Endoloop ligation after endoscopic mucosal resection using a transparent cap: A novel method to treat small rectal carcinoid tumors

Abstract

Background: Local endoscopic resection is an effective method for the treatment of small rectal carcinoid tumors, but remnant tumor at the margin after resection remains to be an issue.

Aim: To evaluate the efficacy and safety of resection of small rectal carcinoid tumors by endoloop ligation after cap-endoscopic mucosal resection (LC-EMR) using a transparent cap.

Methods: Thirty-four patients with rectal carcinoid tumors of less than 10 mm in diameter were treated by LC-EMR (n = 22) or endoscopic submucosal dissection (ESD) (n = 12) between January 2016 and December 2017. Demographic data, complete resection rates, pathologically complete resection rates, operation duration, and postoperative complications were collected. All cases were followed for 6 to 30 mo.

Results: A total of 22 LC-EMR cases and 12 ESD cases were enrolled. The average age was 48.18 ± 12.31 and 46.17 ± 12.57 years old, and the tumor size was 7.23 ± 1.63 mm and 7.50 ± 1.38 mm, respectively, for the LC-EMR and ESD groups. Resection time in the ESD group was longer than that in the LC-EMR group (15.67 ± 2.15 min vs 5.91 ± 0.87 min; P < 0.001). All lesions were completely resected at one time. No perforation or delayed bleeding was observed in either group. Pathologically complete resection (P-CR) rate was 86.36% (19/22) and 91.67% (11/12) in the LC-EMR and ESD groups (P = 0.646), respectively. Two of the three cases with a positive margin in the LC-EMR group received transanal endoscopic microsurgery (TEM) and tumor cells were not identified in the postoperative specimens. The other case with a positive margin chose follow-up without further operation. One case with remnant tumor after ESD received further local ligation treatment. Neither local recurrence nor lymph node metastasis was found during the follow-up period.

Conclusion: LC-EMR appears to be an efficient and simple method for the treatment of small rectal carcinoid tumors, which can effectively avoid margin remnant tumors.

Keywords: Endoscopic mucosal resection; Endoscopic submucosal dissection; Ligation; Rectal carcinoid.

Figure 1

Utilizing endoloop ligation after cap-endoscopic mucosal resection using a transparent cap to remove rectal carcinoid tumor. Pathology suggested positive margins and further transanal endoscopic microsurgery pathology was negative. A: Endoscopy showing a rectal carcinoid about 10 mm in diameter; B: An electric snare mounted on the transparent cap on the inner lens end; C: Wound after resection; D: Nylon endoloop device installed on the inner lens end; E: Wound after nylon endoloop ligation resection; F: Endoscopic resection of the intact tumor; G: Pathological specimen suggesting a carcinoid, vertical margin positive (× 10); H: Positive immunohistochemical staining for CD56 (× 100); I: Positive immunohistochemical staining for chromogrin (× 100); J: Positive immunohistochemical staining for Syn (× 100); K: Immunohistochemical staining for Ki-67 (< 2%; × 100); L: Transanal endoscopic microsurgery surgery did not identify tumor cells (× 10).