Lumen-apposing Metal Stent Deployment Research Articles

Safety and efficacy of early versus late removal of LAMS for pancreatic fluid collections.

Background and study aims Optimal timing for removal of lumen-apposing metal stents (LAMS) for effective drainage of pancreatic fluid collections (PFC) while minimizing adverse events (AE) is unknown. Outcomes of early (≤ 4 weeks) or delayed (> 4 weeks) LAMS removal on both clinical efficacy and the incidence of AE were assessed. Patients and methods This was a retrospective analysis of a prospectively maintained registry of PFC drainage between November 2016 and September 2021. Clinical success was defined as a 75% decrease in fluid collection volume with no need for reintervention at 6 months. AE were defined using the American Society for Gastrointestinal Endoscopy lexicon. Multiple logistic regression analysis was performed to determine variables associated with clinical success and AE. Results A total of 108 consecutive PFCs were included. LAMS deployment was technically successful in 103 of 108 cases (95.4%). Failure was associated with collection diameter ≤ 4 cm (odds ratio [OR] 24.0, P = 0.005) and presence of more than 50% necrotic material (OR 20.1, P = 0.01). Stents were left in place for a median of 48 days. Patients with early stent removal (< 4 weeks) had clinical success in 70.0% of cases, which was significantly less than in the group with delayed stent removal (96.4%, P = 0.03). On multiple regression analysis, clinical failure was associated with early stent removal (OR 25.5, P = 0.003). AEs occurred in 8.7% of cases (9/103). There were no predictors of AE. Notably, delayed stent removal did not predict the occurrence of AE. Conclusions Early LAMS removal (< 4 weeks) did not prevent AEs but did lead to increased clinical failure.

Preferred techniques for endoscopic ultrasound-guided gastroenterostomy: a survey of expert endosonographers.

Background and study aims Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is an emerging procedure that lacks technical standardization with limited adoption beyond expert centers. We surveyed high-volume endosonographers about the technical aspects of EUS-GE to describe how the procedure is currently performed at expert centers and identify targets for standardization. Methods Invitations to complete an electronic survey were distributed to 21 expert EUS practitioners at 19 U.S. centers. Respondents were surveyed about technical aspects of EUS-GE, indications, efficacy, safety, and attitudes toward the procedure. Results All 21 (100%) invited expert endoscopists completed the survey. Nine (42.9%) reported performing >10 EUS-GEs in the last 12 months. About half (47.6%, 10/21) puncture the target loop prior to lumen-apposing metal stent (LAMS) introduction, most often to confirm the loop is jejunum. No respondents reported guidewire placement prior to LAMS introduction. Most (71.4%, 15/21) do not use a guidewire at any time, while 28.6% (6/21) reported wire placement after distal flange deployment to secure the tract during apposition. Eight (38.1%, 8/21) reported at least one major adverse event, most commonly intraperitoneal LAMS deployment (87.5%, 7/8). Factors most often reported as advantageous for EUS-GE over enteral stenting included lack of papilla interference (33.3%, 7/21) and decreased occlusion risk (23.8%, 5/21). Conclusions Significant variation in performance technique for EUS-GE exists among expert US endoscopists, which may hinder widespread adoption and contribute to inconsistencies in reported patient outcomes. The granularity provided by these survey results may identify areas to focus standardization efforts and guide future studies on developing an ideal EUS-GE protocol.

EUS-guided gastrojejunostomy using a pre-existing PEG with jejunal extension for target bowel opacification

Video 1Contrast instillation into the jejunum using the pre-existing jejunal extension tubing from the PEG with jejunal extension followed by lumen-apposing metal stent deployment under endosonographic vision, securing the gastrojejunostomy.

Iatrogenic perforation during lumen-apposing metal stent deployment closed using an over-the-scope stent fixation clip device

Video 1Endoscopic closure of an iatrogenic perforation caused during EUS-guided gastrojejunostomy for malignant gastric outlet obstruction treated with an over-the-scope stent fixation clip device.

