Evaluating long-term attachment of two different endoclips in the human gastrointestinal tract

Through-the-scope clip retention rates and performance in a porcine model

Background and study aims Limited comparative data exist to guide optimal through-the-scope (TTS) clip selection. The aim of this study was to compare the efficacy, retention, and safety of three industry-leading TTS clips on tissue that mimics common clinical scenarios. Methods A survival study involving six domestic pigs was undertaken. Three commonly used clip models were selected: Assurance (STERIS, Mentor, Ohio, United States), Resolution (Boston Scientific, Boston, Massachusetts, United States), and SureClip (Micro-Tech, Ann Arbor, Michigan, United States). To mimic clinical practice, the following scenarios were assessed: (1) normal mucosa; (2) cold snare resection; and (3) hot mucosal resection simulating fibrotic ulcers. Deployment of clips was randomized to target sites. Repeat endoscopy was performed 2 weeks following placement. Endoscopists rated the ease of use of clip placement on a Likert scale of 1 to 5. Results Fifty-four clips (18 Assurance, 18 Resolution, and 18 SureClip) were placed in six pigs. Mucosal healing was noted at all sites on follow up. Overall retention was nine of 18 (50.0%) SureClip, 10 of 18 (55.6%) Assurance, and 13 of 18 (72.2%) Resolution ( P =0.369). There was no difference in clip retention on normal and cold snare resection sites; however, clip retention was significantly higher for Resolution clips on fibrotic ulcers (50.0% versus 0% for Assurance and 0% SureClip, P =0.03). No adverse events were reported. Ease of use was equivalent across all models. Conclusions All clips were equivalent in efficacy and safety with successful clip deployment and mucosal healing. Overall retention rate was low for fibrotic tissue, with an improved retention rate observed with Resolution clips.

The risk factors for prolonged hemostatic clip retention after endoscopic submucosal dissection for gastric neoplasm

BACKGROUND

Endoscopic hemostatic clipping is a safe and efficient treatment used to manage bleeding or perforation during endoscopic submucosal dissection (ESD) for gastric neoplasm. However, the natural history of applied hemoclips during ESD has not been elucidated. As prolonged clip retention limits the use of magnetic resonance imaging and may impede the ulcer healing process, we investigated the factors associated with prolonged hemoclip retention during gastric ESD.

METHODS

We retrospectively reviewed 199 patients who underwent gastric ESD with hemoclip application from January 2006 to January 2019. The primary outcome was the prolonged hemoclip retention rate 3 months after ESD. We examined the records of subjects followed at 3, 6, and 12 months and then annually after ESD to monitor clip retention.

RESULTS

The prolonged hemoclip retention rate at 3 months was 27.1% (54/199). The risk of hemoclip retention was significantly lower at the antrum (19.6%, P = 0.03). Hemoclips at the angle tended to remain longer than other locations in the stomach (40.6%, P = 0.081) while there was no difference in the number of applied clips depending upon the location of the lesion. By Kaplan-Meier survival analysis, clips at the antrum detached significantly earlier than those at other locations (P = 0.011).

CONCLUSIONS

Most of the hemostatic clips attached during ESD were spontaneously removed by 3 months after gastric ESD. However, clips positioned at angle are suspected to have a high probability of prolonged retention. With this in mind, more attention is needed when using hemoclips on angle.

Compatibility of endoclips in the gastrointestinal tract with magnetic resonance imaging

There are no clear guidelines on the compatibility between endoclips that remain in the gastrointestinal (GI) tract and magnetic resonance imaging (MRI). The purpose of this study was to investigate the effect of 3T (T) MRI on endoclips placed in excised pig tissues. Two types of endoclips were assessed: Olympus EZ (HX-610-135L) and QuickClip Pro (HZ-202LR). We assessed tissue damage or perforation and detachment of endoclips under 3T MRI magnetic field. We also evaluated the magnitude of force required to detach the endoclips from the porcine tissue. We measured the magnetic force acting on the Olympus EZ clips. QuickClip Pro clips were used as a control in this study. There was no tissue damage and no detachment of the endoclips (Olympus EZ and QuickClip Pro) during 3T MRI. The force required to detach the Olympus EZ clips ranged from 0.9 to 3.0 N. The translational magnetic force acting on the endoclips was 3.18 × 10^-3 N. Ex vivo experiments showed that the magnetic field generated by 3 MRI did not cause tissue damage or perforation and did not detach the endoclips. Olympus EZ clips and QuickClip Pro clips in the GI tract appear to be safe during 3T MRI.

