STATE-OF-THE-ART PRESENTATION: THE BASIS IS THE FRONTIER FOR THIRD SPACE ENDOSCOPY

Background: G-POEM has emerged as a treatment for medically refractory gastroparesis. Safe and effective mucosal closure is necessary to avoid potential morbidity. The aim of this study was to compare outcomes between the novel through-the-scope (TTS) suture system (X-Tack, Apollo, EndoSurgery) and the existing over-the-scope (OTS) endoscopic suture device (Overstitch, Apollo Endosurgery) for mucosal incision closure after G-POEM.
Methods: Dual-center retrospective analysis of prospective databases on consecutive patients who underwent G-POEM with mucosal incision closure with either the TTS or OTS suturing systems from September 2018 to September 2022. Primary outcomes were the proportion of patients with complete closure and endoscopic suturing technical success. Failed closure was defined as incomplete closure based on contrast extravasation on post-procedural imaging or incomplete closure-related adverse events. Endoscopic suturing technical success was defined as complete mucosal closure with the TTS or OTS suture alone. Secondary outcomes included closure time and adverse events.
Results: One-hundred twenty patients (mean age 51.4 ± 13.8 years; 80% women; mean gastroparesis cardinal symptom index score of 3.2 ± 1.1) underwent G-POEM with mucosal incision closure with TTS (n=36) or OTS (n=84) suturing. G-POEM technical success was 100%. Table 1 summarizes characteristics between the TTS vs OTS suture groups. A transverse mucosal incision was performed for most cases (97.2% in TTS and 100% in OTS suturing groups; p=0.3). There were no statistically significant differences in the length of mucosal incision, submucosal tunneling or pyloromyotomy between the two groups. Procedural times between TTS and OTS suturing were as follows: mucosal incision closure (17.5 ± 10.8 vs. 12.2 ± 4.8 min; p=0.6) and total procedure (48.4 ± 16.8 vs. 59.4 ± 9.9 min; p=0.6), respectively. Complete closure was achieved in 100% (36/36) and 98.8% (83/84) in the TTS and OTS suture groups, respectively (p=1.0). In the single case of failed closure, subsequent complete closure was achieved with TTS clips. Endoscopic suturing technical success was significantly higher with OTS as compared to TTS suturing (91.7% vs 66.7%; p=0.002), with adjunct TTS clips used for complete closure in all remaining cases. There was 1 case of perforation in the OTS suturing group (0.8%) which required surgical intervention with full recovery.
Conclusion: The novel TTS suture system is safe and effective for mucosal incision closure after G-POEM. There was no difference in complete closure rate or procedural times between TTS and OTS suturing. Patients who underwent OTS suturing were less likely to require additional adjunct TTS clips for complete closure when compared to the TTS suture system. Additional prospective comparative trials and cost-effectiveness analyses are warranted.

Background and Aims:
Bleeding and delayed perforation are two known complications from endoscopic submucosal dissection (ESD) which can be reduced with mucosal closure. Mucosal closure, however, further prolongs a lengthy ESD procedure. One of the mucosal closure devices that has been studied in the past is over the scope endoscopic suturing system (OTSS). A novel through-the-scope endoscopic helix tack suture system (TTSS) is now available. We aim to compare the closure time, technical and clinical success, and cost effectiveness between OTSS and TTSS.

Methods:
This is a single center, prospective, randomized trial. All patients having ESD with anticipated closure were randomized 1:1 to closure with either the TTSS (the study group) or the OTSS (the control group.) The primary outcome was the “closure time” (CT) defined as the time between first bite/tack and the last cinch/endoclip. A related measure called “overall closure time” (OCT) was defined as time between the end of dissection to the last cinch/endoclip and this represented setup and closure time. Secondary outcomes included the rates of technical success, closure related adverse events and cost effectiveness.

Results:
40 patients were randomized (20 each to OTSS and TTSS). There was no significant difference between groups in baseline characteristics such as mean age in years (62.2 vs. 61.8, P=0.92), male gender (55% vs. 50%, P=0.75), proportion of colorectal polyps (80% vs. 85%, P=0.91), right colon polyps (20% vs. 30%, P=0.72) and mean size of resected specimen in mm (40.9 ±17.0 x 29.8 ±12.7 vs. 40.4±17.5 x 26.0 ±8.5). Closure with primary device was successful in 17 (85%) cases in OTSS group and 18 (90%) cases in TTSS group (P=0.63). There was no significant difference in mean CT between groups (18.4 ±16.9 mins for OTSS vs. 23.3 ±13.9 mins for TTSS ,P=0.36). Mean OCT for OTSS was 32.0 ±21.7 mins vs. 39.5 ±20.9 mins for TTSS (P=0.31). No closure related intraprocedural complications were noted. Two episodes of self-limited delayed bleeding occurred with resumption of antiplatelets in patients with OTSS failures (one had been partially closed with endoclips, the other crossed over to TTSS). Of the lesions located in the right colon, closure with primary device was achieved in two out of four cases (50%) in OTSS group compared to all six cases in TTSS group (100%) (P=0.13). No delayed perforations were noted. Mean total cost of closure was not significantly different between groups (P=0.61) but was significantly lower in TTSS group for lesions <35mm in length (P=0.008).

