The revised Atlanta criteria more accurately reflect severity of post-ERCP pancreatitis compared to the consensus criteria.

Background and objective: Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is the most prevalent complication after ERCP with an incidence of 3.5%. PEP severity is classified according to either the consensus criteria or the revised Atlanta criteria. In this international cohort study we investigated which classification is the strongest predictor of PEP-related mortality. Methods: We reviewed 13,384 consecutive ERCPs performed between 2012 and 2017 in eight hospitals. We gathered data on all pancreatitis-related adverse events and compared the predictive capabilities of both classifications. Furthermore, we investigated the correlation between the two classifications and identified reasons underlying length of stay. Results: The total sample consisted of 387 patients. The revised Atlanta criteria have a higher sensitivity (100 vs. 55%), specificity (98 vs. 72%) and positive predictive value (58 vs. 5%). There is a significant difference (p < 0.001) between the two classifications. In 124 patients (32%), the length of stay was influenced by concomitant diseases. Conclusion: The revised Atlanta classification is superior in predicting mortality and better reflects PEP severity. This has important implications for researchers, clinicians and patients. For the diagnosis of PEP pancreatitis, the consensus criteria remain the golden standard. However, the revised Atlanta criteria are preferable for defining PEP severity.

Rome IV. Gallbladder and Sphincter of Oddi Disorders.

The concept that motor disorders of the gallbladder, cystic duct and sphincter of Oddi can cause painful syndromes is attractive and popular, at least in the USA. However, the results of commonly performed ablative treatments (cholecystectomy and sphincterotomy) are not uniformly good. The predictive value of tests that are often used to diagnose dysfunction (dynamic gallbladder scintigraphy and sphincter manometry) is controversial. Evaluation and management of these patients is made difficult by the fluctuating symptoms and the placebo effect of invasive interventions. A recent stringent study has shown that sphincterotomy is no better than sham treatment in patients with post-cholecystectomy pain and little or no objective abnormalities on investigation, so that the old concept of sphincter of Oddi dysfunction (SOD) type III is discarded. ERCP approaches are no longer appropriate in that context. There is a pressing need for similar prospective studies to provide better guidance for clinicians dealing with these patients. We need to clarify the indications for cholecystectomy in patients with Functional Gallbladder Disorder (FGBD) and the relevance of sphincter dysfunction in patients with some evidence for biliary obstruction (previously SOD type II, now called "Functional Biliary Sphincter Disorder - FBSD") and with idiopathic acute recurrent pancreatitis.

Gadolinium as an alternative contrast agent for therapeutic ERCP in the iodine-allergic patient.

Performance of endoscopic retrograde cholangiopancreatography (ERCP) requires an intraductal contrast agent. The contrast of choice is an iodine-based agent. The alternatives in patients with a severe allergy to iodinated contrast are limited. We undertook a retrospective review of the success and safety of gadolinium as an alternative radiocontrast agent in patients with allergy to iodine-based contrast in a series of five patients in a tertiary care pancreaticobiliary referral center. The five patients underwent a total of six ERCP procedures using a gadolinium chelate as the radiocontrast agent. ERCP was technically successful in all cases, including pancreatic endotherapy. There were no contrast-related adverse reactions. Gadolinium is concluded to be a reasonable alternative to iodine-based ERCP contrast in selected patients. It provides inferior image quality compared to standard iodine-based contrast but was not technically limiting in our small experience.

Preliminary pneumoperitoneum facilitates transgastric access into the peritoneal cavity for natural orifice transluminal endoscopic surgery: a pilot study in a live porcine model.

