Early successes and late failures in the prevention of post endoscopic retrograde cholangiopancreatography

Acute pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography （ERCP）. The only way to prevent this complication is to avoid an ERCP all together. Because of the risks involved, a careful consideration should be given to the indication for ERCP and the potential risk/benefit ratio of the test. Once a decision to perform an ERCP is made, the procedure should be carried out with meticulous care by an experienced endoscopist, and with a minimum of pancreatic duct opacification. Several pharmacologic agents have been tested, but to date the most important method of reducing post ERCP pancreatitis is the placement of pancreatic stent. Pancreatic stents should be placed in all patients at high risk of this complication such as those undergoing pancreatic sphincterotomy, pancreatic duct manipulation and intervention, and patients with suspected sphincter of Oddi dysfunction. Pancreatic stents should be also considered in patients requiring precut sphincterotomy to gain biliary access.     

PROPHYLACTIC PANCREAS STENTING FOLLOWED BY NEEDLE‐KNIFE FISTULOTOMY IN PATIENTS WITH SPHINCTER OF ODDI DYSFUNCTION AND DIFFICULT CANNULATION: NEW METHOD TO PREVENT POST‐ERCP PANCREATITIS

Introduction: The aim of the present study was to reduce post‐endoscopic retrograde cholangiopancreatography (ERCP) complications with a combination of early needle‐knife access fistulotomy and prophylactic pancreatic stenting in selected high‐risk sphincter of Oddi dysfunction (SOD) patients with difficult cannulation. Methods: Prophylactic pancreatic stent insertion was attempted in 22 consecutive patients with definite SOD and difficult cannulation. After 10 min of failed selective common bile duct cannulation, but repeated (>5×) pancreatic duct contrast filling, a prophylactic small calibre (3–5 Fr) pancreatic stent was inserted, followed by fistulotomy with a standard needle‐knife, then a standard complete biliary sphincterotomy followed. The success and complication rates were compared retrospectively with a cohort of 35 patients, in which we persisted with the application of standard methods of cannulation without pre‐cutting methods. Results: Prophylactic pancreatic stenting followed by needle‐knife fistulotomy was successfully carried out in all 22 consecutive patients, and selective biliary cannulation and complete endoscopic sphincterotomy were achieved in all but two cases. In this group, not a single case of post‐ERCP pancreatitis was observed, in contrast with a control group of three mild, 10 moderate and two severe post‐ERCP pancreatitis cases. The frequency of post‐ERCP pancreatitis was significantly different: 0% versus 43%, as were the post‐procedure (24 h mean) amylase levels: 206 U/L versus 1959 U/L, respectively. Conclusions: In selected, high‐risk, SOD patients, early, prophylactic pancreas stent insertion followed by needle‐knife fistulotomy seems a safe and effective procedure with no or only minimal risk of post‐ERCP pancreatitis. However, prospective, randomized studies are awaited to lend to support to our approach.     

Estimation of the stent placement above the intact sphincter of Oddi against malignant bile duct obstruction

Background In endoscopic biliary stenting against malignant biliary obstruction, stent blockage remains as an important problem. Stent blockage occurs as a result of bacterial adherence to the inner wall of the stent. We evaluated the stent placement above the intact sphincter of Oddi to retain the function of the sphincter of Oddi as a bacteriological barrier.Methods Sixteen patients with malignant biliary obstruction were assessed as the patients with the stent above the intact sphincter of Oddi. Sixteen patients with malignant biliary obstruction were assessed as the patients with the conventional stent placement across the sphincter of Oddi. Tannenbaum 10-Fr. stents were used in both the groups.Results The median patency periods of the stent were 255 days (25th to 75th percentiles, 212–454 days; range, 39–454 days) for the group of the stents placed above the sphincter of Oddi and 82 days (25th to 75th percentiles, 48–131 days; range, 22–196 days) for the group of the stents placed across the sphincter of Oddi, respectively, with significant difference (P = 0.0001). The occlusion rates of stents placed above and across the sphincter of Oddi were 37.5% and 93.8%, respectively, with significant difference (P = 0.0008). The dislocation rates of the stent were 0% and 6.3%, respectively (not significant).Conclusions Placement of the stent above the intact sphincter of Oddi was associated with longer stent patency and lower occlusion rate.     

