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

Abstract

Background 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. Methods 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. Results 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. Conclusion 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.

Study of the Changes of Gastric Wall Mucosa Optical Properties under the Impact of Aqueous Solutions of Haemoglobin and Glucose for Improving Conditions of the Laser Coagulation

“…The contactless laser coagulation and ablation of pathologic formations in different organs is widely used in modern clinics [1][2][3][4][5][6][7][8]. The minor invasiveness of the procedure reduces the risk of postoperative complications.…”

“…The minor invasiveness of the procedure reduces the risk of postoperative complications. The sources used for this purpose include, particularly, the ytterbium (1075 nm) [3], СО2 (9.4-10.6 µm) [5], Nd:YAG (1064 nm) [1,4], diode (980, 808, 810 nm) [2,6,7], and other lasers. The main advantage of lasers generating at the wavelengths that coincide with the absorption bands of water is the small depth of light penetration into tissues, which prevents the damage of the adjacent healthy tissue, underlying the affected area [5,8].…”

Analysis of opto-thermal interaction of porcine stomach tissue with 808-nm laser for endoscopic submucosal dissection

“…For tissue ablation in surgical procedures, di®erent types of laser have been used previously such as potassium titanyl phosphate (KTP), neodymiumdoped yttrium aluminium garnet (Nd:YAG) and CO 2 laser. The most widely used variety is CO 2 gas laser which has a wavelength of 9.4-10.6 m. Au et al 4 showed that irradiation with CO 2 laser can cut lesions and maintain hemostasis simultaneously because the target tissue's high absorption protects the surrounding tissues from damage and the laser creates a clear cut surface. Also, it has advantage of better visibility due to low level of hemorrhaging.…”