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Background and Aims: Duodenoscope contamination is associated with notable patient morbidity and mortality and can occur despite high-level disinfection protocols, requiring a solution that protects against contamination of the endoscope in the first place., Methods: We assessed a newly cleared, single-use device to seal the distal end of duodenoscopes while preserving optics and other endoscope functionality and tested its ability to protect against contamination using dye immersion tests and microbial inoculation., Results: Dye immersion tests revealed a complete seal with no leakage. Rigorous microbial challenge tests showed the device can both protect against contamination of the endoscope by external microbes ("outside-in" protection) and shield instruments from contact with pre-existing microbial biofilm on or around the elevator that may have survived reprocessing ("inside-out" protection). Optical and mechanical performance of the endoscope was not compromised by the addition of the device., Conclusions: The results show that this disposable device provides 2-way protection to the duodenoscope from microbial contamination, without the potential for disrupting current equipment, technique, and workflow., (Copyright © 2020 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Diagnosis of GI neuromuscular diseases is mostly on the basis of symptomatology and is often unreliable. Pathologic analysis of affected tissue (eg, the myenteric plexus and muscle) is a potentially valuable method for both diagnosis and advancement of our knowledge about the biologic basis for these syndromes. However, until now access to the deeper layers of the GI tract has been limited, generally requiring invasive surgical techniques., Methods: We report a "close-then-resect" endoscopic full-thickness biopsy sampling (EFTB) technique using an over-the-scope clip and telescope for rectal muscle biopsy sampling in patients with suspected severe neuromuscular gut disorders. The main outcome measures were technical success and adverse events., Results: Thirteen patients (11 women; mean age 27 ± 5.4 years) with diffusely delayed colonic transit underwent EFTB. The mean (± standard deviation) procedure time was 30 ± 5.2 minutes. The mean size of the resected specimen was 18 ± 3.5 mm. Histologic full-thickness tissue samples were achieved for all patients. Postprocedural adverse events were reported in 2 patients, and both were graded as mild (1 self-limited bleeding and 1 with rectal pain). Hematoxylin and eosin staining of tissue samples confirmed adequate cross-sectional imaging of muscularis propria in all patients with excellent demonstration of the myenteric plexus and both layers of muscle. Two patients demonstrated a decrease in interstitial cells of Cajal as demonstrated by CD117 staining. No cases demonstrated appreciable inflammation involving myenteric ganglia., Conclusions: Diagnostic EFTB with modified over-the-scope clip for the close-then-resect method appears to be a safe and effective technique to obtain adequate full-thickness rectal specimens, allowing for both quantitative and qualitative analysis for the diagnosis of neuromuscular GI dysmotility., (Copyright © 2019 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background and Aims: The safety and efficacy of peroral endoscopic myotomy (POEM) when performed by gastroenterologists in the endoscopy unit are currently unknown. The aims of this study were to assess (1) the safety and efficacy of POEM in which all procedures were performed by 1 gastroenterologist in the endoscopy unit, and (2) the predictors of adverse events and nonresponse., Methods: All consecutive patients who underwent POEM at 1 tertiary center were included. Clinical response was defined by a decrease in the Eckardt score to 3 or lower. Adverse events were graded according to the American Society for Gastrointestinal Endoscopy lexicon's severity grading system., Results: A total of 60 consecutive patients underwent POEM in the endoscopy suite with a mean procedure length of 99 minutes. The mean length of submucosal tunnel was 14 cm and the mean myotomy length was 11 cm. The median length of hospital stay was 1 day. Among 52 patients with a mean follow-up period of 118 days (range 30-750), clinical response was observed in 48 patients (92.3%). There was a significant decrease in Eckardt score after POEM (8 vs 1.19, P < .0001). The mean lower esophageal sphincter pressure decreased significantly after POEM (29 mm Hg vs 11 mm Hg, P < .0001). A total of 10 adverse events occurred in 10 patients (16.7%): 7 rated as mild, 3 as moderate, and none as severe. Procedure length was the only predictor of adverse events (P = .01). pH impedance testing was completed in 25 patients, and 22 (88%) had abnormal acid exposure, but positive symptom correlation was present in only 6 patients. All patients with symptomatic reflux were successfully treated with proton pump inhibitors., Conclusions: POEM can be effectively and safely performed by experienced gastroenterologists at a tertiary care endoscopy unit. Adverse events are infrequent, and most can be managed intraprocedurally. Post-POEM reflux is frequent but can be successfully managed medically., (Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Better pancreatic cyst fluid biomarkers are needed., Objective: To determine whether metabolomic profiling of pancreatic cyst fluid would yield clinically useful cyst fluid biomarkers., Design: Retrospective study., Setting: Tertiary-care referral center., Patients: Two independent cohorts of patients (n = 26 and n = 19) with histologically defined pancreatic cysts., Intervention: Exploratory analysis for differentially expressed metabolites between (1) nonmucinous and mucinous cysts and (2) malignant and premalignant cysts was performed in the first cohort. With the second cohort, a validation analysis of promising identified metabolites was performed., Main Outcome Measurements: Identification of differentially expressed metabolites between clinically relevant cyst categories and their diagnostic performance (receiver operating characteristic [ROC] curve)., Results: Two metabolites had diagnostic significance-glucose and kynurenine. Metabolomic abundances for both were significantly lower in mucinous cysts compared with nonmucinous cysts in both cohorts (glucose first cohort P = .002, validation P = .006; and kynurenine first cohort P = .002, validation P = .002). The ROC curve for glucose was 0.92 (95% confidence interval [CI], 0.81-1.00) and 0.88 (95% CI, 0.72-1.00) in the first and validation cohorts, respectively. The ROC for kynurenine was 0.94 (95% CI, 0.81-1.00) and 0.92 (95% CI, 0.76-1.00) in the first and validation cohorts, respectively. Neither could differentiate premalignant from malignant cysts. Glucose and kynurenine levels were significantly elevated for serous cystadenomas in both cohorts., Limitations: Small sample sizes., Conclusion: Metabolomic profiling identified glucose and kynurenine to have potential clinical utility for differentiating mucinous from nonmucinous pancreatic cysts. These markers also may diagnose serous cystadenomas., (Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background: Peroral endoscopic myotomy (POEM) was developed to reduce lower esophageal sphincter pressure in patients with achalasia. POEM is technically challenging and time consuming. The creation of an esophageal submucosal tunnel is a major and integral part of the procedure. Dissection of the submucosal fibers is a lengthy task., Objective: To present our initial experience with the use of a novel gel with dissecting properties for facilitating submucosal tunneling during POEM., Setting: Johns Hopkins Hospital., Intervention: POEM., Results: The gastroscope was successfully introduced into the submucosal space in all pigs. The gel in the submucosal space was easily suctioned through the working channel of the gastroscope and did not interfere with endoscopic visualization. The esophageal submucosal tunnel was noted to be already formed upon entry into the submucosal space in all 5 pigs. Esophageal submucosal dissection was not required in any case. "Auto-tunneling" by the dissecting gel stopped at the level of the lower esophageal sphincter. Further tunneling into the gastric cardia was needed in all pigs. The average procedure (including myotomy) time was 28 minutes., Limitations: Animal experiments., Conclusion: Gel consistently resulted in efficient auto-tunneling without any complications. This gel has the potential to revolutionize POEM and endoscopic submucosal dissection if its safety and efficacy are replicated in other animal studies and subsequently in human trials., (Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Introduction: Sphincter function is a common problem in gastroenterology and leads to disorders such as GERD and fecal incontinence., Objective: We hypothesized that transplantation of skeletal muscle-derived cells (MDCs) into GI sphincters may improve their function, leading to a more physiological approach to treating these disorders., Design: We performed experiments to test the potential of MDCs to survive and differentiate within the GI smooth muscle in order to gain further knowledge on the biology of skeletal muscle transplantation in GI smooth muscle sphincters as well as to test the safety and feasibility of endoscopic injection of MDCs in a large animal model., Setting: Animal laboratory., Interventions: Adult male Sprague-Dawley rats and adult male beagle dogs were used. Rat-derived and dog-derived MDCs were prepared in vitro and labeled with DiI. DiI-labeled, rat-derived MDCs (200,000/4 muL phosphate buffered saline solution) were injected bilaterally in the pyloric wall of rats, and survival, differentiation, and in vitro contractility were assessed 1 month after transplantation. Dog-derived MDCs (4.0 x 10(6) cells) were also injected into the lower esophageal sphincter of 3 beagle dogs by using a standard variceal sclerotherapy needle after baseline esophageal manometry and pH monitoring. The dogs were treated with daily cyclosporine, and 2 weeks later esophageal manometry was repeated and the esophagus was examined histologically. Differentiation of grafted cells was assessed by immunofluorescence, using specific antibodies to markers of the smooth muscle phenotype (smooth muscle actin) and of the skeletal muscle phenotype (skeletal muscle myosin)., Results: In rats, grafted MDCs were visualized based on DiI fluorescence and were found to be localized within the muscle wall and in the muscularis mucosa. In vitro organ bath studies showed a significant increase in the contractile response of the pyloric sphincter to exogenous acetylcholine. In dogs, MDC injection resulted in a significant increase in baseline lower esophageal sphincter pressure. Further, in 1 dog with significant baseline acid reflux, MDC injection resulted in a reduction of acid reflux, with the fraction of time with pH <4 decreasing from 26.5% to 1.5%. Transplanted MDCs were seen adding bulk to the lower esophageal area and were well-integrated into the surrounding tissue. Immunofluorescence analysis revealed weak expression of skeletal muscle myosin in grafted MDCs and no expression of smooth muscle actin in either rats or dogs., Limitations: Animal study., Conclusion: MDCs can survive and integrate into GI smooth muscle and augment their contractile response. Thus, they may have potential for the treatment of a variety of conditions.