Reply to: diagnostic power of fecal calprotectin in inflammatory and functional intestinal disorders

Abstract

Objective. A retrospective clinical audit was carried out to identify whether relaxation of the sphincter of Oddi (SO) by botulinum toxin (BTX) injection can select patients with episodic functional post-cholecystectomy biliary pain who will benefit from endoscopic sphincterotomy. Patients and methods. Sixty-four patients complaining of functional post-cholecystectomy biliary pain with a frequency of at least four episodes per month had 100 units of BTX injected into their SO muscle in four aliquots. After review patients with a pain free interval following BTX injection of at least 4 weeks were offered biliary endoscopic sphincterotomy and their outcome assessed. Results. Of the 64 patients 46 (72%) had at least four pain free weeks after BTX therapy and 44 of these 46 patients (96%) went on to experience pain relief following endoscopic sphincterotomy. Of the 64 patients 41 had sphincter of Oddi manometry prior to BTX injection. Every patient with sphincter of Oddi hypertension defined by manometry and at least 4 weeks' pain relief following BTX (24) had pain relief following sphincterotomy. Fifteen (94%) of the 16 patients who did not undergo manometry but reported at least 4 weeks' pain relief after BTX had pain relief after sphincterotomy. Conclusion. Botulinum toxin relaxation of the SO may be a useful method of predicting the symptom response to endoscopic sphincterotomy in patients who have episodic functional biliary pain.     

Sphincter of oddi (pancreatic) hypertension and recurrent pancreatitis

Major papilla pancreatic sphincter dysfunction, a variant of sphincter of Oddi dysfunction, causes pancreatitis and pancreatic-type pain. The gold standard for diagnosis is sphincter of Oddi manometry, most commonly performed at endoscopic retrograde cholangiopancreatography (ERCP). Noninvasive testing, such as secretin-stimulated transabdominal or endoscopic ultrasound assessment of pancreatic duct diameter, is less reliable and has relatively low sensitivity. Two thirds of patients with biliary sphincter of Oddi dysfunction have elevated pancreatic basal sphincter pressure. To maximize the diagnostic yield of sphincter of Oddi dysfunction, both the biliary and pancreatic sphincter pressures should be measured. Patients with sphincter of Oddi dysfunction may respond to biliary sphincterotomy alone, but evaluation of their pancreatic sphincter is warranted if symptoms persist after biliary therapy alone. Whether both biliary and pancreatic sphincters should be treated at the first ERCP session is controversial. Biliary and pancreatic endoscopic sphincterotomies are associated with two-to fourfold increased incidence of pancreatitis following the procedure in patients with pancreatic sphincter hypertension. Prophylactic pancreatic duct stenting reduces the frequency and severity of complications by greater than 50%.     

Endoscopic manometry of the sphincter of Oddi and pancreatic duct in patients with chronic pancreatitis

Summary Conclusion Endoscopic manometry in patients with chronic pancreatitis has demonstrated some manometric abnormalities in the sphincter of Oddi, but these abnormalities have no significant role in the pathogenesis of chronic pancreatitis. Background The study was undertaken to determine whether the sphincter of Oddi dysfunction plays a significant role in the pathogenesis of chronic pancreatitis. Methods Manometric investigation was performed in 32 patients with chronic pancreatitis. Twenty-three of them had alcohol-induced chronic pancreatitis, seven had biliary pancreatitis, and two patients had annular pancreas with chronic pancreatitis. Fifteen of them had dilated main pancreatic duct. Twenty-one cholecystectomized patients with no abnormality of the pancreas and biliary system served as controls. Results This study showed no significant difference in the mean pressures in the pancreatic duct, sphincter of Oddi (basal and phasic), and frequency of the sphincter of Oddi phasic contractions when comparing patients and controls. Sphincter of Oddi basal pressure (26–44 mmHg) was markedly increased in seven patients, whereas three patients (two of them had increased sphincter of Oddi basal pressure) had increased pancreatic duct pressure (20–24 mmHg). Increased numbers of retrograde contractions were found in seven patients.     

