This clip demonstrates a long segment of barrettes with a large nodule at the bottom end. The nodule has a central 2C depressed area with some oozing and raises a concern of it being a submucosal SM invasive cancer. Acetic acid spray is now being performed mainly to identify any other neoplastic foci in the remaining barrettes. It is worth noting that the nodular area shows a very early loss of aceto-whitening which is suggestive of it being malignant. Acetic acid results in further oozing from the nodule and also highlights the irregular surface pattern confirming the suspicion of it being SM invasive nodule. However the remaining barrettes looked healthy. The margins of this nodular area are now being marked with a dual knife using a forced coagulation mode at 20 watts and these markings are continued all around to pre-mark the resection zone. Once the marking is achieved a strategically planned submucosal injection is performed to elicit the lifting sign in an area very close to the suspected site of deep invasion as shown here. After a little delay submucosal lift begins to appear and this is very important as it confirms the feasibility and safety of endoscopic resection in the absence of which the procedure would have been aborted at this stage. Further injections are then performed to achieve a good submucosal fluid cushion on the oral side of the lesion as shown here. A dual knife is now being inserted through the biopsy port of the endoscope to start the mucosal incision as shown here. The incision is started on the oral side of the lesion and continued until a mucosal flap can be lifted to allow access to the submucosal plane. The distal hood plays a crucial role here in lifting the mucosal flap, allowing the scope to be inserted into the submucosal space and, most importantly, in maintaining the orientation of the scope in the correct plane, as shown here, with the lesion at the top and muscle layer at the bottom. Small gentle strokes of the knife are then delivered in a horizontal plane to incise the submucosal fibres. During this phase of endoscopic submucosal dissection, ESD, it is important to be aware of the planes, which are constantly changing, as shown here, with the lesion on the left and the muscle on the right, so the endoscopist is now cutting the submucosal fibres in a vertical plane, with the knife always moving away from the muscle. As the submucosal fibres are incised, inadvertently some small vessels are being cut, which leads to oozing. The bleeding vessel is identified by the endoscopist and a firm pressure is applied by the distal hood to slow down the oozing until the coag grasper can be inserted. The coag grasper captures the vessel very precisely, as shown here, before coagulating it using a soft coagulation mode, 50 watts, to achieve adequate haemostasis. It is worth noting the importance of distal hood in haemostasis. The knife is now being changed over to a hook knife, as that area is difficult to dissect with a dual knife. The hook knife is hooked into the submucosal fibres and pulled up and away from the muscle to avoid any perforation, as shown here. Once the tricky area is dealt with, the endoscopist reverts back to a dual knife to perform the last bit of incision and achieve a complete single-piece resection of the lesion. Once the lesion is resected, then a very careful assessment of the ESD base is performed to look for any visible vessel or micro-perforation which might require our attention. The specimen is then retrieved and pinned before it is sent to histopathology.

barrettes

large nodule

submucosal invasive cancer

acetic acid spray

neoplastic areas