Efficacy and safety of an internal magnet traction device for endoscopic submucosal dissection: ex vivo study in a porcine model (with video)

Efficacy, safety, and advantages of magnetic anchor-guided endoscopic submucosal dissection vs conventional endoscopic submucosal dissection: A retrospective paired cohort study

BACKGROUND

Endoscopic submucosal dissection (ESD) has been recommended as the first-line treatment for early gastric cancer (EGC). However, poor visualization of the operative field increases both the procedure time and the risk of complications, especially for large and difficult lesions. We introduced a novel technique, magnetic anchor-guided ESD (MAG-ESD) and compared it with conventional ESD (C-ESD) for the treatment of large EGCs in terms of efficacy, safety, and advantages.

METHODS

Patients with large EGCs who underwent MAG-ESD or C-ESD at the First Affiliated Hospital of Xi'an Jiaotong University from March 2020 to March 2022 were retrospectively enrolled in this study. The patients in the MAG-ESD cohort were matched to those in the C-ESD cohort using propensity score-based matching. The operation time, submucosal dissection time, complete resection status, magnetic anchor, adverse event rate, and tumor recurrence rate were evaluated.

RESULTS

Twenty-two patients who underwent MAG-ESD were ultimately matched to those who underwent C-ESD. The median operation time of MAG-ESD and C-ESD was 43 minutes (IQR, 35.2-49.5) and 50.5 minutes (IQR, 42.0-76.0), respectively, among which the submucosal dissection time was 7.6 minutes (IQR, 5.2-10.4) and 14.8 minutes (IQR, 10.8-19.6), respectively. The operation time of MAG-ESD was shorter than that of C-ESD, especially the submucosal dissection time (P < .05). There was a lower incidence of adverse events associated with MAG-ESD (P < .05) when magnetic anchors were successfully placed and retrieved.

CONCLUSION

MAG-ESD is feasible, effective, safe, and simple for the treatment of large EGCs at different sites and has a high anchor success rate, which could shorten the operation time and reduce the adverse event rate.

Magnetic ring-assisted endoscopic submucosal dissection for gastric lesions with submucosal fibrosis: A preliminary study in beagle model

BACKGROUND

During endoscopic submucosal dissection (ESD) for gastric lesions with fibrosis, appropriate traction could provide clear submucosal dissection visualization to improve safety and efficiency of procedures. Therefore, the aim of this study was to evaluate the feasibility of magnetic ring-assisted ESD (MRA-ESD) for gastric fibrotic lesions.

METHOD

In the eight healthy beagles, 2-3 mL of 50% glucose solution was injected into submucosal layer of the stomach to induce gastric fibrotic lesions. A week after submucosal injection, two endoscopists at different levels performed MRA-ESD or standard ESD (S-ESD) for gastric simulated lesions, respectively. The magnetic traction system consisted of external handheld magnet and internal magnetic ring. The feasibility and procedure outcomes of the magnetic traction system were mainly evaluated.

RESULTS

Forty-eight gastric simulated lesions with ulceration were confirmed to have submucosal fibrosis formation by preoperative endoscopic ultrasonography. The magnetic traction system could be easily established, only took 1.57 min, and allowed excellent submucosal visualization. The total procedure time was significantly shorter in the MRA-ESD group than in the S-ESD group for both endoscopists (mean: 46.83 vs. 25.09 min, p < 0.001), and this difference was accentuated in non-skilled endoscopist. There was significant difference between two groups in bleeding and perforation rates. Histological analysis showed the depth of resected specimens was a little deeper around the fibrotic portion in the S-ESD group (p < 0.001).

CONCLUSION

The magnetic ring-assisted ESD technique may be an effective and safe treatment for gastric fibrotic lesions and may shorten the endoscopic learning curve for non-skilled endoscopists.

Endoscopic applications of magnets for the treatment of gastrointestinal diseases

Endoscopic treatment of gastrointestinal diseases has developed rapidly in recent years, due to its minimally invasive nature. One of the main contributing factors for this progress is the improvement of endoscopic instruments, which are essential for facilitating safe and effective endoscopic interventions. However, the slow learning curve required in the implementation of many advanced endoscopic procedures using standard devices is associated with a high risk of complications. Other routine procedures may also be complicated by unexpected difficulties. Based on the ferromagnetic properties of many objects, both internal and external magnetic devices have been developed and applied for multiple endoscopic interventions. The applications of magnets, mainly including compression, anchoring and traction, facilitate many difficult procedures and make it feasible to operate procedures that were previously impossible. Other novel endoscopic applications, such as magnetic nanoparticles, are also under development. In this article, we reviewed published studies of endoscopic applications of magnets for the treatment of gastrointestinal diseases such as precancerous lesions and cancer, obstruction, stricture, congenital and acquired malformations, motility disorders, and ingestion of foreign bodies. Since several endoscopic applications of magnets may also be relevant to surgery, we included them in this review.

