Endoscopic mucosal resection with the grasp-and-snare technique through a double-channel endoscope in humans

Endoscopic mucosal resection and endoscopic submucosal dissection with an external additional working channel (EMR+ and ESD+) are equivalent to using a double-channel endoscope: a systematic evaluation in a porcine ex vivo model

BACKGROUND AND AIMS

With an external additional working channel (AWC) endoscopic mucosal resection (EMR) as well as endoscopic submucosal dissection (ESD) can be extended to techniques termed "EMR+" and "ESD+." These novel techniques are systematically compared to EMR and ESD under the use of a double-channel endoscope (DC).

METHODS

Our trial was conducted prospectively in a pre-clinical porcine animal model (EASIE-R simulator) with standardized gastric lesions measuring 3 or 4 cm.

RESULTS

EMR+ and EMR DC showed both good results for 3 cm lesions with no adverse events and an en bloc resection rate of 73.33% (EMR+) and 60.00% (EMR DC, p = 0.70). They came to their limits in 4 cm lesions with muscularis damages of 20.00% (EMR+), 13.33% (EMR DC, p ≥ 0.99) and decreasing en bloc resection rates of 60.00% (EMR+) and 46.67% (EMR DC, p = 0.72). ESD+ and ESD DC were both reliable concerning en bloc resection rates (100% in all groups) and adverse events (0.00% in 3 cm lesions, 12.50% muscularis damages in both ESD+ and ESD DC in 4 cm lesions). Resection time was slightly shorter in all groups with the AWC compared to DC although only reaching significance in 3 cm ESD lesions (p < 0.05*).

CONCLUSIONS

With the AWC, a standard endoscope can easily be transformed to double-channel functionality. We could show that EMR+ and ESD+ are non-inferior to EMR and ESD under the use of a double-channel endoscope. Consequently, the AWC presents an affordable alternative to a double-channel endoscope for both EMR and ESD.

Comparison of endoscopic treatments for small gastric adenomas

BACKGROUND

Gastric adenomas can be successfully treated with endoscopic resection, including endoscopic submucosal dissection (ESD) and endoscopic mucosal resection (EMR). The aim of this study was to evaluate and compare the efficacy of ESD and EMR with circumferential precutting (EMR-P) in the treatment of small gastric adenomas.

METHODS

This study included 1014 gastric adenomas ≤ 15 mm in diameter treated with ESD or EMR-P from 2012 to 2019, retrospectively. Propensity score matching between the ESD and EMR-P groups (1:1 to 3:1) was performed according to age, sex, tumor size, tumor location (upper, middle, and lower thirds), morphology, and preprocedural histology. The procedure time and the rates of en bloc resection, complete resection, adverse events, and local recurrence were compared between the two groups.

RESULTS

After propensity score matching, 478 lesions (ESD: 295, EMR-P: 183) were analyzed. The rates of en bloc resection (94.9% vs. 93.4%, p = 0.498), complete resection (93.6% vs. 90.2%, p = 0.177), bleeding (8.1% vs. 3.8%, p = 0.063), and local recurrence (0.0% vs. 1.4%, p = 0.185) did not significantly differ between the two groups. The procedure time was significantly longer for ESD than for EMR-P (p < 0.001). In the EMR-P group, the complete resection rate was significantly lower in the upper third than in the middle and lower thirds (p < 0.001).

CONCLUSION

EMR-P is as effective as ESD for the treatment of small gastric adenomas. However, the efficacy of EMR-P is lower for gastric adenomas in the proximal stomach.

Efficacy of the pocket-creation method with a traction device in endoscopic submucosal dissection for residual or recurrent colorectal lesions

Background/Aims

Endoscopic submucosal dissection (ESD) for residual or recurrent colorectal lesions after incomplete resection is challenging because of severe fibrosis. This study aimed to compare the efficacy of the pocket-creation method (PCM) with a traction device (TD) with that of conventional ESD for residual or recurrent colorectal lesions.

Methods

We retrospectively studied 72 patients with residual or recurrent colorectal lesions resected using ESD. Overall, 31 and 41 lesions were resected using PCM with TD and conventional ESD methods, respectively. We compared patient background and treatment outcomes between the PCM with TD and conventional ESD groups, respectively. The primary endpoints were en bloc resection and R0 resection rates. The secondary endpoints were the dissection speed and incidence of adverse events.