S358 Endoscopic Ultrasound-Directed Transgastric ERCP for Pancreatic Duct Stent Placement to Treat Pancreatic Ascites

Introduction: Endoscopic ultrasound (EUS)-Directed transGastric ERCP (EDGE) is an advanced procedure utilized to enable pancreaticobiliary access in patients with Roux-en-Y gastric bypass anatomy. We hereby present a case of refractory pancreatic ascites from a persistent pancreatic duct (PD) leak treated with EDGE and transpapillary PD stenting. Case Description/Methods: A 62-year-old White female with history of morbid obesity with Roux-en-Y gastric bypass and biliary pancreatitis with prior cholecystectomy was referred for refractory pancreatic ascites causing significant abdominal pain, poor oral intake and weight loss necessitating total parenteral nutrition. MRCP showed a PD leak in the body as cause for ascites (Fig. 1). After multidisciplinary team discussion, a staged EDGE for PD stenting was pursued. The gastric remnant was identified endosonographically through the jejunum, a 19G needle was advanced into it and 500 ml of saline was instilled to dilate the remnant. A 0.025 guidewire was coiled in the remnant and a 15mm by 10 mm cautery enhanced lumen apposing metal stent (LAMS) delivery system was used to create a jejunogastrostomy followed by LAMS deployment. LAMS was post dilated to 15 mm and ERCP was pursued after 10 days. During ERCP, PD leak at the body was confirmed on the pancreaticogram. A 5 Fr by 15 cm single pigtailed stent was deployed to bridge this leak. A large biliary sphincterotomy was also performed for a subjectively stenotic major papilla. Follow up CT scan after 1 month showed resolution of pancreatic ascites and repeat ERCP confirmed resolution of the PD leak. The biliary and pancreatic stents were removed. The jejunogastrostomy stent was removed after three months. She continues to remain asymptomatic and is tolerating a regular diet. Discussion: This case demonstrates the successful use of EDGE procedure for management of refractory pancreatic ascites from a pancreatic duct leak. EDGE for pancreatic endotherapy in Roux-en-Y gastric bypass anatomy is a safe and effective alternative to more invasive laparoscopy or percutaneous gastrostomy access to the gastric remnant and should be considered in cases with ascites. Watch the video at https://tinyurl.com/ACGAbstractS358Figure 1.: MRCP With Pancreatic Duct Leak.

S2901 Afferent Limb Syndrome Treated With Non-Cautery-Enhanced Lumen Apposing Metal Stent: An Alternate Approach

Introduction: Afferent limb syndrome (ALS) is a known complication after gastrojejunostomies from mechanical obstruction of the afferent limb (AL). Recently endoscopic ultrasound (EUS) guided gastroenterostomy placement has provided an alternate to surgical correction. However this approach is not always technically possible. We describe a case successfully treated with endoluminal non-cautery enhanced lumen apposing metal stent (LAMS) placement. Case Description/Methods: A 63 year old woman with a history of ileocolonic Crohns disease (diagnosed at age 25), status post multiple surgeries including ileocolic resections and Billroth II gastrectomy, was referred with persistent abdominal pain. She was recently diagnosed with acute pancreatitis with CT concerning for dilated afferent jejunal limb, a luminal stricture near the biliary anastomosis and dilated intra and extra hepatic bile ducts (Figure a). She underwent two deep enteroscopies revealing a stricture in the AL from intra-abdominal adhesion. This was dilated with minimal improvement in symptoms and imaging. After multi-disciplinary discussion it was decided to attempt EUS guided drainage of the AL to promote drainage of pancreatico- biliary secretions. During the procedure a significant amount of food residue was identified in the gastric remnant. The dilated afferent limb was visualized endosonographically adjacent to the posterior stomach at an acute angle. Considering large amount of food in the stomach, difficult angulation to deploy the AXIOS stent and concern for food entering the already obstructed limb after stent deployment it was decided to reconsider this approach. The AL was then explored with a therapeutic upper endoscope with stenosis at 10 cm from the anastomosis. A wire was passed through the stenosis under fluoroscopy. It was decided to place a stent using the 15 x 10 mm LAMS stent system considering short (< 1 cm) stricture. Using non cautery technique both flanges were deployed successfully across the stricture under fluoroscopic and endoscopic guidance with decompression of the AL (Figure b,c). 1 month follow up imaging demonstrated continued decompression of the AL. Discussion: EUS guided gastrojejunostomy has been increasingly used for ALS. However it can be challenging in situations where a good window cannot be identified. In such settings using a traditional luminal route to reach the stenosis and placing a non-cautery enhanced LAMS can provide a viable alternative.Figure 1.: (a) Dilated afferent limb with stricture (arrows), (b) post non-cautery enhanced LAMS deployment, (c) Fluoroscopy image post LAMS deployment

Lumen apposing metal stents versus tubular self-expandable metal stents for endoscopic ultrasound-guided choledochoduodenostomy in malignant biliary obstruction.

