Faculty Bibliography

Endoscopic mucosal resection (EMR) is standard of care for removal of large laterally spreading colon polyps, but is often complicated by residual neoplastic tissue which is difficult to resect using standard methods.Large prospective studies from tertiary referral centers report 20% recurrence and 13% incomplete resection (A Moss2015). We introduced a new technique to improve resection of visible residual neoplasia (S Andrawes, 2014).Hot avulsion (HA) is a combination of mechanical traction with simultaneous application of short bursts of cutting current to shear adherent tissue, primarily neoplastic remnants which cannot be removed with a snare due to inability to grasp tissue.Use of hot biopsy forceps has been largely discarded due to concern for perforation,serositis,and delayed bleeding.A change in methodology, which emphasizes mechanical traction and cutting current, has altered the application with minimal risk.The advent of this technique has resulted in reduction of incomplete resection of difficult polyps. We performed a retrospective single center review of all consecutive patients undergoing EMR with adjuctive HA over a 3 year period by a single endoscopist to establish a safety profile for HA.Data collection included patient demographics, polyp size and location, intra and post-procedural complications, and time to onset of complications. A total of 134(55%) women and 110(45%) men, mean age 65, were included with 254 unique polyps (using hot avulsion) removed in 244 colonoscopies.10 patients had more than one polyp removed in a session.Average polyp size was 34mm.Polyps were predominantly in the right colon (69%). No clinically significant intra-procedural bleeding was noted.Two intra-procedure perforations were noted and were treated endoscopically.One was directly related to hot avulsion and treated with endoscopic suturing.The other was related to EMR and was closed using hemostatic clips.One patient(0.4%) was found to have a controlled perforation on CT imaging on day 4 post-op resolved with conservative management.It is unclear if this related to EMR or HA.Clinically significant bleeding requiring intervention occurred in six cases (5 treated with clips and 1 with coagulation).Importantly, there was no evidence of post polypectomy syndrome or transmural injury. Perforation definitely related to HA occurred in one patient and was endoscopically recognized and treated.A single delayed perforation of unclear cause was managed conservatively. Post-procedure bleeding required intervention in six patients and felt to be unrelated to the use of HA. Using appropriate parameters for this method, we conclude that hot avulsion is a safe method for adjunctive removal of visible residual neoplasia. [Formula presented] [Formula presented]
Copyright

EFTR is a safe and effective for resection of colorectal lesions. One limitation to EFTR, however, is lesion size, typically requiring size less than 2cm. For larger lesions, a hybrid technique using EMR followed by EFTR has been described, though this can be associated with risk for perforation with deployment of the clip into the EMR defect.We present our initial experience with hybrid EMR-EFTR in a series of consecutive patients treated in our center, and compare results to EFTR alone.
Study Design: Single-center retrospective cohort study,comparing consecutive pts who underwent EFTR alone(45%)to those who required EMR with EFTR(55%).All procedures were performed by a single, trained endoscopist.Primary outcomes were technical success,R0 resection with respect to vertical margins,and adverse events.Pt demographics,indication,and lesion/procedural characteristics were collected and analyzed.
Method(s): Standard colonoscopy was performed, advancing to the lesion to be resected.In those who underwent EFTR alone, the periphery of the lesion was marked with a cautery probe in four quadrants. The colonoscope was then withdrawn and a second colonoscope with attached cap,clip,snare,and sleeve was reintroduced and advanced to the lesion.Alligator forceps were used to grasp the lesion and retract it within the cap.Full thickness clip was then deployed followed by snare excision of entrapped tissue.For those in the hybrid group with lesions deemed too large for EFTR,we first performed EMR of the periphery to reduce lesion size and allow for EFTR of the central target area.In all cases, tissue was pinned,measured,and sent to pathology.
Result(s): Primary indication for hybrid EMR-EFTR was lesion size.Mean lesion size in the EFTR group was 16mm and 34mm in the hybrid group. Mean procedure time was 67 minutes in EFTR group and 100 minutes in the hybrid group. Histology confirmed R0 resection in 93% in EFTR group and negative vertical margins were found in 78% of lesions in hybrid group. 2 of 4 patients in the hybrid group with positive vertical margins were due to technical failure.In 1 pt the snare was inadvertently closed,with tissue resection prior to clip deployment resulting in a wall defect. A dual grasping forceps was used to pull the margins of the defect into the cap followed by clip deployment with no adverse sequelae. Complications were relatively rare. 1pt who did not take antibiotic as prescribed developed appendicitis, which required surgery 72hrs after procedure.1pt underwent elective surgery for a T2 cancer. Surgical specimen and lymph nodes showed no evidence of invasive cancer
Conclusion(s): Hybrid EMR-EFTR for colorectal lesions is a safe and effective for resection of lesions that are otherwise too large for EFTR alone.There were no adverse events related to deployment of the clip into tissue with EMR defect.This approach is a alternative to ESD or surgery. [Figure presented][Figure presented]
Copyright

