BACKGROUND

Laparoendoscopic single-site surgery and natural orifice transluminal endoscopic surgery attempt to reduce transabdominal port sites. These require all instruments to pass through a single access point, leading to instruments collide or work at unfamiliar angles. Thus, we designed an internal grasper under magnetic anchoring guide system (MAGS) platform and investigated its utility and operability.

METHODS

We measured the configuration for magnetic force decay over distance using a standardized, ex vivo laboratory testing apparatus. An electronic balance was used to measure the force of the gallbladder pull in ten patients with gallbladder stones. One pig (11 mm abdominal wall thickness) underwent a compressed trial of MAGS platform. The device was left in place for 20 min before tissue sections were harvested, and histologic assessment was performed. The utility and operability were investigated in four pigs (38-280 kg weight).

RESULTS

The magnetic attraction force decayed exponentially over distance; the force of pulling gallbladder was 7.46 ± 0.54 N. This pairing of components allowed for coupling to a theoretical distance of 10 mm. No gross tissue damage was observed. H-E stain showed no necrosis in all specimens. One failed due to wall thickness of 45 mm. Others showed the critical view, triangulation of instruments was obtained, and instrument collision or "sword fighting" was reduced.

CONCLUSIONS

The MAGS platform overcomes limitations such as collisions and lack of triangulation, reduces transabdominal port sites, and is easy to operate. However, our internal grasper requires the abdominal wall thickness below 10 mm.