EUS-guided choledochoduodenostomy (EUS-CDS) is an effective option for biliary drainage in malignant biliary obstruction. Lumen apposing metal stents (LAMS) are increasingly been used for EUS-CDS. It is unknown how LAMS compare to tubular self-expandable metal stents (SEMS) for EUS-CDS. Our aim is to compare the clinical outcomes of LAMS versus SEMS for EUS-CDS. Single-center retrospective cohort study of consecutive patients with unresectable malignant biliary obstruction who underwent EUS-CDS after failed ERCP for initial biliary drainage between 2011 and 2019. Clinical outcomes were compared between patients who had conventional covered SEMS and LAMS placed for EUS-CDS. Outcome measures included unplanned procedural events, technical success, clinical success, adverse events and reinterventions. Survival was analyzed by the Kaplan-Meier method. During the study period 57 patients met inclusion criteria (37 LAMS, 20 SEMS). All EUS-CDS were technically successful (LAMS group 95% CI 90.3-100%, SEMS group 95% CI 83.2-100%). There were no differences between groups in unplanned procedural events (4 LAMS deployment issues, 2 mild bleeding in SEMS group; 10 vs 10.8%), clinical success (37/37 [100%] vs 19/20 [95%]), and short-term adverse events (5/37 [13.5%] vs 4/20 [20%], p = 0.71). Complete follow-up data were available in 41 patients for a mean of 376 ± 145days. Endoscopic reintervention was required for duodenal stent placement (n = 9) or biliary stent dysfunction (n = 4), with no difference between LAMS and SEMS group (6/37 [16.2%] vs 7/20 [35%]). There were no differences in overall survival between both groups. EUS-guided choledochoduodenostomy after failed ERCP has equally high technical and clinical success rates with either LAMS or SEMS in patients with malignant biliary obstruction. No differences in adverse events, reinterventions and survival were seen with either type of stent. The cost-effectiveness of LAMS vs SEMS for EUS-guided choledochoduodenostomy remains to be proven.

Long-term placement of lumen-apposing metal stent after endoscopic ultrasound-guided duodeno- and jejunojejunal anastomosis for direct access to excluded jejunal limb.

Management of biliary disorders in patients with altered anatomy may be challenging. Endoscopic ultrasound (EUS)-guided gastrointestinal anastomosis using a lumen-apposing metal stent (LAMS) was introduced to allow endoscopic retrograde cholangiography (ERC) in such cases. However, the appropriate stent indwelling time remains uncertain. We report long-term LAMS deployment after duodenojejunal or jejunojejunal anastomosis (EUS-DJA) to allow endoscopic reinterventions in cases of recurrences. 11 consecutive patients underwent EUS-DJA with long-standing LAMS between January 2017 and December 2018. Over a 12-month period, ERC treatment was carried out with multiple endoscopic sessions across the DJA. Technical success was 91 % (10/11) for EUS-DJA and 100 % for ERC. Four patients presented stricture recurrence at a mean of 489 days (standard deviation [SD] 31.7) after the end of ERC treatment. A novel ERC across the LAMS anastomosis was feasible in all cases. At a mean of 781 days (SD 253.1), all LAMS remained in place with no evidence of complications. Long-term LAMS placement after EUS-DJA may be feasible and safe for direct access to the excluded limb.

Endoscopic Ultrasound Guided Gastroenterostomy: What Is the Learning Curve?

Endoscopic ultrasound guided gastroenterostomy (EUS-GE) is a minimally invasive option for gastric outlet obstruction. It requires skills in endoscopic ultrasound, fluoroscopy, and lumen-apposing metal stent deployment. The aim of this study was to determine the learning curve for EUS-GE. Consecutive patients undergoing EUS-GE by a single operator were included from a prospective registry over 3 years. Demographics, procedure info, postprocedure follow-up data, and adverse events were collected. Nonlinear regression and cumulative sum analyses were conducted for the learning curve. Clinical success was defined as tolerating a diet postprocedure. Twenty-three patients were included (39% male, mean age 65.8 y). Technical success was achieved in 22 (96%) patients. Clinical success was achieved in 21/22 (95%) patients. Average follow-up time 10.8 months (9.1 SD). Five patients had minor postprocedure complications; 1 patient had a periprocedural esophageal tear treated with clips. Four patients required repeat intervention for stent revision or removal if no longer needed.Median procedure time was 88 minutes (range: 45 to 140 min). Cumulative sum chart shows 88-minute procedure time was achieved at the seventh procedure indicating efficiency. Even with bridging of a misdeployed lumen-apposing metal stent, the procedure duration further reduced with consequent procedures indicating continued improvement with experience (nonlinear regression P<0.0001). Endoscopists experienced in EUS-GE achieve a reduction in procedure time over successive cases, with efficiency reached at 88 minutes and a learning rate of 7 cases. Misdeployed stents that require bridging add to the procedure time even after competency is achieved but do not affect the overall learning curve trend.

EUS guided gallbladder drainage.

