Diagnosing and Treating Pancreatic Disease
ERCP is predominantly used as a therapeutic intervention. Increasing numbers of patients with comorbidities, complications, and history of unsuccessful ERCPs are being referred to academic medical centers to receive endotherapy of pancreatic diseases. Often endoscopic therapy of pancreatic diseases requires expertise and technical resources that are more widely available in large medical centers. High-resolution video duodenoscopes and fluoroscopy aid in the selective cannulation of the ducts of Santorini and Wirsung.
Evidence is accumulating that pancreatic sphincterotomy is useful in at least some settings for treatment of sphincter of Oddi dysfunction (SOD), chronic pancreatitis, and pancreas divisum. Biliary sphincterotomy is often performed for extraction of biliary stones, SOD, and other biliary disorders that are responsible for pancreatitis. Selective pancreatic sphincterotomy of the main pancreatic duct sphincter is usually performed with a sphincterotome using wire-guided cannulation and 'cut' current. Sphincterotomy of the pancreatic sphincter is usually performed with a stent in place to provide guidance. Sphincter of Oddi manometry of the pancreatic duct can identify patients who are at high risk and respond to sphincterotomy.
Small-caliber plastic stents placed into the main pancreatic reduce the risk of pancreatitis after ERCP. These short flexible plastic endoprostheses assure adequate transphincteric drainage of pancreatic secretions for several days after ERCP (Fig. 1). The stent often migrates spontaneously, but can also be easily removed endoscopically. Although stent placement is a very useful strategy, the risk of post-ERCP pancreatitis can be further reduced with the administration of a single dose of rectal indomethacine. Longer stents can be employed for the purpose of improving drainage across a pancreatic duct stricture. External drainage using a naso-cystic catheter in the pancreatic duct can provide long-term drainage of a fistula or pseudocyst.
(Enlarge Image)
Figure 1.
X-ray image of a pancreatic stent adjacent to the bile duct.
Direct endoscopic examination of the main pancreatic duct can be performed using small-diameter 'baby' scopes that can provide high-resolution imaging of strictures, stones, and filling defects. The higher risk of pancreatitis with the use of the 'baby' scopes makes routine use not possible. However, in main duct intraductal papillary mucinous neoplasm (IPMN), pancreatoscopy can define the extent of the disease and guide sampling of ductal masses.
EUS-FNA is now the principal technique applied to obtain tissue from a pancreatic malignancy. A linear endosonoscope is used to image the pancreas from the stomach or duodenum, and guide the placement of a small-diameter aspiration needle into a focal lesion (Fig. 2). Aspirated cytologic material can be examined with cytologic techniques or digital image analysis (DIA) and fluorescence in-situ hybridization (FISH). These advanced imaging techniques improve the sensitivity by 10%, but with proportional reductions in specificity. FNA of cystic lesions is performed with similar techniques except usually only one needle pass is performed.
(Enlarge Image)
Figure 2.
EUS image of a pancreatic mass with fine needle aspiration. EUS, endoscopic ultrasound.
Using techniques similar to FNA, EUS can be used to guide the placement of transgastric or transduodenal stents into pancreatic pseudocysts. Over a wire guidance system, track dilation can be performed using balloons or dilators, followed by the placement of stents. New self-expanding metal stents are available for improved drainage and access. Pseudocysts should only be punctured when the wall has had sufficient time to mature and after pseudoaneurysm has been ruled out by careful imaging. Small to moderately sized pseudocysts (<4–6 cm) that communicate with the pancreatic duct are good candidates for endoscopic transpapillary stenting. For larger lesions requiring transmural drainage, EUS guidance is preferable.
Endoscopic Procedures for Managing Pancreatic Disease
ERCP is predominantly used as a therapeutic intervention. Increasing numbers of patients with comorbidities, complications, and history of unsuccessful ERCPs are being referred to academic medical centers to receive endotherapy of pancreatic diseases. Often endoscopic therapy of pancreatic diseases requires expertise and technical resources that are more widely available in large medical centers. High-resolution video duodenoscopes and fluoroscopy aid in the selective cannulation of the ducts of Santorini and Wirsung.
Sphincterotomy
Evidence is accumulating that pancreatic sphincterotomy is useful in at least some settings for treatment of sphincter of Oddi dysfunction (SOD), chronic pancreatitis, and pancreas divisum. Biliary sphincterotomy is often performed for extraction of biliary stones, SOD, and other biliary disorders that are responsible for pancreatitis. Selective pancreatic sphincterotomy of the main pancreatic duct sphincter is usually performed with a sphincterotome using wire-guided cannulation and 'cut' current. Sphincterotomy of the pancreatic sphincter is usually performed with a stent in place to provide guidance. Sphincter of Oddi manometry of the pancreatic duct can identify patients who are at high risk and respond to sphincterotomy.
Stent Placement
Small-caliber plastic stents placed into the main pancreatic reduce the risk of pancreatitis after ERCP. These short flexible plastic endoprostheses assure adequate transphincteric drainage of pancreatic secretions for several days after ERCP (Fig. 1). The stent often migrates spontaneously, but can also be easily removed endoscopically. Although stent placement is a very useful strategy, the risk of post-ERCP pancreatitis can be further reduced with the administration of a single dose of rectal indomethacine. Longer stents can be employed for the purpose of improving drainage across a pancreatic duct stricture. External drainage using a naso-cystic catheter in the pancreatic duct can provide long-term drainage of a fistula or pseudocyst.
(Enlarge Image)
Figure 1.
X-ray image of a pancreatic stent adjacent to the bile duct.
Pancreatoscopy
Direct endoscopic examination of the main pancreatic duct can be performed using small-diameter 'baby' scopes that can provide high-resolution imaging of strictures, stones, and filling defects. The higher risk of pancreatitis with the use of the 'baby' scopes makes routine use not possible. However, in main duct intraductal papillary mucinous neoplasm (IPMN), pancreatoscopy can define the extent of the disease and guide sampling of ductal masses.
Endoscopic Ultrasound-guided Fine Needle Aspiration
EUS-FNA is now the principal technique applied to obtain tissue from a pancreatic malignancy. A linear endosonoscope is used to image the pancreas from the stomach or duodenum, and guide the placement of a small-diameter aspiration needle into a focal lesion (Fig. 2). Aspirated cytologic material can be examined with cytologic techniques or digital image analysis (DIA) and fluorescence in-situ hybridization (FISH). These advanced imaging techniques improve the sensitivity by 10%, but with proportional reductions in specificity. FNA of cystic lesions is performed with similar techniques except usually only one needle pass is performed.
(Enlarge Image)
Figure 2.
EUS image of a pancreatic mass with fine needle aspiration. EUS, endoscopic ultrasound.
Endoscopic Ultrasound-guided Stent Placement
Using techniques similar to FNA, EUS can be used to guide the placement of transgastric or transduodenal stents into pancreatic pseudocysts. Over a wire guidance system, track dilation can be performed using balloons or dilators, followed by the placement of stents. New self-expanding metal stents are available for improved drainage and access. Pseudocysts should only be punctured when the wall has had sufficient time to mature and after pseudoaneurysm has been ruled out by careful imaging. Small to moderately sized pseudocysts (<4–6 cm) that communicate with the pancreatic duct are good candidates for endoscopic transpapillary stenting. For larger lesions requiring transmural drainage, EUS guidance is preferable.
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