Comparison of standard endoscopic submucosal dissection (ESD) versus an optimized ESD technique for the colon: an animal study

Is there a best choice of equipment for colorectal endoscopic submucosal dissection?

INTRODUCTION

Endoscopic submucosal dissection (ESD) is a widely used technique to remove early neoplastic lesions. It was primarily used in the initial days to treat gastric lesions, but recently, the horizon of this endoscopic procedure has expanded, which has allowed us to manage other technically more complex locations, such as the colorectum.

AREAS COVERED

There has been an exponential growth regarding the wide range of devices available in the market for performing colorectal ESD. As a result, the aim of this review is to highlight the indication of this endoscopic technique, which device is best suited for which indication, as well as future trajectories in this field.

EXPERT OPINION

Although some devices have proven to be more advantageous than others in this area, very often the choice is still subjective, which is commonly attributed to individual preferences and experience. However, an accurate knowledge of the available tools and their functioning, with their pros and cons, is fundamental for any endoscopist venturing into the field of third space endoscopy. In this way, one can choose which device best suits a particular situation, along with simultaneously having the wealth of knowledge related to therapeutic armamentarium at our disposal in the endoscopy suite.

Colorectal Endoscopic Submucosal Dissection: Performance of a Novel Hybrid-Technology Knife in an Animal Trial

Endoscopic submucosal dissection (ESD) was developed for the removal of benign and early malignant lesions in the gastrointestinal tract. We aimed to evaluate the performance and safety of a novel high-pressure waterjet-assisted ESD knife in colorectal applications. Six female German Landrace pigs with an average weight of 62 kg (range 60-65 kg) were used in this prospective, randomized, and controlled study. Twenty-four ESDs were performed by three endoscopists: Twelve each with the new Erbe HYBRIDknife® flex T-Type (HK-T) and the Olympus DualKnife® J (DK-J), including six rectal and six colonic ESDs per instrument. The order of performance was randomized regarding anatomic position and instrument. As the primary endpoint, ESD knife performance characteristics were combined and rated on a 5-point Likert scale, with 5 Likert points (LP) representing the best response (5 = very good). The HK-T was rated significantly better than the DK-J (4.7 LP versus 4.4 LP, p = 0.0295), mainly because of HK-T injection ability (5 LP versus 3 LP, p < 0.0001) and hemostasis (5 LP versus 4 LP, p = 0.0452). There was no difference in procedure time (HK-T: 35 min versus DK-J: 34 min, p = 0.8005), resection diameter (3.1 cm versus 2.8 cm, p = 0.3492), injection volume (41 mL versus 46 mL, p = 0.5633), and complication rates. HK-T is as effective as DK-J in colorectal ESD in terms of dissection quality but has better injection and hemostatic properties. The impact of these technical advantages on the ESD treatment of patients with large superficial colorectal lesions remains to be clinically verified.

The efficient of application of a fine magnetic traction system simplifies colorectal endoscopic submucosal dissection: A porcine study

BACKGROUND

Sometimes it is difficult to maintain good visualization of the submucosal layer during colorectal endoscopic submucosal dissection (ESD). This study aimed to evaluate the feasibility and efficacy of a novel traction method, the fine magnetic traction system (FMTS), in colorectal ESD.

METHODS

ESD was performed 10, 15, or 30 cm from the anus in the colorectums of 10 Bama miniature pigs with or without FMTS. The circumcision and dissection per unit time (cm²/min), en bloc resection, perforation and bleeding rates, size and integrity of the specimen and submucosal injection times were analysed.

RESULTS

A total of 60 ESD procedures were performed with or without FMTS assistance. The en bloc resection rates were 100% at 10 and 15 cm from the anus in both the control group (conventional ESD) and the FMTS group. However, at 30 cm from the anus, these rates were only 10% and 70% (p = 0.006). The resection speeds (control vs. FMTS) at the 10, 15, and 30 cm points were 0.35 ± 0.07 cm²/min vs. 0.39 ± 0.19 cm²/min (p = 0.56), 0.30 ± 0.09 cm²/min vs. 0.38 ± 0.02 cm²/min (p = 0.04), and 0.11 cm²/min vs. 0.26 ± 0.10 cm²/min, respectively.

CONCLUSIONS

The FMTS provides effective counter-traction and efficiently reduces the risks and difficulties of difficult colonic ESD in the porcine model.

Endoscopic submucosal dissection in colorectal neoplasia performed with a waterjet system-assisted knife: higher en-bloc resection rate than conventional technique

BACKGROUND/AIMS

Colorectal endoscopic submucosal dissection (ESD) is burdened by its associated high risk of adverse events and long procedure time. Recently, a waterjet-assisted knife was introduced to simplify and speed up the procedure. The aim of this study was to evaluate the efficacy and safety of waterjet-assisted ESD (WESD) compared to that of the conventional ESD (CESD) technique.

METHODS

The charts of 254 consecutive patients who underwent colorectal ESD between January 2014 and February 2021 for colorectal neoplasms were analyzed. The primary outcome was the en-bloc resection rate. Secondary outcomes were complete and curative resection rates, the need to switch to a hybrid ESD, procedure speed, the adverse event rates, and the recurrence rates.

RESULTS

Approximately 174 neoplasias were considered, of which, 123 were removed by WESD and 51 by CESD. The en-bloc resection rate was higher in the WESD group (94.3% vs. 84.3%). Complete resection rates and curative resection rates were similar. The need to switch to a hybrid ESD was greater during CESD (39.2% vs. 13.8%). Procedure speed and adverse event rates were similar. During follow-up, one recurrence occurred after a WESD.

CONCLUSION

WESD allows a high rate of en-bloc resections and less frequently requires a rescue switch to the hybrid ESD compared to CESD.

Is it time for Cold-Endoscopic Submucosal Dissection? A feasibility study in an esophageal and colorectal live porcine model

Background and study aims  Use of cold endoscopic resection has increased due to excellent results with it and the ability to avoid electrosurgery related complications. The aim of this study was to evaluate the feasibility and safety of cold-endoscopic submucosal dissection (C-ESD) in an in vivo porcine model. Patients and methods  C-ESD with circumferential incision and submucosal dissection with a predominantly cold technique was tested in the esophagus and colorectum. Incision and dissection were attempted with a cold technique with a biopsy forceps and an endoscopic Maryland dissector. Large vessels were pre-coagulated with the latter device. Different traction methods were applied. Results  Twelve dissections were performed: four esophageal, four colonic, and four rectal. Tunnel and pocket methods were applied successfully. Full C-ESD was possible in the colorectum. In the esophagus, an initial incision had to be done with electrocautery. No major bleeding occurred. Two perforations occurred in the colon, one was endoscopically treated. Conclusions  Full C-ESD is feasible in the colorectum, whereas a small hot incision is needed in the esophagus. However, in 50 % of the colonic cases, there were perforations caused by the biopsy forceps making the circumferential incision. Therefore, potential benefits of endoscopic resection without cautery would warrant futures studies in humans initially in esophagus and rectal locations.