Background: Gastric electrical stimulation has been used for the treatment of drug refractory GI motility disorders and for the treatment of obesity. Both these indications have involved surgical placement of gastric electrodes, which adds to the complexity and cost of the procedure. Endoscopic placement is therefore an attractive alternative approach for this therapy., Objective: Our purpose was to investigate the feasibility, safety, and efficacy of percutaneous endoscopic electrodes for gastric electrical stimulation., Design and Setting: Experimental animal study in hound dogs., Interventions: Percutaneous endoscopic transgastric electrode (PETE) placement was carried out by using a pair of gastric pacing wires attached to a percutaneous endoscopic gastrostomy tube. In addition, 4 pairs of gastric serosal electrodes were implanted surgically for comparison. The efficacy of the percutaneous endoscopic electrodes was defined by their ability to entrain gastric slow waves and the induction of dysrhythmia., Results: (1) The PETE recorded gastric slow waves comparable to the serosal electrodes. (2) Gastric electrical stimulation with long pulses delivered by the PETE, at a frequency of 10% higher than the intrinsic gastric slow wave frequency, entrained gastric slow waves. (3) Gastric electrical stimulation delivered by the PETE, at a tachygastric frequency, induced gastric dysrhythmia., Limitations: This was an animal study; however, its results are expected to be reproducible in humans, with PETE kept in place for even a longer duration than 6 to 8 weeks., Conclusion: PETE placement is both feasible and safe. PETEs are effective, having a potential for use in treatment of both gastroparesis and obesity.

