The rectum is considered a feasible and safe area in which to perform endoscopic submucosal
dissection (ESD) [1]
[2]. Therefore, ESD is a suitable approach for the treatment of high risk rectal adenomas.
However, scarred and fibrotic polyps have recently been described as the only preoperative
predictor of failed ESD in the rectum [2]
[3]. Transanal endoscopic microsurgery (TEM) has been shown to be an effective treatment
for lower rectal carcinomas staged as T1 or T2 [4], owing to the depth of the resection.
We present the case of a 25 mm 0-Is type adenoma with wide scarred areas caused by
two previous failed TEMs, located 3 cm away from the dentate line ([Fig. 1]), in a 75-year-old man without any relevant medical history.
Fig. 1 Intensely scarred adenoma located 3 cm away from the dentate line.
The pocket creation method was adopted because of the expected submucosal fibrotic
tissue [5]. The first stage of the tunnel was created without any drawbacks using an Erbejet-2-HybridKnife
(Erbe Elektromedizin GmbH, Tübingen, Germany). However, when the area below the lesion
was reached, dramatic fibrotic tissue became visible. This finding made it extremely
difficult to identify a feasible cutting line between the submucosal and muscular
layers. At this point (stage 2), we decided to carry out a transmural dissection between
the transverse and longitudinal muscular layers, in order to reach a feasible cutting
line inside the submucosal layer ([Fig. 2], [Fig. 3], [Video 1]). Consequently, we successfully achieved en bloc resection of the lesion (stage
3). Subsequently, the muscular defect was closed using endoclips (Resolution; Boston
Scientific, Marlborough, Massachusetts, USA). The patient was discharged 72 hours
after the procedure.
Fig. 2 Transmural dissection planning diagram. a Different layers exposed during the procedure. b Final result. Red line indicates the previous location of the adenoma. SM, submucosal
layer; ML, muscular layer.
Fig. 3 Detailed endoscopic transmural hydro-dissection procedure. a – c Initial step: tunnel creation across the submucosal layer. d Submucosal and muscular layer fusion without a feasible traditional cutting line.
e Cutting of transverse and longitudinal muscular layer. f Dissection phase between transverse and longitudinal layer. g Remaining longitudinal muscular layer and perirectal fatty tissue exposed inside
the tunnel. h Endoscopic submucosal dissection in retroflex position across the submucosal layer.
i – k Final dissection steps. l Specimen mounted onto cork.
Video 1 Endoscopic transmural hydro-dissection by pocket creation method of a sessile scarred
polyp located in the lower rectum.
The histopathological analysis revealed a transmural specimen with high grade dysplasia
(R0 resection), intense fibrotic submucosal tissue, and superficial muscular propria
layer ([Fig. 4]).
Fig. 4 Microscopic analysis of the dissected specimen, focusing on the different stages
of the procedure. SML, submucosal layer; ML, muscular layer.
In conclusion, the pocket creation method performed in fibrotic and scarred lesions
located in the lower rectum, allowed a safe and deep dissection across muscular layers.
This approach might support ESD as a rescue therapy following failed TEM.
Endoscopy_UCTN_Code_TTT_1AO_2AG
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