Feasibility and learning curve of unsupervised colorectal endoscopic submucosal hydrodissection at a Western Center

OBJECTIVES

Colorectal endoscopic submucosal dissection (CR-ESD) is an evolving technique in Western countries. We aimed to determine the results of the untutored implementation of endoscopic submucosal hydrodissection for the treatment of complex colorectal polyps and establish the learning curve for this technique.

METHODS

This study included data from 80 consecutive CR-ESDs performed by a single unsupervised western therapeutic endoscopist. To assess the learning curve, procedures were divided into four groups of 20 each.

RESULTS

En bloc resection was achieved in 55, 75, 75 and 95% cases in the consecutive time periods (period 1 vs. 4, P = 0.003). Curative resection was achieved in 55, 75, 70 and 95%, respectively (P = 0.037). Overall, series results demonstrated R0 resection in 75% of cases, with 23.7% requiring conversion to endoscopic piecemeal mucosal resection, and 1.25% incomplete resections. Complications included perforations (7.5%) and bleeding (3.7%). Multivariate analysis revealed factors more likely to result in association with non en bloc vs. En bloc resection, where polyp size ≥35 mm [70 vs. 23.4%; odds ratio (OR) 13.2 (1.7-100.9); P = 0. 013], severe fibrosis [40 vs. 11.7%; OR 10.2 (1.2-86.3); P = 0.033] and where carbon dioxide for insufflation was not used [65 vs. 30%; OR 0.09 (0.01-0.53); P = 0.008].

CONCLUSION

CR-ESD by hydrodissection has good safety and efficacy profile and offers well tolerated and effective treatment for complex polyps. As such, this technique may be useful in the West, in centers, where previous gastric ESD is not frequent or Japanese mentoring is not possible.

Predictive mechanics-based model for depth of cut (DOC) of waterjet in soft tissue for waterjet-assisted medical applications

The use of waterjet technology is now prevalent in medical applications including surgery, soft tissue resection, bone cutting, waterjet steerable needles, and wound debridement. The depth of the cut (DOC) of a waterjet in soft tissue is an important parameter that should be predicted in these applications. For instance, for waterjet-assisted surgery, selective cutting of tissue layers is a must to avoid damage to deeper tissue layers. For our proposed fracture-directed waterjet steerable needles, predicting the cut depth of the waterjet in soft tissue is important to develop an accurate motion model, as well as control algorithms for this class of steerable needles. To date, most of the proposed models are only valid in the conditions of the experiments and if the soft tissue or the system properties change, the models will become invalid. The model proposed in this paper is formulated to allow for variation in parameters related to both the waterjet geometry and the tissue. In this paper, first the cut depths of waterjet in soft tissue simulants are measured experimentally, and the effect of tissue stiffness, waterjet velocity, and nozzle diameter are studied on DOC. Then, a model based on the properties of the tissue and the waterjet is proposed to predict the DOC of waterjet in soft tissue. In order to verify the model, soft tissue properties (constitutive response and fracture toughness) are measured using low strain rate compression tests, Split-Hopkinson-Pressure-Bar (SHPB) tests, and fracture toughness tests. The results show that the proposed model can predict the DOC of waterjet in soft tissue with acceptable accuracy if the tissue and waterjet properties are known. Graphical Abstract (Left) An overview of the problems of traditional steerable needles and the solutions provided by waterjet steerable needles. (A) Traditional tip-steerable needles and tip-bent needles suffer from poor curvature, especially in soft tissues. (B) Traditional steerable needles are unable to accomplish many bends because the cutting force only results from drastic tissue deformation. (C) The first step for realization of waterjet steerable needles is to understand and model the interaction between waterjet and soft tissues at the tip (predictive model for depth of cut). (D) Then, the equilibrium between shapes cut in the tissue and the straight elastic needle should be understood. (Right) Waterjet steerable needles in which the direction of the tissue fracture is contr olled by waterjet and then the flexible needle follows. The first step for waterjet steerable needle realization is to predict the depth of waterjet cut.

Primary Tracheal Mucosa-Associated Lymphoid Tissue Lymphoma Treated with a Water-Jet Hybrid Knife: A Case Report

Primary mucosa-associated lymphoid tissue (MALT) lymphoma of the trachea is very rare and is easily misdiagnosed as a bronchogenic carcinoma or benign tracheal tumor. Here, we report a clinical case where a new clinical approach involving a water-jet hybrid knife was employed in the diagnosis and treatment of primary tracheal MALT lymphoma.

Electromagnetic assisted endoscopic submucosal dissection is more efficient than water-jet assisted and conventional ESD in experimental model

BACKGROUND AND STUDY AIMS

The adequate visualization of the dissection line, inside the submucosal layer, supposes the main challenging issue in ESD. For this reason, several counter traction methods have been developed focused on overcoming this handicap. One of which, Magnetic anchor guided - ESD (MG-ESD) is an attractive alternative. However, the usefulness of this approach has been scarcely assessed and compared with other ESD strategies. Therefore, the aim of this study is to compare three different ESD alternatives in experimental faction.

METHODS

This was a prospective non-randomized study, in which three different ESD techniques were performed in an ex-vivo gastric porcine model by an endoscopist slight expertise in ESD: conventional ESD, waterjet assisted ESD and MG-ESD. MG-ESD was performed using two different magnets: inner Neodymiun ringed shape magnet attached to the simulated lesions by an endoclip and external electromagnet connected to a Single Output Adjustable 24V/0.3A Power Supply Unit.

RESULTS

Forty-six ESD procedures were performed: 24 conventional ESD, 12 waterjet-assisted ESD and 10 MG-ESD. Average size of the simulated lesions was 33.86 mm. No differences in terms of safety and efficacy were registered between the three approaches. Nevertheless, MG-ESD proved to be faster and more efficient than conventional ESD and water-jet assisted ESD (min per cm ² 10.85 vs. 7.43 vs. 3,41; P  = 0.001).

CONCLUSIONS

MG-ESD could be a feasible alternative to conventional ESD even at the beginning of the learning curve. Therefore, researches focused on developing appropriate ESD magnetic devices and further comparative studies must be promoted, in order to assess the reliable usefulness of the magnet-assistance in ESD.

Endoscopic submucosal tunnel dissection of upper gastrointestinal submucosal tumors: A comparative study of hook knife vs hybrid knife

AIM

To compare the efficacy and safety of a hook knife (HO) with a hybrid knife (HK) during endoscopic submucosal tunnel dissection (ESTD) procedure.