Background: We previously demonstrated that the thoracic cavity could be safely accessed by submucosal endoscopy with the mucosal flap safety valve (SEMF) technique., Objectives: To evaluate the technical feasibility of transesophageal access to the heart and epicardial ablation., Design: One-week survival study with 5 porcine models., Settings: Animal laboratory with general anesthesia., Interventions: High-pressure carbon dioxide injection and balloon dissection created a large submucosal working space for insertion of a cap-fitted endoscope. A myotomy was performed inside the submucosal space. The thoracic cavity was endoscopically accessed through the myotomy site. A pericardial window was created with a needle-knife. A spot coagulation of the epicardium was performed with a heat probe and a hook-knife. The myotomy site was sealed with the overlying mucosal flap, and the mucosal entry site was closed with clips., Main Outcome Measurements: An endoscopy and a necropsy were performed to study the esophagus, mediastinum, pericardial space, and cautery locations on the epicardium one week after the procedure., Results: Epicardial coagulation was successfully performed within 30 minutes in 4 of the 5 pigs. Follow-up endoscopy demonstrated completely sealed myotomy sites by the overlying mucosal flap. There was no gross contamination or signs of contamination in the thoracic cavity. The pericardial space was normal in appearance. The epicardial coagulation sites were healing, without exudative ulceration., Conclusions: The SEMF technique allowed endoscopic access to the upper mediastinum, the pericardium, and the epicardium via the esophagus, along with a minimal intervention on the epicardium.

