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Transanal Endoscopic Microsurgery

Washington DC Rectal Surgeons

Transanal Endoscopic Microsurgery - TEM - is a minimally invasive surgical technique that allows the surgeon to operate on problems in the mid and upper rectum without having to make an incision through the abdomen. The instruments are specially designed so that the procedure can be performed through the anus and in the rectum. An operating proctoscope (a 2 inch wide tube) is placed through the anus and positioned over the lesion. The rectum is filled with carbon dioxide gas so there is room to work. A special microscope is used to look at the area directly and with a video camera. Long instruments are then used to grasp, cut, and suture.

The TEM technique may be recommended for patients with polyps that are too large to be removed with a colonoscope and small cancers that have not yet invaded into the muscle layer of the bowel wall. Lesions up to 15-20 centimeters above the anal opening may often be removed with this method.

Eligibility & Preparation

Some patients may require an endorectal ultrasound or a CT scan to determine how deeply a tumor has spread into the bowel wall or whether the disease has spread to lymph nodes or distant sites such as the liver or lungs.

If you have any significant medical problems, a medical clearance report is needed from your primary care doctor. You should call his or her office to arrange for this. If you have heart problems, you may need clearance from a cardiologist who may order additional tests.

You will need to complete a bowel preparation on the day before surgery to clean out the colon and rectum in order to reduce the risk of infection. Do not eat or drink anything for at least 8 hours before the operation. Follow the preparation directions supplied closely.

The Procedure

Sometimes, the lesion may be too high in the rectum or the rectum may be too narrow for the operating scope. In these situations, the procedure may be converted to an abdominal operation. As in any surgical procedure, there is the risk of bleeding. In order to reduce this risk, you should not take aspirin, dipyridamole (Persantine), Plavix, ibuprofen (Advil, Motrin, etc.), Aleve, or other non-steroidal anti-inflammatory medications (NSAIDs) for 10 days before your surgery as these medications interfere with platelet function and increase the risk of bleeding. If there is any question, check with your physician.

Infection is a possible complication but is quite rare. If the lesion is large or very wide, the rectum may be narrowed (strictured) after closing the defect in the wall. This usually stretches out in time but dilation or other treatments may be necessary. The most common problem in men is difficulty urinating after the procedure. Occasionally, this requires placement of a urinary catheter temporarily. If the lesion is in the front of the rectum in a woman, it is possible to develop a fistula (tunnel) into the vagina. Fortunately, all of these complications are fairly rare.

Advantages of the Procedure

TEM is an attractive alternative to abdominal surgery. The procedure is performed entirely through the anus. Therefore, no abdominal incision is made which means minimal pain and a much faster recovery time. In fact, most patients are sent home the same day as the surgery. The risk of complications, such as infection and hernias, is also much lower with TEM than with abdominal surgery. Patients are able to return to normal activities much more quickly – usually 1-2 weeks after surgery versus 5-6 weeks after abdominal surgery.


Most patients are discharged from the hospital when the anesthetic has worn off, about three to four hours after the surgery. You must be accompanied home by a responsible adult that you know. Occasionally, patients may be kept overnight for monitoring.

Although most patients only experience minimal discomfort after the operation, your doctor will prescribe pain medication. You will need to keep your stools soft and passing easily after surgery. This is accomplished by eating a high fiber diet, and taking stool softeners and fiber supplements.

If you notice large amounts of blood or pus from the rectum, increased pain or fever you should call immediately.

You will need to follow-up with your doctor after the operation to check the operative site and to look for new polyps or problems. A return visit in 3 for a proctoscopic examination is generally recommended. A Fleets enema should be taken just prior to the visit. You will then need to have a repeat colonoscopy at one year and regularly thereafter as indicated by your surgeon or gastroenterologist.

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