'description': 'The primary clinical endpoint is pain relief. Average and maximal daily clinical pain intensity scores will be recorded in a patient pain diary based on a 0-10 visual analogy scale (VAS), with registration of the baseline pain intensity scores the week prior to intervention and weekly recordings continued for a 3 months period after intervention. Mean values of pain scores will be calculated over 1 week to adjust for day-to-day variability in pain intensity. The difference in pain scores between patients receiving active treatment (ESWL and ERCP) and sham treatment are compared, with the primary comparison of average pain scores 3 months after intervention. Weekly telephone interviews from a study co-ordinator will be undertaken to facilitate accurate registration and compliance pain score).', 'timeFrame': '3 months after intervention'}

Please estimate the sample size based on the assumption: 
The study aims for a power of 90% with a two-sided significance level of 0.05 and accounts for a 10% dropout rate.
Sample size determination
        The study is powered to detect a minimal difference between groups of 30% in the average clinical pain score 3âmonths after intervention [34]. On the basis of an assumed SD of 45%, we determine that a study with 48 patients per group is needed to provide power of 90% (to allow secondary endpoints) with the use of a two-sided significance level of 0.05 [35]. To allow a 10% dropout rate, the sample size is set at 106 patients.