METHODS

Between August 2012 and December 2015, the ESTD procedure was performed for 83 upper GI submucosal lesions, which originated from the muscularis propria layer identified by upper endoscopy and endoscopic ultrasonography. Of these, 34 lesions were treated by a HO, whereas 49 lesions were treated by a HK. Data regarding age, gender, presenting symptoms, tumor location and size, procedure time, complications, en bloc resection rate and others were analyzed and compared between the two groups.

RESULTS

There were no significant differences in the age, gender, presenting symptoms and tumor location between the two groups. ESTD was successfully completed in all the patients, and no case was converted to laparoscopy. The mean procedure time was significantly shorter in the HK group than in the HO group (41.3 ± 20.3 min vs 57.2 ± 28.0 min, P = 0.004). The mean frequency of device exchange was 1.4 ± 0.6 in the HK group and significantly less than 3.3 ± 0.6 in the HO group (P < 0.001). The differences in tumor size and histopathological diagnoses were not significant between the two groups (P = 0.813, P = 0.363, respectively). Both groups had an equal en bloc resection rate and complete resection rate. Additionally, the complication rate was similar between the two groups (P = 0.901). During the follow-up, no recurrence occurred in either group.

CONCLUSION

We demonstrate for the first time that HO and HK do not differ in efficacy or safety, but HK reduces the frequency of device exchange and procedure time.

Waterjet submucosal dissection of porcine esophagus with the HybridKnife and ERBEJET 2 system: a pilot study

Background and study aims Esophageal endoscopic submucosal dissection (ESD) is technically difficult because of narrow working spaces and ease of perforation due to the lack of serosa. HybridKnife is a recently developed ESD device that is combined with the high pressure waterjet ERBEJET 2 system to lift mucosa. We hypothesized that this waterjet could make submucosal dissection safer and studied this in porcine esophagus. Materials and methods Water pressures of 30 - 70 bar were tested to determine the appropriate pressure for waterjet ESD with HybridKnife (WJ-ESD) in one pig. WJ-ESD safety and completion were compared with those of conventional ESD using DualKnife (C-ESD) as a reference. Each of three virtual esophageal lesions in two pigs were resected alternatively using both methods from the lower to upper esophagus. For WJ-ESD, the submucosa, apart from hard fibrous tissues, was dissected using water pressure alone. Results Using 50 bar of water pressure resulted in the best balance between proper dissection and view-disturbing water backflow. The dissection speeds for the lower, middle, and upper esophagus were 0.2, 0.9, and 0.2 cm²/min in 50 bar WJ-ESD and 1.1, 0.5, and 1.0 cm²/min in C-ESD, respectively. Minor bleeding was frequent in WJ-ESD, but was easily stopped by electrocoagulation with the same needle. No perforation was observed in either procedure. Thermal damage to dissected tissues appeared mild, and the extent of muscle injury was lower for WJ-ESD (4, 6, and 8 %) compared with C-ESD (14, 16, and 7 %). Conclusions WJ-ESD could be completed safely for porcine esophagus with less damage to the muscle layer compared with C-ESD.

A local structured training program with live pigs allows performing ESD along the gastrointestinal tract with results close to those of Japanese experts

BACKGROUND AND AIMS

The high specific skill needed by ESD limit its widespread use in Europe and animal training is recommended in Europe to improve the results of ESD that are far from Japanese at present. We create a local training program using live pigs as models, along with our human cases, to provide continuous exposure to the technique.

METHODS

Between February 2013 and December 2015, two young operators performed 55 pig gastric ESDs in parallel with 62 human cases for large superficial cancerous lesions. The number and training dates of pig cases were adapted to those of the human cases to achieve continuous exposure to ESD cases.

RESULTS

The en bloc, R0, and curative resection rates were 100%, 85.5% (53/62), and 77.5% (48/62), respectively with no recurrence observed during the one year follow up. There was no statistically significant difference in terms of the R0 or curative resection rates among ESDs performed during 2013-2015 (R0: 80% vs. 86.6% vs. 86.4%; Curative: 80% vs. 86.6% vs. 73%).

CONCLUSION

A local structured training program using live pig models was used to train endoscopists for ESD in humans with high safety and efficiency, similar to results published by Japanese experts.

Endoscopic submucosal dissection with the Nestis® jet injector system with a bifunctional catheter: first prospective clinical trial (NCT: 2012-A00272-41)

BACKGROUND

The Enki-2 water jet system (Nestis SAS^®, Lyon, France) with dual injection and dissection capability significantly reduced ESD procedure time and perforation rates in animal studies. The study aim was to evaluate its efficacy and safety in patients with superficial neoplastic lesions.

METHODS

A prospective study including 18 patients with esophageal, gastric and rectal superficial neoplasms treated by ESD using Enki-2 was designed.

RESULTS

Eighteen lesions (6 esophageal, 3 gastric, 9 rectal, mean diameter 43.5 mm) in 17 patients (10 men, mean age 65.9) were included. The mean procedure time was 65.6 min. One patient needed clipping for an incomplete muscle tear during procedure; there were neither delayed bleedings nor perforation. The "en bloc" resection rate was 100 %, the R0 resection rate was 88.9 % (16/18 lesions), and the curative resection rate was 77.8 %. The 3-month disease-free rate was 92.3 % (12/13 patients, 13/14 lesions, 1 patient lost to follow-up). The 12-month disease-free rate was 69.2 % (9/13 patients, 10/14 lesions, 4 patients lost to follow-up).

CONCLUSIONS

ESD with Enki-2 water jet system is effective and safe for superficial neoplastic digestive lesions.

A laser-induced pulsed water jet for layer-selective submucosal dissection of the esophagus

Background and aims: Conventional water jet devices have been used for injecting fluid to lift up lesions during endoscopic submucosal dissection or endoscopic mucosal resection procedures. However, these devices cannot dissect the submucosal layer effectively. Here we aim to elucidate the dissection capability of a laser-induced pulsed water jet and to clarify the mechanism of dissection with layer selectivity. Materials (Subjects) and methods: Pulsed water jets were ejected from a stainless nozzle by accelerating saline using the energy of a pulsed holmium: yttrium-aluminum-garnet laser. The impact force (strength) of the jet was evaluated using a force meter. Injection of the pulsed jet into the submucosal layer was documented by high-speed imaging. The physical properties of the swine esophagus were evaluated by measuring the breaking strength. Submucosal dissection of the swine esophagus was performed and the resection bed was evaluated histologically. Results: Submucosal dissection of the esophagus was accomplished at an impact force of 1.11-1.47 N/pulse (laser energy: 1.1-1.5 J/pulse; standoff distance: 60 mm). Histological specimens showed clear dissection at the submucosal layer without thermal injury. The mean static breaking strength of the submucosa (0.11 ± 0.04 MPa) was significantly lower than that of the mucosa (1.32 ± 0.18 MPa), and propria muscle (1.45 ± 0.16 MPa). Conclusions: The pulsed water jet device showed potential for achieving selective submucosal dissection. It could achieve mucosal, submucosal, and muscle layer selectivity owing to the varied breaking strengths.