Background: Gastric electrical stimulation (GES), which has been reported to have therapeutic potentials for gastroparesis and obesity, involves the surgical placement of electrodes with the patient under general anesthesia. New methods are needed for implanting GES electrodes in a safer and more feasible way., Objective: Our purpose was to investigate the safety and feasibility of placing electrodes endoscopically for GES., Design and Setting: A pilot study., Subjects: Six female hound dogs that weighed 13 to 22 kg., Interventions: Endoscopically placed electrodes passed through the abdomen and the stomach wall., Main Outcome Measurements: The study was performed in dogs surgically implanted with gastric serosal electrodes and endoscopically implanted electrodes. The experiment consisted of a 30-minute baseline, a 30-minute GES, and a 30-minute recovery. GES was performed through endoscopically placed electrodes. Gastric slow waves were simultaneously recorded with the serosal electrodes and the endoscopically placed electrodes., Results: (1) The slow wave frequency recorded from the endoscopically placed electrodes was significantly correlated with that from the serosal electrodes (r = 0.97, P < .002). (2) GES through the endoscopically placed electrodes was able to entrain gastric slow waves. (3) No gastric leakage into the abdominal cavity was noted and the dogs were healthy and comfortable. (4) The endoscopically placed electrodes remained for 2 to 3 weeks., Limitations: The fixation of the electrodes needs to be improved for longer-term uses., Conclusions: GES may be accomplished without surgery by inserting the electrode wire through the abdomen under endoscopy. The study results indicate that the endoscopically placed electrodes are effective for GES and do not result in any adverse events.

Background: Transgastric cholecystectomy is thought to technically and anatomically challenge a single entry flexible endoscopic approach., Objectives: To examine the feasibility of a transgastric-only cholecystectomy, endoscope performance in an upper-abdominal operation, and the usefulness of an offset gastrotomy., Study Design: Animal survival study., Setting: Animal research laboratory., Patients: Six domestic pigs., Main Outcome Measurements: Transgastric access to the gallbladder and technical feasibility of unassisted transgastric cholecystectomy., Interventions: A cephalad submucosal tunnel was created in the anterior gastric wall with a high-pressure CO2 injection. An EMR-cap myotomy was performed distally within the submucosal space and created an offset gastrotomy. An endoscope was inserted into the peritoneal cavity through the myotomy. Access to the gallbladder was compared by using a multibending therapeutic endoscope (R-scope), with a standard double-channel endoscope. A cholecystectomy was performed by using both types of endoscopes. The myotomy site was sealed with the overlying mucosal flap. The mucosal entry point was closed with clips or tissue anchors., Results: A standard double-channel endoscope could access the gallbladder in 2 of 4 attempts. A multibending endoscope accessed the gallbladder in all 4 attempts, including 2 pigs in which the standard scope failed to access the gallbladder. In 4 pigs, a cholecystectomy was completed. Two pigs died during surgery, with air embolization observed in 1. Two pigs survived a planned 1-week survival period., Conclusions: Transgastric cholecystectomy is technically feasible. Transgastric access to the gallbladder may be improved by using submucosal endoscopy with an offset exit gastrotomy by means of the mucosal flap safety-valve technique and a multibending gastroscope.

Background: Gastric restrictive procedures are widely used for the surgical treatment of morbid obesity., Objective: Our purpose was to determine the technical feasibility of endoscopic gastric reduction in a live porcine model., Setting: Acute experiments on 50-kg pigs under general anesthesia., Design and Interventions: After per-oral intubation, the endoscope was inserted into the stomach. A fishing line was sutured to the gastric wall along the fundus approximately 5 cm below the gastroesophageal junction with a prototype endoscopic suturing device (Olympus, Eagle Claw). Then the fishing line was tied to create a small proximal pouch. A flexible sheath was placed on one side of fishing line and additional knots were tied, forming a ring at the outlet of the gastric pouch. The ring was anchored to gastric wall with additional stitches, completing the gastric reduction. Then the animals were killed for postmortem examination., Main Outcome Measurements: The feasibility of endoscopic gastric reduction., Results: We performed 4 acute experiments. It required 12 to 14 stitches in each animal to create gastric reduction. There were no technical problems during the procedures. Postmortem examination demonstrated an approximately 30-mL gastric pouch separated from the rest of the stomach by the line of stitches. There were no complications during the procedure., Limitations: We have not performed survival experiments to determine how long our gastric reduction will last., Conclusions: Endoscopic gastric reduction is technically feasible on a live porcine model.