Cholecystectomy is the gold standard treatment for acute cholecystitis, but it may not be appropriate for patients with significant comorbidities. Percutaneous gallbladder drainage (PT-GBD) and endoscopic transpapillary gallbladder drainage (ET-GBD) are alternatives with good technical and clinical success rates, but are limited by technical challenges and the need for definitive therapy. EUS-guided gallbladder drainage (EUS-GBD) is quickly becoming the preferred modality of treatment at expert centers in this cohort of patients due to increased efficacy and minimal adverse events. Technicalities of the procedure, including selection of access site, should be informed by the ultimate needs and anatomy of each patient. With the evolution of new stents and accessories, including a cautery-enhanced lumen apposing metal stent deployment system, success rates and adverse events are favorable. A review of published case series demonstrates an overall clinical success rate of approximately 97% for EUS-GBD. The most common complication is pneumoperitoneum, so the evolution of self-expanding LAMS is promising. EUS-GBD has been successfully described in cases where definitive therapy or a bridge to cholecystectomy is needed. As the procedure's applications continue to evolve, there should be greater discussion about specific details including access site and stent selection.

EUS-Directed Transgastric Endoscopic Retrograde Cholangiopancreatography (EDGE): The First Learning Curve.

Endoscopic ultrasound (EUS)-directed transgastric endoscopic retrograde cholangiopancreatography (EDGE) is a minimally invasive option for pancreaticobiliary access in patients with Roux-en-Y anatomy. The procedure involves creating a fistulous tract between the remnant stomach or jejunum and the bypassed stomach with the deployment of a lumen-apposing metal stent (LAMS), followed by the advancement of an endoscope through the LAMS to perform an ERCP or EUS. It is a technically challenging procedure, requiring skills in EUS, fluoroscopy, and LAMS deployment. The aim of this study was to determine the learning curve for EDGE. Consecutive patients undergoing EDGE by a single operator were included from a prospective registry over 3 years. Demographics, procedure info, postprocedure follow-up data, and adverse events were collected. Nonlinear regression and cumulative sum analyses were conducted for the learning curve. Technical success was defined as the successful creation of the fistulous tract. Clinical success was defined as successful EUS or ERCP via the LAMS. Nineteen patients were included (21% male, mean age 58.7 y). Indication included symptomatic biliary stricture (n=6, 32%), choledocholithiasis (n=5, 26%), pancreatitis (n=3, 16%). Technical success was 100%. All patients had a 15 mm LAMS placed, 3 (16%) had cautery-enhanced LAMS. Clinical success was achieved in 18/19 (95%) patients. Fourteen patients had an ERCP, 1 patient had a EUS, and 3 patients had both. Adverse events included 2 cases of bleeding, 1 case of post-ERCP pancreatitis, and 1 jejunal perforation during duodenoscope insertion managed endoscopically.Median procedure time was 54.5 minutes (range: 31 to 88 min). Cumulative sum chart shows a 54-minute procedure time was achieved at the ninth procedure hence indicating efficiency. Apart from 2 outliers, the procedure duration further reduced with consequent procedures with the last 3 being under 40 minutes indicating that after 25 to 35 procedures a plateau may be reached indicating mastery (nonlinear regression P<0.0001). Endoscopists experienced in EDGE are expected to achieve a reduction in procedure time over successive cases, with efficiency reached 54.5 minutes and a learning rate of 9 cases. After 25 to 35 procedures, a plateau may be reached indicating mastery.

Gastric access temporary for endoscopy (GATE): a proposed algorithm for EUS-directed transgastric ERCP in gastric bypass patients.

Performing endoscopic retrograde cholangiopancreatography (ERCP) in patients with Roux-en-Y gastric bypass (RYGB) anatomy is technically challenging. Device-assisted enteroscopy and laparoscopic-assisted methods suffer from high failure rates and/or post-procedural complications. A novel endoscopic technique termed EUS-Directed Transgastric ERCP (EDGE) or Gastric Access Temporary for Endoscopy (GATE) has recently emerged, demonstrating excellent technical and therapeutic success. The technique involves endoscopic ultrasound-guided deployment of a lumen-apposing metal stent (LAMS) to gain access into the remnant stomach to facilitate standard ERCP. In this case series, we describe our center's experience and unique approach with the GATE procedure and discuss several key strategies and differences. Patients underwent the GATE procedure via a novel algorithmic approach. Key information on procedural details, technical and clinical success, follow-up, and adverse events was prospectively collected and retrospectively reviewed. 10 patients underwent the GATE procedure from May 2017 to March 2018. Technical and clinical success were both 100%. Gastric and jejunal access points for LAMS deployment were 30% and 70%, respectively. Total procedure time per patient, including LAMS deployment, ERCP, and all follow-up procedures, averaged 2.37 ± 0.63h. 2 out of 10 patients (20%) had adverse events that were resolved either intra-procedurally or after repeat endoscopy with no long-term complications and none requiring surgery. For patients with complete follow-up (n = 7), access tract closure rate was 100% with the aid of a temporary plastic double pigtail stent to facilitate closure. GATE appears to be a safe and effective procedure and may be considered the preferred approach to ERCP in patients with RYGB anatomy at centers with LAMS experience. The procedure offers more definitive and higher range of ERCP interventions compared to traditional methods and is associated with fewer adverse events. Improvements in strategies and methods with the GATE technique may reduce risks and improve outcomes.

