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Background: Gastrojejunostomy is important for palliation of malignant gastric outlet obstruction and surgical obesity procedures. A less-invasive endoscopic technique for gastrojejunostomy creation is conceptually attractive. Our group has developed a compression anastomosis technology based on endoscopically delivered self-assembling magnets for endoscopy (SAMSEN) to create an instant, large-caliber gastrojejunostomy. Objective: To develop and evaluate an endoscopic means of gastrojejunostomy creation by using SAMSEN. Setting: Developmental laboratory and animal facility. Design: Animal study and human cadaveric study. Subjects: Yorkshire pigs (7 cadaver, 5 acute); human (1 cadaver). Interventions: A transoral procedure for SAMSEN delivery was developed in porcine and human cadaver models. Subsequently, gastrojejunostomy creation by using SAMSEN was performed in 5 acute pigs. The endoscope was advanced into the peritoneal cavity through the gastrotomy, and a segment of the small bowel was grasped and pulled closer to the stomach. An enterotomy was created, and a custom overtube was advanced into the small bowel for deployment of the first magnetic assembly. Next, a reciprocal magnetic assembly was deployed in the stomach. The 2 magnetic systems were mated under fluoroscopic and endoscopic guidance. Contrast studies assessed for gastrojejunostomy leak. Immediate necropsies were performed. Main Outcome Measurements: Technical feasibility and complications. Results: Gastrojejunostomy creation by using SAMSEN was successful in all 5 animals. Deep enteroscopy was performed through the stoma without difficulty. No leaks were identified on contrast evaluation. At necropsy, the magnets were properly deployed and robustly coupled together, resistant to vigorous tissue manipulation. Limitations: Acute animal study. Conclusions: Endoscopic creation of immediate gastrojejunostomy by using SAMSEN is technically feasible. [Copyright &y& Elsevier]

Gastric leaks are an ominous complication following Roux-en-Y gastric bypass associated with a high mortality. Surgical revision is often complicated and not without risk. Several series have brought to light endoscopic interventions that may play a role in the management of these patients. This paper provides an overview of the surgical approach to this difficult problem and outlines several endoscopic approaches to gastric leak and fistulae management, including stents, clips, fibrin glue, and endoscopic suturing. [ABSTRACT FROM AUTHOR]

Introduction: Reverse-phase polymers undergo a temperature-dependent liquid-to-gel transition that may provide a more durable cushion for EMR and could yield improvements in safety and efficacy. Objective: Our purpose was to assess the efficacy of poloxamer solution PS137-25 as a submucosal injection. Design: Comparative study among 3 different solutions for EMR using ex vivo and in vivo porcine models. Interventions: A total of 120 gastric submucosal cushions were performed in fresh ex vivo porcine stomachs with saline solution 0.9% (n = 40), hydroxypropyl methylcellulose (HPMC) (n = 40), and PS137-25 (n = 40). Five in vivo porcine colon EMRs were then performed. Main Outcome Measurements: Height and duration of submucosal cushions were measured in the ex vivo model, and the usefulness of reverse-phase polymers was assessed by in vivo en bloc resection. Results: Ex vivo: The height of mucosal elevation was greater with PS137-25 (10.3 ± 2.2 mm) than with saline solution (8.3 ± 2.6 mm) or HPMC (9.05 ± 2.3 mm, not significant). All submucosal elevations with PS137-25 lasted longer (more than 20 minutes) than with saline solution (20.9 ± 11 minutes, P < .01) or HPMC (89 ± 32 minutes, P < .01). After 120 minutes, the elevations obtained with PS137-25 showed no differences in size, shape, or consistency from initial measurements. In vivo: All 5 EMRs were successfully performed after 1 injection of PS137-25. No repeat injections were needed. During resection, a large gel cushion was noted. Conclusions: Mucosal elevation with PS137-25 is more durable than with other substances, with no changes in size or consistency observed over 120 minutes. Additionally, reverse-phase polymers performed well in in vivo colon EMRs. These results suggest that reverse-phase polymers may provide increased safety and efficacy for EMR procedures. [Copyright &y& Elsevier]

Purpose: There is no consensus in the literature regarding the size of a mallet fracture fragment that may lead to subluxation of the distal interphalangeal (DIP) joint. The purpose of this study was to determine the relationship between the size of the dorsal articular fragment and DIP joint subluxation in a cadaveric mallet fracture model. Methods: Twenty-nine fresh-frozen fingers without evidence of DIP joint osteophytes were dissected to the metacarpal base. The mean age of the 17 donors at the time of death was 69 years (range, 46 to 89 years). Obliquely oriented fractures through the dorsal lip of the distal phalanx were randomly created with an osteotome (range, 27% to 69% of the joint surface). Each finger was fully flexed and extended 1,200 times by applying alternating tension to the flexor and extensor tendons. Fluoroscopic images were obtained and digitized for measurements of fracture fragment size and DIP joint subluxation. Results: Sixteen DIP joints remained reduced and 13 distal phalanges subluxated palmarward. Subluxation was not observed when the fracture fragment measured less than 43% of the joint surface, whereas subluxation consistently occurred when the defect measured greater than 52% of the articular surface. Subluxation averaged 18% ± 7% of the overall joint surface in these specimens. There was no correlation between the amount of joint subluxation and the percentage of articular surface damage (p = .22). Conclusions: This study supports the concept that a mallet fracture with a large articular fragment may be unstable. Palmar subluxation of a DIP joint without preexisting arthritic deformity is expected when more than one half of the dorsal articular surface is injured. [Copyright &y& Elsevier]