Background: We have previously reported the feasibility and safety of per-oral transgastric endoscopic procedures in a porcine model., Objective: Our purpose was to evaluate the safety and feasibility of a PEG-like approach to the peritoneal cavity., Settings: Acute experiments on 50-kg pigs under general anesthesia., Design and Interventions: After per-oral intubation, the endoscope was positioned into the body of the stomach, the anterior abdominal wall was transilluminated and punctured with a needle, and a guidewire was inserted into the stomach through the needle. The guidewire was grasped with endoscopic forceps and pulled through the biopsy channel of the endoscope. A sphincterotome was inserted into the gastric wall over the guidewire. Gastric incision was performed and the endoscope was advanced into the peritoneal cavity. The peritoneal cavity was insufflated and endoscopic peritoneoscopy was performed. Then the animal was euthanized and necropsy was performed., Main Outcome Measures: Safety of transgastric entrance to peritoneal cavity., Results: The PEG-like approach was used in 12 pigs. The average procedure time was 11.4 +/- 3.7 minutes. There was only 1 complication related to the access: bleeding from the gastric wall incision was documented when a pure cut (without coagulation) current was used for incision of the gastric wall. There were no complications in the other 11 pigs. The necropsy did not reveal any damage to organs adjacent to the stomach., Limitations: Gastric wall incision is located on anterior gastric wall., Conclusions: The PEG-like transgastric approach to the peritoneal cavity appears technically simple and safe.

Background: Iatrogenic inflammation of the porcine uterine horn may serve as an in vivo appendicitis model for the development of endoscopic transgastric appendectomy., Objective: Five female pigs., Study Design: Animal study., Settings: General anesthesia., Main Outcome Measurements: Anatomical appearance and technical feasibility., Interventions: Three pigs were used to identify an injectable material that would inflame the uterine horn, and 2 pigs were used for a pilot appendectomy. Three types of materials were individually injected into the bilateral uterine horns, and the ideal material to inflame the uterine horn was injected into the right uterine horn for the last 2 pigs. After 24 hours, the injected uterine horns of the first 3 pigs were assessed and a pilot appendectomy was performed in the last 2 pigs., Results: Ethanolamine oleate (EO) injected uterine horns demonstrated similarities to the inflamed human appendix. Simulations of the appendectomy were successfully performed by using the EO model., Limitations: Suboptimal existing tools., Conclusions: This preliminary study demonstrated the technical feasibility to create a model for acute appendicitis by using the porcine uterine horn and transgastric appendectomy.

Background: Perforation is an uncommon but potentially devastating complication of colonoscopy. Surgical closure is the standard of care. Immediate endoluminal closure of a perforation would avoid the morbidity and mortality associated with general anesthesia, laparotomy, and surgical repair., Objectives: To evaluate the feasibility and safety of full-thickness endoscopic closure of colonic perforations with a prototype endoscopic suturing device, the Eagle Claw, in a porcine model., Design: Endoscopic animal experimental study of closure of colon perforation by using a porcine model., Subjects: Ten pigs were included in the study., Interventions: The Eagle Claw was used to close small perforations (1.5 to 2 cm) of the colon created by needle-knife with the animal under general anesthesia by using the endoluminal route. All animals received intravenous antibiotics and were allowed to eat after 24 hours., Main Outcome Measurements: The animals were monitored daily for signs of sepsis and peritonitis. On day 7, they were euthanized. The peritoneal cavity was examined for fecal peritonitis, and the colon perforation site was checked for wound dehiscence and pericolic abscess formation., Results: Endoscopic closure of the colon perforation was successful in 7 animals, and they recovered well without any sepsis or peritonitis. Necropsy did not reveal fecal peritonitis or pericolonic abscess formation at the site of perforation, and the perforation healed well. Closure was successful in 1 animal, but necropsy revealed dehiscence of the colon perforation site. Endoscopic closure was unsuccessful in 2 animals, and these were euthanized immediately., Conclusions: Closure of acute perforation of the colon is feasible with the Eagle Claw endoscopic suturing device in a porcine model.

