Transanal Endoscopic Microsurgery: Advantages and Indications of Submucosal and Full-thickness Resection Techniques

Antonio Maya, MD, Marylise Boutros, MD, Mohammed Elmessiry, MD, Giovanna da Silva, MD, Steven D Wexner, MD, Dana Sands, MD

Cleveland Clinic Florida

INTRODUCTION: Transanal endoscopic microsurgery (TEM) for the excision of rectal lesions can be performed by submucosal (SM) or full-thickness (FT) techniques. We aimed to compare the operative, pathologic and postoperative outcomes of these 2 techniques in order to better define the optimal indications and applications for each method.

METHODS AND PROCEDURES: After IRB approval, patients who underwent resection of rectal tumors by TEM from 11/2005 to 8/2012 were identified from our prospective database. Demographics, operative, pathologic and postoperative variables were obtained from chart review. Outcomes for SM and FT TEM resections were compared using chi-square and Student’s t-tests. A p < 0.05 was considered significant.

RESULTS: Eighty-six patients (median 66 years, 70.7% male) underwent 89 TEM resections (56 FT and 33 SM). The 2 groups were well matched for demographics, ASA score, comorbidity and number of previous incomplete (transanal or endoscopic) polypectomies. The most common indication for TEM in both groups was dysplasia (SM 100% vs. FT 62.5%, p=0.001). FT was preferentially used for adenocarcinoma (SM 0 % vs. FT 25.0%, p=0.001) and carcinoid (SM 0% vs. FT 12.5 %, p=0.03) lesions. The most common tumor location was left lateral (30.3%). Posterior tumors were more frequent in FT (SM 9.09% vs. FT 37.5%, p=0.001). SM technique was associated with more specimen fragmentation (SM 27.2% vs. FT 1.7%, p=0.001) and involved margins (SM 45.5% vs. 17.9%, p=0.001), without any impact on recurrence (SM 3.03% vs. FT 3.70%, p=0.86). There was a trend for specimen size to be larger for SM compared with FT (5.2±3.8 vs. 4.2 cm±1.3, p=0.15). Larger specimens were associated with fragmentation (fragmented 6.9±6.5 vs. nonfragmented 4.4±1.4 cm, p=0.001).There were no differences between FT and SM for mean distance from the anal verge (8.13 cm ±3.32), blood loss (18.2 mL ±19.8), operative time (109.53 minutes ±65.6), intraoperative complications (3.37%), hospital stay (1.62 days, ±1.44) and postoperative complications (SM 15.2% vs. FT 16.1%, p=0.908). Three patients were readmitted (SM 5.35 % vs. FT 0.00, p=0.17). No reoperations were needed. The mean follow-up was 5.6 (1-70) months. The incidences of transient impaired continence were similar between groups (SM 18.2% vs. FT 12.5%, p=0.46) and resolved within 90 days post-TEM.

CONCLUSION: With appropriate patient selection, SM and FT are both safe and effective TEM techniques. FT is associated with free margins and lack of fragmentation; thus, it is better suited for tumors that are highly suspicious for or have proven malignancy. SM resection is associated with more specimen fragmentation and involved margins, without any impact upon disease recurrence. Therefore, the SM technique is better suited for large extensive, high and benign lesions involving the anterior and lateral rectum, as this technique preserves the integrity of the rectal wall, avoiding peritoneal entry.

Session: Poster Presentation

Program Number: P109

« Return to SAGES 2013 abstract archive