By D. Mark Zebley, MD
Natural orifice surgery has been gaining attention lately for its benefits as a minimally invasive approach for some conditions. Yet the concept is not all that new. For more than 10 years, Abington Memorial Hospital has been one of the few institutions in the Delaware Valley performing transanal endoscopic microsurgery—known as a TEM procedure—on patients with large rectal polyps.
While most polyps can be removed during a colonoscopy, some require an operation. TEM allows experienced surgeons to excise polyps that are broader-based or located higher in the rectum, thus allowing the patients to avoid an abdominal operation. If left in place, some of these polyps could become cancerous.
Most patients who are appropriate candidates for transanal endoscopic microsurgery have benign polyps. The procedure is not ideal for excising rectal cancers except in a small population of patients because it does not remove lymph nodes.
Equipment designed for the TEM procedure lets us visualize polyps better than with traditional instruments. A camera and fiber optic light are placed through the anus, reaching as high as eight inches into the rectum (traditional instruments reach only three or four inches). The rectum is gently puffed up with carbon dioxide, to provide better exposure of the operative field.
The surgeon then uses instruments to grab, cut and suction, watching the procedure on monitors linked to the TEM camera. Those equipment capabilities, in addition to the special surgical training our staff has had in the technique, permit us to do a more controlled removal of the polyp.
TEM patients must have a full bowel preparation the day before the procedure and are given general anesthesia and intravenous antibiotics during the 60- to 90-minute operation. There is usually just one large polyp to be removed.
The minimally invasive TEM procedure avoids abdominal surgery or incisions, is pain-free and poses no risk to bowel function, bladder control or sexual function. Patients usually go home the same day and are back to normal eating within a day. By comparison, laparoscopic polyp surgery often requires two to four days in the hospital following surgery.
With rectal cancer patients, our goal is to cure the cancer, but in a way they can tolerate. Doing the right operation is the most important decision. We use TEM only for cancer patients who have medical conditions that would make it difficult for them to recover from the rigors of regular abdominal surgery for rectal cancer.
To help delineate whether a large polyp is cancerous or not—and, therefore, whether TEM is the right procedure to use—patients may be evaluated before surgery with endoscopic ultrasound performed by an Abington specialist. For patients with rectal cancer, this can also help determine whether they would benefit from preoperative radiation and chemotherapy.
D. Mark Zebley, MD, is Surgical Director, G.I. Procedure Unit, at Abington Memorial Hospital (www.amh.org).