BACKGROUND AND STUDY AIMS: Safe entrance into the peritoneal cavity through the gastric wall is paramount for the successful clinical introduction of natural orifice transluminal endoscopic surgery (NOTES). The aim of the study was to develop alternative safe transgastric access to the peritoneal cavity. PATIENTS AND METHODS: We performed 11 survival experiments on 50-kg pigs. In sterile conditions, the abdominal wall was punctured with a Veress needle. The peritoneal cavity was insufflated with 2 L carbon dioxide (CO (2)). A sterile endoscope was introduced into the stomach through a sterile overtube; the gastric wall was punctured with a needle-knife; after balloon dilation of the puncture site, the endoscope was advanced into the peritoneal cavity. Peritoneoscopy with biopsies from abdominal wall, liver and omentum, was performed. The endoscope was withdrawn into the stomach. The animals were kept alive for 2 weeks and repeat endoscopy was followed by necropsy. RESULTS: The pneumoperitoneum, easily created with the Veress needle, lifted the abdominal wall and made a CO (2)-filled space between the stomach and adjacent organs, facilitating gastric wall puncture and advancement of the endoscope into the peritoneal cavity. There were no hemodynamic changes or immediate or delayed complications related to pneumoperitoneum, transgastric access, or intraperitoneal manipulations. Follow-up endoscopy and necropsy revealed no problems or complications inside the stomach or peritoneal cavity. CONCLUSIONS: Creation of a preliminary pneumoperitoneum with a Veress needle facilitates gastric wall puncture and entrance into the peritoneal cavity without injury to adjacent organs, and can improve the safety of NOTES.

A new stapler-based full-thickness transgastric access closure: results from an animal pilot trial.

BACKGROUND AND STUDY AIMS: Reliable closure of the transluminal incision is the crucial step for natural orifice transluminal endoscopic surgery (NOTES) procedures. The aim of this study was to evaluate the feasibility and effectiveness of transgastric access closure with a flexible stapling device in a porcine survival model. PATIENTS AND METHODS: We carried out four experiments (two sterile and two nonsterile) on 50 kg pigs. The endoscope was passed through a gastrotomy made with a needle knife and an 18-mm controlled radial expansion dilating balloon. After peritoneoscopy, a flexible linear stapling device (NOLC60, Power Medical Interventions, Langhorne, Pennsylvania, USA) was perorally advanced over a guide wire into the stomach, positioned under endoscopic guidance, and opened to include the site of gastrotomy between its two arms; four rows of staples were fired. One animal was sacrificed 24 hours after the procedure (progression of pre-existing pneumonia). The remaining animals were survived for 1 week and then underwent repeat endoscopy and postmortem examination. RESULTS: Peroral delivery and positioning of the stapling device involved some technical difficulties, mostly due to the short length (60 cm) of the stapling device. The stapler provided complete leak-resistant gastric closure in all pigs. None of the surviving animals had any clinical signs of infection. Necropsy demonstrated an intact staple line with full-thickness healing of the gastrotomy in all animals. Histologic examination confirmed healing, but also revealed intramural micro-abscesses within the gastric wall after nonsterile procedure. CONCLUSIONS: Gastrotomy closure with a perorally delivered flexible stapling device created a leak-resistant transmural line of staples followed by full-thickness healing of the gastric wall incision. Increasing the length of the instrument and adding device articulation will further facilitate its use for NOTES procedures.

Small prophylactic pancreatic duct stents: an assessment of spontaneous passage and stent-induced ductal abnormalities.

BACKGROUND AND STUDY AIMS: Placing small stents in the pancreatic duct at endoscopic retrograde cholangiopancreatography reduces the risk of pancreatitis. However, this practice means that a second procedure might be required to remove the stent, and stents can also damage the duct. The aims of this study were to determine the frequency of spontaneous dislodgment and to assess the incidence of stent-induced ductal irregularities. PATIENTS AND METHODS: We performed a retrospective analysis of consecutive patients seen over a 3-year period (2001 - 2004) who had undergone placement of a 3-Fr pancreatic duct stent and in whom the fate of the stent had been documented. Radiographs were reviewed to determine stent passage at 30 days. If applicable, follow-up pancreatograms were reviewed to assess for stent-induced ductal abnormalities. Statistical analysis was performed using chi-squared and Fisher's exact tests for proportions, and 95 % binomial confidence intervals (CI) were calculated. RESULTS: Records for 125 consecutive patients who had had 3-Fr pancreatic stents placed were reviewed. The stents had passed spontaneously within 30 days in 110/125 patients (88 %). In the remaining 15 patients (12 %, 95 % CI 6.9 % - 19 %), the stents were still present on follow-up radiographs after a median time of 36 days, (range 31 - 116 days). Stent length, pancreatic sphincterotomy, and pancreas divisum had no effect on the likelihood of spontaneous passage. No stent-induced ductal irregularities were observed. CONCLUSIONS: Nearly 90 % of prophylactic 3-Fr pancreatic duct stents pass spontaneously within 30 days, and these stents were not observed to induce changes in the pancreatic duct.