Endoscopic mucosal resection and endoscopic submucosal dissection of large colonic polyps

Almost all large and complex colorectal polyps can now be resected endoscopically. Piecemeal endoscopic mucosal resection (PEMR) is an established technique with fairly low complication risk and good short-term and medium-term outcomes. Several modifications to the basic injection and snare technique have been developed contributing to safer and more complete resections. Delayed bleeding requiring reintervention is the most troublesome complication in 2-7% of patients, particularly in those with comorbidities and large, right-sided polyps. Endoscopic submucosal dissection (ESD) has become popular in Japan and has theoretical advantages over PEMR in providing a complete, en bloc excision for accurate histological staging and reduced local recurrence. These advantages come at the cost of a more complex, expensive and time-consuming procedure with a higher risk of perforation, particularly early in the procedure learning curve. These factors have contributed to the slow adoption of ESD in the West and the challenge to develop new devices and endoscopic platforms that will make ESD easier and safer. Currently, ESD indications are limited to large rectal lesions, in which procedural complications are easily managed, and for colorectal polyps with a high risk of containing tiny foci of early submucosally invasive cancer, whereby ESD may be curative compared with PEMR.

ENDOSCOPIC GASTRIC SUBMUCOSAL DISSECTION: experimental comparative protocol between standard technique and Hybrid-Knife(r)

BACKGROUND

Endoscopic treatment of superficial gastrointestinal tumors is routinely performed, however the advantages and shortcomings of submucosal pressure-jet dissection is still debated.

OBJECTIVE

- Aiming to compare this technique with conventional submucosal dissection, a study was designed in pigs.

METHODS

- Areas of the antral mucosa of the stomach with a diameter of 2 cm2 (6 per animal) were marked, and resected by means of the hybrid-knife (experimental technique), and Flush-knife or IT-knife (controls). An ERBE ICC 300 electrosurgical unit was adopted. End-points were procedural time, complications, and quality of the resected specimen.

RESULTS

- A total of 27 interventions were conducted in five animals. Time spent with the two options was quite short, and similar: 9.5±3.1 vs 8.0±3.0 minutes (P=0.21). Complications didn't differ (three per group, not significant), and removed specimen looked adequate in both circumstances.

CONCLUSION

- The hybrid-knife technique is an acceptable alternative to submucosal dissection, showing no difference compared to the standard technique taking into consideration the procedure, the presence of complications and the quality of the resected specimen.

Comparison of O-Type HybridKnife to Conventional Knife in Endoscopic Submucosal Dissection for Gastric Mucosal Lesions

Endoscopic submucosal dissection (ESD) has been accepted as a minimal invasive alternative to surgery for localized superficial gastrointestinal neoplasms recently. However, the procedure remains to be technically challenging and time consuming. A new dissecting knife with partially insulated tip has been recently developed with built-in injection capability. The purpose of this study was to investigate whether the efficiency of ESD procedure could be improved with this new device. A total of 78 patients, who underwent ESD with gastric mucosal lesions including flat type polyps, adenoma or early gastric cancer, were randomly assigned to either ESD with O-type HybridKnife or conventional ESD knives without waterjet. Procedure time and related factors of ESD were analyzed. ESD procedure time was 43.0 (interquartile range, IQR 27.0-60.0) minutes in HybridKnife group compared to 60.5 (IQR 44.0-86.3) minutes in the control group (P = 0.001). There was no difference in the clinical outcome and the adverse event rate. The former demonstrated more favorable results in lesions ≤4 cm of specimen size (P ≤ 0.0001) and when located in the distal stomach (P = 0.001), also in lesions with fibrosis (P = 0.008). Multivariate regression analysis showed that O-type Knife (P ≤ 0.0001), specimen size (P ≤ 0.0001), and fibrosis (P ≤ 0.0001) were independent predictors of procedure time. The O-type HybridKnife yielded faster procedure time compared to the conventional knives in gastric ESD with a similar safety profile.

Use of water jet instruments in gastrointestinal endoscopy

In recent years, water jet instruments have been used in the field of gastrointestinal endoscopy, mainly in two clinical situations: Investigation and treatment under endoscopic view. Injecting water jet into the gastrointestinal lumen is helpful for maintaining a clear endoscopic view, washing away blood or mucous in the lumen or on the surface of the tip of the endoscope. This contributes to reducing time and discomfort of examination. Water jet technology is an alternative method for dissecting soft tissue; this method does not harm the small vessels or cause mechanical or thermal damage. However, its use in clinical settings has been limited to the transmucosal injection of water into the submucosal layer that elevates the mucosa to prepare for endoscopic mucosal resection or endoscopic submucosal dissection, instead of tissue dissection, which may occur because of the continuous water jet. A preclinical study has been conducted using a pulsed water jet system as an alternative method for submucosal dissection by reducing intraoperative water consumption and maintenance of dissection capability. This review introduces recent studies pertaining to using a water jet in gastrointestinal endoscopy and discusses future prospects.

Colorectal endoscopic submucosal dissection: Recent technical advances for safe and successful procedures

Endoscopic submucosal dissection (ESD) is very useful in en bloc resection of large superficial colorectal tumors but is a technically difficult procedure because the colonic wall is thin and endoscopic maneuverability is poor because of colonic flexure and extensibility. A high risk of perforation has been reported in colorectal ESD. To prevent complications such as perforation and unexpected bleeding, it is crucial to ensure good visualization of the submucosal layer by creating a mucosal flap, which is an exfoliated mucosa for inserting the tip of the endoscope under it. The creation of a mucosal flap is often technically difficult; however, various types of equipment, appropriate strategy, and novel procedures including our clip-flap method, appear to facilitate mucosal flap creation, improving the safety and success rate of ESD. Favorable treatment outcomes with colorectal ESD have already been reported in many advanced institutions, and appropriate understanding of techniques and development of training systems are required for world-wide standardization of colorectal ESD. Here, we describe recent technical advances for safe and successful colorectal ESD.

High pressure jet injection of viscous solutions for endoscopic submucosal dissection (ESD): first clinical experience

BACKGROUND

Long lasting elevation is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water jet injection of saline solution or by viscous macromolecular solutions. In a previous animal study, we assessed the Nestis Enki II system to combine jet injection and viscous solutions. In the present work, we used this combination in humans in different sites of the digestive tract.

METHODS

We retrospectively report all of the consecutive ESD procedures performed with jet injection of viscous solutions in four centers. Information was collected about the lesion, the procedure, the histological result, and the outcomes for the patient.