EUS-guided fiducial marker placement for radiotherapy in rectal cancer: feasibility of two placement strategies and four fiducial types

Background and study aims  To facilitate image guidance during radiotherapy of rectal cancer, we investigated the feasibility of fiducial marker placement. This study aimed to evaluate technical success rate and safety of two endoscopic ultrasound (EUS)-guided placement strategies and four fiducial types for rectal cancer patients. Patients and methods  This prospective multicenter study included 20 participants who were scheduled to undergo rectal cancer treatment with neoadjuvant short-course radiotherapy or chemoradiation. EUS-guided endoscopy was used for fiducial placement at the tumor site (n = 10) or in the mesorectal fat and in the tumor (n = 10). Four fiducial types were used (Visicoil 0.75 mm, Visicoil 0.50 mm, Cook, Gold Anchor). The endpoints were technical success rate and retention of fiducials, the latter of which was evaluated on cone-beam computed tomography scans during the first five radiotherapy fractions. Results  A total of 64 fiducials were placed in 20 patients. For each fiducial type, at least three fiducials were successfully placed in all patients. Technical failure consisted of fiducial blockage within the needle (n = 2) and ejection of two preloaded fiducials at once (n = 4). No serious adverse events were reported. In three patients, one of the fiducials was misplaced without clinical consequences; two in the prostate and one in the intraperitoneal cavity. After a median time of 17 days after placement (range 7 - 47 days), a total of 42/64 (66 %) fiducials were still present (24/44 intratumoral vs. 18/20 mesorectal fiducials, P  = 0.009). Conclusions  Placement of fiducials in rectal cancer patients is feasible, however, retention rates for intratumoral fiducials were lower (55 %) than for mesorectal fiducials (90 %).

Clips for managing perforation and bleeding after colorectal endoscopic mucosal resection

INTRODUCTION

The most commonly used treatment for advanced colorectal adenomas is endoscopic mucosal resection (EMR). The increased number of EMRs since the introduction of the screening program for colorectal cancer has resulted in an increase in EMR-related complications. This review summarizes the current knowledge for the use of clips for the treatment and prevention of complications after EMR.

AREAS COVERED

The historical development of clips is summarized and their properties are evaluated. An overview is presented of the evidence for therapeutic and prophylactic clipping for bleeding or perforation after EMR in the colon. Several clipping techniques are discussed in relation to the efficacy of wound closure. Furthermore, new techniques that will likely influence the use of clips in the future endoscopic practice, such as endoscopic full-thickness resection (eFTR) are also highlighted.

EXPERT COMMENTARY

Most research focuses on prophylactic clipping for delayed bleeding after EMR of large adenomas. We advocate a distance of 0.5-1.0 cm between aligning clips. This focus may likely shift from bleeding to perforation. Here, endoscopic treatment with through-the-scope clips and large-diameter clips may well replace surgery. The future role of clips will also depend on the further development of new endoscopic technologies, such as eFTR.

Choosing the right through-the-scope clip: a rigorous comparison of rotatability, whip, open/close precision, and closure strength (with videos)

BACKGROUND AND AIMS

Many new through-the-scope clips are available, and physicians often select clips based on physical characteristics and/or cost. However, functional profiles may be equally important and have not been methodically assessed. We evaluated 5 commercially available clips: Resolution 360, Instinct, Quick Clip Pro, Dura Clip, and SureClip.

METHODS

We rigorously compared clips on multiple characteristics, including rotatability, overshoot, open/close precision, and tensile/closure strength. Clips were tested in 4 different endoscope configurations: (1) straight, (2) duodenal sweep, (3) full retroflexion, and (4) across the duodenoscope elevator.

RESULTS

For rotatability, the Resolution 360 was the fastest due to its unique functionality in allowing primary MD control in rotation (P < .05). The Resolution 360, SureClip, and Dura Clip were able to rotate through the prescribed sequence across all scope configurations. For overshoot, the SureClip and Resolution 360 had the least overshoot for the straight configuration at 0%. All clips had >75% overshoot at more strained configurations. For open/close precision, the SureClip and Dura Clip showed precise opening/closing with the ability to stop at any point. The remaining clips exhibited abrupt opening with more controlled closure. For tensile strength, the Quick Clip Pro generated the highest peak force as would be required in lateral tissue manipulation (4.8 lb, P < .005). For closure strength, the Instinct overall showed the most gel compression, and along with the Resolution 360, showed 100% deployment success for all gel tissue thicknesses (up to 10 mm).

