Magnetic hydrogel-assisted endoscopic submucosal dissection of large intestine in vitro animal experimental study

Magnetic anchor-guided endoscopic submucosal dissection (MAG-ESD) has significant advantages in the treatment of difficult lesions (Mortagy et al. in World J Gastroenterol 23:2883-2890, 2017). However, the main problem of MAG-ESD is that the placement of the magnetic anchor in vivo often requires the withdrawal and reinsertion of the endoscope, which prolongs the operation time (Zhang et al. in Tech Coloproctol 27:679-683, 2023). We introduced a novel technique, magnetic hydrogel-assisted ESD, and compared it with conventional ESD to explore its advantages and disadvantages.

We uniformly configured 0.5% sodium alginate (Sanchez-Ballester et al. in Carbohydr Polym 270:118399, 2021) (SA) solution, 1% CaCl₂ solution and nano-Fe₃O₄ (Chen et al. in Electromagn Biol Med 34:309-316, 2015) to produce a magnet hydrogel with ideal ratios. Fresh isolated porcine colons were used as a model; these were divided into a magnetic hydrogel-assisted ESD group and conventional ESD group to assess whether magnetic hydrogel-assisted ESD was feasible and advantageous.

The median submucosal dissection time for magnetic hydrogel-assisted ESD (MHA-ESD) and conventional ESD was 15.13 min (IQR 11.21-19.05) and 17.89 min (IQR 13.74-22.04), respectively. The submucosal dissection time for MHA-ESD was significantly shorter compared to conventional ESD (P = 0.0368). Similarly, the submucosal dissection speed for MHA-ESD and conventional ESD was 74.81 mm²/min (IQR 72.18-80.39) and 60.86 mm²/min (IQR 58.96-67.77), respectively. The MHA-ESD group demonstrated a significantly faster submucosal dissection speed compared to the conventional ESD group (P < 0.001).

Compared with conventional ESD, MHA-ESD significantly accelerates the speed of submucosal dissection, effectively improves surgical efficiency, and enhances procedural convenience, thereby reducing the overall difficulty of ESD.