Gregory A. Cote

A Randomized Trial of Rectal Indomethacin to Prevent Post-ERCP Pancreatitis

BACKGROUND Preliminary research suggests that rectally administered nonsteroidal antiinflammatory drugs may reduce the incidence of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). METHODS In this multicenter, randomized, placebo-controlled, double-blind clinical trial, we assigned patients at elevated risk for post-ERCP pancreatitis to receive a single dose of rectal indomethacin or placebo immediately after ERCP. Patients were determined to be at high risk on the basis of validated patient- and procedure-related risk factors. The primary outcome was post-ERCP pancreatitis, which was defined as new upper abdominal pain, an elevation in pancreatic enzymes to at least three times the upper limit of the normal range 24 hours after the procedure, and hospitalization for at least 2 nights. RESULTS A total of 602 patients were enrolled and completed follow-up. The majority of patients (82%) had a clinical suspicion of sphincter of Oddi dysfunction. Post-ERCP pancreatitis developed in 27 of 295 patients (9.2%) in the indomethacin group and in 52 of 307 patients (16.9%) in the placebo group (P=0.005). Moderate-to-severe pancreatitis developed in 13 patients (4.4%) in the indomethacin group and in 27 patients (8.8%) in the placebo group (P=0.03). CONCLUSIONS Among patients at high risk for post-ERCP pancreatitis, rectal indomethacin significantly reduced the incidence of the condition. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00820612.).

Alcohol and Smoking as Risk Factors in an Epidemiology Study of Patients With Chronic Pancreatitis

BACKGROUND & AIMS Alcohol has been implicated in the development of chronic pancreatitis (CP) in 60%-90% of patients, although percentages in the United States are unknown. We investigated the epidemiology of alcohol-related CP at tertiary US referral centers. METHODS We studied data from CP patients (n = 539) and controls (n = 695) enrolled in the North American Pancreatitis Study-2 from 2000 to 2006 at 20 US referral centers. CP was defined by definitive evidence from imaging or histologic analyses. Subjects and physicians each completed a study questionnaire. Using physician-assigned diagnoses, patients were assigned to an etiology group: alcohol (with/without other diagnoses), nonalcohol (any etiology of CP from other than alcohol), or idiopathic (no etiology identified). RESULTS The distribution of patients among etiology groups was: alcohol (44.5%), nonalcohol (26.9%), and idiopathic (28.6%). Physicians identified alcohol as the etiology more frequently in men (59.4% men vs 28.1% women), but nonalcohol (18% men vs 36.7% women) and idiopathic etiologies (22.6% men vs 35.2% women) more often in women (P < .01 for all comparisons). Nonalcohol etiologies were equally divided among obstructive, genetic, and other causes. Compared with controls, patients with idiopathic CP were more likely to have ever smoked (58.6% vs 49.7%, P < .05) or have a history of chronic renal disease or failure (5.2% vs 1.2%, P < .01). In multivariate analyses, smoking (ever, current, and amount) was independently associated with idiopathic CP. CONCLUSIONS The frequency of alcohol-related CP at tertiary US referral centers is lower than expected. Idiopathic CP and nonalcohol etiologies represent a large subgroup, particularly among women. Smoking is an independent risk factor for idiopathic CP.

Incidence of Sedation-Related Complications With Propofol Use During Advanced Endoscopic Procedures

BACKGROUND & AIMS Propofol is an effective sedative in advanced endoscopy. However, the incidence of sedation-related complications is unclear. We sought to define the frequency of sedation-related adverse events, particularly the rate of airway modifications (AMs), with propofol use during advanced endoscopy. We also evaluated independent predictors of AMs. METHODS Patients undergoing sedation with propofol for advanced endoscopic procedures, including endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, and small-bowel enteroscopy, were studied prospectively. Sedative dosing was determined by a certified registered nurse anesthetist with the goal of achieving deep sedation. Sedation-related complications included AMs, hypoxemia (pulse oximetry [SpO(2)] < 90%), hypotension requiring vasopressors, and early procedure termination. AMs were defined as chin lift, modified face mask ventilation, and nasal airway. We performed a regression analysis to compare characteristics of patients requiring AMs (AM+) with those who did not (AM-). RESULTS A total of 799 patients were enrolled over 7 months. Procedures included endoscopic ultrasound (423), endoscopic retrograde cholangiopancreatography (336), and small-bowel enteroscopy (40). A total of 87.2% of patients showed no response to endoscopic intubation. Hypoxemia occurred in 12.8%, hypotension in 0.5%, and premature termination in 0.6% of the patients. No patients required bag-mask ventilation or endotracheal intubation. There were 154 AMs performed in 115 (14.4%) patients, including chin lift (12.1%), modified face mask ventilation (3.6%), and nasal airway (3.5%). Body mass index, male sex, and American Society of Anesthesiologists class of 3 or higher were independent predictors of AMs. CONCLUSIONS Propofol can be used safely for advanced endoscopic procedures when administered by a trained professional. Independent predictors of AMs included male sex, American Society of Anesthesiologists class of 3 or higher, and increased body mass index.

