Endoscopic Full Thickness Resection of Carcinoid Tumors in the Duodenal Bulb, a Case Series. Primary Author, Sarah Dwyer. Co-Author, Schaefer Mock. These are our disclosures. Small Bowel Carcinoid Tumors are a type of narrow endocrine tumor with low metastatic potential and are often found incidentally during endoscopy. The classic means for removal included a pancreatic duodenectomy, or Whipple procedure. However, this surgery has a high risk of morbidity. Therefore, endoscopic therapies have moved to the forefront of duodenal carcinoid removal. Such procedures, including banding without resection, endoscopic mucosal resection, or endoscopic submucosal dissection, were classically used for patients who fall in Stage 1 or 1b with only mucosal or submucosal involvement. However, EMR is limited to mucosal lesions and can lead to recurrence. ESD, on the other hand, has a high rate of end-block resection, but it is time-consuming, also carrying a higher risk of post-procedural complications such as perforation and bleeding. More recently developed is endoscopic Full Thickness Resection, an alternative procedure which allows us to seal off the tissue surrounding the tumor before performing a full thickness removal. This technology thus confers a lower risk of perforation and bleeding in the small bowel. While some studies have demonstrated the role of EFTR in resecting carcinoid tumors in the rectum, there is little research about its use in resecting carcinoids in the small bowel. The following video demonstrates the successful use of EFTR in removing carcinoid tumors from the small bowel in three patients. Here we present three cases of well-differentiated neuroendocrine tumors of the duodenal bulb, which were staged T1B because of their submucosal involvement on endoscopic ultrasound. After obtaining serological markers and PET net imaging, each case was discussed in a multidisciplinary neuroendocrine tumor board with medical and surgical oncology, as well as therapeutic endoscopy. The consensus was to recommend endoscopic ultrasound in possible resection of the masses. We used a similar procedure for each of the three cases shown here. We will first discuss case one, an 81-year-old male with past medical history of COPD, pulmonary hypertension, and CHF with a 25-millimeter well-differentiated neuroendocrine tumor of the duodenal bulb, staged T1B. The patient underwent an endoscopy under high-definition white light, narrow band imaging, and methylene blue chromoscopy, demonstrating the mucosal mass in the duodenal bulb. An endoscopic ultrasound was performed, showing involvement of the lesion into the submucosal layer, and thus staging this at T1B. After we visualized and staged the tumors, we proceeded to endoscopic full-thickness resection, utilizing an over-the-scope CLIP system with bare-claw CLIP and SNARE with the high-cutting current settings seen here. This is a pure cutting current, which allows for rapid tissue destruction without deep thermal injury. Because the EFT-R system has a 13-millimeter diameter, we first dilate the upper esophageal sphincter and pylorus with the 18-19-20-millimeter balloon. We then use a cautery marking device to mark the borders of the tumor. In this case, the lesion was 25 millimeters in size. We next center the over-the-scope CLIP system around the tumor by using a grasping tool to pull the tumor into the cap of the device. It is important to note that this is the most difficult stage because the tumor can slip, so deep purchase and lack of CO2 insulflation and suction are necessary to maintain tissue planes. As we pull the tissue into the cap, we fill the cap with water to displace the air that is providing a pushing force against the tissue. Of note, we do not use suction during this procedure because it puts the lesion at an oblique angle with a higher risk of perforation. Next, one team member provides traction while the other deploys the bear claw CLIP and snare at high cutting currents. This allows us to seal off the tissue with the bear claw CLIP before resecting the tumor with the snare. We then remove the specimen using grasping forceps, ink the deep margin, pin to the paraffin, and put it in a formalin container. This allows us to fix the tissue on paraffin and ensure we have negative resection margins. We were able to achieve negative margins in all three cases. We took a similar approach with our second case, a 78-year-old male with past medical history including COPD, CHF, AFib, and multiple previous abdominal surgeries with a 22-millimeter well-differentiated neuroendocrine tumor of the duodenal bulb, stage T1b. After observing the mass in the duodenal bulb with high-definition white light, narrow band imaging, and methylene blue chromoscopy, we dilated the upper esophageal sphincter and pylorus with the 181920 balloon. We followed the same procedure of marking around the tumor with the electrocautery device. Again, we pull the tumor into the cap. This required a few attempts to pull an adequate amount of tissue into the cap. In this case, after the clip was released, the snare did not properly deploy, so we needed to manually use a snare with the same electrocautery settings to resect the clipped tumor. Every three months following the initial procedure, each patient received surveillance endoscopy. In all cases, there was no residual mass, and biopsy showed no residual neoplasm up to one year following the procedure. In two of the three cases, the clip was not retained, and there was a visible scar as seen here. Additionally, there was no evidence of a visible lesion with one-year follow-up PETnet imaging. Two of the three cases had normal chromogranin A levels at all follow-up points, and the first case had chromogranin A levels that trended down to 145 nanograms per milliliter compared to a normal level of 140 nanograms per milliliter. EFTR was successfully used to resect carcinoid tumors in the duodenal bulb, affording negative margins at resection and no evidence of disease recurrence after one year in all three cases. This procedure may be used to effectively resect tumors in the upper GI tract, including in patients whose comorbid conditions may make them poor candidates for surgery. While complications include perforation with potential impact to the gastroduodenal artery, bile duct, head of the pancreas, or portal vein, the risk of perforation is theoretically lower than ESD because of the ability to seal off the tissue using the clip before resecting with a snare. These three patients with carcinoid tumors of the duodenal bulb have no evidence of disease recurrence by imaging and pathology at one year following EFTR using an over-the-scope clip system. Also, this procedure possibly prevented the need for a morbid surgery that may not have been an option for two of our three patients who had multiple comorbid conditions. These are our references.

Endoscopic Full Thickness Resection

EFTR

carcinoid tumors

small bowel

well-differentiated neuroendocrine tumors