Background: Plastic stents are routinely placed in the pancreaticobiliary system to facilitate drainage. A second endoscopy is often required for stent removal. We have developed magnetic pancreaticobiliary stents that can be removed by using an external hand-held magnet, thereby obviating the need for a second endoscopy. Objective: To develop and test magnetic pancreaticobiliary stents and retrieval system in ex-vivo and in-vivo porcine models. Setting: Animal laboratory. Design: Benchtop and animal study. Animals: 5 pigs. Interventions: Design: Computer simulations determined both the optimal design of cylindrical magnets attached to the distal aspect of existing plastic stents and the optimal design of the external hand-held magnet. Benchtop ex-vivo experiments measured magnetic force to validate the design. In-vivo analysis: In 5 Yorkshire pigs, magnetic stents were deployed into the common bile duct by using a conventional duodenoscope. An external hand-held magnet was applied for stent removal. Stent insertion and removal times were recorded. Main Outcome Measurements: Technical feasibility. Results: Magnetic stents of varying lengths and calibers were successfully created. In ex-vivo testing, the capture distance was 10.0 cm. During in-vivo testing, the magnetic stents were inserted and removed easily. The mean insertion and removal times were 3.2 minutes and 33 seconds, respectively. Limitations: Animal study, small numbers. Conclusions: Magnetic pancreaticobiliary stents and associated retrieval system were successfully designed and tested in the acute porcine model. An external, noninvasive means of stent removal potentially obviates the need for a second endoscopy, which could represent a major gain both for patients and in health care savings. [ABSTRACT FROM AUTHOR]

Background: Early recurrent hemorrhage after endoscopic intervention for acute upper GI bleeding (UGIB) can approach 20% and leads to increased morbidity and mortality. Little has changed over the past several decades regarding immediate posthemorrhage surveillance, and there has likewise been no significant improvement in outcomes. Objective: To develop and test an endoscopically implantable wireless biosensor for real-time detection of fluorescein-labeled blood in ex vivo and in vivo porcine models of UGIB. Setting: Animal laboratory. Design: Benchtop and acute animal studies. Subjects: Five pigs. Interventions: UGIB models were surgically created in living pigs. Biosensors were endoscopically deployed in the stomach using standard endoscopic clips. The ability to detect acute UGIB and estimated blood loss leading to biosensor activation were recorded. Feasibility of wireless data transmission out of the body to an external computer and cell phone was assessed. Main Outcome Measurements: Technical feasibility and immediate complications. Results: A porcine UGIB model was successfully created. Biosensors were able to detect all acute bleeding events and wirelessly transmit out of the body, and successfully sent an emergency text message to the intended cell phone in all cases. Average estimated blood loss leading to biosensor activation was 30 mL (10–75 mL). Limitations: Animal study; small numbers. Conclusions: An endoscopically implantable wireless biosensor successfully detected acute hemorrhage in a porcine UGIB model and sent an emergency cell-phone alert in real time. [ABSTRACT FROM AUTHOR]

Background: Natural Orifice Transluminal Endoscopic Surgery (NOTES) is a developing, minimally invasive surgical approach whose potential benefits are being investigated. Little is known about secure access site closure and early healing kinetics of transvisceral access. Study Design: Transvisceral access incisions were created in the colon (C-NOTES, n = 8) and stomach (G-NOTES, n = 8) for peritoneal exploration. Incisions were closed primarily with endoloops, endoclips, or t-tags. Macroscopic and histologic analyses performed on postoperative day 7 assessed gross appearance, granulation tissue, inflammation, ulceration, and complications. Results: Macroscopically, incisions appeared closed without intraperitoneal spillage. Incisions closed by endoloop and t-tags showed intense granulation tissue fill of defect despite partial (G-NOTES, n = 3) and transmural ulceration (C-NOTES, n = 8; G-NOTES, n = 3). Of the 30 t-tags applied, 40% broke or deployed into the peritoneal cavity. Endoclip closures (C-NOTES, n = 1; G-NOTES, n = 1) did not show histologic mucosal continuity. Healing complications included transmural necrosis (C-NOTES, n = 1; G-NOTES, n = 1), foreign body material (C-NOTES, n = 3; G-NOTES, n = 2), and microabscesses (G-NOTES, n = 1). Conclusions: This study provides a reproducible model to assess noninvasive repair of planned visceral perforations. Of investigated technologies, endoloop closure was favored for transcolonic incisions, and t-tags with omental patch for transgastric incisions, although these have significant limitations. Endoclips were inadequate for primary closure, but may be useful as an adjunctive closure modality. Additional studies are needed to examine visceral repair at later time points, as they will help determine the quality and kinetics of repair of a variety of incision closure strategies. This study demonstrates the need for improved technologies to more reliably close visceral transluminal defects. [Copyright &y& Elsevier]