ESD

Fig. 11.1

A case of hybrid ESD. (a) Laterally spreading tumor non-granular type, 25 mm in size, rectum. (b) Non-lifting sign is seen after injection due to fibrosis. (c) Circumferential surrounding mucosal incision using an ESD knife. (d) Submucosal dissection was conducted using an ESD knife with the tip hood. (e) The lesion became around 15 mm in size. (f) Snaring was conducted with hard-type snare. Resection of the lesion including enough submucosal layer was performed just on the surface of muscle layer. (g) The ulcer bed after en bloc resection. (h) Resected specimen

11.3 Indications

Endoscopic treatment is a therapeutic technique and simultaneously an important diagnostic technique as a total excisional biopsy. In the cases of T1 colorectal carcinoma, it is possible to evaluate the deepest invasive part of the tumors and to consider histological diversity through the complete resected specimen. Actually, the frequency of T1 carcinoma increases as the tumor size increases [3]. With multi-piecemeal resection, which makes the pathological reconstruction of a tumor difficult, precise histological evaluation is also difficult, and the local residual rate is higher [7]. For large lesions with size larger than half of the circumference of the colorectal lumen, piecemeal EMR should be avoided, and actual ESD or a surgical operation should be proceeded based on the skill level of the endoscopist and the status of the lesion.

The indications of hybrid ESD to require a precise histopathologic evaluation the same as ESD proposed by the JGES Guidelines other than tumor size (over 20 mm up to 30–40 mm in size) are as follows: (1) large lesions in which en bloc resection using snare EMR treatment is difficult; (2) mucosal lesions with fibrosis, caused by prolapse due to biopsy or peristalsis of the lesion; (3) local residual early carcinoma after endoscopic resection; and (4) sporadic localized tumors in chronic inflammation such as ulcerative colitis [6]. However, safety and standardization of ESD for colorectal tumors have not been yet established. Treatment strategy for choosing among conventional EMR, hybrid ESD, and actual ESD should be discussed based on the clinicopathological characteristics of the lesions, endoscopist’ skill level, and patients’ condition.

11.4 Approach Strategy

With regard to the conditions for performing hybrid ESD, stable endoscopic operability of the lesion by the endoscopists is an essential requirement. If the conditions are unstable because of breathing and heartbeat interfere with endoscopic maneuverability for actual ESD, the endoscopists should interrupt performing ESD procedure and change for rescue hybrid ESD or laparoscopic surgery. The transparent tip hood is essential in hybrid ESD, and the hood facilitates the application of tension for insertion of the endoscope into the submucosa and good visual field. Furthermore, holding the front mucous membrane with the hood thus makes it possible to perform a stable dissection.

A solution of indigo carmine in glycerin-fructose is injected around the tumor to lift the submucosa. After circumferential mucosal incision using a ESD knife or a tip of snare, a mixture of glycerol and hyaluronic acid was injected for submucosal dissection. In hybrid ESD, the trick to hooking the submucosa with the ESD knife is to apply the appropriate traction to the submucosa with the tip hood [8]. It is important to tip the ESD knife upward and pull it through the hole with the forceps. Further submucosal dissection proceeds until the remaining submucosal tissue becomes approximately less than 15–20 mm in size [8]. Submucosal dissection should be performed to be fastened the tumors by a snare. Final resection is made by snaring when the length of the slit on the snare handle becomes less than 5 mm in size. Sufficient submucosal dissection and an approach to horizontal cutting apart side are important to the success of en bloc resection by snare EMR at the final stage (Fig. 11.2). When the tumors have severe fibrosis in the submucosal layer, submucosal dissection should be continued until the snaring is successfully done. Hard-type snare is suitable to prevent slip of the snare from the tumor.