Magnetic bead-assisted endoscopic submucosal dissection: a gravity-based traction method for treating large superficial colorectal tumors

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) has always been challenging for endoscopists, but the procedure can be facilitated after adequate exposure of submucosal layer and cutting line. We developed a traction method based on gravity for facilitating colorectal ESD, referred as magnetic bead-assisted ESD (MBA-ESD). This study aimed to compare the safety and effectiveness of MBA-ESD and conventional ESD for treating large superficial colorectal tumors.

METHODS

This retrospective study included consecutive patients with large (≥ 20 mm in their maximal diameter) superficial colorectal tumors who underwent MBA-ESD or conventional ESD at our endoscopy center between June 2017 to January 2018. Each patient in the MBA-ESD group was matched to a patient in the conventional ESD group using propensity scores.

RESULTS

Thirteen patients in each group were matched for the analyses. The baseline characteristics were balanced after propensity matching. The incidence of overall complications was significantly lower in the matched MBA-ESD group (0% vs. 38.5%, P = 0.039), while similar rates of en bloc resection, R0 resection, curative resection, and tumor recurrence were noted. Although without statistic difference, dissection time and speed were improved when using MBA-ESD (33 min vs. 40 min, P = 0.111; and 21 mm²/min vs. 16 mm²/min, P = 0.143, respectively).

CONCLUSIONS

MBA-ESD is a feasible, safe, and effective method for treating large superficial colorectal tumors. Further large, prospective and controlled studies are needed to fully assess this method.

An internal magnet traction device reduces procedure time for endoscopic submucosal dissection by expert and non-expert endoscopists: ex vivo study in a porcine colorectal model (with video)

BACKGROUND

Efficacy of an internal magnet traction device (MTD) for gastric endoscopic submucosal dissection (ESD) by an expert endoscopist has been reported. We hypothesized that use of the MTD would enhance the performance of colorectal ESD in a non-expert endoscopist in ESD compared to the conventional technique. Primary aim of this study was to compare procedure times between conventional ESD (C-ESD) and MTD-assisted ESD (MTD-ESD) by expert and non-expert endoscopists in ESD. Secondary aims included rate of en bloc resection, iatrogenic injury, visualization score of the submucosal layer, and endoscopist satisfaction score.

METHODS

A total of 56 lesions were created in an ex vivo porcine colorectum. Two endoscopists completed C-ESD (n = 28) and MTD-ESD (n = 28). Lesions measured 3 cm in diameter and were located on either the anterior or posterior colorectal wall. The MTD consisted of a small neodymium magnet and nylon monofilament attached to a through-the-scope clip. The first MTD was deployed on the opposing colorectal wall of the target lesion and a second MTD was then deployed directly onto the distal margin of the lesion.

RESULTS

Total procedure time for MTD-ESD was significantly shorter than C-ESD for both expert (median: 15.8 vs. 19.3 min, p < 0.05) and non-expert (median: 21.3 vs. 33.9 min, p < 0.001) endoscopists. All lesions were resected en bloc. There was no iatrogenic muscularis propria injury in the MTD-ESD group. For both the expert and non-expert, scores for MTD-ESD were significantly higher for submucosal layer visualization (p < 0.05) and endoscopist satisfaction (p < 0.001) compared to C-ESD.

CONCLUSIONS

Use of the MTD significantly reduced procedure time for both expert and non-expert endoscopists performing ESD. Improving the efficiency, safety, and satisfaction of ESD with such a device particularly for non-expert endoscopists is appealing and could potentially minimize the complexity and duration of the procedure allowing for more widespread use of the technique.

Safety and efficacy of magnetic anchoring electrode-assisted irreversible electroporation for gastric tissue ablation

BACKGROUND

Irreversible electroporation (IRE) is an emerging tissue ablation technique, which is safe for sites where thermal-basis techniques are not suitable. The aim of this study is to evaluate the safety and efficacy of magnetic anchoring electrode (MAE)-assisted IRE for normal gastric tissue ablation in a rabbit model.

METHODS

IRE (500 V, 100 μs, 99 pulses, 1 Hz) of the gastric wall was performed in 24 adult New Zealand rabbits with a novel catheter-mounted MAE with fluoroscopy and a surgical approach. Procedure time, procedure-related bleeding, perforation, and other complications were recorded. Animals were sacrificed at 30 min, 1 day, 3 days, 7 days, 14 days, and 28 days post-IRE. The stomach was removed en bloc, and the diameter of each lesion was measured. Histopathological analyses by Hematoxylin-Eosin (H&E), masson trichrome, alpha-smooth muscle action (α-SMA), and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) were performed.

RESULTS

Gastric tissue ablation with MAE-assisted IRE was successfully performed without any interruption. No perforation or bleeding was observed during IRE or throughout the follow-up period. A demarcated hemorrhage was found in the ablated area upon gross examination. H&E staining showed complete cell death with inflammatory infiltration, edema, and hemorrhaging. TUNEL presented diffuse positive cells in the ablated area. The tissue scaffold was well preserved without damage as indicated by Masson trichrome staining. Ulceration was observed starting from 3 days post-IRE. The mucosal layer was gradually recovered and regenerated within 14-28 days. No other complication was observed post-IRE.

CONCLUSIONS

MAE-assisted IRE is safe and effective for normal gastric tissue ablation and the gastric wall recovered in 14-28 days post-IRE.