RESULTS

In total, 45 resections were completed by six operators: five experts and one beginner with only one previous experience in human ESD. Lesions were located in the esophagus (10), the stomach (11), the duodenum (1), the colon (1) and the rectum (22). Average maximal lesion diameter was 4.8 cm (SD 2.4, range 2 - 11 cm), average lesion surface area was 19.8 cm(2) (SD 17.7, range 2.2 - 72 cm(2)), and average duration of procedure was 79.9 min (SD 50.3 min, range 19 - 225 min). ESD could be conducted while the endoscope was retroflexed at its maximum in 26 cases. Four adverse events were observed: two diminutive perforations and two delayed bleeding occurrences treated conservatively. The R0 resection rate was 91.1 %. The catheter was obstructed in six occurrences of bleeding.

CONCLUSION

Endoscopic submucosal dissection using high pressure injection of viscous macromolecular solutions is safe and effective in different parts of the digestive tract. It does not impede working with the endoscope in the maximal retroflexed position.

New isolated bovine colon model dedicated to colonic ESD hands-on training: development and first evaluation

INTRODUCTION

ESD is the reference method to achieve en bloc resections for large digestive lesions. Nevertheless, it is a difficult and risky technique. Animal models exist to teach the initial skills, particularly in Japan, where pigs' stomachs are dedicated models to gastric ESD. In Europe, we have to develop different strategies of teaching with dedicated colon models. A pig colon is a good model but thinner and narrower than a human's. In this present work, we evaluated a bovine colon model to perform rectal ESD in retroflexion.

METHODS

First, we prepared six bowels to precise the preparation protocol. Then, two endoscopists unexperienced in ESD performed 64 procedures on eight models. Learning curves and factors of variation were studied.

RESULTS

A precise protocol to prepare the colon was defined. The two students achieved en bloc resection in 89.1 % of cases with a rate of 6.2 % of perforations. A large heterogeneity appeared between the speed and the success rate depending mainly on the age of the animal bowel. Using calf colons, the failure rates were higher (p = 0.002) and the speed was lower (p < 0.001) than for adult bovine ones. A learning curve appeared with, respectively, 0.49 and 0.59 cm(2)/min throughout the study. No significant difference appeared between measured and calculated specimen areas.

DISCUSSION

Bovine colon is a new model to teach ESD in colorectal conditions. The bovine age is important to homogenize the model. A learning curve existed with a time procedure decreasing throughout the study. Further studies are needed to evaluate the precise learning curve with more students.

CONCLUSION

A bovine colon model is a suitable model to teach colorectal ESD. Nevertheless, an adult bovine colon model is more homogeneous than a calf one.

The dissection profile and mechanism of tissue-selective dissection of the piezo actuator-driven pulsed water jet as a surgical instrument: laboratory investigation using Swine liver

BACKGROUND/PURPOSE

The water jet technique dissects tissue while sparing cord-like structures such as blood vessels. The mechanism of such tissue-selective dissection has been unknown. The novel piezo actuator-driven pulsed water jet (ADPJ) system can achieve dissection with remarkably reduced water consumption compared to the conventional water jet; however, the system's characteristics and dissection capabilities on any organ have not been clarified. The purposes of this study were to characterize the physical properties of the novel ADPJ system, evaluate the dissection ability in swine organs, and reveal the mechanism of tissue-selective dissection.

METHODS

The pulsed water jet system comprised a pump chamber driven by a piezo actuator, a stainless steel tube, and a nozzle. The peak pressure of the pulsed water jet was measured through a sensing hole using a pressure sensor. The pulsed water jet technique was applied on swine liver in order to dissect tissue on a moving table using one-way linear ejection at a constant speed. The dissection depth was measured with light microscopy and evaluated histologically. The physical properties of swine liver were evaluated by breaking strength tests using tabletop universal testing instruments. The liver parenchyma was also cut with three currently available surgical devices to compare the histological findings.

RESULTS

The peak pressure of the pulsed water jet positively correlated with the input voltage (R(2) = 0.9982, p < 0.0001), and this was reflected in the dissection depth. The dissection depth negatively correlated with the breaking strength of the liver parenchyma (R(2) = 0.6694, p < 0.0001). The average breaking strengths of the liver parenchyma, hepatic veins, and Glisson's sheaths were 1.41 ± 0.45, 8.66 ± 1.70, and 29.6 ± 11.0 MPa, respectively. The breaking strength of the liver parenchyma was significantly lower than that of the hepatic veins and Glisson's sheaths. Histological staining confirmed that the liver parenchyma was selectively dissected, preserving the hepatic veins and Glisson's sheaths in contrast to what is commonly observed with electrocautery or ultrasonic instruments.

CONCLUSIONS

The dissection depth of liver tissue is well controlled by input voltage and is influenced by the moving velocity and the physical properties of the organ. We showed that the device can be used to assure liver resection with tissue selectivity due to tissue-specific physical properties. Although this study uses an excised organ, further in vivo studies are necessary. The present work demonstrates that this device may function as an alternative tool for surgery due to its good controllability of the dissection depth and ability of tissue selectivity.

High-pressure jet injection of viscous solutions for endoscopic submucosal dissection: a study on ex vivo pig stomachs

BACKGROUND

Long-lasting lifting is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water-jet injection of saline solution or by injection of viscous macromolecular solutions. Combination of the jet injection and the macromolecular viscous solutions has never been used yet. We assessed the ability of a new water-jet system to inject viscous solutions in direct viewing and in retroflexion. We compared jet injection of saline solution and hyaluronate 0.5 % to perform ESD on ex vivo pig stomachs in order to evaluate the benefits of macromolecular solutions when injected by a jet-injector system.

METHODS

This is a prospective comparative study in pig stomachs. Using the jet injector, four viscous solutions were tested: hydroxyethyl starch, glycerol mix, hyaluronate sodic (0.5 %), and poloxamer mix. Ten ESDs larger than 25 mm (five in direct viewing and five in retroflexion) and one larger than 10 cm were performed with each solution. ESD with hyaluronate jet injection was then compared with ESD with saline jet injection by performing 50 ESDs in each group. A single, minimally-experienced operator conducted all the procedures.

RESULTS

All 145 resections were complete, including all marking points with two perforations. Eleven jet ESDs per solution were conducted without any injection issue. In the second part of the study, when compared with saline, significant benefit of hyaluronate was observed on dissection speed (0.80 vs. 1.08 cm(2)/min, p < 0.001).

CONCLUSION

This is the first report on a jet-injector system allowing injection of macromolecular viscous solutions even with retroflexed endoscope. Jet injection of macromolecular solutions can speed up dissection in comparison with saline, and should now be tested on humans.

Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: A pilot animal study

AIM: To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model.

METHODS: Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endsocope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation.

RESULTS: Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure.