Pancreatic duct stent placement prevents post-ERCP pancreatitis in patients with suspected sphincter of Oddi dysfunction but normal manometry results

BACKGROUND: Placement of a pancreatic duct (PD) stent reduces post-ERCP pancreatitis rates in high-risk patients. Patients with suspected sphincter of Oddi dysfunction (SOD) who are found to have normal manometry results (SOM) are also at high risk for this complication. OBJECTIVE: Our purpose was to determine whether PD stent placement reduces pancreatitis rates in this patient population. DESIGN: Non-randomized, retrospective study. SETTING: Large, tertiary referral center. PATIENTS: From January 1999 to December 2005, patients who underwent ERCP with normal SOM were identified from our ERCP database. Incidence of patient/procedure risk factors for post-ERCP pancreatitis, trainee participation, and prior sphincter therapy were evaluated. INTERVENTIONS: PD stent placement. MAIN OUTCOME MEASUREMENT: Pancreatitis rates. RESULTS: A total of 403 patients were available for analysis: 169 had a PD stent placed (group 1) and 234 did not (group 2). Overall, pancreatitis rates were 2.4% in group 1 and 9.0% in group 2 (P= .006, odds ratio 4.1, 95% CI 1.4-12.0). Other than increased PD opacification in group 1 (P< .001), the incidence of risk factors for pancreatitis, trainee participation, or prior sphincter therapy was similar between the 2 groups. In patients with an intact papilla, stent placement reduced the rate of pancreatitis from 11.5% to 2.7% (P= .012). In patients with prior sphincter therapy, no benefit was seen from stent placement, although there was a trend to decreased pancreatitis rates in stented patients with prior pancreatobiliary sphincterotomy. LIMITATIONS: Nonrandomized, retrospective design. CONCLUSION: Temporary PD stent placement reduces pancreatitis rates in patients with suspected SOD but normal SOM and an intact papilla. Their routine use is recommended when evaluating this difficult, high-risk patient population.     

The sphincter of Oddi and acute pancreatitis--revisited

BackgroundOne of the rare causes of recurrent acute pancreatitis is sphincter of Oddi dysfunction. This condition is objectively diagnosed by manometry of the sphincter of Oddi. An abnormally elevated sphincter of Oddi basal pressure has been shown to predict patients who have a successful outcome after transduodenal sphincteroplasty and pancreatic duct septoplasty.MethodsForty-nine patients presenting with recurrent pancreatitis and who had manometric stenosis of the sphincter of Oddi were treated by transduodenal division of the sphincter of Oddi. Clinical follow-up was conducted over a minimum of 2 years.ResultsIn all, 43 patients were either cured or improved. None of these patients had any further episodes of pancreatitis. Three of these patients developed recurrent symptoms and were noted to have restenosis of the sphincter of Oddi. They were treated by insertion of an endoscopic stent into the pancreatic duct.ConclusionThe results from this series of patients re-affirm the efficacy of transduodenal sphincteroplasty and septoplasty for treatment of sphincter of Oddi stenosis in patients presenting with recurrent acute pancreatitis.     

Mechanical prevention of post-ERCP pancreatitis by pancreatic stents: results,techniques, and indications

Impaired pancreatic drainage may be most important in the pathophysiology of post-ERCP pancreatitis. When there is a mechanical problem, there is often a mechanical solution. Pancreatic stenting reduces the incidence and severity of post-ERCP pancreatitis in high-risk patients. Young patients with suspected sphincter of Oddi dysfunction or prior pancreatitis and those undergoing procedures with either a difficult cannulation, precut and/or pancreatic sphincterotomy should be strongly considered for pancreatic stenting. Stents should be removed within about one week or have the proximal flaps removed to allow early spontaneous distal migration. Pancreatic stent placement following biliary intervention can occasionally be difficult. In cases where the primary goal is pancreatic therapy, one should consider establishing pancreatic access before addressing the bile duct. A pancreatic stent can then serve as a guide for sphincterotomy, but most importantly, protect against post-ERCP pancreatitis.     

