Flexible CO₂ laser and submucosal gel injection for safe endoluminal resection in the intestines

The CO₂ laser’s unique wavelength of 10.6 μm has the advantage of being readily absorbed by water but historically limited it to line-of-sight procedures. Through recent technological advances, a flexible CO₂ laser fiber has been developed and holds promise for endoluminal surgery. We examined whether this laser, along with injection of a water-based gel in the submucosal space, will allow safe dissection of the intestines and enhance the potential of this tool for minimally invasive surgery.

Using an ex vivo model with porcine intestines, spot ablation was performed with the flexible CO₂ laser at different power settings until transmural perforation. Additionally, excisions of mucosal patches were performed by submucosal dissection with and without submucosal injection of a water-based gel.

With spot ablation at 5 W, none of the specimens was perforated by 5 min, which was the maximum recorded time. The time to perforation was significantly shorter with increased laser power, and gel pretreatment protected the intestines against spot ablation, increasing the time to perforation from 6 to 37 s at 10 W and from 1 to 7 s at 15 W. During excision of mucosal patches, 56 and 83% of untreated intestines perforated at 5 and 10 W, respectively. Gel pretreatment prior to excision protected all intestines against perforation. These specimens were verified to be intact by inflation with air to over 100 mmHg. Furthermore, excision of the mucosal patch was complete in gel-pretreated specimens, whereas 22% of untreated specimens had residual islands of mucosa after excision.

The flexible CO₂ laser holds promise as a precise dissection and cutting tool for endoluminal surgery of the intestines. Pretreatment with a submucosal injection of a water-based gel protects the intestines from perforation during ablation and mucosal dissection.