Background: Localization of the proximal jejunum is important for creation of gastrojejunal anastomosis to palliate gastric outlet obstruction or for treatment of obesity with gastric bypass., Objective: To facilitate identification of the proximal jejunum during transgastric endoscopic gastrojejunostomy with the use of an endoscopic transilluminator (ET)., Design and Setting: Acute experiments in a live porcine model., Interventions: The ET is a 3500-mm long, 6F radio-opaque tube with a fiberoptic core that lights up at its distal end. When situated in the intestinal lumen, it transilluminates the bowel wall. With the animal under general anesthesia with endotracheal intubation, a colonoscope was advanced to the proximal jejunum. A plastic tube (3500-mm long, 3.5 mm in diameter) was passed through the biopsy channel and placed into the small bowel. The colonoscope was withdrawn, leaving the tube in place. The ET was introduced into the jejunum through the tube. A gastric wall incision was made and the endoscope was advanced to the peritoneal cavity. The transilluminated loop of the proximal jejunum was identified and gastrojejunal anastomosis was made by use of a previously reported endoscopic technique., Main Outcome Measurements: Identification of the proximal jejunum., Results: Eleven pigs (average weight 55 kg) had ET placement. In all of the pigs, placement of the ET was performed easily to the proximal small bowel, and the proximal jejunum was successfully localized by either direct visualization of the transilluminated loop only or with the aid of fluoroscopy. The tip of the ET was usually located about 50 to 70 cm distal to the ligament of Treitz. There were no complications related to the use of ET., Limitations: The device has not yet been evaluated in humans., Conclusions: The ET is a safe instrument and can be used to identify the proximal jejunum to facilitate endoscopic gastrojejunostomy.

Background: Despite several attempts to make the conventional tubular stents with a central lumen for flow less susceptible to a biofilm buildup and thereby prevent clogging, this goal has remained elusive. We hypothesized that the creation of pathways for fluid flow around the stent instead of through it would avoid this problem. The aim of our study was to report the development and the evaluation of a novel lumen-less stent., Methods: By using a software computer modeling, a 10F "winged" stent was designed. A pilot feasibility study was performed by using a prototype of this stent for endoscopic biliary drainage in 5 patients with malignant biliary obstruction., Observations: Modeling data revealed that the winged stent offers a larger surface area for flow, higher velocity of flow, and increased flow rates compared with the conventional tubular stent. In the clinical trial, there was a significant decrease of serum bilirubin after the placement of this stent (serum bilirubin before and 2 weeks after stent placement, 14.94 +/- 5.7 mg/dL vs. 2.86 +/- 1.4 [p < 0.004]), accompanied by radiologic evidence of decompression of the biliary system., Conclusions: We have shown that it is possible to provide adequate biliary drainage by using a stent without a lumen. Such a design may have potential clinical advantages over existing designs.

Background: Control of bleeding from major arteries in the upper-GI tract remains difficult with currently available endoscopic devices. We designed an endosuture device that uses a curved needle and extracorporeal knotting, and assessed the device in stopping arterial bleeding in a bench model., Methods: Harvested porcine splenic arteries (2-mm diameter) were tunneled submucosally in pig stomach with the open end protruding into an artificially created mucosal defect. The outer end of the vessel was connected to a pulsatile pump, and red ink was infused at a pressure of about 100 mm Hg. The stomach was installed on an Erlangen endo-training model. The suturing device (Eagle Claw II), mounted outside an endoscope, has an eyed, curved needle that carries a 3-0 nylon thread. After puncture, the thread was retrieved by using a hook. Three-throw square knots were tied at the thread extracorporeally and were pushed into place by using a knotting cap. The criteria of successful plication was defined as hemostasis after knotting, no leakage at pressures of >200 mm Hg, and the vessel was completely encircled by the suture., Results: A total of 25 sutures were made with the mean time of 9.38 minutes (standard deviation 1.51). Control of the bleeding was obtained with 17 sutures (68%). The causes for failure were the following: a suture was too shallow (4), a loose knot (2), incorrect suture position (1), and stomach-wall edema (1)., Conclusions: Control of bleeding from large arteries by using endoscopic suturing is possible. Continued refinements of the device are required.