Through the Scope Removal and Resheath of a Lumen Apposing Metal Stent as Salvage Technique After Misdeployment During EUS-Guided Choledochoduodenostomy Presidential Poster Award

Introduction EUS-guided choledochoduodenostomy offers a less invasive option for the management of biliary obstruction due to pancreatic head tumor after failed ERCP or impossibility to reach the papilla. Lumen apposing metal stent (LAMS) deployment using electrocautery-enhanced catheters has decreased procedure times under one minute. Broader availability of this stents has shifted its use from highly specialized therapeutic endoscopists to others with minimal or no therapeutic experience. Although a relatively fast procedure, complications are common and management options are required. Case description We present the case of a 42-year-old patient with a non-resectable stage IV pancreatic head cancer presenting with cholangitis. The papilla was not accessible due to duodenal stricture. EUS-guided choledochoduodenostomy with an 8x8mm LAMS was performed using an electrocautery enhanced delivery cathether. Access was obtained using a free hand technique. Although the catheter appeared to be into the common bile duct (CBD) the distal flange deployed between the CBD and the duodenal wall. A guidewire was inserted and the partially deployed LAMS was removed over the wire through the scope. The stent was re-sheathed and advanced over the wire. The distal flange was deployed again between the CBD and the duodenal wall leading to the notion that the image of the guidewire into the CBD was a ghost image. The partially deployed stent was removed again over the wire and re-sheathed. Given the possibility of a ghost image we removed the guidewire and obtained access through a nearby point performing a successful delivery of the stent and creating the choledochoduodenostomy that drained pus abundantly. A perforation wasn't visible. The patient presented with mild discomfort after the procedure but no signs of perforation. Discussion Although EUS-guided choledochoduodenostomy with LAMS deployment using an electrocautery-enhanced catheter has greatly facilitated the technique broadening its use, possible complications should not be underestimated. This case highlights two practical tips: 1/ a guidewire should always be available and proficiency in over the wire exchanges is recommended; and 2/ a half deployed 6x8mm or 8x8mm LAMS using this delivery system can be safely removed through the scope. In our experience in bench models larger stents are prone to dislodge during removal obstructing the working channel. Watch the video: https://goo.gl/iSCkn9

Gastric Access Temporary for Endoscopy (GATE): An Algorithmic Approach Towards LAMSAssisted Temporary Reversal of Gastric Bypass Anatomy to Perform Foregut Procedures Presidential Poster Award

