CT evaluation of acupuncture needles inserted into sacral foramina.

OBJECTIVE To use CT scanning to evaluate the precision with which acupuncture needles can be inserted into sacral foramina to establish sacral nerve modulation by electroacupuncture. METHODS The subjects were five adult women (mean age 71.6 years). These five cases were divided into two groups. In the first three subjects (group A) the intention was to insert acupuncture needles in the S3 and S4 foramina; in the remaining two subjects (group B) the intention was to insert acupuncture needles in the S2 and S3 foramina. RESULTS CT scanning showed that in subject 1 of group A, the acupuncture needle intended for insertion in S3 was actually in the S4 foramen, and the acupuncture needle intended for insertion in S4 was actually distal to the sacral body. In subjects 2 and 3, the acupuncture needles were inserted accurately in the S3 and S4 foramina. In the three subjects who had acupuncture needles inserted in the S4 foramen, the tip of the acupuncture needle was an average distance of 6.0 mm from the rectum. The acupuncture needles inserted in subjects 4 and 5 of group B were inserted accurately into the S2 and S3 foramina. CONCLUSIONS Inserting acupuncture needles into the sacral foramina of S2 and S3 at an angle of about 60° has the potential to be used for sacral nerve modulation by repeated electroacupuncture stimulation. Needling may be less accurate in subjects with higher body mass index. Because of the potential risk of perforating the rectum with the needle, this technique must be used by specialists only. TRIAL REGISTRATION NUMBER 2013-026.