Results

En bloc resection was feasible in all cases with PCM with TD, but failed in 22% of cases of conventional ESD. The R0 resection rates for PCM with TD and conventional ESD were 97% and 66%, respectively. Dissection was significantly faster in the PCM with TD group (13.0 vs. 7.9 mm²/min). Perforation and postoperative bleeding were observed in one patient in each group.

Conclusions

PCM with TD is an effective method for treating residual or recurrent colorectal lesions after incomplete resection.

Evaluation of improved bi-manual endoscopic resection using a customizable 3D-printed manipulator system designed for use with standard endoscopes: a feasibility study using a porcine ex-vivo model

Background and study aims  A major drawback of endoscopic en-bloc resection technique is its inability to perform bimanual tasks. Although endoscopic platforms that enable bimanual tasks are commercially available, they are neither approved for various locations nor adaptable to specific patients and indications. Methods  Based on evolution of an adaptive 3D-printable platform concept, system variants with different characteristic properties were evaluated for ESD scenarios, ex-vivo in two locations in the stomach and colorectum. Results  In total 28 ESDs were performed (7 antrum, 7 corpus in inversion, 7 cecum, 7 rectum) in a porcine ex-vivo setup. ESD was feasible in 21 cases. Investigated manipulator variants are differently well suited for performing ESD within the varying interventions scenarios. Dual-arm manipulators allowed autonomous ESD, while single-arm flexible manipulators could be used more universally due to their compact design, especially for lesions difficult to access. Pediatric scopes were too frail to guide the overtube-manipulators in extremely angled positions. Working in the rectum was impaired using long-sized manipulator arms. Conclusions  The presented endoscopic platform based on 3D-printable and customizable manipulator structures might be a promising approach for future improvement of ESD procedure. With regard to localization, especially flexible manipulators attached to standard endoscopes appear to be most promising for further application of specific and individualised manipulator systems.

Efficacy and safety of grasping forceps-assisted endoscopic resection for gastric neoplasms: A multi-centre retrospective study

BACKGROUND

Endoscopic submucosal dissection (ESD) is widely accepted for early gastric cancer (EGC) without lymph node metastasis, although ESD is challenging, even for small lesions, in the greater curvature (GC) of the upper (U) and middle (M) thirds of the stomach. Grasping forceps-assisted endoscopic resection (GF-ER) is a type of endoscopic mucosal resection that is performed via a double-channel endoscope.

AIM

To investigate the safety and efficacy of GF-ER vs ESD in the GC of the stomach’s U and M regions.

METHODS

We retrospectively reviewed the medical records of 506 patients who underwent ER of 522 EGC lesions in the stomach’s U and M regions in three institutions between January 2016 and May 2020. Nine lesions from eight patients who underwent GF-ER for EGC (the GF-ER group) were compared to 63 lesions from 63 patients who underwent ESD (the ESD group). We also performed a subgroup analysis of small lesions (≤ 10 mm) in 6 patients (7 lesions) from the GF-ER group and 20 patients (20 lesions) from the ESD group.

RESULTS

There were no statistically significant differences between the GF-ER and ESD groups in the en bloc resection rates (100% vs 100%) and the R0 resection rates (100% vs 98.4%). The median procedure time in the GF-ER group was shorter than that in the ESD group (4.0 min vs 55.0 min, P < 0.01). There were no adverse events in the GF-ER group, although five perforations (8.0%) and 1 case of postoperative bleeding (1.6%) were observed in the ESD group. When we only considered lesions that were ≤ 10 mm, the median procedure time in the GF-ER group was still shorter than that in the ESD group (4.0 min vs 35.0 min, P < 0.01). There were no adverse events in the GF-ER group, although 1 case of perforation (1.6%) were observed in the ESD group.

CONCLUSION

These findings suggest that GF-ER may be an effective therapeutic option for small lesions in the GC of the stomach’s U and M regions.

Devices and techniques for endoscopic treatment of residual and fibrotic colorectal polyps (with videos)

BACKGROUND AND AIMS

Residual neoplasia after macroscopically complete EMR of large colon polyps has been reported in 10% to 32% of resections. Often, residual polyps at the site of prior polypectomy are fibrotic and nonlifting, making additional resection challenging.