Dynamic imaging of the pancreas using real-time endoscopic ultrasonography with secretin stimulation

Background: Obstructive disorders of the pancreas, including strictures, stones, sphincter of Oddi dysfunction, and pancreas divisum, are diagnostic and therapeutic challenges. Conventional extracorporeal ultrasound with secretin stimulation has been used as a noninvasive study to detect obstruction and predict outcome of therapy. Inconsistent results have been obtained because of the inherent limitations of standard ultrasonography. The aim of this study was to evaluate the behavior of the main pancreatic duct by endoscopic ultrasonography during secretin stimulation and to diagnose obstructive disorders of the pancreas. Methods: Secretin-stimulated endoscopic ultrasound (SSEUS, 1 IU/kg secretin) was performed in 20 control subjects (no pancreatic or biliary disease), 40 patients with symptomatic chronic pancreatitis, 40 patients with symptomatic pancreas divisum, 20 patients with suspected sphincter of Oddi dysfunction, and 20 patients with suspected occlusion of pancreatic duct stents. Ductal diameter was measured by endoscopic ultrasonography at baseline and at 1-minute intervals, after administration of secretin, for 15 minutes. A result was determined to be abnormal when a 1 mm or greater dilation of the pancreatic duct was observed from baseline after secretin administration. Results: Of the 40 patients with symptomatic chronic pancreatitis, SSEUS correctly predicted obstructive pathology (stones, strictures) in 12 of 13 patients (92%). Of the 40 patients with symptomatic pancreas divisum, 22 underwent stent therapy (16 of 22 with resolution of symptoms). SSEUS accurately predicted response to stent therapy in 13 patients (81%). Seven of twenty patients with suspected sphincter of Oddi dysfunction had abnormal sphincter manometry. SSEUS accurately predicted sphincter dysfunction in only 4 of 7 patients (57%). Finally, 20 patients with suspected occlusion of pancreatic duct stents were studied. Of the 14 stent occlusions confirmed at ERCP, SSEUS correctly predicted premature occlusion in 12 patients (86%). Conclusions: SSEUS appears to be a useful diagnostic modality in the evaluation of patients with suspected obstructive disorders of the pancreas and it can predict which patients may respond to endoscopic therapy. (Gastrointest Endosc 1998;48:580-7.)     

Manometry based randomised trial of endoscopic sphincterotomy for sphincter of Oddi dysfunction

BACKGROUND—Endoscopic sphincterotomy for biliary-type pain after cholecystectomy remains controversial despite evidence of efficacy in some patients with a high sphincter of Oddi (SO) basal pressure (SO stenosis).
AIM—To evaluate the effects of sphincterotomy in patients randomised on the basis of results from endoscopic biliary manometry.
METHODS—Endoscopic biliary manometry was performed in 81 patients with biliary-type pain after cholecystectomy who had a dilated bile duct on retrograde cholangiography, transient increases in liver enzymes after episodes of pain, or positive responses to challenge with morphine/neostigmine. The manometric record was categorised as SO stenosis, SO dyskinesia, or normal, after which the patient was randomised in each category to sphincterotomy or to a sham procedure in a prospective double blind study. Symptoms were assessed at intervals of three months for 24 months by an independent observer, and the effects of sphincterotomy on sphincter function were monitored by repeat manometry after three and 24 months.
RESULTS—In the SO stenosis group, symptoms improved in 11 of 13 patients treated by sphincterotomy and in five of 13 subjected to a sham procedure (p = 0.041). When manometric records were categorised as dyskinesia or normal, results from sphincterotomy and sham procedures did not differ. Complications were rare, but included mild pancreatitis in seven patients (14 episodes) and a collection in the right upper quadrant, presumably related to a minor perforation. At three months, the endoscopic incision was extended in 19 patients because of manometric evidence of incomplete division of the sphincter.
CONCLUSION—In patients with presumed SO dysfunction, endoscopic sphincterotomy is helpful in those with manometric features of SO stenosis.


Keywords: sphincter of Oddi; manometry; endoscopic sphincterotomy; motility; bile duct; pancreas     

Idiopathic recurrent pancreatitis: long-term results after ERCP, endoscopic sphincterotomy, or ursodeoxycholic acid treatment

