Transanal endoscopic microsurgery.

TEM has been used effectively to treat large rectal polyps and early rectal malignancy for more than 20 years in Europe. Until recently, only a few specialized centers offered TEM in the United States, where it is now gaining popularity. Many hospitals have purchased equipment and are offering TEM; however, the equipment is expensive and the learning curve is steep. Therefore, it is essential that anyone performing TEM have an adequate number of cases to develop and maintain expertise in this technique. That being said, TEM remains unique when compared with laparoscopy and other minimally invasive techniques that incorporate less invasive methods of performing old operations. TEM allows surgeons to perform operations that were impossible before the development and acceptance of this technique.