Submucosal endoscopic esophageal myotomy: a novel experimental approach for the treatment of achalasia.

BACKGROUND AND STUDY AIMS: The most permanent method of treating achalasia is a surgical myotomy. Because of the requirement for a mucosal incision and the risk of perforation, this procedure has not generally been approached endoscopically. We hypothesized that we could perform a safe and robust myotomy by working in the submucosal space, accessed from the esophageal lumen. MATERIALS AND METHODS: Four pigs were used for this experiment. Baseline lower esophageal sphincter (LES) pressures were recorded and the pigs underwent upper endoscopy using a standard endoscope. A submucosal saline lift was created approximately 5 cm above the LES and a small nick was made in the mucosa in order to facilitate the introduction of a dilating balloon. After dilation, the scope was introduced over the balloon into the submucosal space and advanced toward the now visible fibers of the LES. The circular layer of muscle was then cleanly incised using an electrocautery knife in a distal-to-proximal fashion, without complications. The scope was then withdrawn back into the lumen and the mucosal defect was closed with endoscopically applied clips. The entire procedure took less than 15 minutes. Manometry was repeated on day 5 after the procedure and the animals were euthanized on day 7. RESULTS: LES pressures fell significantly from an average of 16.4 mm Hg to an average of 6.7 mm Hg after the myotomy. The necropsy examinations revealed no evidence of mediastinitis or peritonitis. CONCLUSIONS: Endoscopic submucosal esophageal myotomy is feasible, safe, and effective in the short term. It has the potential for being useful in patients with achalasia. The submucosal space is a novel and potentially important field of operation for endoscopic procedures.

Peroral transgastric endoscopic primary repair of a ventral hernia in a porcine model.

BACKGROUND AND STUDY AIMS: Multiple studies have demonstrated the feasibility of peroral transgastric endoscopic procedures in animal models. The aim of the study was to evaluate the feasibility of a peroral transgastric endoscopic approach to repair abdominal wall hernias. PATIENTS AND METHODS: We performed acute experiments under general anesthesia with endotracheal intubation using 50-kg pigs. Following peroral intubation an incision of the gastric wall was made and the endoscope was advanced into the peritoneal cavity. An internal anterior abdominal wall incision was performed with a needle knife to create an animal model of a ventral hernia. After hernia creation an endoscopic suturing device was used for primary repair of the hernia. After completion of the hernia repair the endoscope was withdrawn into the stomach and the gastric wall incision was closed with endoscopic clips. Then the animals were killed for necropsy. RESULTS: Two acute experiments were performed. Incision of the gastric wall was easily achieved with a needle knife and a pull-type sphincterotome. A large (3 x 2 cm) defect of the abdominal wall (ventral hernia model) was closed with five or six sutures using the endoscopic suturing device. Postmortem examination revealed complete closure of the hernia without any complications. CONCLUSIONS: Transgastric endoscopic primary repair of ventral hernias in a porcine model is feasible and may be technically simpler than laparoscopic surgery.

Do all patients with abnormal intraoperative cholangiogram merit endoscopic retrograde cholangiopancreatography?