Role of EUS for preoperative evaluation of cholangiocarcinoma: a large single-center experience.

BACKGROUND Accurate preoperative diagnosis and staging of cholangiocarcinoma (CCA) remain difficult. OBJECTIVE To evaluate the utility of EUS in the diagnosis and preoperative evaluation of CCA. DESIGN Observational study of prospectively collected data. SETTING Single tertiary referral hospital in Indianapolis, Indiana. PATIENTS Consecutive patients with CCA from January 2003 through October 2009. INTERVENTIONS EUS and EUS-guided FNA (EUS-FNA). MAIN OUTCOME MEASUREMENTS Sensitivity of EUS for the detection of a tumor and prediction of unresectability compared with CT and magnetic resonance imaging (MRI); sensitivity of EUS-FNA to provide tissue diagnosis, by using surgical pathology as a reference standard. RESULTS A total of 228 patients with biliary strictures undergoing EUS were identified. Of these, 81 (mean age 70 years, 45 men) had CCA. Fifty-one patients (63%) had distal and 30 (37%) had proximal CCA. For those with available imaging, tumor detection was superior with EUS compared with triphasic CT (76 of 81 [94%] vs 23 of 75 [30%], respectively; P < .001). MRI identified the tumor in 11 of 26 patients (42%; P = .07 vs EUS). EUS identified CCA in all 51 (100%) distal and 25 (83%) of 30 proximal tumors (P < .01). EUS-FNA (median, 5 passes; range, 1-12 passes) was performed in 74 patients (91%). The overall sensitivity of EUS-FNA for the diagnosis of CCA was 73% (95% confidence interval, 62%-82%) and was significantly higher in distal compared with proximal CCA (81% vs 59%, respectively; P = .04). Fifteen tumors were definitely unresectable. EUS correctly identified unresectability in 8 of 15 and correctly identified the 38 of 39 patients with resectable tumors (53% sensitivity and 97% specificity for unresectability). CT and/or MRI failed to detect unresectability in 6 of these 8 patients. LIMITATION Single-center study. CONCLUSION EUS and EUS-FNA are sensitive for the diagnosis of CCA and very specific in predicting unresectability. The sensitivity of EUS-FNA is significantly higher in distal than in proximal CCA.

Risk of post-ERCP pancreatitis with placement of self-expandable metallic stents

BACKGROUND There are conflicting data on the risk of post-ERCP pancreatitis (PEP) related to self-expandable metallic stents (SEMSs). OBJECTIVE To compare rates of PEP in patients who undergo biliary drainage with SEMSs or polyethylene stents (PSs). DESIGN Retrospective, cohort study. SETTING Tertiary-care medical center. PATIENTS This study involved patients undergoing ERCP for malignant biliary obstruction between January 2005 and October 2008. INTERVENTION First-time placement of a SEMS or PS for biliary decompression. MAIN OUTCOME MEASUREMENTS Early post-ERCP complications, particularly PEP. RESULTS We identified 544 eligible patients, 248 SEMSs (102 covered), and 296 PSs. The etiology of malignant biliary obstruction was similar between groups, with 55% from pancreatic cancer. The frequency of PEP was significantly higher in the SEMS group (7.3%) versus the PS group (1.3%) (OR 5.7 [95% CI, 1.9-17.1]). On univariate analysis, patient age of <40 years, a history of PEP, and at least 1 pancreatic duct injection were also significant predictors of PEP, whereas female sex and having pancreatic cancer were not. When significant variables were added to a multiple-predictor regression model, the odds of PEP from SEMS placement increased to 6.8 (95% CI, 2.2, 21.4). However, the frequency of PEP was similar between covered (6.9%) and uncovered (7.5%) SEMSs (OR 0.9 [CI, 0.3-2.4]). Purported SEMS-specific risk factors, including the use of cSEMSs, overlapping SEMSs, or having a biliary sphincterotomy were not found to be significant contributors to the higher risk. LIMITATIONS Retrospective design. CONCLUSION After we controlled for confounding variables, the frequency of PEP was significantly higher with placement of a SEMS compared with a PS. Rates of PEP were comparable with use of covered and uncovered SEMSs.

