Patients with symptomatic pancreatic stones and suitable ductal morphology (uniformly dilated duct through the tail) on MRCP are the best candidates for endotherapy. Patients having radio-opaque stones confirmed on fluoroscopy are subjected to ESWL prior to ERCP in our unit. We do not routinely recommend ERCP prior to ESWL in patients with radio-opaque stones (5>mm in size) as pancreatic stones are hard, impacted within the duct and at times do not even allow guidewires to be negotiated around the stones. Placing a pancreatic stent prior to ESWL is not mandatory as radio-opaque pancreatic stones can easily be targeted under X-ray guidance with the ESWL machine. On the other hand, patients with radio-lucent calculi can undergo ERCP directly as these stones are soft and amenable to endoscopic basket/balloon extraction, provided they are small in size. Patients with large radiolucent calculi require additional methods like balloon sphincteroplasty of the pancreatic orifice (Video 13.1) or insertion of a nasopancreatic tube (NPT) followed by ESWL under C-arm guidance.

A thorough pre-procedure history and clinical examination are done for all patients before planning pancreatic endotherapy in the form of ESWL and ERCP. Characteristics of abdominal pain, weight loss, steatorrhoea, diabetes, alcohol/smoking habits, and details of prior therapy and surgery are noted in detail. Routine biochemistry is done which includes fasting and postprandial sugars, renal parameters, CA 19- 9, calcium, vitamin A/B12/D3 levels, and if needed parathyroid hormone. A dynamic fluoroscopic examination is performed preferably on a rotatable C-arm to assess the stones for consistency, number, and location. This is necessary to decide the approximate number of shock waves required to pulverize the stones. An MRCP is then obtained to accurately assess the pancreatic ductal morphology and look for associated pancreatic ductal strictures, bile duct strictures, pseudocyst , pancreas divisum , ductal disruption, or pancreatic mass. If a mass is suspected, a contrast-enhanced CT scan and EUS-FNA should be routinely performed. An altered anatomy, significant duodenal narrowing, and portal hypertension are considered relative contraindications for pancreatic endotherapy and alternative therapy is offered to these patients.

ESWL is performed in our unit by a trained radiology technician under the guidance of a gastroenterologist although urologists may offer this service as well. We use the Dornier Compact Delta II lithotripter (Dornier Med Tech, Wessling, Germany) with an integrated C-arm system that facilitates accurate localization of the shock waves on the radio-opaque pancreatic stones . The ideal extracorporeal shock wave lithotripter should have an isocentric shock head allowing for a small focal point of less than 5 mm (Fig. 13.3). This prevents scattering of the shock waves and damage to the surrounding pancreatic parenchyma or the kidney. The focal point energy usually ranges from 0.1 to 0.6 mJ/mm². The Dornier machine energy level can be adjusted from Level 1 (10 kV) to Level 6 (16 kV). ESWL is usually performed under intravenous sedation/analgesia or epidural analgesia because the therapy can be painful. Oxygen saturation and cardiac tracings are continuously monitored during the procedure. The procedure is usually performed with the patient in the supine position, and the shock head touching the abdomen from above. The patient is sometimes tilted to one side by placing a bolster below the back in order to achieve effective contact with the shock head. The stones are then localized in two axes perpendicular to one another and shock wave therapy is commenced. It is best to start with low-intensity shock energy at Level 1 or Level 2 and to slowly increase it. Averages of 3000–8000 shocks are delivered in one session of ESWL. This can be completed in around 120 min. Depending upon the stone load, single or multiple sessions of shock wave therapy are administered on alternate days until effective pulverization of the stones is achieved. For patients with multiple stones, on average 2–3 sessions are necessary. The end point of ESWL therapy should be complete pulverization of the stones into powder and not just fragmentation. Pulverized stones should be less than 3 mm in size and usually lose their density, shape, and spread in the duct along the longitudinal axis.

The patient then underwent ESWL to pulverize the stones. Two sessions of ESWL were given on alternate days for a total of 15,000 shocks administered (7000 & 8000). This procedure was performed with intravenous sedation , and he tolerated the procedure well. Post-ESWL, repeat fluoroscopy examination revealed nicely pulverized stones spread along the entire duct (Fig. 13.4).

We prefer to perform ERP at least 48 h after the last session of ESWL in order to allow the ESWL induced edema to settle. ERP completed less than 2 days after ESWL were associated with higher rates of failure (84 %) compared to ERP performed more than 2 days after ESWL (18 %) [14, 15]. It is done under total intravenous anesthesia with the patient in the supine or prone position to give proper anatomical orientation of the pancreatic morphology on fluoroscopy. A therapeutic duodenoscope with a working channel of 4.2 mm (e.g., TJF−160 or 180 Olympus, Tokyo, Japan; ED-3490TK, Pentax Medical, Montvale, NJ) should be used. The goal of ERCP should be complete ductal clearance of all stone material.

Initial cannulation of the pancreatic duct is best achieved using a tapered tip ERCP cannula, such as the Contour cannula (Boston Scientific, Marlborough, Massachusetts, USA). However, a tapered tip cannula from any other manufacturer can be used for this purpose. A double/triple lumen sphincterotome can also be used as this is a planned therapeutic procedure .

