A combined abdominal and transsacral approach is recommended for the removal of large retrorectal tumors. In this case, the patient should be prepped with both the abdominal and sacral regions exposed. The retrorectal or presacral area is approached transabdominally by the same approach that is used for abdominoperineal resection (see Chapter 101). The sacral portion of the operation is described here. Small tumors may be approached transsacrally without entering the abdomen. The combined approach provides adequate exposure for complete and adequate excision. This is especially important with tumors that extend up into the pelvis, and this approach allows excellent hemostatic control.

Place the patient in the right lateral decubitus position. Make a transverse incision, about 10 cm in length, over the sacrococcygeal joint. Confirm the position of the sacrococcygeal joint by palpation with an index finger within the anal canal if necessary. Deepen this incision until the periosteum of the bone is encountered. Divide the sacrococcygeal joint with heavy scissors. The coccyx may be removed with the specimen. Enter the retrorectal space by sharp and blunt dissection. It will be necessary to divide the periosteum and ligamentous attachments at the sacrococcygeal joint to do this. The next large structure that will be encountered is the muscular wall of the rectum which can easily be surrounded and dissected free. Many tumors are attached to the coccyx or lower segments of the sacrum. Up to the third segment of the sacrum may be removed at the time of tumor resection without functional impairment. Removal of the sacral nerve roots up to S1 or S2 has been relatively well tolerated and is preferable to tumor recurrence.