METHODS

This document reviews devices and methods for the endoscopic treatment of fibrotic and/or residual polyps. In addition, techniques reported to reduce the incidence of residual neoplasia after endoscopic resection are discussed.

RESULTS

Descriptions of technologies and available outcomes data are summarized for argon plasma coagulation ablation, snare-tip coagulation, avulsion techniques, grasp-and-snare technique, EndoRotor endoscopic resection system, endoscopic full-thickness resection device, and salvage endoscopic submucosal dissection.

CONCLUSIONS

Several technologies and techniques discussed in this document may aid in the prevention and/or resection of fibrotic and nonlifting polyps.

Endoscopic submucosal dissection with an additional working channel (ESD+): a novel technique to improve procedure time and safety of ESD

Background and aims

A new external additional working channel (AWC) was recently introduced by which endoscopic submucosal dissection (ESD) can be converted to a technique termed “ESD+ ”. We aim to systematically evaluate this novel technique in flat gastric lesions and compare it to classical ESD.

Methods

The study was prospectively conducted in a pre-clinical ex vivo animal model (EASIE-R simulator) with porcine stomachs. Prior to intervention, we set standardized lesions measuring 3 cm or 4 cm in antegrade as well as in retrograde positions.

Results

Overall, 64 procedures were performed by an experienced endoscopist. Both techniques were reliable and showed en bloc resection rates of 100%. Overall, ESD+ reduced time of procedure compared to ESD (24.5 vs. 32.5 min, p = 0.025*). Particularly, ESD+ was significantly faster in retrograde lesions with a median of 22.5 vs. 34.0 min in 3 cm retrograde lesions (p = 0.002*) and 34.5 vs. 41.0 min (p = 0.011*) in 4 cm retrograde lesions. There were 0 perforations with both techniques. In ESD+ , 1 muscularis damage occurred (3.13%) compared to 6 muscularis damages with ESD (18.75%, p = 0.045*).

Conclusions

By its grasp-and-mobilize technique, ESD+ allows potentially faster and safer resections of flat gastric lesions compared to conventional ESD in an ex vivo porcine model. The potential advantages of ESD+ in terms of procedure time may be particularly relevant for difficult lesions in retrograde positions.

Electronic supplementary material

The online version of this article (10.1007/s00464-020-07808-w) contains supplementary material, which is available to authorized users.

Endoscopic mucosal resection with an additional working channel (EMR+) in a porcine ex vivo model: a novel technique to improve en bloc resection rate of snare polypectomy

Background and study aims  Recently, a new external additional working channel (AWC) was introduced by which conventional endoscopic mucosal resection (EMR) can be improved to a technique termed "EMR+". We first evaluated this novel technique in comparison to classical EMR in flat lesions. Methods  The trial was prospectively conducted in an ex vivo animal model with porcine stomachs placed into the EASIE-R simulator. Prior to intervention, standardized lesions were set by coagulation dots, measuring 1, 2, 3 or 4 cm. Results  Overall, 152 procedures were performed. EMR and EMR+ were both very reliable in 1-cm lesions, each showing en bloc resection rates of 100 %. EMR+ en bloc resection rate was significantly higher in 2-cm lesions (95.44 % vs. 54.55 %, P  = 0.02), in 3-cm lesions (86.36 % vs. 18.18 %, P  < 0.01) and also in 4-cm lesions (60.00 % vs. 0 %, P  < 0.01). Perforations occurred only in EMR+ procedures in 4-cm lesions (3 of 20; 15 %). Conclusions  With its grasp-and-snare technique, EMR+ facilitates en bloc resection of larger lesions compared to conventional EMR. In lesions 2 cm and larger, EMR+ has demonstrated advantages, especially concerning en bloc resection rate. At 3 cm, EMR+ reaches its best discriminatory power whereas EMR+ has inherent limits at 4 cm and in lesions of that size, other techniques such as ESD or surgery should be considered.

Novel technique for endoscopic en bloc resection (EMR+) - Evaluation in a porcine model

BACKGROUND

Endoscopic en bloc resection of larger polyps is relevant because risk of advanced neoplasia or malignancy correlates with tumor size. Recurrence rates after piecemeal endoscopic mucosal resection (EMR) are high and endoscopic submucosal dissection (ESD) is associated with higher complication rates in the western world.

