Transanal Endoscopic Microsurgery, often abbreviated to 'TEM', is a surgical procedure that is used to remove polyps from the rectum that cannot be removed during a colonoscopy. Benign polyps that are either too large, or are flat, cannot be removed in a colonoscopy procedure, so TEM is required instead.
The procedure is very similar to laparoscopic (i.e. 'minimally invasive' or 'keyhole') surgery, however it is not suitable for the treatment of rectal cancer or for the removal of malignant (i.e. cancerous) polyps.
Transanal Endoscopic Microsurgery is conducted under a general anaesthetic and generally takes 45-90 minutes to complete.
The procedure involves the removal of the polyp/s using surgical instruments which are introduced to the rectum via the anus. To assist the surgeon in performing the operation, the rectum is first inflated using carbon dioxide.
After any polyps are removed the affected part of the rectum is repaired with stitches.
As it not always possible to identify whether or not a polyp is benign or cancerous during the procedure, all tissue removed during surgery is sent for analysis. Roughly one in ten polyps removed are found to have some cancer cells present during pathology testing, in which case further surgery may be required to treat any remaining cancer.
In most cases there is very little or no pain after the procedure and most patients are able to return home the day after surgery.
There are no specific postoperative guidelines, however it is possible that bowel motions may become more frequent and/or urgent for a few weeks after the procedure. There may also be looser bowel motions than normal and some (normally very minor) faecal incontinence.