OBJECTIVE: In about 30% of cases, the etiology of acute recurrent pancreatitis remains unexplained, and the term "idiopathic" is currently used to define such disease. We aimed to evaluate the long-term outcome of patients with idiopathic recurrent pancreatitis who underwent endoscopic cholangiopancreatography (ERCP) followed by either endoscopic biliary (and seldom pancreatic) sphincterotomy or ursodeoxycholic acid (UDCA) treatment, in a prospective follow-up study. METHODS: A total of 40 consecutive patients with intact gallbladder entered the study protocol after a 24-month observation period during which at least two episodes of pancreatitis occurred. All patients underwent diagnostic ERCP, followed by biliary or minor papilla sphincterotomy in cases of documented or suspected bile duct microlithiasis and sludge, type 2 sphincter of Oddi dysfunction, or pancreas divisum with dilated dorsal duct. Patients with no definite anatomical or functional abnormalities received long-term treatment with UDCA. After biliary sphincterotomy, patients with further episodes of pancreatitis underwent main pancreatic duct stenting followed by pancreatic sphincterotomy if the stent had proved to be effective. RESULTS: ERCP found an underlying cause of pancreatitis in 70% of cases. Patients were followed-up for a period ranging from 27 to 73 months. Effective therapeutic ERCP or UDCA oral treatment proved that occult bile stone disease and type 2 or 3 sphincter of Oddi dysfunction (biliary or pancreatic segment) had been etiological factors in 35 of the 40 cases (87.5%) After therapeutic ERCP or UDCA, only three patients still continued to have episodes of pancreatitis. CONCLUSIONS: Diagnostic and therapeutic ERCP and UDCA were effective in 92.5% of our cases, over a long follow-up, indicating that the term "idiopathic" was justified only in a few patients with acute recurrent pancreatitis.     

Endoscopic biliary and pancreatic sphincterotomy

Opinion statement Endoscopic sphincterotomy is performed on the biliary and pancreatic sphincters for a variety of indications such as removal of stones, as part of treatment of strictures, to facilitate placement of stents, for closure of ductal leaks, and other indications. Pancreatic sphincterotomy has been increasingly performed for the treatment of papillary stenosis, sphincter of Oddi dysfunction, and for chronic and acute recurrent pancreatitis. Efficacy is clear for more traditional indications, but is not as well defined for some of the latter indications. Minor papillotomy is most often performed for acute recurrent pancreatitis associated with pancreas divisum, sometimes for chronic pancreatitis, and for other indications. Equipment, techniques, and safety of sphincterotomy have improved significantly over the past decades. Success rates are substantially higher when a sphincterotomy is performed by high-volume endoscopists. However, complications such as pancreatitis, bleeding, and perforation can still occur in up to 10% of cases and may occasionally be severe. Patients with the least clear indication or chance of benefit from sphincterotomy, such as those with suspected sphincter of Oddi dysfunction or suspected but absent bile duct stones, are at highest risk of complications. Complications are less frequent, but fully not eliminated, with an experienced endoscopist or an expert in the field. Risk of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP) with biliary and/or pancreatic sphincterotomy can be substantially reduced by placement of a small-caliber pancreatic stent. Major challenges include defining the settings in which sphincterotomy is most likely to be effective, selection of appropriate patients for therapeutic ERCP by utilization of alternative imaging techniques such as magnetic resonance cholangiopancreatography and endoscopic ultrasound, and dissemination of newer techniques into practice to ensure optimal safety and efficacy for sphincterotomy.     

Sphincter of Oddi dysfunction and pancreatitis

Sphincter of Oddi dysfunction （SOD） is a term used to describe a group of heterogenous pain syndromes caused by abnormalities in sphincter contractility. Biliary and pancreatic SOD are each sub-classified as type Ⅰ, Ⅱ or Ⅲ, according to the Milwaukee classification. SOD appears to carry an increased risk of acute pancreatitis as well as rates of post ERCP pancreatitis of over 30%. Various mechanisms have been postulated but the exact role of SOD in the pathophysiology of acute pancreatitis is unknown. There is also an association between SOD and chronic pancreatitis but it is still unclear if this is a cause or effect relationship. Management of SOD is aimed at sphincter ablation, usually by endoscopic sphincterotomy （ES）. Patients with type Ⅰ SOD will benefit from ES in 55%-95% of cases. Sphincter of Oddi manometry is not necessary before ES in type Ⅰ SOD. For patients with types Ⅱ and Ⅲ the benefit of ES is lower. These patients should be more thoroughly evaluated before performing ES. Some researchers have found that manometry and ablation of both the biliary and pancreatic sphincters is required to adequately assess and treat SOD. In pancreatic SOD up to 88% of patients will benefit from sphincterotomy. Therefore, there have been calls from some quarters for the current classification system to be scrapped in favour of an overall system encompassing both biliary and pancreatic types. Future work should be aimed at understanding the mechanisms underlying the relationship between SOD and pancreatitis and identifying patient factors that will help predict benefit from endoscopic therapy.     

