Biliary Obstruction Chronic pancreatitis is an inflammatory process that is progressive in nature. It is not uncommon to find involvement of the bile duct (2.7–9%) as it courses through the head of the pancreas. Inflammation and scarring, as well as pseudocysts in the pancreatic head, may result in common bile duct strictures. In most fibrosing biliary strictures, the common bile duct is dilated and tapers at the site of the obstruction, namely the head of the pancreas (Figure 37 and 38). As a result of strictures, there may be biochemical evidence of biliary obstruction (elevated serum bilirubin and alkaline phosphatase).
Endoscopic Therapy
Drainage should be performed in patients with biliary obstruction as evidenced by a dilated common bile duct and jaundice, or a markedly elevated alkaline phosphatase, in attempts to prevent long-term complications such as secondary biliary cirrhosis. Endoscopic treatment of benign and malignant biliary strictures offers low mortality and morbidity. Biliary drainage and stenting offers relief of jaundice and cholestasis. Biliary sphincterotomy may be performed for decompression and to facilitate stent placement (Figure 39). Endoscopic therapy for common bile duct strictures has shown regression of stenosis after stent placement. Endoscopic treatment may be used as a first-line therapeutic measure, and may be a definitive therapy in those patients who present as poor surgical risks. Chronic pancreatitis and common bile duct stricture may cause pain of biliary or pancreatic origin. After endoscopic biliary stenting, relief of pain may help predict which patients would benefit from surgical biliary drainage. Endoscopic intervention can be used as a temporary measure to relieve symptoms and allow time for observation of the disease course to assess additional treatment options.
Surgical Therapy — Choledochojejunostomy
There are a variety of surgical methods to treat biliary obstruction. The goals of surgery include removing stones, opening strictures, or bypassing the obstruction. The Roux-en-Y choledochojejunostomy is indicated in patients who have recurrent stones, intrahepatic stones, or distal biliary strictures. A Roux-en-Y choledochojejunostomy involves complete transection of the common bile duct and an end-to-side anastomosis (Figure 40).
The procedure is performed with the anastomosis high on the bile duct into the common hepatic duct to ensure adequate perforation (which may prevent stenosis of the anastomosis site). Sometimes, an access loop to the abdominal wall is useful for biliary tract access in patients with intrahepatic strictures or stones. The end-to-side anastomosis is performed in a single layer between the end of the bile duct and side of the jejunum. In the setting of chronic pancreatitis, surgical management of biliary obstruction seems to provide good long-term results.
Percutaneous Therapy
Percutaneous fine-needle aspiration under fluoroscopic guidance may be accomplished using catheters as radiopaque markers. Transhepatic tube tracts facilitate endoluminal biopsy to obtain tissue samples under direct vision. Transhepatic stents, placed over guide wires, allow percutaneous palliation. The intubation facilitates biliary drainage with bile being delivered to the duodenum and small intestine (Figure 41).
 | | Figure 41. A, Percutaneous pigtail stent placement; B, corresponding radiographic image. |
Stents may remain in place for approximately 3–4 months. Like other endoprostheses, complications include occlusion, dislodgement and migration, all of which require intervention.
Pseudocysts — Communicating and Noncommunicating The most common complication of chronic pancreatitis (occurring in approximately 25% of patients, especially those with alcoholic chronic pancreatitis) is the collection of pancreatic juices outside of the normal boundaries of the ductal system called pseudocysts (Figure 42A). Most pseudocysts resolve spontaneously. Mature pseudocysts are enclosed by fibrous tissue and are often situated in the body of the pancreas. They may be classified as communicating (connecting to the pancreatic duct) or noncommunicating (independent of the pancreatic duct) (Figure 42B).
 | | Figure 42. A, B, Types of pancreatic pseudocysts. |
Although the mechanism of pseudocyst formation is speculative, it is thought to result from rupture of a pancreatic duct, activation of interstitial pancreatic juices, parenchymal necrosis, intraductal leakage, and local mesothelium cells reacting to walled-off a fluid collection by formation of a fibrous membrane. Pain is the major presenting symptom in cases of pancreatic pseudocysts. Transabdominal ultrasound is helpful in the diagnosis and management (Figure 43). CT scanning has also proven to be an accurate method of diagnosis and provides structural detail on duct size (Figure 44).  | | Figure 44. CT scan demonstrating a pancreatic pseudocyst. |
Pseudocysts larger than 6 cm rarely spontaneously resolve. Although conservative management is recommended, intervention should be undertaken when symptoms of persistent abdominal pain, pseudocyst enlargement, or complications occur. Treatment includes excision and internal or external drainage.
Endoscopic Therapy for Communicating Pseudocysts
Diagnostic endoscopic retrograde cholangiopancreatography (ERCP) is performed once the patient is considered an appropriate candidate for endoscopic drainage. Appropriate identification and management of ductal obstruction are important in management of pseudocysts.
