Long-term Outcomes by Transanal Total Mesorectal Excision (taTME) for Rectal Cancer

Elizabeth A Myers, DO, Mounica Gummadi, BA, Gerald J Marks, MD, John H Marks, MD. Lankenau Institute for Medical Research

INTRODUCTION:  The challenge of performing good TME dissection, particularly in the distal 1/3 of the rectum, has spurred interest in new techniques.  Robotic surgery has been advocated by some to overcome the technical difficulties of surgery in the distal rectum.  More recently a “new” approach, the transanal total mesorectal excision (taTME), has been popularized to address this problem.  While great interest in this technique exists, little data of long term outcomes are available.  We have been utilizing a taTME approach to facilitate the distal dissection and allow a known distal margin for difficult cases and in the present study, we provide our long-term outcomes using the taTME approach in the management of rectal cancer.

METHODS AND PROCEDURES: From a prospectively maintained rectal cancer database, we identified 379 consecutive rectal cancers treated with sphincter preservation surgery (SPS) through a combined taTME and abdominal approach.  Perioperative, pathological, and oncologic outcomes including local recurrence (LR), distant metastasis (DM), and survival were analyzed.

RESULTS: 379 patients with rectal cancer underwent taTME with mean follow up of 5.5 years.  91% of the cancers were in the distal rectum.  70.2% of patients were men and 52% of cancers were tethered or fixed on presentation.   97% received neoadjuvant radiotherapy (mean 5419 cGy, range 3000-8580 cGy; 5-FU based); average time from completion of neoadjuvant therapy to surgery was 10.5 weeks. 182 and 197 patients underwent completion of their operation through open and laparoscopic (Lap) abdominal approaches, respectively.  Median blood loss was 400 cc (mean: Open 907 cc, Lap 382 cc).  96% of TME specimens were complete or near complete, 94% had a negative circumferential resection margin (CRM), and 98.6% had a negative distal margin.  Overall perioperative morbidity and mortality rates were 18% and 0.3%, respectively. Overall LR, DM, and KM5YAS were 7.6% (Open, 10.8%; Lap, 4.8%), 20% (Open, 18.1%; Lap 21.2%), and 89% (Open, 90%; Lap, 92%), respectively.  

CONCLUSION:  This is the first report of long term data using taTME and shows low risk for local recurrence with an excellent overall survival.  Our data with 5 year follow-up supports this approach for rectal cancer, showing that adequate distal and circumferential margins with very good quality TME specimens can be obtained using this technique.  While randomized trials will be required to confirm these findings, our long term results support the promising reports of early experiences in the literature.