A survey of physician practices on prophylactic pancreatic stents

BACKGROUND: Several prospective studies confirm that prophylactic stent placement in the pancreatic duct (PD) during high-risk ERCP procedures decreases the risk of post-ERCP pancreatitis. Inconsistencies exist regarding the indications for prophylactic PD stent placement, the type of stent used, and stent follow-up. OBJECTIVE: To assess the current practice patterns of expert biliary endoscopists regarding prophylactic pancreatic duct stents. DESIGN: An anonymous survey was mailed to 54 expert biliary endoscopists, assessing volume of procedures, stent indications, method of placement, and follow-up. RESULTS: A total of 91% (49/54) of surveys were returned and analyzed. Prophylactic PD stents were used by 96% of respondents. Stent use was universal during ampullectomy and pancreatic sphincterotomy. Most also used stents for minor papillotomy (93%) and sphincter of Oddi dysfunction (SOD) confirmed by manometry (82%). Endoscopists disagreed on the following: pre-cut sphincterotomy (71%), prior post-ERCP pancreatitis (64%), suspected SOD (58-69%), and traumatic sphincterotomy (44%). Endoscopists used straight stents (33%), pigtail stents (30%), or a combination (33%). Internal flanges were always used by 14%, never used by 54%, and sometimes used by 32%. Stent size and length varied widely, as did the time stents were left in place, and the retrieval method. CONCLUSIONS: Expert biliary endoscopists agree that prophylactic PD stenting is indicated during ERCP in high-risk patients. Wide variation exists in patient selection and stent placement technique.     

Does a pancreatic duct stent prevent post-ERCP pancreatitis? A prospective randomized study

BACKGROUND: Pancreatitis is the most frequent complication of ERCP. Injury to the papilla during ERCP could obstruct pancreatic duct outflow and initiate pancreatitis. A randomized prospective study was performed to evaluate the effect of pancreatic duct stent placement on the frequency and severity of post-ERCP pancreatitis in a selected group of patients. METHODS: The study group consisted of patients over 18 years of age at high risk for post-ERCP pancreatitis because of a difficult cannulation, sphincter of Oddi manometry, and/or the performance of endoscopic sphincterotomy. Patients were prospectively randomized to have a pancreatic duct stent placed or no stent upon completion of the ERCP. The endoprosthesis used was either a 5F nasopancreatic catheter or 5F, 2-cm long pancreatic stent. Study endpoints were the frequency and severity of post-ERCP pancreatitis. RESULTS: Patients undergoing pancreatic duct stent placement had a lower frequency of post-ERCP pancreatitis as compared with those in the control group (28% vs. 5%; p < 0.05). Pancreatitis tended to be less severe in patients who had pancreatic duct drainage. CONCLUSIONS: Pancreatic duct stent insertion after ERCP reduces the frequency of post-ERCP pancreatitis in patients at high risk for this complication.     

Sphincter of Oddi dysfunction and bile duct microlithiasis in acute idiopathic pancreatitis

Although there are numerous causes of acute panc-reatitis, an etiology cannot always be found. Two potential etiologies, microlithiasis and sphincter of Oddi dysfunction, are discussed in this review. Gallbladder microlithiasis, missed on transcutaneous ultrasound, is reported as the cause of idiopathic acute pancreatitis in a wide frequency range of 6%-80%. The best diagnostic technique for gallbladder microlithiasis is endoscopic ultrasound although biliary crystal analysis and empiric cholecystectomy remain as reasonable options. In contrast, in patients who are post-cholecystectomy, bile duct microlithiasis does not appear to have a role in the pathogenesis of acute pancreatitis. Sphincter of Oddi dysfunction is present in 30%-65% of patients with idiopathic acute recurrent pancreatitis in whom other diagnoses have been excluded. It is unclear if this sphincter dysfunction was the original etiology of the first episode of pancreatitis although it appears to have a causative role in recurring episodes since sphincter ablation decreases the frequency of recurrent attacks. Unfortunately, this conclusion is primarily based on small retrospective case series; larger prospective studies of the outcome of pancreatic sphincterotomy for SOD-associated acute pancreatitis are sorely needed. Another problem with this diagnosis and its treatment is the concern over potential procedure related complications from endoscopic retrograde cholangiopancreatography （ERCP）, manometry and pancreatic sphincterotomy. For these reasons, patients should have recurrent acute pancreatitis, not a single episode, and have a careful informed consent before assessment of the sphincter of Oddi is undertaken.     