CONCLUSIONS

Each clip has a unique physical and functional profile, which may be a factor in selection depending on the clinical circumstance.

MRI visibility of gold fiducial markers for image-guided radiotherapy of rectal cancer

BACKGROUND AND PURPOSE

A GTV boost is suggested to result in higher complete response rates in rectal cancer patients, which is attractive for organ preservation. Fiducials may offer GTV position verification on (CB)CT, if the fiducial-GTV spatial relationship can be accurately defined on MRI. The study aim was to evaluate the MRI visibility of fiducials inserted in the rectum.

MATERIALS AND METHODS

We tested four fiducial types (two Visicoil types, Cook and Gold Anchor), inserted in five patients each. Four observers identified fiducial locations on two MRI exams per patient in two scenarios: without (scenario A) and with (scenario B) (CB)CT available. A fiducial was defined to be consistently identified if 3 out of 4 observers labeled that fiducial at the same position on MRI. Fiducial visibility was scored on an axial and sagittal T2-TSE sequence and a T1 3D GRE sequence.

RESULTS

Fiducial identification was poor in scenario A for all fiducial types. The Visicoil 0.75 and Gold Anchor were the most consistently identified fiducials in scenario B with 7 out of 9 and 8 out of 11 consistently identified fiducials in the first MRI exam and 2 out of 7 and 5 out of 10 in the second MRI exam, respectively. The consistently identified Visicoil 0.75 and Gold Anchor fiducials were best visible on the T1 3D GRE sequence.

CONCLUSION

The Visicoil 0.75 and Gold Anchor fiducials were the most visible fiducials on MRI as they were most consistently identified. The use of a registered (CB)CT and a T1 3D GRE MRI sequence is recommended.

Endoclip Magnetic Resonance Imaging Screening: A Local Practice Review

PURPOSE

Not all endoscopically placed clips (endoclips) are magnetic resonance imaging (MRI) compatible. At many institutions, endoclip screening is part of the pre-MRI screening process. Our objective is to determine the contribution of each step of this endoclip screening protocol in determining a patient's endoclip status at our institution.

METHODS

A retrospective review of patients' endoscopic histories on general MRI screening forms for patients scanned during a 40-day period was performed to assess the percentage of patients that require endoclip screening at our institution. Following this, a prospective evaluation of 614 patients' endoclip screening determined the percentage of these patients ultimately exposed to each step in the protocol (exposure), and the percentage of patients whose endoclip status was determined with reasonable certainty by each step (determination).

RESULTS

Exposure and determination values for each step were calculated as follows (exposure, determination): verbal interview (100%, 86%), review of past available imaging (14%, 36%), review of endoscopy report (9%, 57%), and new abdominal radiograph (4%, 96%), or CT (0.2%, 100%) for evaluation of potential endoclips. Only 1 patient did not receive MRI because of screening (in situ gastrointestinal endoclip identified).

CONCLUSIONS

Verbal interview is invaluable to endoclip screening, clearing 86% of patients with minimal monetary and time investment. Conversely, the limited availability of endoscopy reports and relevant past imaging somewhat restricts the determination rates of these. New imaging (radiograph or computed tomography) is required <5% of the time, and although costly and associated with patient irradiation, has excellent determination rates (above 96%) when needed.

Deployment of a Short, Single-Opening Endoscopic Clip Versus a Long, Reopening Endoscopic Clip in Clinical Practice

BACKGROUND

Endoscopic clips vary in their designs and costs. Clip wastage is a common problem, and this is dependent on the success of its deployment.

AIMS

The aim of this study is to compare the rates of successful deployment between two different commonly used endoscopic clips.

METHODS

A single-center, retrospective study was conducted. Endoscopy reports of patients with clips deployed over 24 months were reviewed. We compared a long-pronged, reopening endoscopic clip (type A: Resolution clip; Boston Scientific, Natick, MA, USA) versus a short-pronged, single-opening clip (type B: QuickClip2; Olympus Medical Systems Corp, Japan). The main outcome was clip deployment success rate. Secondary outcomes were predictors of successful deployment, cost, and wastage.

RESULTS

Of 14,690 endoscopic cases, 472 clips (171 type A and 301 type B) were deployed in 262 procedures. Type A clips had a significantly higher successful deployment rate (147/171, 86.0 %) than type B clips (221/301, 73.4 %) (p = 0.002). On multivariate analysis, variables independently associated with successful deployment included using type A clips (OR 2.07, 95 % CI 1.20-3.55; p = 0.009) and clips placed in the lower gastrointestinal tract (OR 3.48, 95 % CI 1.64-7.40; p = 0.001). The cost of using type A clips was higher than type B clips (p < 0.001). Type B clips were associated with more wastage (p = 0.049).