CONCLUSION: Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation.

Experimental application of pulsed laser-induced water jet for endoscopic submucosal dissection: mechanical investigation and preliminary experiment in swine

BACKGROUND AND AIM

A current drawback of endoscopic submucosal dissection (ESD) for early-stage gastrointestinal tumors is the lack of instruments that can safely assist with this procedure. We have developed a pulsed jet device that can be incorporated into a gastrointestinal endoscope. Here, we investigated the mechanical profile of the pulsed jet device and demonstrated the usefulness of this instrument in esophageal ESD in swine.

METHODS

The device comprises a 5-Fr catheter, a 14-mm long stainless steel tube for generating the pulsed water jet, a nozzle and an optical quartz fiber. The pulsed water jet was generated at pulse rates of 3 Hz by irradiating the physiological saline (4°C) within the stainless steel tube with an holmium-doped yttrium-aluminum-garnet (Ho:YAG) laser at 1.1 J/pulse. Mechanical characteristics were evaluated using a force meter. The device was used only for the part of submucosal dissection in the swine ESD model. Tissues removed using the pulsed jet device and a conventional electrocautery device, and the esophagus, were histologically examined to assess thermal damage.

RESULTS

The peak impact force was observed at a stand-off distance of 40 mm (1.1 J/pulse). ESD using the pulsed jet device was successful, as the tissue specimens showed precise dissection of the submucosal layer. The extent of thermal injury was significantly lower in the dissected bed using the pulsed jet device.

CONCLUSION

The results showed that the present endoscopic pulsed jet system is a useful alternative for a safe ESD with minimum tissue injury.

Water-jet dissector for endoscopic submucosal dissection in an animal study: outcomes of the continuous and pulsed modes

BACKGROUND

Endoscopic submucosal dissection (ESD) allows en bloc resection of early neoplastic lesions of gastrointestinal tract. Lesions are lifted by submucosal fluid injection before circumferential incision and dissection. High-pressure fluid injection using water jet (WJ) technology is already used for lifting and dissection in surgery. The study was designed to assess WJ for ESD submucosal lifting and dissection.

METHODS

An experimental, randomized comparative, "in vivo" nonsurvival animal study on 12 pigs was designed. Stomach mucosal areas were delineated and resected using three ESD techniques: technique A-syringe injection and IT knife dissection; technique B-WJ continuous injection and IT knife dissection; technique C-WJ injection and WJ pulsed dissection. Injection and dissection speeds and complications rates were assessed.

RESULTS

Water jet continuous injection is faster than syringe injection (B faster than A, p = 0.001 and B nonsignificantly faster than C, p = 0.06). IT knife dissection is significantly faster after WJ continuous injection (B faster than A, p = 0.003). WJ pulsed dissection is significantly slower than IT knife dissection (C slower than A and B, both p < 0.001). The overall procedure speed was significantly higher and the immediate bleedings rate was significantly lower for technique B than A and C (overall procedure speed p = 0.001, immediate bleedings p = 0.032 and 0.038 respectively). There were no perforations with any technique.

CONCLUSIONS

Water jet fluid continuous injection speeds up ESD, whereas pulsed WJ dissection does not.

Ex vivo and in vivo models for endoscopic submucosal dissection training

Endoscopic submucosal dissection is a technically challenging but highly effective technique for the treatment of well selected early neoplasms in the digestive tract. Although it is frequently performed in East Asian countries, the Western world has not adopted this technique yet, probably due in part to the difficulty to learn it. Ex vivo and in vivo animal models are invaluable tools to overcome at least the beginning of the learning curve, although the initial step is the acquisition of basic knowledge about early diagnosis of neoplasias, and observing real procedures in expert centers. The practical issues, advantages, and disadvantages of the ex vivo and in vivo models are discussed.

Wide field endoscopic resection for advanced colonic mucosal neoplasia: current status and future directions

Most colonic adenomas are ≤ 10 mm and are routinely treated by colonoscopic polypectomy with long-term health benefits. Nonpolypoid lesions ≥ 20 mm, whether sessile or flat and laterally spreading, are forms of advanced mucosal neoplasia that cannot be managed by conventional polypectomy and are often referred for surgery. However, the majority of these lesions when carefully assessed are found to be noninvasive and can be safely and effectively treated by advanced endoscopic techniques including endoscopic mucosal resection or endoscopic submucosal dissection with resultant cost, morbidity, and mortality benefits. Lesion assessment is a critical component. Enhanced imaging methods provide the opportunity for accurate pathological characterization, informing treatment decisions, without the need for previous histologic confirmation. Techniques of advanced endoscopic resection are still in evolution and further improvements, including hybrid techniques, bringing less technically challenging and shorter procedures with superior safety can be reasonably expected in the next decade. Safety is a fundamental consideration. Methods of early recognition of complications, risk stratification, and management pathways are being developed and refined. Standardization, validation, and adoption of these technological developments will improve endoscopic interpretation and therapy and in combination with an increased understanding of adenoma molecular biology, will result in a progressively more individualized lesion-specific endoscopic approach. The future of advanced endoscopic resection in the colon is promising, and the next few years should see the boundaries of endoscopic resection expand well beyond the limits of what we know today.

Peroral Endoscopic Myotomy for Esophageal Achalasia by HybridKnife: A Case Report

This paper presented a case of esophageal achalasia treated by peroral endoscopic myotomy with HybridKnife and discuss the feasibility and the possible advantages of using it.

Peroral Endoscopic Myotomy for Esophageal Achalasia by HybridKnife: A Case Report

This paper presented a case of esophageal achalasia treated by peroral endoscopic myotomy with HybridKnife and discuss the feasibility and the possible advantages of using it.

Endoscopic submucosal dissection of early gastric neoplasia with a water jet-assisted knife: a Western, single-center experience

BACKGROUND

Endoscopic submucosal dissection (ESD) of early gastric neoplasia has not yet been established in Western countries because of a lack of data and the difficult, time-consuming, and hazardous nature of the method. Some of the technical limitations may be overcome by use of a water jet-assisted knife, which allows a combination of a high-pressure water jet and electrosurgical interventions.

OBJECTIVE

To evaluate the efficacy and safety of water jet-assisted ESD (WESD) with a water jet-assisted knife in selected patients with early gastric neoplasia.

DESIGN

Single-center, prospective study.

PATIENTS

This study involved 29 consecutive patients (13 female; median age 61 years; age range 35-93 years) with early gastric neoplasia that met the expanded criteria of the Japanese Gastric Cancer Association. Histology of biopsies had shown gastric adenocarcinoma in 21 cases, adenoma in 8 case, and suspicion of a GI stromal tumor in 1 case. The median maximal diameter of the lesions was 20 mm (range 10-40 mm).