Mechanisms of CFTR Functional Variants That Impair Regulated Bicarbonate Permeation and Increase Risk for Pancreatitis but Not for Cystic Fibrosis

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system.

Performance characteristics of molecular (DNA) analysis for the diagnosis of mucinous pancreatic cysts

BACKGROUND Diagnosis of mucinous pancreatic cysts (MPCs) is challenging due to the poor sensitivity of cytology provided by EUS-guided-FNA (EUS-FNA). OBJECTIVE To quantify the test characteristics of molecular (DNA) analysis in suspected low-risk MPCs. DESIGN A prospective cohort study performed in between 2008 and 2011. SETTING Academic referral center. PATIENTS Consecutive patients who underwent EUS-FNA of suspected MPCs. INTERVENTION EUS-FNA and molecular (DNA) analysis of cyst fluid. MAIN OUTCOME MEASUREMENTS The sensitivity and specificity of molecular analysis in the diagnosis of MPCs using the criterion standard of surgical pathology in resected cysts. RESULTS Patients with suspected MPCs underwent EUS-FNA and cyst fluid DNA analysis. Surgical resection was performed in 48 patients (17%), confirming a mucinous pathology in 38 (79%). In this group, molecular analysis had a sensitivity of 50% and a specificity of 80% in identifying MPCs (accuracy of 56.3%). The combination of molecular analysis with cyst fluid carcinoembryonic antigen (CEA) and cytology resulted in higher MPC diagnostic performance than either one of its individual components, with a sensitivity, specificity, and accuracy of 73.7%, 70%, and 72.9%, respectively. There was no significant difference in accuracy between molecular analysis and CEA/cytology in this group. LIMITATIONS Single-center experience. CONCLUSION Molecular analysis aids in the diagnosis of MPCs when cytology is nondiagnostic or cyst fluid is insufficient for CEA or its level is indeterminate. Our results do not support the routine use of molecular analysis, which should be used selectively after review of imaging findings and cyst fluid studies. Further studies are needed to assess DNAs performance in malignant cysts.

Obesity as a risk factor for sedation-related complications during propofol-mediated sedation for advanced endoscopic procedures

BACKGROUND There are limited data on the safety of anesthesia-assisted endoscopy by using propofol-mediated sedation in obese individuals undergoing advanced endoscopic procedures (AEPs). OBJECTIVE To study the association between obesity (as measured by body mass index [BMI]) and the frequency of sedation-related complications (SRCs) in patients undergoing AEPs. DESIGN Prospective cohort study. SETTING Tertiary referral center. PATIENTS A total of 1016 consecutive patients undergoing AEPs (BMI <30, 730 [72%]; 30-35, 159 [16%]; >35, 127 [12%]). INTERVENTION Monitored anesthesia sedation with propofol alone or in combination with benzodiazepines and/or opioids. MAIN OUTCOME MEASUREMENTS SRCs, airway maneuvers (AMs), hypoxemia, hypotension requiring vasopressors, and early procedure termination were compared across 3 groups. RESULTS There were 203 AMs in 13.9% of patients, hypoxemia in 7.3%, need for vasopressors in 0.8%, and premature termination in 0.6% of patients. Increasing BMI was associated with an increased frequency of AMs (BMI <30, 10.5%; 30-35, 18.9%; >35-26.8%; P < .001) and hypoxemia (BMI <30, 5.3%; 30-35, 9.4%; >35, 13.4%; P = .001); there was no difference in the frequency of need for vasopressors (P = .254) and premature termination of procedures (P = .401). On multivariable analysis, BMI (odds ratio [OR] 2.0; 95% CI, 1.3-3.1), age (OR 1.1; 95% CI, 1.0-1.1), and American Society of Anesthesiologists class 3 or higher (OR 2.4; 95% CI, 1.1-5.0) were independent predictors of SRCs. In obese individuals (n = 286), there was no difference in the frequency of SRCs in patients receiving propofol alone or in combination (P = .48). LIMITATIONS Single tertiary center study. CONCLUSIONS Although obesity was associated with an increased frequency of SRCs, propofol sedation can be used safely in obese patients undergoing AEPs when administered by trained professionals.

Similar efficacies of biliary, with or without pancreatic, sphincterotomy in treatment of idiopathic recurrent acute pancreatitis.

