Saline-immersion therapeutic endoscopy facilitated en bloc endoscopic submucosal-subserosal dissection of a sigmoid diverticulum containing a refractory adenomatous lesion

Underwater resection has become a well-recognized alternative approach to standard endoscopic resection techniques [1]. Based on the same principles, saline-immersion therapeutic endoscopy (SITE) was introduced as an “evolution of the underwater technique” with several potential advantages [2]. SITE facilitates endoscopic submucosal dissection (ESD) through maintenance of the submucosal lift, intrinsic buoyancy (obviating the need for traction), enhanced dissection, and improved visibility [2] [3].

A 69-year-old woman without comorbidities was referred to our tertiary center for ESD of a refractory sigmoid tubulovillous adenoma (Paris 0-IIa, JNET 2A) ([Fig. 1]), arising from and fully occupying a diverticulum within a tight, strictured segment of the sigmoid colon. Endoscopic resection had been attempted three times at other hospitals without success and the patient was referred to us in order to avoid sigmoid colectomy.

Fig. 1 Refractory sigmoid tubulovillous adenoma arising from and fully occupying a diverticulum.

Given the tightness of the strictured sigmoid segment, alternative options, including full-thickness resection, were deemed impossible. SITE-facilitated endoscopic submucosal-subserosal dissection (ESSD) was performed under conscious sedation ([Video 1]). A gastroscope incorporating water-jet and NearFocus functions (GIF-H290; Olympus, Tokyo, Japan), a short ST hood (Fujifilm, Tokyo, Japan), and a 1.5-mm FlushKnife-BTs (Fujifilm) were used. No gaseous insufflation was used and the ESSD was performed exclusively using SITE ([Fig. 2], [Fig. 3]). Saline immersion eliminated any fluid–gas interfaces; its combination with NearFocus also enhanced optical clarity for more precise dissection with minimal contact, as well as visualization of submucosal vessels. SITE-ESSD ensured meticulous and safe dissection of the whole diverticulum from the surrounding muscularis propria and subserosal space. En bloc diverticular excision was achieved in 90 minutes. Complete R0 resection of the low grade adenoma was confirmed by histopathology ([Fig. 4]). The patient received antibiotics prophylactically and was admitted for 72 hours of observation. No intra- or post-procedural adverse events occurred.

Video 1 Saline-immersion therapeutic endoscopy facilitated submucosal-subserosal dissection of a diverticulum with a refractory lesion.

Fig. 2 Endoscopic submucosal-subserosal dissection assisted by saline-immersion therapeutic endoscopy.

Fig. 3 Procedure performed exclusively using saline immersion with no gaseous insufflation.

Fig. 4 Histopathology image showing the adenoma occupying the diverticulum (red arrows) surrounded by healthy mucosa (green arrows).

SITE-ESSD is a useful, safe, and effective technique even for challenging cases. In this scenario, with great care, and meticulous dissection with minimal contact, SITE-facilitated expansion of the submucosal and subserosal layers, along with intrinsic buoyancy, obviated the need for traction, and allowed for safe and effective en bloc sigmoid “diverticulectomy” as an alternative to sigmoid colectomy.

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• References

• 1 Maida M, Sferrazza S, Murino A. et al. Effectiveness and safety of underwater techniques in gastrointestinal endoscopy: a comprehensive review of the literature. Surg Endosc 2021; 35: 37-51
• 2 Despott EJ, Murino A. Saline-immersion therapeutic endoscopy (SITE): an evolution of underwater endoscopic lesion resection. Dig Liver Dis 2017; 49: 1376
• 3 Despott EJ, Hirayama Y, Lazaridis N. et al. Saline immersion therapeutic endoscopy facilitated pocket-creation method for endoscopic submucosal dissection (with video). Gastrointest Endosc 2019; 89: 652-653