Introduction: The incidence of duodenal polyps is approximately 1% in retrospective studies and up to 4.6% in one prospective study. Resection of suspected adenomas is recommended as they have a high incidence of development of high grade dysplasia or cancer. Endoscopic resection is associated with high rates of bleeding and perforation. Technical complexity, including involvement of the major papilla need for forward and side- viewing endoscopes, and angulation of the folds makes complete resection challenging. We present a large cohort of duodenal polyp resections including large complex polyps to emphasize complications and to provide recommendation for best clinical practice.
Aim(s): To evaluate the overall safety and efficacy of endoscopic resection of duodenal polyps Methods: A retrospective review of a database of duodenal polyps resected by a single endoscopist (GBH)between June 2016 and November 2018 was performed. The database includes ampullary and non-ampullary and sporadic or genetic syndrome associated (Familial adenomatous polpyposis, Peutz-Jeghers)polyps. Polyps resected by cold biopsy were excluded. This is a descriptive study which includes patient demographics, polyp size and location, resection technique, pathology, complications, and recurrence.
Result(s): The study included 69 procedures to remove 80 polyps total. Size ranged from 0.5cm to 7.0cm and 41 (51%)of the polyps were greater than 2 cm. Endoscopic technique was predominantly snare mucosal resection. Polyps greater than 5cm were generally not resected in a single procedure due to risk of complications and by intention underwent serial resection procedures. Intraprocedural bleeding occurred in 13% of procedures and was controlled entirely endoscopically. Post-polypectomy bleeding occurred in 10% and was managed either endoscopically or conservatively in all cases without surgery. Among larger polyps >2cm, the post-polypectomy bleeding rate was 12.5%. No bleeding was seen in the 22 polypectomy defects closed with clips. A total of three perforations occurred. One required surgical management, one was closed with an over-the-scope clip, and one was closed with a combination of endoscopic sutures and clips. Two patients underwent surgery for incomplete endoscopic resection. Follow up data was available for 27 patients with a mean of 10 months. Excluding the 5 patients who underwent serial procedures to complete resection, there were 7 recurrences out of 22 complete resections (32%).
Conclusion(s): This large series shows that duodenal polyp resection can be successfully performed with appropriate precautions. In contradistinction to the colon, there is little disadvantage to multiple sessions to reduce bleeding risk. Closure of defects with clips when feasible reduces the risk of bleeding. All patients with unclosed defects greater than 2cm should be admitted for overnight observation. [Figure presented][Figure presented]
Copyright

Background: The majority of benign colorectal lesions can be removed using endoscopic mucosal resection techniques. For lesions that are tethered down, nonlifting, invasive or in anatomically challenging locations, advanced endoscopic techniques or surgical resection are typically required. A novel endoscopic full-thickness resection (FTR) device (FTRD, Ovesco Endoscopy, Tuebingen, Germany) was recently approved for use in the United States. Safety and efficacy data on the use of this device have not previously been reported from North America. We present our initial experience with the over-the-scope FTRD in a series of consecutive patients treated in our center. Study Design: We performed a single-center retrospective cohort study, of consecutive patients who underwent endoscopic FTR since its approval in mid-2017. All procedures were performed by a single experienced endoscopist who received training in the use of the device. Primary outcomes were technical success, R0 resection, and adverse events. Patient demographics, indication, and procedural characteristics were collected and analyzed. Method: Routine colonoscopy with an adult colonoscope was advanced to the lesion to be resected. The peripheries of the lesions were marked with a specific cautery probe in four quadrants. The colonoscope was then withdrawn and a second colonoscope with the attached hood, clip, snare, and sleeve was re-introduced and advanced to the lesion. An alligator forceps was used to grasp the lesion to pull it into the hood. The full thickness 'bearclaw' clip was then deployed followed immediately by snare excision of the entrapped tissue. The tissue was pinned, measured, and then sent to pathology. Results: FTR was attempted in a total of 10 patients (Table 1). The primary indication for FTR was non-lifting adenoma (5 patients, 50%). For three patients the indication was an inaccessible location (appendiceal/diverticular), and another two were referred for removal of subepithelial carcinoids. The size of the lesions averaged 16 mm and ranged up to 40 mm in one patient in whom a hybrid resection (EMR + FTR) was performed. The majority of lesions were flat (Paris class IIc or IIa + IIc). Technical success was achieved in nine of ten patients (Table 2). For one 89-year old patient, the procedure was aborted due to difficulties in advancing the FTRD through a tortuous sigmoid colon. Procedure duration averaged 71 minutes. R0 resection of the lesion was achieved in eight patients (pathology pending in one) in whom the FTR device was deployed. One significant adverse event was recorded: the FTR device clip was not deployed prior to full thickness snare incision in one patient resulting in a large perforation. The defect edges were then approximated and the FTR clip was deployed with successful closure of the perforation with no adverse sequela

