Focusing on the role of endoscopy in chronic pancreatitis management – taking nature’s help

Chronic pancreatitis is a multifactorial inflammatory condition of the pancreas characterized by recurrent or persistent episodes of abdominal pain and associated with exocrine or endocrine insufficiency. The etiology and presentation, as well as patients’ pancreatic ductal morphology, vary considerably in different parts of the world.

The treatment of symptomatic chronic pancreatitis usually depends upon the pancreatic ductal morphology, which in turn is largely dependent upon the etiology of the disease. Complex ductal morphology and stricture-predominant disease is usually seen in patients with an alcohol-related etiology whereas stone-predominant disease with a uniformly dilated pancreatic duct is seen patients with an idiopathic or genetic etiology.

“Though described as a novel alternative approach when the papilla route fails, it can be used in only the 45 % of patients with this bifid confirmation.”

Endoscopic treatment of symptomatic chronic pancreatitis has been practiced for over 25 years with varying early and medium-term clinical results, and extracorporeal shockwave lithotripsy (ESWL) has emerged as the cornerstone for treatment of patients with stone-predominant disease. Pancreatic ductal stones are peculiarly more difficult to treat as they are usually hard, multiple, and impacted in the pancreatic duct epithelium. In addition, if the pancreatic stones are associated with ductal strictures and complex disease, endotherapy results are likely to be unsatisfactory. The treatment protocol can therefore vary from endotherapy to surgery depending upon the etiology and ductal morphology [1] [2] [3] [4] [5] [6].

In a retrospective analysis in this issue of Endoscopy, Chang-Il Kwon et al. [7] have described a novel technique for decompressing the pancreatic duct through the minor papilla, in a series of 16 patients with chronic pancreatitis in whom endoscopic therapy through the major papilla and duct of Wirsung (the ventral pancreatic duct) had failed. All the 16 patients who met the eligibility criteria, had obstructing stone(s) in the duct of Wirsung that precluded passage of instruments across them. In 50 % of these patients, attempts to pulverize the stones with ESWL had failed and in 50 % ESWL had not been attempted. The authors therefore approached the main pancreatic duct through the minor papilla by going through the persistent duct of Santorini (dorsal pancreatic duct) and bypassed the obstruction by placing pancreatic stent(s). In 15/16 patients there were > 2 stones with a dilated main pancreatic duct upstream; 14/16 patients had an associated stricture downstream to the stone(s).

Clinical success was defined as significant pain improvement with patient satisfaction and no further hospital admissions for pain during the study period. In 12/16 patients (75 %), the authors achieved clinical success. In those patients who responded to initial stenting through the minor papilla, additional endoscopic retrograde cholangiopancreatographies (ERCPs) with stent upsizing were done. In 5/12 of the responders (41.7 %), the authors also performed stone removal from the upstream dilated pancreatic duct through the minor papilla. During the study period (median 196 days), 11/12 (92 %) were able to discontinue analgesics entirely. The stents through the minor papilla were kept for a median of 161 days. In 25 % patients (4/16), the treatment failed and they underwent surgery or medical management.

The authors concluded that when traditional endoscopic methods fail via the major papilla, the dorsal pancreatic duct bypass method should be considered as an alternative approach through the minor papilla.

It is important to understand that endotherapy of chronic pancreatitis can be very demanding because of the wide variability in the pathophysiology of the disease as well as in the ductal morphology. Various modalities, such as sphincterotomy, stone extraction, stent placement, and ESWL, have been used alone or in combination to treat patients who have symptomatic chronic pancreatitis. In patients having radio-opaque and hard stones, ESWL has emerged as the cornerstone of therapy. The success of ESWL, however, depends upon the hardness of the stone(s), the quality of the ESWL machine and the operator’s experience of using ESWL. Because of the variability in the pathophysiology, etiology, and pathomorphology of the disease from country to country and from region to region, the endotherapy protocols can vary widely [8] [9] [10].

In addition, it is interesting to note that the pancreas is an organ with an unusually complex embryological developmental process. The ventral bud that arises from the bile duct is connected with the bile duct through the duct of Wirsung whereas the dorsal bud leads to the minor papilla through the duct of Santorini. However the ventral bud rotates and finally comes below the dorsal bud that goes on to form a significant portion of the main pancreas. The duct of Santorini and duct of Wirsung fuse, and finally the dorsal pancreas drains through the duct of Wirsung (originally the duct of the ventral pancreatic bud) [11]. Because of this complex developmental process, five variations of the pancreatic ducts are seen in humans.

In 45.6 %, that is, almost half of cases, there is no duct of Santorini and the entire pancreas is drained through the duct of Wirsung onto the major papilla. In 4.6 % of cases there is the condition, often labelled as pancreas divisum, where the dorsal and ventral ducts have not fused during development. In this condition, the dorsal duct (duct of Santorini) drains a significant portion of the pancreas via the minor papilla, and the ventral duct (duct of Wirsung) drains the uncinate process and part of the head and opens into the major papilla, but there is no or incomplete communication between the two ducts. However, in 45 % of cases, there is a bifid configuration with a dominant duct of Wirsung opening on the major papilla and a persistent duct of Santorini joining the duct of Wirsung and opening on the minor papilla [12].

Therefore, though the authors have described this as a novel alternative approach when the major papilla route fails, it can be utilized in only the 45 % of patients who have this bifid configuration of ductal anatomy provided by nature. In addition to this limitation, their study does have some other limitations, as the authors have accepted, such as retrospective design, limited number of patients, lack of validated pain questionnaire, and a limited follow-up. 

However, in patients with chronic pancreatitis who have impacted stones and are symptomatic, endotherapy is not easy and can be associated with failure. The authors must therefore be commended on their persistence and success in finding an alternative endoscopic approach to a difficult clinical problem.

• References

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