Transanal Endoscopic Surgery With Peritoneal Entry: A Word of Caution

George Molina, MD, Liliana Bordeianou, MD, Paul Shellito, MD, Patricia Sylla, MD. Massachusetts General Hospital

INTRODUCTION: Peritoneal entry with loss of pneumoperitoneum during TEM can be safely managed with full-thickness suture closure in experienced hands. Early results with transanal minimally invasive surgery (TAMIS) demonstrated preliminary safety, but the overall experience with upper rectal tumors across multiple platforms is limited.

METHODS: Transanal endoscopic surgery cases performed at a single institution between 2008 and 2014 were retrospectively reviewed. Surgical indications, patient and lesion variables, intraoperative complications and 30-day postoperative morbidity were analyzed. Fisher’s exact test was used to compare categorical variables.

RESULTS: 78 transanal endoscopic procedures were performed in 76 patients including 40 females and 36 males with mean age of 61 (range, 21-86). Procedures were performed using the rigid TEO (65.4%), rigid TEM (26.9%), or TAMIS platform (7.7%). Indications included endoscopically unresectable adenomas (50%), T1 cancers (27%), carcinoid tumors (7.7%), T2/T3 cancer (6.4%), rectal ulcers (3.8%) and other benign lesions (5.1%).The uppermost aspect of lesions was an average 9.5 cm (range, 4-20 cm) from the anal verge (AV) and located 4-7 cm (43.6%), 8-11 cm (24.4%), or 12-20 cm (32%) from the AV. Lesions were primarily posterior (32%), lateral (30.8%), anterior (19%), or near circumferential (19.2%). Peritoneal entry was noted in 22/78 cases (28.2%) including 18/72 (25%) TEM and 4/6 (67%) TAMIS (p<0.05). Lesions associated with peritoneal entry included one lesion (4.5%) located 4-6 cm, 7 lesions (32%) located 7-11 cm, and 14 lesions (63%) located 12-20 cm from the AV (p<0.001). Peritoneal entry complicated full-thickness dissection of 60% of near circumferential and 36% of anterior lesions vs. 20% of posterior and 12.5% of lateral lesions. All 4 TAMIS cases complicated by peritoneal entry involved lesions located 10-15 cm from the AV, and were converted to TEM due to critical loss of adequate exposure. All defects associated with peritoneal entry were successfully closed with TEM platforms except in 2 patients with lesions 15 and 20 cm from the AV, where conversion to laparoscopic low anterior resection (LAR) with diversion was required due to inadequate suture closure of rectal defects. The average specimen size was 3.9 cm (range, 1.3-8.5 cm) and average length of stay (LOS) was 1.5 days (range, 0-6 days). Overall margin positivity was 10.1% following resection of 9 adenomas and one T3 rectal cancer. Overall 30-day morbidity was 16.7% including conversions to LAR (2), urinary retention (5), atrial fibrillation (2), minor bleeding (1), congestive heart failure (1), fever (1) and presacral abscess requiring drainage (1). Peritoneal entry was not associated with an increase incidence of perioperative complications (9% vs. 17.8%, p=0.3) or LOS (1.7 vs. 1.4 days, p=0.4).

CONCLUSIONS: In this relatively high risk TEM and TAMIS series with one third of lesions located in the upper rectum or rectosigmoid, safe management of peritoneal entry using TEM platforms was feasible in 91% of cases without significant increase in morbidity. TAMIS for upper rectal lesions was associated with a high risk of conversion, and should be reserved for low and mid-rectal lesions with a lower risk for peritoneal entry.