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is commonly used for postoperative evaluation of an abnormal intraoperative cholangiogram (IOC). Although a normal IOC is very suggestive of a disease-free common bile duct (CBD), abnormal studies are associated with high false-positive rates. This study aimed to identify a subset of patients with abnormal IOC who would benefit from a postoperative ERCP. METHODS: This prospective study investigated 51 patients with abnormal IOC at laparoscopic cholecystectomy who underwent postoperative ERCP at two tertiary referral centers over a 3-year period. Univariate and multivariate logistic regression analyses were performed to determine predictors of CBD stones at postoperative ERCP. RESULTS: For all 51 patients, ERCP was successful. The ERCP showed CBD stones in 33 cases (64.7%), and normal results in 18 cases (35.2%). On univariate analysis, abnormal liver function tests (p < 0.0001) as well as IOC findings of a large CBD stone (p = 0.03), multiple stones (p = 0.01), and a dilated CBD (p = 0.07) predicted the presence of retained stones at postoperative ERCP. However, on multivariable analysis, only abnormal liver function tests correlated with the presence of CBD stones (p < 0.0001). CONCLUSIONS: One-third of patients with an abnormal IOC have a normal postoperative ERCP. Elevated liver function tests can help to identify patients who merit further evaluation by ERCP. The use of less invasive methods such as endoscopic ultrasound or magnetic resonance cholangiopancreatography should be considered for patients with normal liver function tests to minimize unnecessary ERCPs.

Transgastric endoscopic splenectomy: is it possible?

BACKGROUND: We have previously reported the feasibility of diagnostic and therapeutic peritoneoscopy including liver biopsy, gastrojejunostomy, and tubal ligation by an oral transgastric approach. We present results of per-oral transgastric splenectomy in a porcine model. The goal of this study was to determine the technical feasibility of per-oral transgastric splenectomy using a flexible endoscope. METHODS: We performed acute experiments on 50-kg pigs. All animals were fed liquids for 3 days prior to procedure. The procedures were performed under general anesthesia with endotracheal intubation. The flexible endoscope was passed per orally into the stomach and puncture of the gastric wall was performed with a needle knife. The puncture was extended to create a 1.5-cm incision using a pull-type sphincterotome, and a double-channel endoscope was advanced into the peritoneal cavity. The peritoneal cavity was insufflated with air through the endoscope. The spleen was visualized. The splenic vessels were ligated with endoscopic loops and clips, and then mesentery was dissected using electrocautery. RESULTS: Endoscopic splenectomy was performed on six pigs. There were no complications during gastric incision and entrance into the peritoneal cavity. Visualization of the spleen and other intraperitoneal organs was very good. Ligation of the splenic vessels and mobilization of the spleen were achieved using commercially available devices and endoscopic accessories. CONCLUSIONS: Transgastric endoscopic splenectomy in a porcine model appears technically feasible. Additional long-term survival experiments are planned.

Developing an animal model of massive ulcer bleeding for assessing endoscopic hemostatic devices.

BACKGROUND: Existing animal models of ulcerative bleeding are not suitable for endoscopic investigation. We describe a new porcine model of massive arterial bleeding in the stomach and its use for assessing a novel endoscopic suturing device. METHODS: Two animal models were investigated. In model 1, the short gastric artery (mean diameter 2 mm) was divided near its gastric end. A mucosal defect was created near the greater curve and the divided artery was brought into the lumen of the stomach through a submucosal tunnel. An inflatable plastic cuff was placed around the base of the artery. Cuff deflation led to massive bleeding. In model 2, the short gastric artery was carefully exposed along a segment of 2 cm on the side facing the stomach. It was then anchored to a small gastrostomy made at the posterior wall near the vessel. At endoscopy an ulcer-like lesion could be seen with a pulsatile vessel at the base and brisk bleeding could be started by cutting a hole in the artery using endoscissors. The pigs were heparinized by an intravenous bolus of 110-300 units per kilogram, in both models. A prototype suturing device, the Eagle Claw, was inserted using a gastroscope and the curved needle was driven around the bleeding artery. Extracorporeal knotting or intracorporeal ligation was done endoscopically. RESULTS: Pulsatile arterial bleeding was successfully created in four pigs using model 1, and in another four pigs using model 2. Model 2 was more reproducible and less time-consuming to create. Endoscopic suturing controlled arterial bleeding in five out of eight pigs with a single stitch and in another three pigs with an additional stitch. CONCLUSION: This animal model provides reproducible massive hemorrhage suitable for endoscopic studies. Control of gastric bleeding from large arteries by endoscopic suturing is possible.

Transoral obesity surgery: endoluminal gastroplasty with an endoscopic suture device.