INTERVENTION

All procedures were done with patients under sedation with propofol. The water jet-assisted knife was used for setting coagulation markers around the neoplastic lesions, then for circumferential incision and dissection in combination with repeated submucosal injection of saline solution with a water jet system. Bleeding was treated with diathermia by use of the water jet-assisted knife or hemostatic forceps in case of failure or larger vessels. Clips were used for closure of perforations.

MAIN OUTCOME MEASUREMENTS

Complete resection of neoplasia, procedure time, complication and recurrence rates.

RESULTS

According to endoscopic criteria, complete resection of the targeted area could be achieved in all cases, with an en bloc resection rate of 90%. The median procedure duration was 74 minutes (range 15-402 minutes). Exchange of the device was needed in only 10 cases because of severe bleeding from larger vessels, which could be managed by use of hemostatic forceps. The 30-day morbidity rate was 4 of 30 (13.8%) because of postprocedure pain in 3 cases and delayed bleeding in 1 case. A 93-year-old patient died the night after WESD without evidence of a procedure-related complication. Histology of the resected specimens showed adenocarcinoma in 20 cases, adenoma in 7, no neoplasia in 2, and a plasmacytoma in 1. Complete resection (R0) was histologically confirmed in 18 of 28 patients (64.3%) with resected neoplastic specimens. A horizontal or vertical neoplasia-free margin could not be confirmed in 9 cases and 1 case, respectively. Complete local remission of neoplasia was achieved in 25 of 28 patients (89.3%) who were followed over a median period of 22 months (range 6-44 months). In 1 patient, a metachronous gastric adenocarcinoma was identified 54 weeks after initial WESD.

LIMITATIONS

Noncontrolled study with a limited number of patients.

CONCLUSION

The use of a water jet-assisted knife simplifies ESD because exchange of devices is rarely needed. WESD promises to be effective and safe. The study demonstrates that the high rates of en bloc resection of early gastric neoplasia reported in Asia can be reproduced in Western referral centers. However, histology may not always confirm complete resection of horizontal tumor margins. In spite of the unfavorable histology results, the high rate of complete local remission of neoplasia promises that surgical treatment of early gastric neoplasia can be avoided in the majority of cases.

Endoscopic submucosal dissection for removal of superficial gastrointestinal neoplasms: A technical review

Endoscopic submucosal dissection (ESD) is now the most common endoscopic treatment in Japan for intramucosal gastrointestinal neoplasms (non-metastatic). ESD is an invasive endoscopic surgical procedure, requiring extensive knowledge, skill, and specialized equipment. ESD starts with evaluation of the lesion, as accurate assessment of the depth and margin of the lesion is essential. The devices and strategies used in ESD vary, depending on the nature of the lesion. Prior to the procedure, the operator must be knowledgeable about the treatment strategy(ies), the device(s) to use, the electrocautery machine settings, the substances to inject, and other aspects. In addition, the operator must be able to manage complications, should they arise, including immediate recognition of the complication(s) and its treatment. Finally, in case the ESD treatment is not successful, the operator should be prepared to apply alternative treatments. Thus, adequate knowledge and training are essential to successfully perform ESD.

Beyond the snare: technically accessible large en bloc colonic resection in the West: an animal study

BACKGROUND

Endoscopic submucosal dissection (ESD) and circumferential submucosal incision endoscopic mucosal resection (CSI-EMR) are techniques for en bloc excision of large sessile colonic lesions. Our aims were to compare the efficacy, safety and learning curve of colonic hybrid knife (HK) ESD versus CSI-EMR for en bloc excision of 50 mm diameter hemi-circumferential artificial lesions in a porcine model.

PATIENTS AND METHODS

Two separate 50 mm diameter areas of normal recto-sigmoid mucosa were marked out in each of ten pigs. One was excised with HK-ESD using succinylated gelatin (SG) submucosal injection. The other was isolated with CSI with the Insulated Tip Knife 2 followed by SG submucosal injection then EMR with a large snare. Euthanasia and colectomy was performed at 72 h followed by blinded histopathology assessment.

RESULTS

En bloc excision rates were: HK-ESD 100% versus CSI-EMR 20% (P = 0.008). The mean number of resections per lesion was HK-ESD 1 versus CSI-EMR 3 (P = 0.001). The mean dimensions of the largest specimen per technique were HK-ESD 63 × 54 mm versus CSI-EMR 49 × 41 mm (P = 0.005). Procedure duration mean was HK-ESD 54 min versus CSI-EMR 22 min (P < 0.001). When procedure duration was adjusted for the size of the resected en bloc specimen, a statistically significant and accelerated learning effect was noted for HK-ESD (r = -0.83, P = 0.003). There were no perforations and no significant bleeding.

CONCLUSIONS

HK-ESD with SG submucosal injection is superior to CSI-EMR for en bloc excision of 50 mm diameter lesions in a porcine model. The technique is rapidly learnt. This novel approach may lower the barrier to colonic ESD for Western endoscopists.

Endoscopic submucosal dissection with a flexible Maryland dissector: randomized comparison of mesna and saline solution for submucosal injection (with videos)

BACKGROUND

Endoscopic submucosal dissection (ESD) is increasingly used for en bloc removal of GI lesions. Current ESD techniques have limitations including long procedure times, technical difficulty, and complications.

OBJECTIVE

To compare mesna with saline solution for ESD.

DESIGN

Blinded, randomized, controlled, porcine study in live animals.

SETTING

Animal laboratory.

INTERVENTION

Twelve gastric lesions were marked by using electrocautery. After submucosal injection, a circumferential mucosal incision was created, and ESD was performed by using a flexible Maryland dissector. Half of the ESDs were performed with submucosal injection of mesna.

MAIN OUTCOME MEASUREMENTS

Primary outcome was the time to dissect the submucosal plane. Secondary outcomes were total ESD time, specimen size, and procedure related complications.

RESULTS

The average (± SD) time for dissecting the submucosal plane was 15 minutes (range 10-22 ± 4.8 min) in the group with submucosal mesna injection and 16 minutes (range 8-29 ± 8.3 min) in the control group (P = 1.0). Complete en bloc resection including all of the electrocautery markings was achieved in all cases. Injection of mesna did not provide any benefit over saline solution in terms of overall ESD time (24 ± 7.3 min vs 28 ± 11 min; P = .42). There were no perforations. Four hemorrhages requiring intervention were encountered during the procedures in the control group, compared with no bleeding in the mesna group (P = .09).

LIMITATIONS

Animal model, limited sample size.

CONCLUSION

Submucosal mesna injection did not affect procedure times but was associated with a trend toward a lower incidence of intraprocedural bleeding.