Transpapillary stent placement is recommended as an initial therapy for patients with relatively small pseudocysts that communicate with the main pancreatic duct. Pancreatic sphincterotomy is performed to facilitate stent placement. Dilation is carried out if ductal strictures are present. Obstructive pancreatic stones should also be removed. Pancreatic duct stents (usually 7–8.5 F, thin-walled) are placed in the pancreatic duct extending into the duodenum (Figure 45). The stent is removed with resolution of the pseudocyst, approximately 4–6 weeks later. The success rate is greater than 70%.
Endoscopic Therapy for Noncommunicating Pseudocysts
Transmural puncture is recommended for patients with large noncommunicating pseudocysts that compress the stomach or duodenum on CT scan. Especially in patients with complete obstruction of the duct, transmural puncture is the only feasible endoscopic alternative. All patients undergoing this procedure are given preoperative antibiotics. A needle-knife sphincterotomy is used to create a small incision through the gastric or duodenal wall into the pseudocyst. After needle-knife entry into the pseudocyst cavity, a guidewire is placed, followed by balloon dilation (Figure 46B). Finally, two or more catheter double-pigtailed stents are placed (Figure 46C), decompressing the pseudocyst (Figure 46D). Endoscopic ultrasound or endoscopic needle localization may be used to guide the puncture and identify a safe entry site into the pseudocyst.
 | | Figure 46. A-D, Technique of transgastric endoscopic pseudocyst drainage. |
Surgical Therapy
Surgical management may be indicated for pancreatic pseudocysts with persistent symptoms, cyst enlargement, or complications. Anastomosis of the internal pseudocyst to a portion of the gastrointestinal tract (usually the stomach) facilitates internal drainage. A Roux-en-Y limb of the proximal jejunum or duodenum may be used. In cases where a pseudocyst is located in the body of the pancreas adherent to the stomach, a cystogastrostomy is performed (Figure 47A). Anterior gastrotomy is performed, the cyst is aspirated by needle, and a 3-cm opening is made. Anastomosis of the pseudocyst to the posterior gastric wall facilitates pseudocyst drainage (Figure 47B).
Roux-en-Y cystojejunostomy is useful for the drainage of multiple pseudocysts that are not adherent to the duodenum or the stomach. During this procedure, the pseudocyst is entered, its contents evacuated, and it is attached to the jejunal limb. Pseudocysts in the head of the pancreas are drained into the duodenum by transduodenal cystoduodenostomy. A site in the duodenum, in close proximity to the pseudocyst, is identified and a lateral duodenotomy is made. The pseudocyst is entered through the medial wall of the duodenum. Sutures are placed to control bleeding and the lateral duodenotomy is closed.
Percutaneous Therapy
Another treatment option for pseudocyst management in chronic pancreatitis is percutaneous drainage (Figure 48, A and B).
During percutaneous drainage, a needle is inserted through both gastric walls while the position of the catheter is monitored with a gastroscope or fluoroscopically. Pseudocyst drainage into the stomach may be facilitated by placement of a double-pigtailed catheter. Alternately, an indwelling J-shaped catheter facilitates external drainage and may be used in cases where pseudocyst contents are viscous (Figure 49). These methods are less invasive than surgery and provide an alternative for patients who are at high risk for surgical management.
Duodenal Obstruction Chronic pancreatitis may be characterized by fibrosclerosing processes that may constrict the pancreatic and bile ducts, and lead to obstruction of the duodenum. Although this is fairly infrequent, duodenal obstructions in patients with chronic pancreatitis reflect an advanced stage of the disease. Enlargement and inflammation of the head of the pancreas may cause a duodenal narrowing. In this setting, the duodenum may become retracted with fibrotic scarring following pancreatic inflammation (Figure 50).
Endoscopic Therapy
Endoscopic insertion of self-expanding metal stents has been shown to maintain lumen patency in high-risk patients unable to tolerate surgery. The endoscope is passed down the esophagus through the stomach and the pylorus, and into the duodenum, where a guidewire is passed through the duodenal narrowing with subsequent dilation. An expandable stent is pushed into position. The self-expanding metal stent is made of thin, stainless steel wire shaped like a double helix forming a cylinder. The stent is left in place and expands, widening the lumen (Figure 51).
 | | Figure 51. A, B, Enternal stent placement for duodenal obstruction. |
Surgical Therapy
Pancreaticoduodenectomy, or Whipple procedure, has been recommended for treatment of chronic pancreatitis primarily involving the head of the pancreas. The procedure has a mortality rate of less than 5% and 25–30% morbidity. The procedure is indicated for patients who have failed previous duct drainage procedures, those with multiple small pseudocysts located in the head of the pancreas and/or uncinate portions of the gland, those with symptomatic gastric or biliary obstruction associated with extensive fibrosis or multiple pseudocysts, and, finally, those with hemorrhage from inflammatory aneurysms involving major peripancreatic vessels. Standard pancreaticoduodenectomy involves resection of the head of the pancreas, duodenum, gallbladder, distal common bile duct, and antrum (Figure 52). In chronic pancreatitis, preservation of the antrum and proximal 1–2 cm of duodenum is a necessary modification in preserving the pylorus and minimizing severe endocrine insufficiency. Pain relief is achieved in 60–80% of patients in the first several years after surgery.
