Obstructive Pancreatitis

Obstructive pancreatitis is a form of chronic pancreatitis that develops when something blocks or narrows the main pancreatic duct, causing inflammation and damage to the pancreas over time.

Table of contents

• What Is Obstructive Pancreatitis?
• Causes of Obstruction
• Signs and Symptoms
• How It Is Diagnosed
• Treatment Options

What Is Obstructive Pancreatitis?

Obstructive pancreatitis occurs when something blocks or creates a narrowing in the pancreatic duct, the tube that carries digestive enzymes from the pancreas to the small intestine^[1]. When this duct becomes blocked, the digestive enzymes that the pancreas produces cannot flow normally. Instead, they build up and become activated while still inside the pancreas, causing the organ to become inflamed and damaged^[1].

Unlike other forms of chronic pancreatitis that are commonly caused by alcohol use, obstructive pancreatitis develops specifically because of a physical blockage in the pancreatic duct system^[4]. This condition can lead to permanent changes in the pancreas over time, including scarring and loss of normal function^[5].

The pancreas is an organ located behind the stomach that has two main jobs: it produces enzymes that help digest food, and it makes hormones like insulin that regulate blood sugar levels^[1]. When obstructive pancreatitis damages the pancreas, both of these functions can be affected.

Causes of Obstruction

Several different conditions can cause obstruction of the pancreatic duct and lead to obstructive pancreatitis. One of the most common causes is gallstones that slip out of the gallbladder and block the bile duct or pancreatic duct^[2]. This prevents pancreatic enzymes from traveling to the small intestine and forces them back into the pancreas, where they begin to irritate and damage pancreatic cells^[2].

Other causes of obstruction identified in surgical cases include duodenal wall cysts, problems with pancreas divisum (an anatomic variation where the pancreatic ducts don’t join normally), tumors blocking the duct, ectopic pancreatic tissue, and blockage by foreign material^[4]. In some cases, the obstruction can be caused by strictures or narrowing of the duct, stones within the pancreatic duct itself, or pseudocysts (fluid-filled sacs that develop as complications of pancreatitis)^[5].

Anatomic abnormalities present from birth, such as pancreas divisum or choledochal cysts, can also create conditions that lead to obstruction^[3]. Tumors of the pancreas should be considered as a potential cause, especially in patients older than 40 years of age who develop pancreatitis without another clear cause^[3].

Signs and Symptoms

The main symptom of obstructive pancreatitis is pain in the upper part of the abdomen^[5]. This pain typically spreads to the back and can vary in how severe it feels^[1]. The pain may come and go, but it usually doesn’t disappear completely^[1]. Many people notice the pain becomes worse after eating^[1].

The abdominal pain may feel better when sitting upright, leaning forward, or curling in a ball, and it may feel worse when lying flat, coughing, exercising, or eating larger meals^[1]. Some people may feel tenderness when the abdomen is touched^[1].

As chronic obstructive pancreatitis progresses and damages the pancreas, other symptoms may develop. These include indigestion and pain after eating, loss of appetite and unintended weight loss, and fatty or oily bowel movements that may float in the toilet^[1]. These symptoms occur because the damaged pancreas can no longer produce enough digestive enzymes to properly break down food, especially fats^[1].

Nausea and vomiting may also occur^[2]. In some cases, people may develop jaundice, a yellowing of the skin or eyes, particularly if the obstruction involves the bile duct^[6].

How It Is Diagnosed

Diagnosing obstructive pancreatitis requires careful evaluation by healthcare professionals. If obstructive pancreatitis is suspected, contrast-enhanced computed tomography (CT), which is a detailed imaging scan, is typically the best initial test for diagnosis^[5]. This scan can show gallstones, the extent of inflammation, and signs of obstruction in the pancreatic duct^[2].

However, CT scans may not always show changes in the early stages of the disease^[5]. When this happens, other imaging methods may be needed. These include magnetic resonance imaging (MRI), magnetic resonance cholangiopancreatography (MRCP), or endoscopic ultrasonography, sometimes with a biopsy^[5].

Endoscopic ultrasonography is often preferred over endoscopic retrograde cholangiopancreatography (ERCP) for diagnosis because it is safer and can evaluate both the pancreatic tissue and the duct system^[5]. During endoscopic ultrasound, a thin tube with a camera and ultrasound device is inserted through the mouth and into the digestive system to get detailed images of the pancreas and surrounding structures^[2].

Blood tests are also performed to check levels of pancreatic enzymes and assess how the pancreas and related organs are functioning^[2]. Diligent pre-operative assessment is important because identifying the specific cause of obstruction helps determine the best treatment approach^[4].

Treatment Options

Treatment for obstructive pancreatitis focuses on relieving the blockage and managing symptoms. The specific approach depends on what is causing the obstruction and how severe the condition has become.

Endoscopic procedures can be used to treat certain types of obstructions. During an ERCP procedure, doctors can insert special tools through an endoscope to open blocked ducts, break up or remove gallstones, remove tumors in the ducts, or place stents (small tubes) to keep ducts open and restore the flow of pancreatic fluid^[15]. Endoscopic treatment is recommended for symptomatic strictures, stones, and pseudocysts^[5].

If gallstones are the cause of the obstruction, they may need to be removed, followed by removal of the gallbladder in a procedure called cholecystectomy^[11]. Ideally, the gallbladder should be removed within two weeks of an attack of pancreatitis unless the person is too unwell for surgery^[12].

For some patients, surgery becomes necessary, particularly when endoscopic treatment is not sufficient or when there are complications^[4]. The type of surgery depends on whether the pancreatic duct is enlarged. Decompressive surgical procedures, such as lateral pancreaticojejunostomy (a procedure that creates a new connection between the pancreatic duct and the small intestine), are used for large duct disease when the pancreatic duct is dilated to 7 millimeters or more^[5].

Resection procedures, such as the Whipple procedure or pancreaticoduodenectomy, are used for small duct disease or when there is enlargement of the head of the pancreas^[5]. In reviewed surgical cases, all patients with obstructive pancreatitis underwent pancreaticoduodenectomy^[4]. These surgical procedures typically result in significant pain relief^[5].

Pain management is an important part of treatment. Medications for pain relief are given to help control discomfort^[11]. Patients may also need pancreatic enzyme supplements in pill form to help their body digest fat and protein properly^[19].

Dietary changes are also important. Patients are typically advised to eat a low-fat diet with small, frequent meals instead of three large meals^[5][19]. It is critical to avoid alcohol completely, as it can worsen the condition^[5][19]. Stopping tobacco use is also recommended^[5].