AIM

To develop a modified endoscopic en bloc resection technique using an external additional working channel and novel agent for submucosal injection.

METHODS

EMR+ was considered as modified grasp and snare technique. For simultaneous use of a grasping and cutting device a novel additional working channel was used (AWC^®, Ovesco Endoscopy, Tübingen, Germany). AWC^® is installed on the outer surface of the endoscope, covered with a plastic sleeve and designed for single use. For submucosal injection a new agent consisting of poloxamers was used (LiftUp^®, Ovesco Endoscopy, Tübingen, Germany). The agent is liquid at room temperature and forms a stable and permanent gel cushion after injection. Safety of LiftUp^® has been shown in a pre-clinical study in domestic pigs. LiftUp^® is commercially not yet available but approval is expected in early 2019. EMR+ was first developed ex vivo (explanted pig stomach) and subsequently evaluated in vivo (stomach, porcine model, 3 domestic pigs). Main outcome measurements were: Procedure time, macroscopic en bloc resection and adverse events.

RESULTS

Concept of EMR+ was first developed ex vivo (explanted pig stomach). Ex vivo, 22 resections were performed after technique was established. Median procedure time (measured from begin of injection to extraction of resection specimen) was 7 min (range 5-11, SD 1.68) and median size of resection specimens was 30 mm × 26 mm × 11 mm ex vivo. Subsequently 13 resections were performed in vivo (stomach, porcine model, 3 domestic pigs). In vivo, median procedure time (measured from begin of injection to extraction of resection specimen) was 5 min (range 3-12, SD 2.72) and median size of resection specimens was 35 mm × 35 mm × 11 mm. In vivo, resection was macroscopic complete in 92.3%, major adverse events were not observed. In one case (7.7%) minor periprocedural bleeding was observed and managed by coagulation.

CONCLUSION

EMR+ appeared to be effective and safe and was easy and fast to perform in the porcine model. EMR+ needs to be further evaluated clinically in comparative trials.

Improved endoscopic resection of large flat lesions and early cancers using an external additional working channel (AWC): a case series

Background  En-bloc resection of large, flat lesions or early stages of cancer is challenging. No bimanual tasks are possible using standard endoscopes. Dual-channel endoscopes are not available everywhere and have a small distance between the channels. Patients and methods  A new external additional working channel (AWC) (Ovesco, Tuebingen, Germany) was designed and developed potentially enabling bimanual tasks. Fixed to the tip of a standard gastroscope or pediatric colonoscope, a second endoscopic tool can be inserted through the AWC and used for tissue retraction during endoscopic resection. Results  In the upper and lower gastrointestinal tract, endoscopic mucosal resection (EMR) with a modified grasp-and-snare technique and endoscopic submucosal dissection (ESD) were performed successfully using the AWC in eight patients. Complications were acute arterial bleeding post-EMR in two cases treated by endoscopic clipping. Conclusions  We conclude that a newly developed external additional working channel (AWC) enables endoscopic resection of large lesions in the upper and lower gastrointestinal tract. Potential benefits are its suitability for EMR and ESD, no need for a dual-channel endoscope and an adjustable distance of working channels.

Endoscopic submucosal dissection of gastric neoplasms using a snare tip

BACKGROUND

Endoscopic submucosal dissection (ESD) enables the complete removal of gastric lesions regardless of tumor size. ESD is typically performed using one of several available electrocautery knives and endoscopic mucosal resection (EMR) is performed using a diathermic snare. We aimed to investigate the clinical outcomes and complications in patients in whom a snare tip was used for ESD.

MATERIALS AND METHODS

We retrospectively evaluated the medical records of 30 patients who underwent removal of a gastric lesion using a snare tip by ESD or hybrid ESD (ESD with snaring). For hybrid ESD, snaring was performed after an adequate submucosal dissection. The clinical outcomes according to the endoscopic procedure performed were evaluated.

RESULTS

ESD was performed in 12 patients and hybrid ESD was performed in 26 patients. Overall en-bloc and complete resection rates were both 97.4%. There was one case where piece-meal resection was performed in the hybrid ESD group. There were no procedure related complications such as perforation or bleeding. The mean specimen size was 2.8 ± 0.6 cm in the ESD group and 2.3 ± 0.5 cm in the hybrid ESD group (p = .031). The mean procedure time did not differ between the two methods (12.8 min in ESD and 9.7 min in hybrid ESD, p = .060).