Introduction: ESD is a well-established technique for ensuring en bloc resection of advanced benign neoplasm and early cancer. The advantage of this technique includes a curative resection, accurate histological evaluation and lower recurrence rate. The disadvantages are the long learning curve, the time required and increased rates of perforation and bleeding. We undertook a review of consecutive patients undergoing ESD by a western endoscopist to compare the outcomes achieved with that of our major Asian centers. Current guideline suggest ESD should achieve at least an 80% rate of R0 resection. Aim: To assess the efficacy, safety and outcomes in North American Centers and to compare the results with those reported from Asia. Methods: A retrospective study of consecutive ESD performed by a single endoscopist (G.B.H) between 2008 and 2017 was undertaken. Primary procedural outcome were technical success, defined as en bloc resection of the lesion in a single piece and clinical success defined as R0 resection with histologic confirmation of negative vertical and horizontal margins. Secondary outcomes were complication rates and recurrence for neoplastic lesions. Results: A total of 126 procedures were performed. The primary indication for ESD was cancer in 48 cases (38%), high-grade dysplasia in 33 cases (26%), nondysplastic in 34 cases (27%), low-grade dysplasia in 11 (9 %). The average tumor size was 38 mm (6-130 mm). En bloc resection was achieved in 121 of 126 cases (96%), whereas R0 resection was achieved in 101 of 126 cases (80%). Non curative resection was due to positive horizontal margin in 13 and vertical margin in 12. The results were analyzed for 3 different periods which reflects experiences and case volume. The technical success and R0 resection rates for 2008-2011, 2012-2014, and 2015-2017 were 86% and 77%, 96% and 70%, and 100% and 88% respectively. There were 5 (4%) intra-op bleedings and 4 (3%) intra-op perforations. All complications were managed endoscopically and no patient required surgical intervention for complication. Conclusion: ESD performed in Western centers can achieve success rate comparable to Asian endoscopists. However, there is a long learning curve in large part related to fewer cases and lack of formal training. (Table Presented)

BACKGROUND AND AIMS: Wide-area transepithelial sampling (WATS) with computer-assisted 3-dimensional analysis is a sampling technique that combines abrasive brushing of the Barrett's esophagus (BE) mucosa followed by neural network analysis to highlight abnormal-appearing cells. METHODS: We performed a randomized trial of referral BE patients undergoing surveillance at 16 medical centers. Subjects received either biopsy followed by WATS, or vice versa. The primary outcome was rate of detection of HGD/EAC using WATS in conjunction with biopsy compared with biopsy alone using standard histopathologic criteria. Secondary aims included evaluating neoplasia detection rates (1) based on the procedure order (WATS vs biopsy first) (2) of each procedure separately, and (3) the additional time required for WATS. RESULTS: One hundred sixty patients (mean age 63.4 years, 76% male; 95% white) completed the trial. The median circumferential and maximal BE extents were 1.0 (IQR: 0.0-5.0) cm and 4.0 (IQR, 2.0-8.0) cm, respectively. The diagnostic yield for biopsy alone was as follows: HGD/EAC, 7 (4.4%); low-grade dysplasia (LGD), 28 (17.5%); non-dysplastic BE (NDBE), 106 (66.25%); and no BE, 19 (11.9%). The addition of WATS to biopsy yielded an additional 23 cases of HGD/EAC (absolute increase, 14.4%; 95% CI, 7.5%-21.2%). Among these 23 patients, 11 were classified by biopsy as NDBE, and 12 as LGD/IND; 14 received biopsy and 9 WATS first (p=NS) and the majority (n=21; 91.7%) had a prior dysplasia history. WATS added average of 4.5 minutes to the procedure. CONCLUSION: Results of this multicenter, prospective, randomized trial demonstrate that the use of WATS in a referral BE population increases the detection of HGD/EAC.

