Introduction Underwater Endoscopic Mucosal Resection (UEMR) is a relatively new technique, which has been developed for endoscopic resection of colonic lesions. In this technique submucosal injection is not required for many of the lesions. We present here the experience of two UK centres.
Methods All of the UEMR procedures were performed by two experienced interventional endoscopists: NS performed 16 cases at St Mark’s hospital in London, and SI performed 18 cases at Russells Hall Hospital in Dudley. Patient data was collected prospectively. A Hybrid technique, i.e. injection of lifting solution or use of Argon Plasma Coagulation (APC) together with UEMR, was employed if the lesion was traversing a fold/removed in retroflexed position or if there was remnant tissue post resection, respectively.
Results From May 2015 to February 2016, a total of 34 patients (mean age 64 years, range 35–85, males n = 21) have had UEMR of 35 lesions performed by the two operators. The lesions (mean size 33 mm, range 7–160 mm) were located in right colon (n = 5), transverse colon (n = 2), left colon (n = 9), and rectum (n = 19). Seven of the lesions (20%) were recurrence post previous traditional EMR. The morphology of the lesions were either flat (n = 21) or sessile (n = 14). Hybrid technique was employed as follows: Lifting (n = 14), APC (n = 4), and a combination of lifting and APC (n = 2). Histopathology of the lesions demonstrated low grade dysplasia (n = 29), high grade dysplasia (n = 4), and other (n = 2; One hyperplastic polyp, and one sessile serrated lesion). Complete endoscopic resection (at index procedure) was achieved in 34 out of the 35 lesions (97.1%); a large lesion (160 mm in size), which was crossing over two folds, was resected at two planned sessions. There was no immediate bleeding or perforation, but there was one case of delayed bleeding (2.8%). The procedures, which were performed either with no sedation or analgesia (n = 9), with light sedation and analgesia (n = 18), or with Entonox inhalation as required (n = 7), were well-tolerated with a pain score of zero or one (zero = no pain; one = minimal pain).
Conclusion In our experience, underwater endoscopic mucosal resection seems to be a safe and a well-tolerated procedure. It can be an alternative to the traditional EMR, which requires either air or CO2 insufflation, and submucosal injection in all lesions. However, the air or CO2 insufflation significantly thins the bowel wall during the EMR, and submucosal injection does not only create a potential risk of seeding neoplastic cells into deeper wall layers,1 but it also prolongs the procedure time. Follow-up data is required to assess the short- and long-term recurrence rate associated with UEMR.
Reference 1 Binmoeller, KF. J Interv Gastroenterol 4:4:113–116.
Disclosure of Interest None Declared