Gastroenterological Endoscopy. Группа авторов

risk factors for PEP have been identified, predictors of severity are lacking. The only drug prophylaxis for PEP that has proven efficient is intrarectal administration of 100 mg of diclofenac or indomethacin, and this has been adopted as standard therapy to be given for any ERCP performed on an intact papilla (or involving manipulations on the pancreatic duct).^98,101 In addition, it was recently shown that such prophylaxis should be given systematically before the procedure and not “on demand” according to the per-procedures findings or events.¹⁰² Over the past 20 years, two major endoscopic techniques for preventing PEP in high-risk patients have been developed: guidewire-directed biliary cannulation¹⁰³ and prophylactic pancreatic stent (PPS) insertion. Four meta-analyses of prospective, randomized trials comparing PEP rates with and without PPS insertion conclude that PPS not only reduces PEP rates but also decreases the rate of severe cases of PEP in high-risk patients.^104,105,¹⁰⁶ This finding was confirmed in the intention-to-treat analysis of studies investigating the risk of PEP development, which included patients in whom PPS insertion failed.¹⁰⁷ Nevertheless, PPS placement is associated with an adverse event rate of 4%,¹⁰⁷ mainly related to guidewire- or stent-induced pancreatic duct injuries. The additional benefit of PPS in average-risk ERCPs when NSAIDs are administered is unclear, and its use should be limited to higher risk cases, mainly when a manipulation of the pancreatic duct is performed, in case of precut or papillectomy or when acinarization is observed. Three- or five-centimeter-long 5 French PPS without internal (proximal) flange but with external (distal) flaps are considered the best choice.^108,109 PPS insertion is strongly recommended, despite the recognized complications, in patients who are at high risk of PEP (

Box 10.2).^98,110,111 Finally, the best way to prevent complications is not to perform the procedure, and recently, one of the most controversial indications, sphincter of Oddi dysfunction type III, associated with highest risk of PEP has been shown to be ineffectively treated with biliary sphincterotomy.¹¹²

Box 10.1 Patient- and procedure-related risk factors of Post-ERCP pancreatitis (PEP)

       Patient-related factors

      • Female gender

      • Young age

      • History of suspected sphincter of Oddi dysfunction

      • History of pancreatitis, recurrent or post-ERCP pancreatitis

       Procedure-related factors

      • Difficult or multiple cannulation attempts

      • Multiple pancreatic contrast injections

      • Pancreatic acinarization

      • Precut sphincterotomy

      • Endoscopic papillary balloon dilation

      • Sphincter of Oddi manometry

      • Distal common bile duct diameter ≤ 10 mm

      • Procedures not involving stone removal

      Source: Adapted with permission from Woods KE, Willingham FF. World J Gastrointest Endosc. 2010; 2(5): 165–78.

Box 10.2 Indications for prophylactic pancreatic stent placement during ERCP

       Definitive

      • Pancreatic sphincterotomy for sphincter of Oddi dysfunction/acute recurrent pancreatitis

      • Ampullectomy

       Highly recommended

      • Difficult biliary cannulation, involving instrumentation or injection of the pancreatic duct

      • Pancreatic sphincterotomy (major and minor)

      • Aggressive instrumentation of the pancreatic duct (cytology brushing, biopsies)

      • Balloon dilatation of an intact biliary sphincter (balloon sphincteroplasty)

      • Prior PEP

      • Precut sphincterotomy starting at the papillary orifice

      Source: Adapted with permission from Devière J. Gastrointest Endosc Clin N Am. 2011; 21(3): 499–510.

      PEP is mild to moderate in >90% of the cases.^98,100 PEP is managed as with pancreatitis from other etiologies.

      10.7 Other Techniques

      Over the last 10 years, the therapeutic capabilities of endoscopy have been extended to techniques involving the passage of instruments through the GI tract or of endoscopes into the submucosal space. Most of these techniques are still in development, and all of these should be done in high-volume centers with extensive technical experience. Some of these procedures, however, have become part of the routine armamentarium in large endoscopy units, such as EUS-guided celiac block/neurolysis for refractory pancreatic pain, EUS-guided cyst drainages, and POEM for achalasia. The major potential complications associated with these techniques are summarized.

      10.7.1 EUS-Guided Celiac Block/Neurolysis

      This technique used for managing pain related to pancreatic cancer or chronic pancreatitis is usually used in cases not manageable with usual drug therapy. It consists of injecting absolute ethanol or corticoids at the bifurcation between the aorta and the celiac trunk. Usually, the needle is flushed with local anesthetic, which is injected initially. This reduces the transient exacerbation of pain (reported in up to 30% of cases) but also confirms the injection takes place outside the stomach and is not intravascular. Indeed, intramural injection may lead to necrosis of the gastric wall and abscess formation (especially when neurolysis is performed), while damage to a vessel can induce bleeding or rare spinal cord injury. Another delayed complication, almost unpreventable, is diarrhea. This occurs in 3 to 5% of the cases, and is often transient and managed symptomatically.^113,114

      10.7.2 EUS-Guided Drainage of Pancreatic Fluid Collections

      Endotherapy has become accepted as a gold standard for management of symptomatic pancreatic pseudocysts and acute fluid collections.¹¹⁵ Complications related with this technique may occur during the procedure or delayed. Periprocedural complications include bleeding, of which the incidence has been dramatically reduced with the use of linear EUS endoscopes to perform the procedure, and leakage of the pseudocyst contents. If a bleeding occurs during the procedure, it is most often due to puncture of a vessel. A coagulation device (Cystotome, Cook Endoscopy, Winston-Salem, North Carolina, United States; Endoflex, Voerde, Germany) can be used and the procedure completed by the placement plastic stents or SEMSs, which will also has a tamponade effect.¹¹⁶ However, there are no established indications for SEMS placement for pseudocyst drainage. Recently developed short, biflanged stents (Axios, Boston Scientific, Marlborough, Massachusetts, United States; Nagi stent, Taewoong, Seoul, Korea; Spaxus stent, Taewoong, Seoul, Korea) are useful for drainage of pseudocysts and necrosis and facilitating access to pancreatic necrosis for direct necrosectomy. They may be associated with severe complications, mainly vascular injuries.¹¹⁷ Leakage following placement usually occurs either by loss of guidewire access after puncture or by misdeployment or slippage into the peritoneal cavity when the collection is not bulging into the GI tract. If such a leak occurs, the first priority is to regain access to the residual cavity and provide adequate decompression.

      Delayed bleeding may also occur within a few days after the procedure. In this case, it is most often due to a pseudoaneurysm, and the initial therapeutic approach should be an interventional angiography.

      Finally, a late complication is recurrence of