Group testing estimation, which utilizes pooled rather than individual units for testing, has been an ongoing area of research for over six decades. While it is often argued that such methods can yield large savings in terms of resources and/or time, these benefits depend very much on the initial choice of pool sizes. In fact, when poor group sizes are used, the results can be much worse than those obtained using standard techniques. Tools for addressing this problem in the literature have been based on either large sample results or prior knowledge of the parameter being estimated, with little guidance when these assumptions are not met. In this paper, we introduce and study random walk designs for choosing pool sizes when only a small number of tests can be run and prior knowledge is vague. To illustrate these methods, application is made to the estimation of prevalence for two diseases among Australian chrysanthemum crops.

Introduction: Cholangiocarcinoma and pancreatic adenocarcinoma account for over 190,000 new clinical cases of pancreatobiliary malignancy worldwide annually. For palliation of obstructive jaundice in these patients, plastic or self-expanding metal stent (SEMS) are placed. However, re-occlusion rates for currently available stents range as high as 36% for uncovered metal stents, 25% for covered metal stents and 52% for plastic stents. Tissue ingrowth accounts for up to 76% of occlusions of bare metal stents.1, 2, 3, 4 Stent occlusion can result in recurrent obstruction and typically requires endoscopic re-intervention. Therefore there is a real clinical need to reduce tissue ingrowth and improve biliary stent patency rates. Aims & Methods: In this study we developed and tested a controlled-release paclitaxel-eluting SEMS designed to prevent tissue hyperplasia and stent occlusion. A 4 cm length uncovered, laser-cut nitinol stent was coated with a polymer matrix allowing slow release of paclitaxel. Naive Yucatan swine were assigned to one of three stent groups: bare control (n=3, no polymer), standard dose paclitaxel (n=6, 149.4 mg paclitaxel) and challenge dose (n=3, 538.0 mg paclitaxel. Two stents were endoscopically implanted in each swine from its assigned group, one in the intrahepatic/hilar region and a second in the common bile duct placed proximal to the papilla. Stents were assessed for migration via digital radiographs for the first 2 weeks and then monthly via endoscopy using SpyGlassTM DS cholangioscopy and cholangiography with a targeted 6 month study endpoint. Results: At 30 days post-implant, no significant tissue reaction to any stent was observed. However, all animals displayed mild biofilm formation and increased intraductal mucus production. Substantial dilation of the common bile duct was observed in 5/11 animals with no apparent relationship between drug coating and duct dilation. At 60 days post-implant, moderate mucus and biofilm formation was observed within the stent, however in only 3 animals biliary ductal dilation persisted and the majority of stents were fully apposed to the duct wall. Although some animals displayed minimal tissue hyperplasia at the proximal end of the stents, no tissue overgrowth or stent embedding was observed in any animal. Up to 60 days post-implant, no persistent clinical symptoms were observed in any animal. Stents in one standard dose animal migrated out of the bile duct between days 15 and 30, this animal is not included in patency results reported. At both 30 and 60 day timepoints, no apparent differences in outcome were observed among the three study groups. Conclusion: At this mid-study follow-up, paclitaxel-eluting stents appear to be safe for use in naive tissue and do not negatively impact function of the biliary system, even at challenge condition doses. Although the cause of bile duct dilation observed in all stent groups has not been conclusively identified, we hypothesize the cause may be distal stent impaction and intermittent (clinically insignificant) obstruction of the papilla and/or stent, resulting in retained mucus and bile. Bile duct dilation, in turn, has reduced the opportunity for tissue overgrowth in all stent groups, which was expected to occur in the bare stent control group by 60 days post-implant5. Given the observed 60% reduction in number of dilated ducts between days 30 and 60, we expect increased rate of apposition. Ongoing efforts include continued follow-up for an additional 120 days, and in a second cohort, determination of in vivo drug release rates in the bile duct over a 30 day period. Future cholangioscopic and histopathological assessment of these swine will further clarify the safety and effectiveness of paclitaxel stent coatings to mediate bile duct tissue ingrowth