Gastrojejunostomy is performed to bypass a duodenal obstruction. During this procedure, the most dependent portion of the gastric greater curvature is anastomosed to the proximal jejunum, thereby bypassing the obstructed portion of the duodenum (Figure 53).
Pancreatic Fistula A pancreatic fistula is an abnormal tract formed by fibrous tissue originating from a pancreatic ductal disruption. If the fistula breaches the pancreas, pancreatic juice may enter the peritoneal or retroperitoneal cavity, resulting in pancreatic ascites. The diagnosis of external pancreatic fistula (Figure 54A) should be entertained when clear fluid drains from a cutaneous orifice. External pancreatic fistula, though rare, is a complication of chronic pancreatitis. It may follow pancreatic biopsy, a leaky pancreatic anastomosis, or percutaneous drainage of a pseudocyst. Treatment consists of fluid replacement, nutritional support and infection control. Somatostatin may be prescribed to suppress pancreatic juices and decrease fistula drainage volume. Most fistulae close spontaneously; however, in those instances of ductal obstruction between the leakage site and the duodenum, endoscopic or surgical intervention may be indicated.  | | Figure 54. A-C, Pancreatic fistula. |
Internal pancreatic fistulae are tracts that develop between the pancreas and hollow abdominal organs (i.e., the colon) (Figure 54B). Figure 54C illustrates a dilated pancreatic duct and fistula tract. These fistulae may present as pseudocysts with or without necrosis of pancreatic tissue. They are more difficult to diagnose, and present with an array of signs and symptoms that are contingent upon the site and rate of the leakage. Treatment of internal fistulae, like external, attempts to minimize pancreatic secretion and drainage of accumulated fluid. The patient is placed on total parenteral nutrition (TPN); paracentesis or thoracentesis may be necessary. Diuretics, high-dose pancreatic enzymes, and octreotide may be used. Medical therapy has proven successful in approximately 50% of patients.
Endoscopic Therapy
Morbidity and mortality figures associated with medical and surgical treatment of pancreatic fistulae are significant. Stent placement in patients with external pancreatic fistulae has been successful in draining the fistula with use of a short transpapillary stent (Figure 55).
 | | Figure 55. A, B, Pancreatic stent placement for treatment of fistula. |
Surgical Therapy
Nonsurgical treatment is recommended as the first course of action because pancreatic fistulae and the resultant fluid collection lack a well-defined wall of granulation or fibrous tissue. Resection of the distal pancreas is considered for treatment of pancreatic fistula. Debridement of infected necrosis with drain placement may be useful. One-third of pancreatic fistulae close spontaneously over the course of a year. In instances where drainage is incomplete, a Roux-en-Y jejunal limb is created and anastomosed to the fistula or a distal pancreaticojejunostomy (Duval procedure) may be performed (Figure 56).
Pancreatic Ascites
A major ductal disruption within the ventral pancreas causes the accumulation of pancreatic fluids or ascites within the abdomen (Figure 57A). Rapid intervention, which includes draining of the site, aids in decompression. The incidence of pancreatic ascites in chronic pancreatitis is relatively rare (less than 1%). Leakage of pancreatic juices, either from the pancreatic duct or a pseudocyst, may cause pancreatic ascites (Figure 57B).  | | Figure 57. A, B, Mechanism of pancreatic ascites. |
Endoscopic therapy for pancreatic ascites employs the placement of a transpapillary stent to decompress the ductal system, relieve downstream obstruction, and hopefully preclude the need for surgical intervention. A stent (usually, 5–10 French, transampullary) is placed across the area of ductal disruption. In patients with a pancreatic fistula, the stent is placed through the disruption and directly into the fluid collection (Figure 58). Pancreatic stent removal is performed after approximately four weeks.
Ductal disruptions unresponsive to medical or endoscopic therapy require surgical intervention. Surgical options that may be considered to manage pancreatic ascites include debridement, duct drainage or resection. The most common procedure is pancreaticoduodenectomy (Whipple procedure) for persistent pancreatic fistula in the head of the pancreas. A distal pancreaticojejunostomy (Duval procedure) may be useful for fistulae within the pancreatic body if the remaining ducts in the head and tail of the gland are patent (Figure 59).
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