BACKGROUND & AIMS The role of sphincter of Oddi manometry (SOM) in the management of patients with idiopathic recurrent acute pancreatitis requires clarification. We evaluated the therapeutic effects of endoscopic sphincterotomy in patients with recurrent acute pancreatitis and the prognostic significance of pancreatic sphincter dysfunction (SOD). METHODS We performed a randomized trial of endoscopic retrograde cholangiopancreatography with SOM for patients with idiopathic recurrent acute pancreatitis. Patients with pancreatic SOD (n = 69) were assigned randomly to groups that received only biliary sphincterotomy (BES) or a combination of biliary and pancreatic sphincterotomy (DES); patients who underwent normal SOM (n = 20) were assigned randomly to groups that received BES or a sham surgery. The primary outcome was incidence of recurrent acute pancreatitis during the follow-up period (minimum, 1 year; maximum, 10 years). We also determined the incidence of chronic pancreatitis and analyzed factors associated with recurrence of acute pancreatitis. RESULTS Among the 69 patients with SOD, 48.5% who received BES and 47.2% who received DES had recurrent acute pancreatitis (95% confidence interval, -22.3 to 24.9; P = 1.0). In patients with normal SOM (n = 20), 27.3% of those who received BES and 11.1% of those who received the sham surgery had recurrent acute pancreatitis (95% confidence interval, -49.5 to 17.2; P = .59). Overall, 16.9% of subjects developed chronic pancreatitis during a median follow-up period of 78 months (interquartile range, 35-108 mo). The odds of recurrent acute pancreatitis during follow-up evaluation were significantly greater among patients with SOD than those with normal SOM (unadjusted hazard ratio, 3.5; 95% confidence interval, 1.07-11.4; P < .04), and remained so after adjusting for potential confounders (hazard ratio, 4.3; 95% confidence interval, 1.3-14.5; P < .02). CONCLUSIONS Among patients with pancreatic SOD, DES and BES have similar effects in preventing recurrence of acute pancreatitis. Pancreatic SOD is an independent prognostic factor, identifying patients at higher risk for recurrent acute pancreatitis. CLINICAL TRIALS REGISTRATION Clinicaltrials.gov (NCT01583517).

Effect of Covered Metallic Stents Compared With Plastic Stents on Benign Biliary Stricture Resolution: A Randomized Clinical Trial

IMPORTANCE Endoscopic placement of multiple plastic stents in parallel is the first-line treatment for most benign biliary strictures; it is possible that fully covered, self-expandable metallic stents (cSEMS) may require fewer endoscopic retrograde cholangiopancreatography procedures (ERCPs) to achieve resolution. OBJECTIVE To assess whether use of cSEMS is noninferior to plastic stents with respect to stricture resolution. DESIGN, SETTING, AND PARTICIPANTS Multicenter (8 endoscopic referral centers), open-label, parallel, randomized clinical trial involving patients with treatment-naive, benign biliary strictures (N = 112) due to orthotopic liver transplant (n = 73), chronic pancreatitis (n = 35), or postoperative injury (n = 4), who were enrolled between April 2011 and September 2014 (with follow-up ending October 2015). Patients with a bile duct diameter less than 6 mm and those with an intact gallbladder in whom the cystic duct would be overlapped by a cSEMS were excluded. INTERVENTIONS Patients (N = 112) were randomized to receive multiple plastic stents or a single cSEMS, stratified by stricture etiology and with endoscopic reassessment for resolution every 3 months (plastic stents) or every 6 months (cSEMS). Patients were followed up for 12 months after stricture resolution to assess for recurrence. MAIN OUTCOMES AND MEASURES Primary outcome was stricture resolution after no more than 12 months of endoscopic therapy. The sample size was estimated based on the noninferiority of cSEMS to plastic stents, with a noninferiority margin of -15%. RESULTS There were 55 patients in the plastic stent group (mean [SD] age, 57 [11] years; 17 women [31%]) and 57 patients in the cSEMS group (mean [SD] age, 55 [10] years; 19 women [33%]). Compared with plastic stents (41/48, 85.4%), the cSEMS resolution rate was 50 of 54 patients (92.6%), with a rate difference of 7.2% (1-sided 95% CI, -3.0% to ∞; P < .001). Given the prespecified noninferiority margin of -15%, the null hypothesis that cSEMS is less effective than plastic stents was rejected. The mean number of ERCPs to achieve resolution was lower for cSEMS (2.14) vs plastic (3.24; mean difference, 1.10; 95% CI, 0.74 to 1.46; P < .001). CONCLUSIONS AND RELEVANCE Among patients with benign biliary strictures and a bile duct diameter 6 mm or more in whom the covered metallic stent would not overlap the cystic duct, cSEMS were not inferior to multiple plastic stents after 12 months in achieving stricture resolution. Metallic stents should be considered an appropriate option in patients such as these. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01221311.