BACKGROUND AND STUDY AIMS: Surgical creation of a small gastric pouch with a restricted outlet is a well-established option for the treatment of morbid obesity. This report describes initial experience with endoscopic transoral stomach partition using a newly designed suturing apparatus. MATERIALS AND METHODS: A fresh porcine stomach was placed in the Erlangen model. A prototype suture device, incorporating a curved needle and an intracorporeal tightening mechanism, was used in this procedure. A long fishing line was first introduced into the stomach, with the two ends left outside. The suturing device, premounted outside a standard gastroscope, was inserted into the stomach and delivered several stitches attaching the fishing line to both the anterior and posterior walls along the line for the stomach to be partitioned. Five throws of half-hitches were tied onto the fishing line extracorporeally and separately pushed into place, creating a gastric pouch just below the esophagogastric junction. A flexible sheath of 8 cm long was then put on one side of the fishing line and pushed into the stomach. Additional extracorporeal knots were tied on the fishing line, forming a restrictive ring at the outlet of the pouch. The ring was then anchored to the stomach wall with similar endosutures. RESULTS: The proximal gastric pouch, with an estimated volume of approximately 100 ml, was successfully created with a restrictive band at its outlet. All of the stitches were securely sutured, with consistent penetration of the muscular layer of the stomach wall. CONCLUSIONS: In a bench model, it is technically possible to accomplish transoral gastroplasty endoscopically with an intraluminal suturing device. Further live animal studies will be needed in order to confirm the efficacy and safety of this procedure before clinical application.

Assessing the adequacy of endoscopically tied knots: a functional approach.

BACKGROUND AND STUDY AIMS: Endoscopic intracorporeal knots have potentially enormous applications in endoscopic surgery. We describe a method for testing the security of various types of endoscopically tied knots using a vessel perfusion manometer system. METHODS: A 4-cm segment of porcine splenic artery was placed on the mucosal surface of a pig stomach. The two ends of the vessel were brought out through the gastric wall and connected to a two-way manometer. One end was also joined to a pressure infusion bag. The stomach was mounted in an Erlangen training model. A long 3/0 nylon thread, previously introduced into the submucosal layer of the stomach and encircling the vessel, was brought out from the mouth. Three-throw square knots, Mayo knots, "surgeon's" knots and five-throw square knots were tied and pushed into place using a cap attached to a gastroscope. The pressure at the two ends of the artery was compared. If the pressure could be increased to over 200 mm Hg at one end without a change in the other, the knot was considered secure. RESULTS: Each type of knot was tested 12 times under endoscopic vision. The range for mean knotting time was 3.4 - 4.5 minutes. Five-throw knots took significantly longer to tie than three-throw knots (P < 0.005). There was one loose knot in each of the three-throw and Mayo groups, and three each in the "surgeon's" and five-throw groups (P > 0.05). CONCLUSIONS: This system is a reliable model for testing intracorporeal knots tied endoscopically. A three-half-hitches square knot with 3/0 nylon, tied using a flexible endoscope and knot-tightening cap, can withstand pressure up to 200 mm Hg.

Evaluation of unexplained acute and acute recurrent pancreatitis using endoscopic retrograde cholangiopancreatography, sphincter of Oddi manometry and endoscopic ultrasound.

BACKGROUND AND STUDY AIMS: Unexplained pancreatitis represents a diagnostic challenge. The aim of this study was to determine the diagnostic utility of endoscopic retrograde cholangiopancreatography (ERCP) with sphincter of Oddi manometry (SOM), bile analysis, and endoscopic ultrasound (EUS) in evaluating such patients. PATIENTS AND METHODS: Of 162 patients referred for evaluation of pancreatitis, 72 with a known cause were excluded. The remainder ( n=90) was classified as having prior acute ( n=24) or recurrent acute pancreatitis ( n=66). Bile sampling and SOM were performed at the time of ERCP. EUS was used to assess for tumors and for chronic pancreatitis. Clinical outcomes were evaluated by questionnaire. RESULTS: ERCP was successful in 88/89 patients (99 %). Manometry was successful in 63/67 patients (94 %), and 56 patients underwent EUS. Findings were categorized into five distinct etiologies: sphincter of Oddi dysfunction (SOD) ( n=28; 31 %), pancreas divisum ( n=18; 20 %), biliary ( n=18; 20 %), idiopathic ( n=18; 20 %) and tumor-related ( n=8; 9 %). Features of moderate or severe chronic pancreatitis by EUS and ERCP criteria were found in 18 patients (21 %); an additional nine patients had chronic pancreatitis by EUS criteria alone. EUS identified all the tumors. The condition was improved in 96 % of all patients undergoing endoscopic therapy. CONCLUSION: An etiology was identified in the majority of patients with unexplained pancreatitis. SOD represented the most common finding. Moderate to severe chronic pancreatitis was found in over one-fifth of these patients. Bile analysis, SOM, and EUS are useful tools in the evaluation of unexplained acute pancreatitis.