Background: To eliminate cumbersome extracorporeal knotting, we designed a new endoscopic suturing device, the Eagle Claw V. The efficacy of the new device was tested on the Erlangen model and was compared with the initial extracorporeal knotting version (Eagle Claw II)., Methods: Segments of porcine splenic arteries were placed on the mucosal surface of the anterior wall of a pig stomach. The two ends of the artery were brought out through the gastric wall and were connected to a two-channel manometer. The Eagle Claw V has a curved needle with a detachable tip. After puncturing the tissue, the needle tip was engaged into a catching cartridge, where the suture had been embedded in a tightening mechanism. The suture could be tightened by simply pulling the end. The Eagle Claw V was used to plicate the splenic arteries mounted on the stomach. Suturing was considered secure if the suture could withstand endoluminal pressure greater than 200 mm Hg that lasted at least 10 seconds., Results: Eleven of 15 stitches (73.3%) gained secure plication of the vessels. The suturing time (mean +/- standard deviation 2.93 +/- 0.80 minutes) was significantly faster than that of the Eagle Claw II (9.38 +/- 1.51 minutes). The device consistently achieved penetration of the muscular layer, and 4 of 15 sutures included the serosa. The 4 failures were because of suture breakage in two, thread entanglement in one, and cartridge dislodgement in one., Conclusions: The present prototype represents significant improvements in the ease of operation and the security of the suture, bringing the technique closer to clinical use for a variety of applications.

Background: We have previously reported the feasibility and the safety of an endoscopic transgastric approach to the peritoneal cavity in a porcine model. We now report successful performance of endoscopic gastrojejunostomy with survival., Methods: All procedures were performed on 50-kg pigs, with the pigs under general anesthesia, in aseptic conditions with sterilized endoscopes and accessories. The stomach was irrigated with antibiotic solution, and a gastric incision was performed with a needle-knife and a sphincterotome. A standard upper endoscope was advanced through a sterile overtube into the peritoneal cavity. A loop of jejunum was identified, was retracted into the stomach, and was secured with sutures while using a prototype endoscopic suturing device. An incision was made into the jejunal loop with a needle-knife, and the filet-opened ends of the jejunal wall were secured to the gastric wall with a second line of sutures, completing the gastrojejunostomy., Observations: Two pigs survived for 2 weeks. Endoscopy and a radiographic contrast study performed after gastrojejunostomy revealed a patent anastomosis with normal-appearing gastric and jejunal mucosa. Postmortem examination demonstrated a well-healed anastomosis without infection or adhesions., Conclusions: The endoscopic transgastric approach to create a gastrojejunostomy is technically feasible and can be performed, with survival, in a porcine model.

Background: We have previously reported the feasibility and safety of the peroral transgastric endoscopic approach for diagnostic peritoneoscopy, liver biopsy, and gastrojejunostomy with long-term survival in a porcine model. This approach eliminates incisions of the abdominal wall, providing a less invasive alternative to diagnostic and therapeutic laparoscopy. We now report successful performance of peroral endoscopic transgastric ligation of Fallopian tubes with long-term survival in a porcine model., Methods: Six female 50-kg pigs had general anesthesia and irrigation of the stomach with an antibiotic solution. Gastric puncture was performed with needleknife electrocautery followed by balloon dilatation of the tract with 20-mm TTS dilating balloon (Microvasive). A standard upper endoscope that underwent high-level disinfection and gas sterilzation was advanced into the peritoneal cavity through a sterile overtube. Both Fallopian tubes were identified and one was ligated using Olympus Endoloops. The other patent tube served as a control. Tubal patency was evaluated by hysterosalpingogram before and after ligation. After a follow-up period of 2-3 weeks, the pigs were sacrificed for postmortem examination., Results: The Fallopian tubes were easily accessed, identified and ligated in all 6 pigs. In each pig, fluoroscopy confirmed complete obstruction of the ligated tube with preserved patency of the other tube. All pigs survived well and ate heartily without any ill-effects. Postmortem examination did not reveal any peritonitis or intra-abdominal adhesions. The Endoloops were in place with complete obstruction of the ligated tubes and patency of the controls. Histopathologic examination of the tubes showed chronic inflammatory infiltrates without abscesses., Conclusions: The peroral endoscopic transgastric approach to ligation of the Fallopian tubes with long-term survival is technically feasible and safe in a porcine model. The endoscopic transgastric approach to the peritoneal cavity has potential for a wide array of diagnostic and therapeutic procedures.