Introduction: Performing endoscopic foregut procedures in patients with Roux-en-Y gastric bypass anatomy is often technically difficult. Historical options include device-assisted enteroscopy and surgically-assisted transgastric access. EUS-Directed trans-Gastric ERCP (EDGE) using a lumen-apposing metal stent (LAMS) has been described for ERCP in this population; however, there is concern for possible gastric fistula following LAMS removal. We describe an algorithmic approach(Gastric Access Temporary for Endoscopy (GATE)) for LAMS-assisted temporary reversal of bypass anatomy that minimizes gastric fistula formation and facilitates a variety of endoscopic procedures. Methods: Study design: Retrospective analysis of prospectively collected data at a single academic center. GATE access/removal: A linear or forward viewing therapeutic EUS scope was used. Based on anatomy, jejunum-to-gastric remnant or gastro-gastric access was created [Figure 1 and 2].The remnant stomach was accessed using a 19-G FNA needle and filled with saline/contrast. A 0.035” guidewire was advanced into the remnant stomach and the FNA needle removed. Using cautery enhanced delivery, a 15 mm x 10 mm LAMS stent was placed and dilated to a minimum of 15 mm. The indicated foregut procedure (ERCP, EUS, ESD, suturing) was then performed via the LAMS. LAMS removal using forceps occurred at the end of the procedure or at a later date [Figure 2], and a double pigtail stent (5 Fr or 10 Fr) was deployed in its place [Figure 3]. Access closure was confirmed by endoscopy and fluoroscopy.768_A Figure 1. Visualization of possible access sites for GATE in RYGB anatomy. (A) Endoscopic route of duodenoscope without LAMS access to engage the ampulla under RYGB anatomy. (B), (C), and (D) illustrate the path of the duodenoscope when a LAMS is placed under EUS guidance, providing access to the remnant stomach from either the gastric pouch, blind limb, or Roux limb respectively.768_B Figure 2. Algorithmic Approach for Patients Undergoing GATE768_C Figure 3. Endoscopic Images of GATE access, removal, and confirmation of fistula closure. (A) Lumen apposing metal stent deployed at fistula tract with guidewire still in place, (B) plastic double pigtail stent in position at fistula tract present in the gastric pouch (circled in red), several weeks after LAMS exchange, and (C) same location of the prior fistula tract having completely closed after stent removal.Results: 10 patients received the GATE procedure from May 2017 to June 2018. GATE access and removal were successful in 10/10 (100%) of patients. Foregut procedure included ERCP in 7, EUS/ERCP in 2, and ESD/suturing in 1. Gastric and jejunal access points for LAMS deployment were 30 and 70% respectively. Total procedure time per patient, including LAMS deployment, indicated procedure, and all follow-up, averaged 3.68±0.88 hours. 2 patients (20%) had complications that completely resolved after conservative management. For patients with complete follow-up (n=7), fistula closure rate was 100%. Conclusion: GATE allowed a variety of foregut endoscopic procedures in gastric bypass anatomy with successful closure in all patients. LAMS exchange to a smaller double pigtail stent appears safe and may minimize risk of residual fistula. This procedure is technically challenging and currently should be performed at centers with LAMS experience.

973 OPEN SESAME: A NOVEL LUMEN APPOSING METAL STENT DEPLOYMENT SYSTEM FOR THE MANAGEMENT OF SHORT LUMINAL STRICTURES

The use of short, fully-covered lumen apposing metal stents (LAMS) has emerged as a novel therapeutic intervention in the management of short luminal strictures. Similar to self-expanding metal stents (SEMS), LAMS are self-expanding and removable. Unlike SEMS, LAMS have lumen-apposing proximal and distal flanges, which may limit the risk of migration. LAMS are designed to be deployed via a therapeutic echoendoscope. When LAMS deployment is attempted with a therapeutic gastroscope, the much longer length of the deployment catheter relative to the gastroscope and inability to luer lock the catheter in place result in unstable endoscopic visualization and need for a second operator. These difficulties predispose to inaccurate stent placement. We demonstrate a video series including four patients with disparate pathologies resulting in luminal strictures in whom we successfully implemented a novel, alternative LAMS deployment system. At bedside, the 10 mm x 15 mm LAMS, which was previously deployed from the catheter, is pulled with standard grasping forceps into the 3.7 mm accessory channel of the therapeutic gastroscope. The scope tip is then advanced to the stricture, and the LAMS is pushed out under fluoroscopy until the distal flange opens. As the scope is slowly withdrawn, the proximal flange is deployed under endoscopic visualization. The deployed stent is then dilated with a through the scope balloon to obtain maximal stent expansion. This technique is now demonstrated in the following patients: 1. A 70 year old woman with ulcerative colitis, status post total proctocolectomy with ileal pouch-anal anastomosis, complicated by refractory pouchitis and pouch-vaginal fistula, on infliximab, presented over a decade later for management of a refractory anastomotic stricture at the inflow tract to the pouch. 2. A 48 year old woman with disseminated tuberculosis and actinomyces complicated by esophageal fistula, status post partially covered esophageal stent placement, since removed, presented with odynophagia 2 months later secondary to an upper esophageal stricture refractory to balloon dilation. 3. A 63 year old woman with HBV cirrhosis status post esophageal variceal band ligation, complicated by mid-esophageal stricture formation less than 2 weeks later, who was initially treated with balloon dilation and fully covered SEMS placement, returned due to stricture recurrence following distal SEMS migration. 4. A 59 year old male with recurrent diverticulitis status post open sigmoidectomy complicated by anastomotic breakdown requiring a diverting loop ileostomy, developed a complete obstruction at the colorectal anastomosis refractory to balloon dilation. With use of our novel technique, we were able to easily and accurately place LAMS across these short luminal strictures, thus obtaining symptom alleviation for our patients and avoiding surgery.

