Position and anatomical landmarks
The patient lies in the prone position on the operating table with a pillow under the pelvis, in such a way that the sacral bone is rotated in a ventral direction. Both cornu of the sacral hiatus are palpated. Thereafter, and more caudally, the sacro-coccygeal joint is marked and palpated.
After sterile preparation of the area and by means of fluoroscopy, one needle is inserted trans-sacrococcygeally (through the sacrococcygeal ligament). A second needle is inserted through the coccygeal disc (Figure 1). In the lateral view, the positions of the needles are checked while contrast agent is being administered (Figure 2).
Figure 1. RF treatment of the Impar ganglion; lateral view.
Figure 2. RF treatment of the Impar ganglion; lateral view with contrast agent in place.
After stimulation at 50 Hz (up to 1 V) and 2 Hz (no motor reaction up to 3 V), each needle is heated up to 80°C for 80 seconds by means of RF.
- The most serious complication after the injection is infection.
- Small subcutaneous bleedings may result in a temporary increase in pain after the injection.
- Local anaesthetic injection with corticosteroids always carries the risk of going through the disc and penetrating the rectum.