Abstract
Variable success with laser ablation of Barrett's columnar lining has been described. Laser ablated areas are reported to heal by normal squamous cells in the presence of acid suppression. The technique, however, requires multiple treatments, and complete ablation is difficult. We have evaluated a new method for mucosal ablation using a recently designed laparoscopic CUSA (Cavitron Ultrasonic Surgical Aspirator) probe with an intraluminal endo-gastric approach. The water content of mucosal cells makes the epithelium sensitive to ultrasonic cavitation and accounts for the tissue selectivity of the CUSA. Methods: The technique was developed using eight 14-16 week Landress pigs (wt 60-80 Ibs.) Cadaveric and in vivo esophageal specimens were used to determine the optimal CUSA settings of amplitude and "cavi-pulse" for mucosal ablation. Mucosal ablation was assessed histologically. A pig model was then used to place an operating gastrostomy port using a percutaneous endoscopic technique. Through the port a laparoscopic CUSA probe was passed and guided into the esophageal lumen using endoscopic guidance from above The CUSA was then applied to the esophageal mucosa under endoscopic surveillance. The esophagus was removed and examined histologically Results: The endo-gastric approach to the esophageal lumen is feasible. The CUSA probe was able to reach 13 cm into the esophagus as measured from the gastroesophageal junction. The tissue selectivity of the CUSA technique resulted in complete ablation of the esophageal mucosa down to the muscularis mucosa with no destruction of the submucosa. Similar mucosal ablation was possible on gastric columnar lining. All of the removed mucosal cells were collected by aspiration for cytology. Blood loss was minimal and perforation did not occur. Discussion: This new technique of ablating esophageal mucosa holds promise for the eradication of Barrett's epithelium without causing damage to the underlying submucosa The removed mucosal cells retain their integrity and morphology which allows for cytological assessment of the ablated epithelium Studies assessing the healing response are currently in progress.