Evaluating ERCP is important but difficult.

ERCP is a valuable technique now practised widely throughout the world. It revolutionised the diagnosis and management of benign and malignant biliary and pancreatic diseases in the 1970s and 1980s. However, recent developments have highlighted the need for detailed evaluation of current ERCP practice. This review is based on a presentation to a recent NIH "state of the science" conference on ERCP, and refers to an article which appears in this issue of Gut from researchers in Hong Kong who report on a randomised controlled trial of endoscopic sphincterotomy in acute cholangitis.

Yield of colonoscopy in patients with nonacute rectal bleeding: a multicenter database study of 1766 patients.

OBJECTIVE: There are few data to guide the choice between colonoscopy and flexible sigmoidoscopy in patients with nonacute rectal bleeding, especially in younger age groups. Our aim was to determine the yield of colonoscopy for significant proximal large bowel disease in the absence of significant distal disease, with special reference to young patients. METHODS: This was a retrospective study of data collected prospectively in 1766 patients (median age 57 yr, 711 women). The endoscopic database (GI-Trac) contained 152 discrete fields for data input. Multiple logistic regression analysis was performed to identify variables independently associated with the presence of isolated significant proximal disease. RESULTS: Young patients had a higher percentage of normal examinations than did older patients. The incidence of diverticular disease, small polyps, large polyps, and cancer rose with increasing age. No patient aged <40 yr had an isolated proximal cancer, but 7% had other significant isolated proximal disease. There was no overall association between age and significant proximal disease in the absence of significant distal disease (p = 0.66). The only variable associated with isolated proximal disease was anemia (odds ratio = 1.81; 95% CI = 1.11-2.93; p = 0.02). CONCLUSION: The yield of colonoscopy (beyond the range of sigmoidoscopy) for neoplasia is low in patients aged <40 yr, but other significant disease may be missed if age is the only criterion determining colonoscopy use.

Cholecystokinin-Stimulated mebrofenin (99mTc-Choletec) hepatobiliary scintigraphy in asymptomatic postcholecystectomy individuals: assessment of specificity, interobserver reliability, and reproducibility.

OBJECTIVES: Cholecystokinin-stimulated hepatobiliary scintigraphy (CCK-HBS) is a noninvasive method reported to be highly accurate in the diagnosis of sphincter of Oddi dysfunction. Our primary aim was to assess the specificity of CCK-HBS by evaluating its ability to exclude disease in 20 asymptomatic postcholecystectomy individuals. Secondary aims were to assess the interobserver reliability in scoring the CCK-HBS examinations between three blinded observers and to assess reproducibility of CCK-HBS repeated in the same individuals. METHODS: Twenty asymptomatic postcholecystectomy individuals with normal liver serum chemistries underwent CCK-HBS on two separate occasions. Three nuclear medicine specialists read each CCK-HBS study in a blinded fashion. RESULTS: There was good agreement between the three observers reading the same scans for both the first scan (kappa = 0.554) and the second scan (kappa = 0.507). There was poor agreement between the first and second scans on the same patient, read by the same nuclear medicine specialist (kappa = 0.062-0.385). The overall specificity of the CCK-HBS score was 77.5%; however, the specificity was only 60% when a true negative was defined as two negative CCK-HBS examinations. CONCLUSIONS: Quantitative CCK-HBS is of poor specificity in asymptomatic postcholecystectomy individuals. Hence, it is of questionable value in excluding sphincter of Oddi dysfunction in patients suspected to suffer from this disorder.