CONCLUSIONS

The snare tip can be used as an electrocautery knife to incise the mucosa and dissect the submucosa during removal of a gastric lesion.

[Endoscopic Treatment of Gastric Adenoma]

Gastric adenoma (dysplasia) is a precancerous lesion. Therefore, managements of gastric adenomas are important for preventing the development of gastric cancers and for detecting gastric cancers at earlier stages. The Vienna classification divides gastric adenomas into two categories: high-grade dysplasia and low-grade dysplasia. Generally, endoscopic resection is performed for adenoma with high-grade dysplasia due to the coexistence of carcinoma and the potential of progression to carcinomas. However, the treatments of adenoma with low-grade dysplasia remain controversial. Currently two treatment strategies for the low-grade type have been suggested; First is the 'wait and see' strategy; Second is endoscopic treatment (e.g., endoscopic mucosal resection, endoscopic submucosal dissection, or argon plasma coagulation). In this review, we discuss the current optimal strategies for endoscopic management of gastric adenoma.

Management of hyperplastic gastric polyp following upper gastrointestinal bleeding in infant with Menkes’ disease

We report a case of an infant with Menkes’ disease (MD) presented at the age of five months, with coffee ground vomiting, melaena with a significant drop of haemoglobin. Urgent endoscopic assessment revealed a friable bleeding trans-pyloric multi-lobulated sessile polyp. Due to further significant upper gastrointestinal bleeding, polypectomy occurred. Endoscopic mucosal resection was performed with a grasp-and-snare technique using a dual channel operating gastroscope. Haemostasis was achieved by application of argon plasma coagulation where required. No perforation occurred. Repeated debridement was required 6 wk after which the growth was excised completely with no further blood transfusion required after that procedure. Histological examination confirmed ulcerated and inflamed hyperplastic polyp. We discuss our endoscopic technique and discuss the reported gastrointestinal manifestation of MD in the literature.

Clipping prevents perforation in large, flat polyps

AIM

To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection (EMR) mucosal defects of large, flat, right sided polyps prevents perforations.

METHODS

IRB approved review of all colonoscopies, and prospective data collection of grasp and snare EMR performed by 2 endoscopists between January 1, 2010 and March 31, 2014 in a community ambulatory endoscopy center. The study consisted of two phases. In the first phase, all right-sided, flat polyps greater than or equal to 1.2 cm in size were removed using the grasp and snare technique. Clipping was done at the discretion of the endoscopist. In the second phase, all mucosal defects were closed using resolution clips. Phase 2 of the study was powered to detect a statistically significant difference in perforation rate with 148 EMRs, if less than or equal to 2 perforations occurred.

RESULTS

In phase 1 of the study, 2121 colonoscopies were performed. Seventy-five patients had 95 large polyps removed. There were 4 perforations in 95 polypectomies (4.2%). The perforations occurred in polyps ranging in size from 1.5 cm to 2.5 cm. In phase 2, there were 2464 colonoscopies performed. One hundred and sixteen patients had 151 large polyps removed, and all mucosal defects were clipped. There were no perforations (P = 0.0016). There were no post-polypectomy hemorrhages in either phase. An average of 2.15 clips were required to close the mucosal defects. The median time to perform the polypectomy and clipping was 13 min, and the median procedure duration was 40 min. Five percent of all patients undergoing colonoscopy in our community based, ambulatory endoscopy center had flat, right sided polyps greater than or equal to 1.2 cm in size.

CONCLUSION

Prophylactic clipping of the mucosal resection defect of large, right-sided, flat polyps reduces the incidence of perforation.

Using a double-channel gastroscope reduces procedural time in performing gastric endoscopic submucosal dissection

Objective:

Complications are important determining factors for safety of endoscopic submucosal dissection (ESD). ESD of large lesions is associated with increased procedural time. This study investigated whether double-channel gastroscope could be used to reduce procedural time in gastric antrum ESD.