CONCLUSIONS

Long-pronged, reopening clips (type A) have a better deployment rate than short-pronged, single-opening clips (type B). Although type A clips had less wastage, the cost per procedure was higher.

Mechanical Hemostasis Techniques in Nonvariceal Upper Gastrointestinal Bleeding

One of the most important advances in gastroenterology has been the use of endoscopic hemostasis techniques to control nonvariceal upper gastrointestinal bleeding, particularly when high-risk stigmata are present. Several options are available, including injection therapy, sprays/topical agents, electrocautery, and mechanical methods. The method chosen depends on the nature of the lesion and experience of the endoscopist. This article reviews the available mechanical hemostatic modalities.

Which clip? A prospective comparative study of retention rates of endoscopic clips on normal mucosa and ulcers in a porcine model

BACKGROUND/AIM

There are currently no data on the relative retention rates of the Instinct clip, Resolution clip, and QuickClip2Long. Also, it is unknown whether retention rate differs when clips are applied to ulcerated rather than normal mucosa. The aim of this study is to compare the retention rates of three commonly used endoscopic clips.

MATERIALS AND METHODS

Six pigs underwent upper endoscopy with placement of one of each of the three types of clips on normal mucosa in the gastric body. Three mucosal resections were also performed to create "ulcers." Each ulcer was closed with placement of one of the three different clips. Repeat endoscopy was performed weekly for up to 4 weeks.

RESULTS

Only the Instinct and Resolution clips remained attached for the duration of the study (4 weeks). At each time point, a greater proportion of Instinct clips were retained on normal mucosa, followed by Resolution clips. QuickClip2Long had the lowest retention rate on normal mucosa. Similar retention rates of Instinct clips and Resolution clips were seen on simulated ulcers, although both were superior to QuickClip2Long. However, the difference did not reach statistical significance. All QuickClip2Long clips were dislodged at 4 weeks in both the groups.

CONCLUSIONS

The Resolution and Instinct clips have comparable retention rates and both appeared to be better than the QuickClip2Long on normal mucosa-simulated ulcers; however this did not reach statistical significance. Both the Resolution clip and the Instinct clip may be preferred in clinical situations when long-term clip attachment is required, including marking of tumors for radiotherapy and anchoring feeding tubes or stents. Either of the currently available clips may be suitable for closure of iatrogenic mucosal defects without features of chronicity.

Comparison of gastrotomy closure modalities for natural orifice transluminal surgery: a canine study

BACKGROUND

Reliable closure of the gastrotomy after transgastric natural orifice transluminal endoscopic surgery (NOTES) remains unresolved.

OBJECTIVE

To compare the technical aspects and clinical and histologic outcomes of NOTES gastrotomy closure techniques.

DESIGN

Experimental study.

SETTING

Animal laboratory.

PATIENTS

Thirty-four dogs, 14 for nonsurvival study and 20 for survival study.

INTERVENTIONS

The animals randomly received different gastrotomy closures after NOTES: endoclip, omentoplasty, over-the-scope-clip (OTSC), and hand-suturing.

MAIN OUTCOME MEASUREMENTS

Procedure time, closure strength, survival, postoperative adverse events, and histologic evaluation of wound healing.

RESULTS

Omentoplasty and OTSC groups needed shorter procedure times and fewer clips than the endoclip group. The endoclip and omentoplasty groups generated similar leakage pressures (34.5 ± 2.6 vs 42.2 ± 4.1 mm Hg, P > .05), both lower than OTSC and hand-suturing groups (81.5 ± 2.1 and 87.0 ± 3.0 mm Hg, respectively, P < .001). Of the 20 animals in the survival study (all 4 groups), only 2 of 6 in the endoclip group were killed prematurely due to sepsis. Necropsy revealed the OTSC group reached a 100% clip retention rate, higher than the endoclip (47.9%) and omentoplasty groups (44.4%, P < .05) rates. Complete healing, defined as intact and continuous gastric layers microscopically, was seen in 83.3% of animals (5 of 6) in the omentoplasty group, comparable with OTSC (4 of 6, 66.7%, P = .500) but higher than the endoclip group (1 of 6, 16.7%, P = .04).

LIMITATIONS

Animal study.

CONCLUSIONS

Omentoplasty is easier and safer for NOTES gastrotomy closure than endoclips and offers safety profile and efficacy similar to OTSC and hand-suturing.