870 OOPS, THE LUMEN-APPOSING METAL STENT (LAMS) MISDEPLOYED! STAY CALM. NOW LET’S RESCUE IT

Reasons for misdeployment of a lumen-apposing metal stent (LAMS) include: Unfamiliarity with the stent, difficult scope position, patient movement and a lack of sufficient space in the lumen being targeted. Consequence of an unaddressed, misdeployed stent can be serious. We present 5 locations and techniques of rescuing misdelpoyed LAMS. Case 1: 56 year old male with severe acute pancreatitis with infected walled off necrosis, undergoing endoscopic necrosectomy. During LAMS deployment, distance of the collection (11mm from duodenum) and patient movement, resulted in duodenal flange almost completely misdeploying into the collection. The last of the tines of the LAMS was grasped with a forcep and repositioned with gentle traction. Case 2: 45 year old male with metastatic pancreatic cancer and a 3rd bout of cholecystitis undergoing cholecystoduodenostomy. Due to patient coughing, the duodenal flange misdeployed into the peritoneum. Unable to reposition this with a forcep, the LAMS was pulled out and access lost. However, using a papillotome and guidewire through the duodenal perforation, access was regained and a new LAMS was placed. Case 3: 38 year old female with Roux-en-Y gastric bypass with choledocholothiasis undergoing EUS-tansgastric fistula for ERCP. The Gastric pouch flange misdeployed in the peritoneum. Balloon dilation allowed us to visualize the LAMS and push it into the gastric remnant. A new LAMS was then deployed allowing for an ERCP. Case 4: 68 year old male with locally advanced pancreatic mass and positive FNA at EUS with a gastric outlet obstruction precluding ERCP, undergoing EUS choledochoduodenostomy. Due to the small bile duct (12mm), the biliary flange misdeployed in the retroperitoneum. After reconstraining the LAMS and redeploying the second time, the LAMS double punctured the bile duct. It was removed and rescued with a 10mm x 10cm biliary FCSEMS. Case 5: 72 year old male admitted with recurrent gastric outlet obstruction post-Whipple, despite dilations, steroids, and stents elected to undergo EUS-gastroenterostomy. After guidewire access into the jejunum, the LAMS was advanced, but instead of penetrating the jejunum, it was pushed it away and deployed in the peritoneum. The LAMS was removed and the gastric perforation closed with an over-the-scope clip. None of the 5 patients needed surgery and were discharged between 1 and 3 days. Prior to procedure, written consent to use a LAMS off-label and a surgeon on standby for a gastroenterostomy should be done. Recognize whether the perforation is on one or both lumenal sides and how can we seal the leak. If spillage of luminal contents has occurred, how will this be managed? Admit the patient, watch for adverse events and communication with providers involved in the patient’s care should follow.

68 EUS-GUIDED GASTROJEJUNOSTOMY WITH LUMEN APPOSING METAL STENT VERSUS ENTERAL STENT PLACEMENT FOR PALLIATION OF MALIGNANT GASTRIC OUTLET OBSTRUCTION

