Transanal Endoscopic Microsurgery in a Major Urban Medical Center

Claire Graves, Beth Krieger, MD, Alex Ky, MD, Randolph Steinhagen, MD, Sanghyun Kim, MD. Mount Sinai School of Medicine, New York, NY

 Introduction: Transanal Endoscopic Microsurgery (TEM) is a minimally invasive surgical technique for local excision of rectal lesions. The specialized rectoscope and endoscopic instruments improve visualization and dexterity in the rectum, allowing for full-thickness local resection beyond the reach of traditional instruments. Current literature on TEM consists predominately of small case series and retrospective reviews, with results that may not be generalizable to other institutions. The objective of this study is to evaluate Mount Sinai Medical Center’s experience with TEM, investigating indications for its use, demographics of the patient population, operative statistics, and complications.
Methods and Procedures: We performed an IRB-approved retrospective chart review of patients who underwent TEM from January 2007 through July 2011. Outcome measures included patient demographics, indications for TEM, lesion characteristics, duration of procedure, length of hospital stay, pathology, complications, and recurrences.
Results: Forty-nine patients were identified from our database as having undergone 50 TEM procedures. Twenty-eight (57%) patients were female, and the mean age was 60 years (range, 33-88 years). Preoperative diagnoses included adenoma (n=24), carcinoma-in-situ (n=8), invasive adenocarcinoma (n=6), carcinoid (n=5), and others (n=7). The average tumor size was 2.0 cm (range = 0.2-6.0 cm), and the average distance from the anal verge was 10 cm (range = 3-18). The average duration of surgery was 71 minutes (range = 8-179 minutes). Twenty-nine procedures (58%) were ambulatory, while 21 patients (42%) required hospitalization after surgery. Post-TEM pathology led to upstaging of 9 lesions (18%) and downstaging of 5 lesions (10%). Four specimens (8%) demonstrated positive margins. We found two intraoperative complications (4%), both rectal perforations managed with low anterior resection. Two of the procedures (4%) were converted: one, as above, to a low anterior resection due to rectal perforation, and the other to transanal excision with clear plastic anoscope for better visualization. We found 3 post-operative complications (6%): one rectal bleeding on post-operative day 10, one abdominal abscess on post-operative day 19, and one chronic diarrhea for 4 months after TEM. Of the 33 patients available for follow-up, 6 had recurrences (18%): 5 recurrent adenomas at an average of 4.6 months after TEM, and one patient with T2N1 carcinoid was found to have a perirectal nodule and liver metastases 4 months post-operatively.
Conclusions: We have found TEM to be a safe and effective technique for local excision of rectal lesions with a low rate of complications. TEM offers the option of local excision at a greater distance from the anal verge than traditional means. In 28% of our cases, TEM was responsible for a change in staging, making it a useful tool for definitive diagnosis before the patient potentially undergoes a more invasive procedure. As a retrospective chart review, this study is limited in its follow-up data. Further prospective studies with long-term follow-up are necessary to better characterize recurrence data and oncologic outcomes.

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