Methods:

A retrospective cohort study of 46 patients with one gastric antrum lesion resected by ESD was conducted between January 2013 and December 2015. The diameter of a lesion was from 2cm to 4cm in 46 patients. EUS before ESD was used to evaluate the submucosal vascular structure and the location of lesion in gastric wall. Forty six lesions had ESD with either the ordinary gastroscope (OS group) (n=24) or the double-channel gastroscope (DC group) (n=22).

Results:

The mean procedural time was significantly lower in the DC group than in the OS group (49.1 minutes vs. 20.5 minutes, p=0.04). There were no significant differences in submucosal injection frequency, specimen size, en bloc resection rate and perforation rate between the two endoscopic groups. There was no recurrence in any case during the follow-up period.

Conclusions:

Our data suggest that ESD utilizing double-channel gastroscope may provide a better platform for quicker ESD with equal safety.

Efficacy of endoscopic mucosal resections for the management of small gastric adenomas with low-grade dysplasia

OBJECTIVE

Gastric adenoma with low-grade dysplasia (LGD) can progress to gastric cancer; however, the optimal therapeutic modality for LGD has not been established. The aim of this study was to assess the efficacy, safety of and local recurrence following endoscopic mucosal resection (EMR) for LGD. Specifically, we compared EMR with circumferential precutting (EMR-P) and EMR using a dual-channel endoscope (EMR-D) for the treatment of LGD ≤2 cm.

MATERIALS AND METHODS

A total of 158 lesions from 147 patients with LGD treated by EMR were retrospectively analyzed. The en bloc resection rate, complete resection rate, procedure time, complication rate and local recurrence rate were compared between EMR-P and EMR-D.

RESULTS

The en bloc resection and complete resection rates of EMR were 91.1% and 90.5%, respectively. The bleeding and perforation rates were 1.3% and 1.3%, respectively. The local recurrence rate following EMR was 2.2%. The en bloc resection and complete resection rates did not differ between EMR-P and EMR-D (88.2% vs. 92.5%, p = not significant (NS); and 90.2% vs. 90.7%, p = NS, respectively). The procedure time was significantly longer for EMR-P compared with EMR-D (16 (5-141) vs. 7 (2-48) min, p < 0.001), and the complication rate was significantly higher for EMR-P (7.8% vs. 0.0%, p = 0.010). Local recurrence was not found in EMR-P, whereas the recurrence rate was 3.2% in EMR-D.

CONCLUSION

EMR is an effective method for the treatment of LGD ≤2 cm. Compared with EMR-P, EMR-D appears to be the more effective, technically simple and safer method.

New endoscopic platform for endoluminal en bloc tissue resection in the gastrointestinal tract (with videos)

BACKGROUND

Endoscopic removal of gastrointestinal tract lesions is increasingly popular around the world. We evaluated feasibility, safety, effectiveness, and user learning curve of new endoscopic platform for complex intraluminal interventions.

METHODS

A novel system, consisting of expandable working chamber with two independent instrument guides (LIG), was inserted into colon. Simulated colonic lesions were removed with endoscopic submucosal (ESD) and submuscular (ESmD) dissection.

RESULTS

In all nine in vivo models, an intraluminal chamber and its dynamic tissue retractors (via LIG) provided a stable working space with excellent visualization and adequate access to target tissue. Endoscopic platform facilitated successful completion of 11 en bloc ESDs (mean size 43.0 ± 11.3 mm, mean time 46.3 ± 41.2 min) and eight ESmD (mean size 50.0 ± 14.1 mm, mean time 48.0 ± 21.2 min). The learning curve for ESD using this platform demonstrated three phases: rapid improvement in procedural skills took place during the first three procedures (mean ESD time 98.7 ± 40.0 min). A plateau phase then occurred (procedures 4-7) with mean procedure time 42.0 ± 13.4 min (p = 0.04), followed by another sharp improvement in procedural skills (procedures 8-11) requiring only 16.3 ± 11.4 min (p = 0.03) to complete ESD. Especially dramatic (p = 0.002) was the time difference between the first three procedures (mean time 98.7 ± 40.0 min) and subsequent eight procedures (mean time 29.1 ± 17.9 min).

CONCLUSIONS

A newly developed endoscopic platform provides stable intraluminal working space, dynamic tissue retraction, and instrument triangulation, improving visualization and access to the target tissue for safer and more effective en bloc endoscopic submucosal and submuscular dissection. The learning curve for ESD was markedly facilitated by this new endoscopic platform.

