Background: Normal saline (NS) plus epinephrine (E) is the traditionally used solution as submucosal fluid cushion for a safe and effective endoscopic mucosal resection (EMR) of sessile colorectal polyps. It was hypothesized that hydroxyethyl starch (HES), an inexpensive and easily available solution might be an ideal solution for prolonged elevation of submucosal cushion for an easy and safe EMR of giant colorectal lateral spreading tumors (LSTs).
Patients and methods: During a 6-year period, patients suffering from colorectal LSTs with a diameter of ≥ 30 mm were randomized to undergo EMR by using either HES+E (group A) or NS+E (group B) for submucosal fluid cushion. All patients who had undergone a colonoscopy set the diagnosis of LSTs. The LSTs were examined with standard white light and narrow-band imaging to accurately delinate their margins before resection. The initial volume of injected solution, the additional amount to maintain the submucosal cushion, the duration of submucosal elevation and post-EMR-related complications were recorded. After EMR, patients had a standard follow-up at 3, 6, and 12 months and further if it was necessary using total colonoscopy.
Results: Forty-nine patients suffering from giant LSTs were included in the study. No difference between the 2 groups was observed in patients' characteristics, size of LSTs, and the initial volume of injected solution. However, the additional amount of solution to maintain submucosal elevation was lower in group A (median, 4 mL; range, 2 to 25) than in group B (median, 6 mL; range, 3 to 8; P=0.001). Moreover, submucosal elevation had a statistically longer duration in group A (median, 18.5 min; range, 14.5 to 28.4) than in group B (median, 20.15 min, range, 9.6 to 13.4; P<0.001), and there was a statistical difference on total procedure time in favor of group A [group A, 20.15 min (12 to 32.5) vs. group B, 22.8 min (18 to 34.5)]. One case of macroperforation, 2 cases of postpolypectomy syndrome, and 1 case of EMR-related bleeding were observed in the HES+E group, whereas 6 cases of EMR-related bleeding were observed in the NS+E group. During a median follow-up of 32 and 34 months, for HES+E and NS+E groups, respectively, 5 and 7 recurrences were observed, which were all treated endoscopically.
Conclusions: HES+E injection produces a more prolonged submucosal elevation and lowers total procedure time than NS+E; however, the safety of EMR is not influenced.