After performing a pancreatogram to assess the ductal morphology, a fully hydrophilic glidewire is passed through the cannula and negotiated past the pulverized stones in the pancreatic duct to the tail. The most useful wire to achieve this is a 0.035, 0.021, or 0.018 in. J tipped Terumo Glide wire (Terumo Corp., Tokyo, Japan), but other wires with a hydrophilic tip, such as the Boston Scientific Dream wire or the Cook Endoscopy Metro Tracer (Cook Medical, Bloomington, IN, USA) are also good alternatives. In patients with complete pancreas divisum, the minor papilla can be cannulated using the same accessories.

In rare instances, if direct access to the pancreatic duct (major or accessory) is not possible through the normal papillary orifice due to edema or retropapillary narrowing, and the pancreatic duct is dilated, an EUS-guided rendezvous technique can be used to enter the pancreatic duct transgastrically and then the guidewire negotiated across the papilla and coiled in the duodenum. The procedure can then be completed with the echoendoscope exchanged to a duodenoscope.

ERCP was done 48 h after effective pulverization of the stones was achieved by ESWL (Video 13.2). A diclofenac suppository (100 mg) was administered as per our routine immediately before ERCP. Pancreatogram obtained from the major papilla showed a uniformly dilated duct through the tail with filling defects in the head region. Pancreatic sphincterotomy was performed using a blended current and a standard sphincterotome (Clevercut, Olympus, Japan or Ultratome XL, Boston Scientific). Large chunks of pulverized stone fragments were then extracted using a wire guided Dormia basket (Olympus Tetra V, Japan), and partial ductal clearance was achieved. At the end of the procedure, a temporary 7 Fr single pigtail stent was placed in the pancreatic duct to ensure an unobstructed flow of pancreatic juice and allow for passage of the residual pulverized stone powder (Fig. 13.5). The patient was observed in the hospital for 2 days and then discharged. He had mild epigastric pain for a day post-ERCP which resolved with non-opioid analgesics.

Patients should be assessed immediately post-procedure for any complications, which have been reported in about 6 % of patients and consists mainly of mild pancreatitis [16]. Other less common post-ERCP complications include bleeding post-sphincterotomy, stent migration or occlusion, duct leak, and pancreatic abscess [17]. Injury to the duct usually occurs with the use of hard, stiff accessories especially in the tail of the pancreas. ESWL-related complications are minimal and include 1 % hemosuccus pancreaticus (Chap. 16) and skin or duodenal wall erythema.

In most cases, the pulverized stones cannot be completely cleared in one procedure. Thus a temporary pancreatic stent is placed to ensure continuous flow of pancreatic juice before the next session. In 3 months, a fluoroscopic examination is done to look for any residual radio-opaque stones. If radio-opaque stones are found, then a repeat session(s) of ESWL occurs before repeating the ERCP to attempt complete ductal clearance. In patients with ductal strictures and upstream stones, if the stricture has not yet resolved multiple large diameter stents (10 Fr) are placed during each subsequent ERCP until the stricture resolves and the stones can be cleared. During each follow-up , the patients are also assessed for pain relief, weight gain, and control of any exocrine and endocrine deficiencies. Pancreatic enzyme supplementation and strict control of blood sugars are advised when necessary. Abstinence from alcohol and smoking are mandatory once pancreatic endotherapy is performed.

At the first follow-up 3 months later, the patient reported significant reduction in his abdominal pain and a weight gain of 3 kg. During ERCP, the previously stent was removed and a repeat pancreatogram was done. It showed a mildly dilated pancreatic duct containing a few residual filling defects. Residual stone fragments were extracted using a basket, and complete duct clearance was achieved. The duct was flushed and irrigated with normal saline, and the patient was given a stent free trial. During subsequent visits at 3 month intervals, the patient remained pain free and had a total 8 kg weight gain. His diabetes was well controlled. At the end of 1 year following stent removal, he remained pain free.

A large amount of data including randomized trials is now available supporting the use of ESWL prior to endoscopic management of pancreatic stones . Success rates of pulverization of pancreatic stones using ESWL range between 38 and 100 %, [18], and ESWL alone can provide significant pain relief [19–21]. However, ESWL followed by ERCP has been shown to achieve the most satisfactory pain relief in patients with chronic calcific pancreatitis. The combination of ESWL with ERCP yields a stone fragmentation rate of 54–100 % and complete or partial pain relief ranging from 48 to 85 % [22–27]. Table 13.1 summarizes seven studies published to date on long-term follow-up (≥ 23 months) of patients undergoing ESWL and ERCP for patients with chronic calcific pancreatitis. The largest study by Tandan et al. [28] included 636 patients of whom 364 were followed for 2–5 years and 272 for over 5 years for nonalcoholic chronic calcific pancreatitis. Clinical outcomes were similar for both groups of patients; they experienced significant improvement in pain scores with 60–69 % remaining pain-free compared to 0 % pre-procedure and 4–6 % having severe pain compared to 25–36 % pre-procedure. Complete duct clearance occurred in 76–78 % of all patients. Weight remained stable or increased in 94–99 % of patients and quality of life improved in 93 %. The two differences between the intermediate (2–5 year) follow-up and long-term (>5 year) follow-up patients were increased need for repeat procedure (47 vs. 29 %, p = 0.007) and rate of diabetes (51 vs. 24 %, p = 0.0001) in the long-term group.