Conclusion:
When used for gastric and colorectal ESD defect closure, the novel TTSS has similar closure time, efficacy and adverse events compared to OTSS. TTSS is a valuable closure tool in OTSS inaccessible areas such as proximal colon. TTSS is more cost effective for closure of lesions smaller than 35mm.

Background: A single-operator, articulating, through-the-scope (TTS) traction device was recently developed to facilitate endoscopic submucosal dissection (ESD). Clinical data on the performance of this device is limited. We report an initial multicenter experience on ESD using this articulating TTS traction device.
Methods: Retrospective analysis of prospectively collected data on all consecutive patients who underwent ESD using this traction device at 5 centers between August 2021 and September 2022. None of the participating endoscopists had prior clinical experience with the traction device. The traction device consists of a scope-mounted hand controller and an articulating distal end (Figure 1). The distal end, which consists of an articulating and rotatable grasper, is inserted through the 3.7 mm instrument channel of a double-channel endoscope. Operation of the traction device with the hand controller allows tissue manipulation and traction with the grasper during ESD (Figure 1). Endpoints included: rates of en-bloc resection, R0 resection, curative resection, and adverse events.
Results: Thirty-one patients (median age 64.6 years; 48.4% women) underwent ESD (median lesion size 40 mm; interquartile range [IRQ]: 27.5-67.5) for lesions in the esophagus (n=2), stomach (n=7), sigmoid colon (n=5), and rectum (n=17). Submucosal fibrosis was encountered in a third of the lesions (32.3%) and baseline histopathology included 6 cases (19.4%) of invasive cancer (Table 1). Median procedure time was 119 minutes (IQR: 64-151). En-bloc, R0 and curative resection were achieved in 93.5%, 90.3%, and 96.8% respectively. The single patient with non-curative resection of an invasive rectal adenocarcinoma underwent surgery. There were no adverse events. There was no recurrence in the 16 patients who underwent follow-up endoscopic surveillance at a median of 6 months (IQR: 3.75-6).
Conclusion: ESD is a technically challenging procedure. Dynamic real-time traction during ESD may help improve both efficacy and safety. This initial multicenter experience demonstrates high resection rates and excellent safety profile when performing ESD with this novel articulating TTS device. Additional studies are needed to assess its cost-effectiveness and compare its usefulness with other traction devices and techniques during ESD.

Background:
Gastroparesis (Gp) patients often have gastroesophageal reflux disease (GERD). Management of GERD in Gp patients is a challenge. Many studies have shown that gastric peroral endoscopic pyloromyotomy (GPOEM or POP) is 80% effective in reducing nausea and vomiting in patients with Gp. This study aims to determine whether GPOEM can improve GERD in Gp Patients.

Methods:
Patients who underwent GPOEM from July 2021 to October 2022 were enrolled in the study. Each patient signed a consent form. GERD Health-Related Quality of Life ( HRQL score 0 to 36, with 36 being the worst) and Reflux Symptom Index ( RSI score 0 to 40, with 40 being the worst) were used to assess patients' GERD. The use of Proton Pump Inhibitors (PPI) before and after GPOEM was documented. Gastroparesis Cardinal Symptom Index (GCSI) was used to assess the severity of Gp before and after GPOEM. We conducted a "Welch two-sample t-test" to find differences in GERD HRQL and RSI scores before and after the procedure. In addition, we used Pearson's chi-square test to identify differences in using PPI before and after G-POEM.

Results: Twenty-three consecutive gastropareses patients were enrolled, with 30.4 % male (average age 63.2) and 69.5% female patients (average age 53.9). Of these, 14 had diabetes, 3 had a history of surgery, and 6 had idiopathic gastroparesis. All patients failed prior dietary/medication therapy; 2 failed endoscopic Botox injections, 1 failed endoscopic dilation, and 1 failed gastric electric stimulation. The mean follow-up was 41 days (range 7 to 61 days). Mean GCSI pre and post-GPOEM were 3.53 and 1.59, respectively. Eighteen had clinical improvement in Gp as defined by decreased mean GCSI score greater than 1, and the remaining five did not have clinical improvement. Welch Two Sample t-test demonstrated a significant decrease in the mean GERD HRQL score from 16.5 to 6.5 after G POEM with a p-value <0.0001 and a significant reduction in mean RSI score from 15.3 to 5.2 after G-POEM with p-value <0.0001. The average decrease in the GERD HRQL score is 64.65% (mean difference in score = 10.06). The average reduction in the RSI score is 65.65% (mean difference in score = 10.15). The proportion of use of PPI before GPOEM was 0.91, and the proportion of PPI use after GPOEM was 0.43. Pearson's chi-square test demonstrated that the proportion of PPI use decreased after the GPOEM procedure with a p-value of 0.0008.

