TEM allows the patient to recover rapidly and the incidence of complications is much lower than that of major open or laparoscopic surgery. In case of recurrence the option of repeat TEM or major laparoscopic or open surgery remain available. TEMS has been slow to gain popularity mainly for reasons of cost, use of specialized instrument and steep learning curve but it is now an established procedure and a valuable therapeutic option which is particularly useful for elderly and unfit patients. Gastroenterologists should be aware of the nature and indications of TEMS in order to advise and refer selected patients with rectal adenomas accordingly.
Conventional major rectal surgery has an impact on quality of life because of side effects of bladder dysfunction or erectile dysfunction. Both those complications can affect adversely the quality of life and patients have to be warned regarding the risk. Conventional rectal or laparoscopic surgery carries the risk of a stoma: a permanent colostomy in the case of an abdominoperineal resection of the rectum or sometime atemporary ileostomy or colostomy in the case of an anterior resection of the rectum. A temporary stoma carries the necessity for one more operation to close it. The presence of a stoma can be both hard to accept and difficult to manage for some patients.
TEMS was first described and developed by G. Buess in the early eighties. It requires specially designed equipment which until recently had a high cost. TEMS also requires a minimal access surgeon who possesses advanced laparoscopic skills since it is essentially a form of laparoscopic surgery performed in a much more confined space. The technique is therefore demanding and one of the problems is that the learning curve is steep because the number of cases is rather small for surgeons to acquire technical expertise. Concentration of cases in certain centres would allow for easier accumulation of experience with the technique.
The equipment necessary for TEMS consists of the operating 4 centimetres diameter sigmoidoscope, the sterioscope, laparoscopic atraumatic forceps, laparoscopic diathermy or vessel sealer, laparoscopic irrigation-suction device. The above instruments are connected to a standard laparoscopic "stack" incorporating a gas source, a light source and a high resolution monitor.
Full bowel preparation is required pre-operatively. The patient is put in lithotomy position and the whole procedure is performed transanally unless there is a complication of intra-abdominal perforation of the rectum. General anaesthetic is used mostly although the author and others have performed cases under spinal anaesthesia.
As an alternative to more radical abdominal surgery, Transanal Endoscopic Microsurgery (TEM) offers a minimally invasive solution for the excision of certain rectal polyps and early stage rectal tumors. TEMS is a useful minimally invasive technique for treatment of certain large or sessile adenomas of the rectum. It can successfully treat those adenomas which are not amenable to colonoscopic excision and can spare some patients the risks and side effects of major rectal surgery. It can be preformed as a short stay procedure even without general anaesthetic, with minimal morbidity and no mortality. In case of malignant transformation or recurrence it is still worth doing TEMS as first line treatment since it does not preclude radical surgery and can be repeated for treatment of recurrences. Gastroenterologists should be aware of the usefulness of TEMS as a therapeutic option in order to advise and refer their patients accordingly.
The patient benefits of TEM as compared to radical abdominal surgery are clear: no major surgery, no large incision, no colostomy, less pain, faster recovery and shorter hospital stay.
Indication of TEM in benign disease
- Rectal polyps
- Carcinoid tumors
- Retrorectal masses
- Anastomotic strictures
- Extrasphincteric fistulae
- Pelvic abscesses
Indication of TEM in malignant disease
- Malignant rectal polyps
- T1-T2 rectal cancer
- Palliative excision of T3 cancer
- Full colonoscopy
- Rule out synchronous lesions
- Rigid proctoscopy
- Determine level and position of lesion
- Endorectal ultrasound
- Confirm stage of lesion/depth of penetration
- Confirm uT0 or uT1 status
- If uT2 or uT3 should do definitive surgery if patient a candidate
- TEM is not generally used to treat N1 disease
- Technically demanding procedure
- Utilizes highly specialized instrumentation
- Advanced endoscopic technique
- Can spare selected patients laparotomy and anterior resection
- Adequate training is imperative
- Patient selection is paramount