Pressure measurements from biliary and pancreatic segments of sphincter of oddi

Using a minimally compliant infusion system and a triple-lumen pressure recording catheter, we obtained endoscopic manometric measurements from both the common bile duct and pancreatic duct segments of the sphincter of Oddi (SO) in 58 patients. Fifteen patients (ages 27–69) had the diagnosis of functional abdominal pain, 19 patients (ages 30–76) had partial biliary obstruction, and 24 patients (ages 15–80) had idiopathic acute recurrent pancreatitis. Resting ductal pressure was similar in the common bile duct and pancreatic duct in all patient groups. In the group with functional pain, basal SO pressure was similar, whether obtained from the common bile duct or pancreatic duct sphincteric segment. Eight of 19 patients with partial biliary obstruction had elevated basal SO pressure. Five of these eight patients had elevated basal SO pressure confined exclusively to the common bile duct segment of the sphincter, while three patients had elevated basal SO in both segments. Conversely seven of 24 patients with acute recurrent pancreatitis had an elevated basal SO pressure, with five patients having pressure elevation only in the pancreatic duct segment while two patients had abnormal basal SO pressure in both segments. We conclude that selective cannulation of the common bile duct and/or the pancreatic duct during manometric study of the SO is necessary in order to diagnose segmental SO dysfunction responsible for partial biliary obstruction or episodes of acute recurrent pancreatitis.     

Pancreatic sphincterotomy： Technique, indications, and complications

Pancreatic sphincterotomy serves as the cornerstone of endoscopic therapy of the pancreas. Historically, its indications have been less well-defined than those of endoscopic biliary sphincterotomy, yet it plays a definite and useful role in diseases such as chronic pancreatitis and pancreatic-type sphincter of Oddi dysfunction. In the appropriate setting, it may be used as a single therapeutic maneuver, or in conjunction with other endoscopic techniques such as pancreatic stone extraction or stent placement. The current standard of practice utilizes two different methods of performing pancreatic sphincterotomy： a pull-type sphincterotome technique without prior stent placement, and a needleknife sphincterotome technique over an existing stent. The complications associated with pancreatic sphincterotomy are many, although acute pancreatitis appears to be the most common and the most serious of the early complications. As such, it continues to be reserved for those endoscopists who perform a relatively high-volume of therapeutic pancreaticobiliary endoscopic retrograde chola ngio-pancreatography.     

Transdermal glyceryl trinitrate for prevention of post-ERCP pancreatitis: A randomized double-blind trial

BACKGROUND: Pancreatic sphincter hypertension increases the risk of pancreatitis in patients undergoing ERCP. Glyceryl trinitrate reduces sphincter of Oddi pressure. This study tested the hypothesis that transdermal glyceryl trinitrate could be effective in the prevention of post-ERCP pancreatitis. METHODS: One hundred forty-four patients undergoing ERCP were randomized: 71 received a 15-mg glyceryl trinitrate patch (glyceryl trinitrate group) and 73 a placebo patch (control group). RESULTS: In the control group, post-ERCP pancreatitis developed in 11 patients versus 3 in the glyceryl trinitrate group (p < 0.05). Twenty-four hour to baseline serum amylase and lipase ratios were lower in the glyceryl trinitrate group (respectively, 3.6 vs. 7.5, p < 0.05; and 5.3 vs. 27.7, p < 0.05). In a multivariate analysis, glyceryl trinitrate patch and the number of pancreatic injections, but not endoscopic sphincterotomy, were independent risk factors for post-ERCP pancreatitis. CONCLUSIONS: The results of this study suggest that use of a transdermal glyceryl trinitrate patch protects against post-ERCP pancreatitis.