Transanal endoscopic microsurgical (TEM) excision is a procedure that enables a colorectal surgeon to remove a benign polyp or cancerous growth from the rectum without removing the rectum and without an abdominal incision.

During the TEM procedure, a 20 cm-long proctoscope (an instrument used for dilating and visually inspecting the rectum) is placed through the anus, allowing the surgeon to visualize and remove the polyp or cancerous growth.

TEM is less invasive than traditional procedures used to remove benign polyps or cancerous rectal tumors, and it reduces complications and side effects associated with taking out the entire rectum. Most patients have minimal pain and are back to normal activities in two to three days.

Washington University colorectal surgeons most often use TEM excision for removal of benign polyps and early cancers that would otherwise require an abdominal surgery and removal of the rectum. In addition, for elderly or infirm patients, the procedure may be considered to remove more advanced cancers in combination with radiation.

Although TEM excision is not a new technique, the cost of the equipment was originally expensive and the technique was untested. However, in recent years, studies have supported use of the procedure,1-4 and it is being more widely used in the United States.

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  1. Neary P, MD, Makin GB, White TJ, White E, Hartley J, MacDonald A, Lee PWR, Monson JRT. Transanal endoscopic microsurgery: A viable operative alternative in selected patients with rectal lesions. Annals of Surgical Oncology. 2003;10:1106-1111.
  2. de Graaf EJ, Doornebosch PG, Stassen LP, Debets JM, Tetteroo GW, Hop WC. Transanal endoscopic microsurgery for rectal cancer. Eur J Cancer. 2002;38: 904–910.
  3. Langer C, Liersch T, Süss M, Siemer A, Markus P, Ghadimi BM, Füzesi L, Becker H. Surgical cure for early rectal carcinoma and large adenoma: transanal endoscopic microsurgery (using ultrasound or electrosurgery) compared to conventional local and radical resection. Int J Colorectal Dis. 2003;18(3):222-229. Epub 2002 Dec 14.
  4. Mentges B, Buess G, Effinger G, Manncke K, Becker HD. Indications and results of local treatment of rectal cancer. British Journal of Surgery. 2005;84(3):348–351.