Conclusion
In this short-term outcome study, 86.96% of patients' GERD HRQL and RSI scores decreased after G-POEM. These findings indicate that GPOEM effectively reduces Gp symptoms and improves GERD symptoms, leading to decreased or more effective use of PPI in these patients. To our knowledge, this is the first study that showed G-POEM significantly improves GERD. However, further studies with a larger patient population and long-term outcomes are needed.

Background
Endoscopic submucosal dissection (ESD) is commonly employed in the treatment of epithelial gastrointestinal tumors, but few studies have explored ESD for treatment of duodenal papillary adenomas (PAs). In this study, we aim to evaluate the feasibility of a modified ESD method as an alternative modality in the resection of PAs.

Methods
A modified ESD method was performed in 10 patients with PAs. After a semicircular mucosal incision, the submucosal dissection was performed with clip traction anchoring the mucosa flap to the contralateral intestinal wall during the operation. The mucosal defect was partially closed with endoclips after en bloc resection of the PAs. The potential advantages of this modified ESD approach for resection of sporadic duodenal PAs were evaluated through retrospective analysis.

Results
All lesions (10/10) were resected en bloc with negative margins (100% R0 resection). No major bleeding or perforation occurred during the operation. No delayed bleeding was observed. There was one case each of melena and early pancreatitis observed post-operatively; however, no endoscopic or surgical intervention was needed. No recurrence was detected after a mean follow-up time of 11.2 months (3-29) months.

Conclusions
From our preliminary experience, ESD is a feasible approach for the treatment of duodenal PAs. It may have a higher en bloc resection rate for PAs compared with traditional method of ampullectomy, especially for lateral spreading tumors. Given multiple study design limitations, further investigation is needed to evaluate the most advantageous applications of ESD to PAs.

Background: Submucosal tunneling endoscopic resection (STER) allows endoscopic removal of subepithelial lesions (SELs) from the upper gastrointestinal (UGI) tract. However, the available data is limited to retrospective single-center studies from Asian countries. In this study, we aimed to evaluate the outcomes of STER for the treatment of UGI SELs across centers in the United States.

Methods: This was a retrospective analysis of patients with UGI SELs who were referred for STER at 7 centers. The study included lesions originating or inseparable from the muscularis propria (MP) layer, SELs with symptoms, potential to be malignant on endoscopic ultrasound (EUS), or with inconclusive diagnosis by EUS-fine needle aspiration (EUS-FNA) but suspicious to be gastrointestinal stromal tumor (GIST). The main outcome measures included the rates of: 1) en bloc resection; 2) en bloc retrieval; 3) transmural resection; 4) adverse events; and 5) recurrence. Factors predicting transmural resection were also assessed.

Results: A total of 40 SELs in 38 patients were included (Table 1). The median lesion size was 25 mm, with 60% of the lesions in the stomach and 40% in the esophagus. Thirty-three (82.5%) lesions had prior sampling with mucosal biopsy (n=4) or EUS-FNA (n=29). The median procedure time was 76 minutes. Complete en bloc resection and en bloc retrieval were both achieved in 38/40 (95%) lesions. Two (5%) patients had incomplete resection due to significant extraluminal growth. STER required transmural resection for 11 (27.5%) lesions. Submucosal fibrosis was encountered in 9 (22.5%) lesions, all with a history of prior sampling. The presence of an extraluminal component (OR 11.1, CI 1.5-77.4) and submucosal fibrosis (OR 9.3, CI 1.2-69.6) were found to be significant factors associated with transmural resection (Table 2). Adverse events occurred in 6/38 (15.8%) patients and were managed without surgery. Mucosal injury occurred in 4 (1 with submucosal fibrosis), severe intra-procedural bleeding in 2, post-procedural leak in 1, and pneumoperitoneum requiring decompression in 3 cases. The rate of adverse events was not significantly higher with transmural resection (p=0.6). The more commonly resected lesions were GISTs (60%) and leiomyomas (32%). No lesion recurrence occurred at a median follow-up of 23 months.

Conclusions: STER is a safe and effective treatment option for UGI SELs, including those originating from the MP layer. Extraluminal extension and submucosal fibrosis from previous sampling were factors associated with the need for transmural resection. Avoidance of tissue sampling may facilitate STER by reducing fibrosis and the need for transmural resection.