Use of prototype two-channel endoscope with elevator enables larger lift-and-snare endoscopic mucosal resection in a porcine model

Background: Flat and depressed lesions are becoming increasingly recognized in the esophagus, stomach, and colon. Various techniques have been described for endoscopic mucosal resection (EMR) of these lesions.

Aims: To evaluate the efficacy of lift-grasp-cut EMR using a prototype dual-channel forward-viewing endoscope with an instrument elevator in one accessory channel (dual-channel elevator scope) as compared to standard dual-channel endoscopes.

Methods: EMR was performed using a lift-grasp-cut technique on normal flat rectosigmoid or gastric mucosa in live porcine models after submucosal injection of 4 mL of saline using a dual-channel elevator scope or a standard dual-channel endoscope. With the dual-channel elevator scope, the elevator was used to attain further lifting of the mucosa. The primary endpoint was size of the EMR specimen and the secondary endpoint was number of complications.

Results: Twelve experiments were performed (six gastric and six colonic). Mean specimen diameter was 2.27 cm with the dual-channel elevator scope and 1.34 cm with the dual-channel endoscope (P = 0.018). Two colonic perforations occurred with the dual-channel endoscope, vs no complications with the dual-channel elevator scope.

Conclusions: The increased lift of the mucosal epithelium, through use of the dual-channel elevator scope, allows for larger EMR when using a lift-grasp-cut technique. Noting the thin nature of the porcine colonic wall, use of the elevator may also make this technique safer.

Reducing complications in upper gastrointestinal endoscopy

This article reviews the principal aspects related to sedation in endoscopy and to the prevention of adverse events in some of the most frequently performed therapeutic upper gastrointestinal (GI) endoscopic procedures (esophageal dilation and stenting, endoscopic resection of upper GI early neoplasia, hemostasis of upper GI bleeding and percutaneous endoscopic gastrostomy insertion). These procedures have an inherent risk of negative outcomes that cannot be entirely avoided. Endoscopic procedures are best performed by well-trained, competent and thoughtful endoscopists in facilities suited to provide for patient safety. Attention to clinical risk management may effectively reduce the frequency and intensity of adverse events, enhance recognition and early detection, and improve responsiveness.

A technical review of flexible endoscopic multitasking platforms

BACKGROUND

Further development of advanced therapeutic endoscopic techniques and natural orifice translumenal endoscopic surgery (NOTES) requires a powerful flexible endoscopic multitasking platform.

METHODS

Medline search was performed to identify literature relating to flexible endoscopic multitasking platform from year 2004-2011 using keywords: Flexible endoscopic multitasking platform, NOTES, Instrumentation, Endoscopic robotic surgery, and specific names of various endoscopic multitasking platforms. Key articles from articles references were reviewed.

RESULTS

Flexible multitasking platforms can be classified as either mechanical or robotic. Purely mechanical systems include the dual channel endoscope (DCE) (Olympus), R-Scope (Olympus), the EndoSamurai (Olympus), the ANUBIScope (Karl-Storz), Incisionless Operating Platform (IOP) (USGI), and DDES system (Boston Scientific). Robotic systems include the MASTER system (Nanyang University, Singapore) and the Viacath (Hansen Medical). The DCE, the R-Scope, the EndoSamurai and the ANUBIScope have integrated visual function and instrument manipulation function. The IOP and DDES systems rely on the conventional flexible endoscope for visualization, and instrument manipulation is integrated through the use of a flexible, often lockable, multichannel access device. The advantage of the access device concept is that it allows optics and instrument dissociation. Due to the anatomical constrains of the pharynx, systems are designed to have a diameter of less than 20 mm. All systems are controlled by traction cable system actuated either by hand or by robotic machinery. In a flexible system, this method of actuation inevitably leads to significant hysteresis. This problem will be accentuated with a long endoscope such as that required in performing colonic procedures. Systems often require multiple operators. To date, the DCE, the R-Scope, the IOP, and the Viacath system have data published relating to their application in human.

CONCLUSION

Alternative forms of instrument actuation, camera control and master console ergonomics should be explored to improve instrument precision, sphere of action, size and minimize assistance required.