Experimental endoscopic submucosal dissection training in a porcine model: learning experience of skilled Western endoscopists

BACKGROUND

Endoscopic submucosal dissection (ESD) demands a new level of endoscopic skill in Europe. A 2-day workshop was set up for trainees to carry out five ESD each in order to obtain the skill level required to perform ESD in the stomach or rectum. This study describes: (i) the workshop setup; (ii) the participant's performance; and (iii) the training effect on post-workshop clinical ESD performance.

METHODS

Eighteen very experienced European endoscopists participated in four half-day (4.5 h) training sessions, with everybody rotating daily through six separate training stations (two each with dual, hook, or hybrid knives) with expert tutors. One anesthetized piglet was used per station and session. After 1 year, the clinical ESD performance was surveyed to estimate the training effect of the workshop.

RESULTS

Overall, 74 ESD were performed, that is, 4.1 ESD per participant. On average ESD lasted 57 min for 6 cm(2) specimens. We detected a 22% rate of perforation (16 of 74 ESD with perforations), mostly attributable to participants with less experience in ESD. Those who started clinical ESD within 1 year after the workshop performed 144 clinical ESD (median 8 [0-20] per trainee) mostly in the stomach (40%) and large bowel (46%) with an acceptable rate of perforation (9.7%) and surgical repair (3.5%) without mortality or persistent morbidity.

CONCLUSION

Intense skill training for ESD is needed to reduce the risk of perforation, as demonstrated by the results of this workshop. We show that experimental ESD training, however, enables skilled European endoscopists to perform ESD in standard locations with moderate risk of perforation during the clinical learning curve.

Endoscopic submucosal dissection for colonic lesions: why and how should we do it?

Endoscopic submucosal dissection (ESD) is a safe and effective alternative to surgery for large non-polypoid colonic lesions and early colorectal carcinoma. In this article, we discuss the development, efficacy and safety of ESD. As the incidence of colorectal cancer is rapidly increasing in Asia, we advocate standardization of ESD program, including patient selection, hardware prerequisites, and training of operators.

Prospective, randomized study of conventional versus HybridKnife endoscopic submucosal dissection methods for the esophagus: an animal study

BACKGROUND

Endoscopic submucosal dissection (ESD) increases en bloc and histologically complete resection rate of neoplastic mucosal tumors but is technically more demanding than EMR. Limited data are available comparing the efficacy and safety of a new ESD designed to overcome these limitations and conventional ESD (C-ESD) techniques.

OBJECTIVE

To compare the safety, efficacy, and operation time of the new HybridKnife ESD (HK-ESD) with C-ESD in the esophagus.

DESIGN

Prospective, randomized, controlled study.

SETTING

Animal research laboratory.

SUBJECTS

Seventeen anesthetized Yorkshire pigs.

INTERVENTIONS

Removal of a 4-cm length of half-circumference esophageal mucosa by C-ESD with Hook knife or Flexknife versus HK-ESD.

MAIN OUTCOME MEASUREMENTS

Procedure time, en bloc and complete resection rate, and complications (bleeding and perforation).

RESULTS

All resections were completed en bloc. Procedure time was shorter in C-ESD. However, it was similar after 12 procedures. Significantly more bleeding occurred during C-ESD (28 vs 12, P = .0007). Histological muscularis propria injuries occurred with equal frequency (16 vs 17) and were mostly seen during the first 11 procedures. There were 3 perforations (2 endoscopic, 1 histological), all with C-ESD.

LIMITATIONS

Nonsurvival study, use of 2 conventional knives, no training period for a new procedure.

CONCLUSIONS

The HK-ESD technique was equally effective as the C-ESD technique for successful en bloc resection and was safer with less bleeding and perforation. Although procedure time was longer in HK-ESD, the difference became nonsignificant after 12 procedures.

Efficient hemostatic method for endoscopic submucosal dissection of colorectal tumors

AIM: To evaluate a new hemostatic method using hemostatic forceps to prevent perforation and perioperative hemorrhage during colonic endoscopic submucosal dissection (ESD).

METHODS: We studied 250 cases, in which ESD for colorectal tumors was performed at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2010. We developed a new hemostatic method using hemostatic forceps in December 2008 for the efficient treatment of submucosal thick vessels. ESD was performed on 126 cases after adoption of the new method (the adopted group) and the new method was performed on 102 of these cases. ESD was performed on 124 cases before the adoption of the new method (the unadopted group). The details of the new method are as follows: firstly, a vessel was coagulated using the hemostatic forceps in the soft coagulation mode according to the standard procedure, and the coagulated vessel was removed using the forceps in the “endocut” mode without perioperative hemorrhage. Secondly, the partial surrounding submucosa was dissected using the forceps in the endocut mode. In the current study, we evaluated the efficacy of this method.

RESULTS: Coagulated vessels were successfully removed using the hemostatic forceps in all 102 cases without severe perioperative hemorrhage. Moderate perioperative hemorrhage occurred in five cases (4.9%); however, it was stopped by immediately reuse of the hemostatic forceps. The partial surrounding submucosa was dissected using the forceps in all 102 cases. In the adopted group, the median operation time was 105 min. The proportion of endoscopic en bloc resection was 92.8% (P < 0.01) compared to 80.6% in the unadopted group. The postoperative hemorrhage and perforation rates were 2.3% and 2.3%. The rate of perforation was significantly lower than that in the unadopted group (9.6%, P < 0.01). We evaluated the ease of use of this method by allowing our three trainees to performed ESD on 46 cases, which were accomplished without any severe hemorrhage.

CONCLUSION: The new method effectively treated submucosal thick vessels and shows promise for the prevention of perforation and perioperative hemorrhage in colonic ESD.

Active gastrointestinal bleeding: Use of hemostatic forceps beyond endoscopic submucosal dissection

To the best of our knowledge, this is the first report of the application of hemostatic forceps in active gastrointestinal (GI) bleeding that is not related to endoscopic submucosal dissection. An 86-year-old woman with chronic intake of low-dose aspirin had a Dieulafoy’s lesion of the third duodenal portion. Bleeding control with epinephrine injection was unsuccessful. A 60-year-old man presented with a bleeding ulcer in the duodenal bulb. Ten days after combined endotherapy, he had recurrent bleeding from two minimal lesions in the same location. A 66-year-old woman under combined antithrombotic treatment was referred to us for chronic GI bleeding of unexplained origin. Endoscopy revealed active diverticular bleeding in the second duodenal portion. A 61-year-old woman underwent endoscopic mucosal resection of superficial gastric adenocarcinoma, which was complicated with immediate bleeding. In all cases, the blood was washed out using a water-jet-equipped, single-channel gastroscope with a large working channel. The bleeding points were pinched and retracted with hemostatic forceps. Monopolar electrocoagulation was performed using an electrosurgical current generator. Hemostasis was achieved. No complications occurred. In conclusion, hemostatic forceps may be an effective as well as safe alternative approach for active GI bleeding of various origins.