Enteral stent placement is commonly performed for palliation of obstructive symptoms caused by malignant gastric outlet obstruction (GOO). EUS-guided gastrojejunostomy (EUS-GJ) with placement of a lumen-apposing metal stent (LAMS) is a novel procedure that may offer long lasting patency with fewer incidence of stent failure, however there is limited data comparing EUS-GJ to enteral stent placement. To compare clinical outcomes and adverse events between EUS-GJ and enteral stent placement in the endoscopic palliation of malignant GOO. A prospectively collected university health care system registry was queried for LAMS, enteral stents, and GOO, and a retrospective analysis was performed. Patients who underwent EUS-GJ and enteral stent placement for the palliation of malignant GOO from 2014-2017 were included. Patients with benign GOO, gastroparesis, or surgically altered anatomy were excluded. Demographics, procedural and technical characteristics, and relevant clinical outcomes were recorded. Adverse events were assessed. Characteristics and clinical outcomes were compared using Fisher’s exact test and Student’s t test when appropriate. A total of 100 consecutive patients who underwent endoscopic palliation of malignant GOO during the study period were analyzed, of which 78 patients underwent enteral stent placement, and and 22 patients underwent EUS-GJ. Mean age was 65.9 ± 11.9 years, and 44.0% of patients were female. A total of 121 stents were placed, including 24 LAMS in the EUS-GJ group and 97 uncovered self expanding metal stents in the enteral stent group. When comparing EUS-GJ and enteral stent cases, technical success was achieved in 100% in both groups, however higher clinical success was attained in the EUS-GJ group compared to enteral stent group (91.7% vs 69.1%, p = 0.036). Mean length of hospital stay following stent placement was similar between the two groups (p = 0.821). The rate of stent failure requiring repeat intervention was significantly higher in the enteral stent group (31.6% vs 8.0%, p = 0.021). The enteral stent group had greater number of adverse events (40.2% vs 20.8%, p = 0.098) and incidence of stent ingrowth (16.5% vs 4.2%, p = 0.189), however this did not reach statistical significance. Misdeployment resulting in perforation occurred in two cases of EUS-GJ, however both cases were managed endoscopically with subsequent successful LAMS deployment in the same session, and neither case required surgery. When compared to enteral stent placement, EUS-GJ has higher rate of initial clinical success and lower rate of stent failure requiring repeat intervention. EUS-GJ should be offered as a minimally invasive alternative for selected patients with malignant GOO in centers with extensive experience.Tabled 1Table 1. Clinical OutcomesEUS-GJ (n, %)Enteral Stent (n, %)p valuePatients22 (22.0)78 (78.0)---Stents Placed24 (19.8)97 (80.2)---Technical Success24 (100.0)97 (100.0)1.000Clinical Success22 (91.7)67 (69.1)0.036Length of Hospital Stay Following Stent Placement (± SD, days)7.4 (9.1)7.9 (8.2)0.821Stent Failure Requiring Re-Intervention2 (8.0)31 (31.6)0.021Time to Re-Intervention (± SD, days)128 (157.0)99.2 (166.5)0.812Total Adverse Events5 (20.8)39 (40.2)0.098Stent Ingrowth1 (4.2)16 (16.5)0.189Stent Obstruction (not including ingrowth)0 (0.0)7 (7.2)0.342Stent Migration0 (0.0)2 (2.1)1.000Inadequate Stent Length0 (0.0)2 (2.1)1.000Bleeding0 (0.0)1 (1.0)1.000Biliary Obstruction0 (0.0)2 (2.1)1.000PEG Placement1 (4.2)5 (5.2)1.000Conversion to EUS-GJ (enteral stent only)---1 (1.0)---LAMS Mesh Erosion (EUS-GJ only)1 (4.2)------LAMS Misdeployment (EUS-GJ only)2 (8.3)------Death Within 30 Days0 (0.0)3 (3.1)1.000Abbreviations: EUS = endoscopic ultrasound GJ = gastrojejunostomy LAMS = lumen apposing metal stent SD = standard deviation Open table in a new tab

Mo1335 LUMEN-APPOSING METAL STENT PLACEMENT FOR WALLED-OFF PANCREATIC NECROSIS: RESULTS OF A PRACTICE PATTERN SURVEY OF US GASTROENTEROLOGISTS

Use of endoscopic ultrasound-guided placement of lumen-apposing metal stents (LAMS) has emerged as an effective treatment for walled-off necrosis (WON) following acute pancreatitis. The optimal protocol for LAMS placement and necrosectomy remains unclear. We sought to identify and characterize variations in the practice of LAMS placement for WON. A 25-question survey was created to collect information about practitioner demographics, LAMS deployment technique, attitudes regarding the timing and method of necrosectomy, and LAMS-related adverse events. The survey was emailed to 341 endoscopists at centers known to use LAMS in the US. A total of 68 surveys were completed for a response rate of 20.0%. Most respondents practiced in academic medical centers (67.2%), had placed 50 or fewer LAMS (86.0%), and almost all reported using LAMS placement as the primary method of WON treatment (92.5%). Most endoscopists reported an increase in referrals for treatment of WON since the introduction of LAMS (80.3%). General anesthesia for LAMS placement was more commonly used by participants (80.6%). At the time of LAMS placement, 72.6% of endoscopists deployed the stent in the device channel and 45.2% performed balloon dilation post-deployment. Despite most respondents reporting experience with stent occlusion as an adverse event, only 15.0% reported placing pigtail stents through the LAMS channel to maintain stent patency. Necrosectomy was performed by 46.8% of participants during index LAMS placement procedure. Concurrent percutaneous drains were used by 16.1%. Approximately half of respondents used hydrogen peroxide lavage at least some of the time. The timing of post-procedure CT scans was highly variable (range of 3 days to 1 month). About half reported a LAMS indwell time greater than 1 month. Survey participants were asked to report whether they had experienced any of the following adverse events at least once: stent occlusion (65.5%), readmission/sepsis (60.0%), bleeding (52.7%), maldeployment (30.9%), and dislodgement (38.2%). Since the introduction of LAMS for the treatment of WON, a convergence of practice patterns has not been demonstrated. Considerable variability exists in almost all aspects of LAMS use including placement technique, necrosectomy practices, follow-up treatment, and stent removal. Further investigation is needed to optimize endoscopic management of WON.Table 2. Necrosectomy PracticesView Large Image Figure ViewerDownload Hi-res image Download (PPT)