Stones, strictures, and chronic pancreatitis

In the early 70s, ERCP offered a new approach for diagnosing chronic pancreatitis and classifying ductal abnormalities. It allowed better understanding of the disease course and decision-making about the best surgical option, if this was indicated. This had a dramatic impact clinically, as well as on surgical techniques where, in many instances, resection has been replaced by less invasive approaches. Along with the development of therapeutic biliary endoscopy, therapeutic options for main pancreatic duct drainage have been described, consisting initially of pancreatic sphincterotomy and removal of floating stones [1] and, soon afterwards, the placement of pancreatic plastic stents to bypass strictures [2] [3]. These treatments were technically challenging as most of the pancreatic calcium carbonate stones were almost impossible to remove and disimpact mechanically and the tight fibrotic strictures of the main pancreatic duct (MPD) were very difficult to dilate, especially with the devices that were available 40 years ago.

The availability of extracorporeal shock wave lithotripsy (ESWL) offered the possibility of achieving a millimetric fragmentation of almost every pancreatic stone [4]. This technique dramatically increased the indications for the endoscopic approach to pain management in chronic pancreatitis and also improved patient outcomes. It was rapidly adopted by several centers and another multicenter study, published in Endoscopy, showed that, after stone fragmentation, calibration of residual strictures with plastic stents for 1 or 2 years could lead to sustained pain relief, even after stent(s) removal, for approximately two-thirds of the patients in the mid and long term [5]. The need for ESWL for proper endoscopic management of this rare disease poses an organizational problem however, as it requires high power lithotripters, which often belong to urology departments, and a specific technique that ideally should be performed by dedicated physicians. Outside of high volume referral centers, given the rarity of the disease, such technical and human investment is difficult.

While endotherapy has replaced surgery for most benign biliopancreatic indications, including the management of symptomatic pseudocysts associated with chronic pancreatitis and pancreatic collections associated with acute pancreatitis, the elective endoscopic drainage of the MPD for pain control in chronic pancreatitis has been much more controversial. Two randomized controlled trials failed to show an efficacy similar to surgery in severe cases, with both trials having been organized by centers where ESWL was not routinely available for such patients, a feature which further illustrates the organizational problem associated with the need for dedicated ESWL for this indication. Nevertheless, real life must still be considered and many patients with painful chronic pancreatitis are not treated by surgery as their first-line management. New techniques, such as intraductal lithotripsy, may be used in selected patients, while endoscopic ultrasound-guided drainage of the MPD is now feasible, although it should be used only with extreme caution in a multidisciplinary environment for this indication.

The rationale for pain management in chronic pancreatitis should probably not be to seek the most invasive or the most sophisticated technique initially. It may be that comparing surgery and endotherapy as the initial treatment is not the right question, because both techniques are invasive and the tendency is to be too aggressive medically with these patients. An RCT comparing ESWL alone with ESWL plus endotherapy in patients with obstructive pancreatic stones did not show any difference in outcomes, but did show a clear benefit in terms of cost and medical needs for the least invasive option [6]. It showed that properly performed stone fragmentation alone was able to induce sustained pain relief in 60 % of patients with painful chronic pancreatitis and cephalic obstructive stones. This indicates that most of the studies performed in the past, or even more recently, probably included a significant proportion of patients with painful pancreatitis who could have been properly managed without any endoscopic or surgical intervention. This must be considered when designing further studies.

Most of the pioneering work on management of stones and strictures in chronic pancreatitis has been published in our journal over the last 40 years. Endoscopic management of chronic pancreatitis is a very specific and demanding area of therapeutic endoscopy. The rarity of the disease and the need for specific equipment probably justify concentrating these patients in selected referral centers, at least at the time when interventional therapy is potentially being offered for these patients. This would include therapeutic planning based on imaging and clinical presentation in an environment where all approaches are available. An assessment of such treatment tailoring would probably require the kind of patient numbers that are difficult to gather, even in a multicenter study, in our Western countries and we would definitively benefit from the help of our colleagues from India in performing such an investigation, given the high incidence of pancreatitis in this region and the concentration of patients in high volume centers where all treatment options are available [7].

Fig. 1 Endoscopic therapy of pancreatic disorders. a The most common indications to intervene the pancreas endoscopically are strictures, leaks and stones. Pancreatic stents are mostly of polyethylene, but there are also varieties made of poylurethane or plytetrafluoroethylene (Teflon). b Pancreatic stent come in many shapes and sizes, with sizes ranging from 2 to 25 cm in length and 3 Fr to 11.5 Fr in diameter. Pancreatic stents can be straight, curved, wedged, or single pigtail. With the exception of single pigtail stents, most other stents have tow distal flaps to prevent inner migration into the pancreatic duct. Some pancreatic stents have side holes supposed (but never shown) to facilitate drainage of pancreatic side ducts. For pain management, standard straight 7 Fr to 10 Fr biliary stents are usually used. Newer Generation stents have tow radiologic markers to improve radiologic visualization during Insertion and when Performing follow-up x-rays of the abdomen. Illustration: Michal Rössler. Legend and figure design: Klaus Mönkemüller.

• References

• 1 Schneider MU, Lux G. Floating pancreatic duct concrements in chronic pancreatitis. Pain relief by endoscopic removal. Endoscopy 1985; 17: 8-10
• 2 Cremer M, Deviere J, Delhaye M. et al. Stenting in severe chronic pancreatitis: Results of medium-term follow-up in seventy-six patients. Endoscopy 1991; 23: 171-176
• 3 Kozarek RA, Patterson DJ, Ball TJ. et al. Endoscopic placement of pancreatic stents and drains in the management of pancreatitis. Ann Surg 1989; 209: 261-268
• 4 Sauerbruch T, Holl J, Sackmann M. et al. Extracorporeal shock wave lithotripsy of pancreatic stones. Gut 1989; 30: 1406-1411
• 5 Roesch T, Daniel S, Scholz M. et al. Endoscopic treatment of chronic pancreatitis: A multicenter study of 1000 patients with long-term follow-up. Endoscopy 2002; 34: 765-771
• 6 Dumonceau JM, Costamagna G, Tringali A. et al. Treatment for painful calcified chronic pancreatitis: extracorporeal shock wave lithotripsy versus endoscopic treatment: a randomised controlled trial. Gut 2007; 56: 545-552
• 7 Tandan M, Reddy DN, Santosh D. et al. Extracorporeal shock wave lithotripsy and endotherapy for pancreatic calculi – a large single center experience. Indian J Gastroenterol 2010; 29: 143-148