Background: Widespread EMR is a novel technique for resection of large areas of mucosa as a single bloc. Large lesion size (>2 cm) is a recognized limitation of current EMR techniques. This study assessed the technical feasibility, efficacy, and safety of widespread EMR in a porcine model., Methods: Widespread EMR was performed in 6 pigs. A submucosal fluid cushion was created in the distal esophagus by using a 0.83% solution of hydroxypropyl methylcellulose. A mucosal strip 5 cm in length and including at least 50% of the luminal circumference was marginated by using a prototype cutting device. The proximal end of the mucosa was stripped from the submucosa by using a grasping forceps. The distal end was snare resected. Resected tissue was assessed histologically. Endoscopy was repeated at weeks 1 and 6. At week 6, a second widespread EMR of the mucosa on the wall opposite the initial resection was attempted to create a full circumferential resection., Results: Widespread EMR was completed in all animals. The esophagus was denuded of mucosa in 5-cm lengths that included 50% of the circumference of the lumen. No procedure-related complication was observed. Histologic assessment demonstrated that the resection specimen included mucosa and submucosa but not muscularis propria. Endoscopy at 1 week revealed mucosal regrowth in two animals and ulceration in 4. At week 6, regrowth of mucosa was noted in all animals. The second wide EMR proved to be technically difficult and was associated with perforation, peri-esophageal abscess, and stricture formation., Conclusions: Wide EMR appears to be technically feasible for removal of large areas of mucosa. Mucosal strips 5 cm long that included over 50% of the luminal circumference were resected safely. Resection was followed by complete regrowth of the mucosa. However, a second wide EMR to create a circumferential resection proved to be technically difficult and unsafe.

Background: Looping of the endoscope in the sigmoid colon and other colonic segments often represents a significant challenge to the performance of comfortable, complete, and swift colonoscopy. This report describes the design and operation of a new device that addresses this problem, together with preliminary preclinical experience with this use of this shape-locking guide (SG-1)., Methods: The shape-locking guide is an overtube that can be converted from a flexible to a rigid configuration on demand. When in the rigid configuration, the shape-locking guide is designed to protect the colon wall from lateral forces exerted by the colonoscope. The shape-locking guide was evaluated in vitro by using an artificial colon model to learn how to operate it, and to assess feasibility for prevention of colon looping. In addition, safety was assessed in vivo in a pig model., Results: In vitro, the shape-locking guide prevented colonic looping and, thereby, aided completion of "colonoscopy" in the artificial colon model. Subsequent in vivo studies demonstrated that use of the shape-locking guide is safe and feasible; it performed well with respect to ease of insertion and avoidance of sigmoid looping. There was no evidence of significant injury to the colon or adjacent abdominal viscera., Conclusions: This preliminary study shows that use of the shape-locking guide is safe and that it has performance characteristics that may assist the performance of colonoscopy. Human trials are being undertaken.

Background: Thermal therapy is the cornerstone of endoscopic treatment of bleeding mucosal lesions of the GI tract. However, there is a 20% failure rate and contact devices may be cumbersome in the treatment of large bleeding areas. A pilot study was conducted to evaluate the safety and efficacy of endoscopic cryotherapy for bleeding mucosal vascular lesions., Methods: Patients with recurrent bleeding from diffuse mucosal vascular lesions were treated with cryotherapy and had endoscopic and clinical follow-up., Results: Twenty-six patients with gastric and duodenal arteriovenous malformations (n = 7), watermelon stomach (n = 7), radiation-induced gastritis (n = 5), and radiation-induced proctitis (n = 7) were treated with mean of 3.4 (1.6) sessions. The best results were achieved in patients with radiation-induced proctitis, with cessation of bleeding in all 7 patients. Cryotherapy was also effective in patients with multiple arteriovenous malformations (86%) and watermelon stomach (71%). It was less effective in patients with radiation-induced damage to stomach and duodenum, although all patients in this group were debilitated because of disseminated malignancy., Conclusions: Cryotherapy is a safe and effective treatment for bleeding from diffuse mucosal lesions of the GI tract. Bleeding from radiation-induced proctitis and multiple arteriovenous malformations is particularly responsive to endoscopic cryotherapy.