Rectal laterally spreading tumors successfully treated in two steps by endoscopic submucosal dissection and endoscopic mucosal resection

A 56-year-old male presented with a LST, 8-9 cm in diameter, located on the posterior wall of the rectum, 10 cm far from the anal verge and occupying 2/3 of the colonic lumen at colonoscopy (Figure 1a). The patient stated abdominal pain and lower gastrointestinal bleeding for 2 years.

Ecoendoscopy (Olympus GFUE160, Milan, Italy) showed a mucosal lesion with an area involving the superficial part of the submucosal layer (sm1), in absence of lymph node involvement.

The ESD/EMR combined procedure was carried out using a double-channel colonoscope (Olympus CF2T160I, Olympus, Milan, Italy) with the patient deeply sedated by propofol. Given the position and size of the lesion, a gastroscope (Olympus Gif Q 165, Olympus, Milan, Italy) retroflexed into the colon was used to resect the distal margin of the polyp.

The sub-mucosal injection of hyaluronic acid was performed around the lesion, previously enhanced with 1% indigo carmine (Figure 1b), followed by pre-cutting the surrounding mucosa of the tumor (Flex-knife Olympus, Tokio, Japan) (Figure 1c). The resection of the biggest part of the lesion was achieved using two knives (Hook-knife and insulation-tipped diathermic knife IT-knife; Olympus, Tokio, Japan). Nevertheless, even using a double-channel colonoscope (with the simultaneous use of forceps and knives), the excision of the central zone of the polyp was not completed. The remnant lesion was, therefore, removed by means of EMR-strip biopsy, with the "piecemeal" technique (Figure 1d). Post-operative course was uneventful. Histological examination revealed a tubulo-villous adenoma with high grade focal dysplasia. At 3 and 12 months' follow-up, no recurrence was detected in the excised area (Figure 1e, f).

A 74-year-old male presented with a LST, 10 cm in diameter, located on the posterior wall of the rectum and 8 cm far from the anal verge at colonoscopy (Figure 2a). The patient stated haematochezia and mucorrea for 12 months. The eco-endoscopy excluded involvement of the submucosa,

ESD was planned; the polyp spray with 1% indigo carmine was carried out, followed by the injection of hyaluronic acid at the base of the lesion and by the pre-cutting of surrounding mucosa of the polyp with the Flex-Knife (Figure 2b).

The circumferentially excision was then performed, from the margin to the central area. Despite the use of dual channel colonoscopy, hook knife and repeated injections of hyaluronic acid, the complete en bloc resection was impossible due to the size of the lesion already excised (Figure 2c, d). The procedure was completed by EMR - strip biopsy- using the "piecemeal" technique (Figure 2e). Histological examination revealed tubulo-villous adenoma with low grade dysplasia. At 6 months' follow up endoscopy showed lack of recurrence (Figure 2f).

A 59-year-old female presented with a LST approximately 8 cm in diameter, located at the recto-sigmoid junction at colonoscopy. The patient stated postdefecatory abdominal pain and rectal bleeding for few months. The ecoendoscopy, performed upon admission, excluded submucosa involvement.

ESD was planned (Figure 3a, b, c). ESD en bloc resection was not possible in consideration of the size and the site of the lesion. Thus, the resection was completed with EMR-strip biopsy, using piecemeal technique (Figure 3d), which allowed for complete removal (Figure 3e). During the procedure, a severe haemorrhage occurred at the base of the polyp and was successfully treated with the injection technique. At histology, a tubulo-villous adenoma with low grade dysplasia was detected. Three months' endoscopy showed intact mucosa in the procedure site (Figure 3f).