Extracorporeal endoscopic submucosal dissection for unblocked resection of anal squamous neoplasm. Our disclosures Case presentation. 63 year old woman had colonoscopy that found a large flat polyp in the rectum approximately 5 centimeters in size. Biopsies revealed anal squamous intraepithelial neoplasia AIN2 in a background of AIN1. Patient was told of HPV on GYN exam since the 1980s. She was referred to our center for endoscopic resection. Here we can see the lesion on underwater examination. The flat portion on the rectal side of the dented line and the wart-like varucus portion on the anal side. On retroflexion again, we can see the flat proximal part of the lesion on the rectal side of the dented line and the varucus part on the anal side. Techniques to be illustrated. For the varucus distal part of the lesion at the anal verge, an innovative extracorporeal ESD approach is illustrated, which is the main focus of this video. For the mid portion in the anal canal, standard pocket and underwater ESD are shown, and for the proximal part of the lesion in the rectum, traction-assisted ESD with clips and rubber band. This graphic illustrates the positioning of the hands and the endoscope for extracorporeal ESD. The endoscope is held like a bovie, but unlike a bovie, it also offers illumination, magnification, and irrigation. A distal cap attachment is not needed since the operator's hand is stabilized by resting on the patient's perianal area. Traction is applied by the operator or assistant with a clamp or even manually, as will be shown on the video. We start by marking the lesion, as shown here. This part of the video shows the marking on the anal side, on the anoderm. And we'll start the dissection also on the anal side and proceed from distal to proximal. We inject a mixture of saline and bupivacaine on the anal side, along with some droplets of methylene blue. This shows the injection on the anal side. And then we proceed with the mucosal incision on the anal side, as shown here. We use dry cut for this. You can see that the incision is extracorporeal. We proceed with some more injection. The needle is not even in the endoscope here, completely extracorporeal. And now you can see the traction that I apply with my left hand. And the right hand is holding the endoscope like a bovie, doing the incision using a hook knife. You can see that we get excellent magnified view and illumination. You can see how I apply traction using my fingers here with the left hand. My gloves are light green and the assistants are dark blue, so you can tell who is doing what in the video. Here I, with my left hand, I use a clamp to put traction as I complete the incision on the anal side here. Here I stretch the anal derm with my fingers, again with the left hand, and here to complete this part of the incision. Here we change to the hybrid multifunctional injecting knife because there is a bit of fibrosis. You can see the dark blue of the assistants hand here, stretching the tissue and pulling on the buttock. And I am holding the clamp with my left hand and with my right hand I am dissecting using the hybrid knife with the endoscope here. You can see a bit of F1 fibrosis there. Now I am even catching the specimen with my fingers and putting direct tension on it for a little bit. The dissection continues mostly with dry cut and precise head currents. And the powerful injection of the knife here achieves good expansion of the submucosa. You can see here direct irrigation from the endoscope when we had a little bit of bleeding. So the endoscope operates as a very enhanced Bovee instrument. After we finish the anal dissection we are now getting into the anal canal where we can convert to traditional ESD. Put the distal cap attachment back on and proceed with traditional ESD using underwater technique here and a bit of pocket technique to continue dissecting the portion of the lesion that is in the anal canal where it's very narrow and obviously it's not a convenient place to use traction. Once we complete the anal canal dissection and we are getting into the rectum there's more space where traction can be applied and also there's enough specimen dissected that now it's folding and flapping around. So some traction will help. We don't need to apply very tight traction. Since we just want to fix the specimen in place we have a good endoscope position to dissect under the specimen. We just want to prevent it from folding on us as we continue the dissection. So now we continue again with the multifunctional knife. The rectum is more vascular. And we use forced current to coagulate these vessels and dry cut or precise sect for the submucosal dissection. And here we are almost done with the submucosal dissection. And once we are done we use a loop cutter to cut a rubber band connecting the two clips. And we use the endoscope to suck the specimen and remove it from the rectum. And this is the defect that is about 60% of the circumference extending to the anal skin. This is the specimen 6 x 3.5 cm with the varicose portion seen. Here is the varicose portion and the scar from the biopsies. And you can see the flat part on the rectal side of the dented line starting there then interrupted by the biopsies and then extending all the way to the other side. And this is the varicose portion. Again the dented line separating the flat portion on the rectal side including the biopsies scar and the varicose portion on the anoderm side. Outcomes. ESD duration 3.2 hours. No postoperative pain but as I indicated we injected bupivacaine for the anal portion of the ESD. Today observation. No adverse events. Pathology. On block ESD with high-grain anal squamous intraepithelial lesion AEN-2 on the background of AEN-1. Margins of resection negative for dysplasia including great margins of 4 mm for AEN-1 and 8 mm for AEN-2. Immunostain showed P16 activation and increased proliferation consistent with HPV driven neoplasia. Follow-up anoscopy and protoscopy at 6 to 12 months intervals by an expert surgeon showed no recurrence or other lesions at 2 years follow-up. On our literature review we found numerous small series and case reports of ESD for anal squamous lesions. However, these lesions did not extend beyond the anal canal and were removed by traditional ESD. Representative references below. To our knowledge this is the first report of extracorporeal ESD. In conclusion, we presented a technique of extracorporeal ESD at the contested territory of the anal verge. The technique is helpful in completing on-block resection of challenging squamous anal lesions that extend distal to the dented line onto the anoderm. The technique illustrates the great versatility of the endoscope which can be used as a monopolar dissection instrument with the additional benefits of focused illumination, field magnification and directed irrigation. Thank you.

Extracorporeal endoscopic submucosal dissection

Anal squamous neoplasm

Rectum

Anal canal

Innovative techniques