Sacral agenesis: usefulness of CT study.

The authors report on a case of sacral agenesis evaluated by Computed Tomography (CT) of the spine. Sacral agenesis is an exceedingly rare, nongenetic, developmental anomaly which consists in an absence of the entire sacrococcygeal complex. Although maternal diabetes appears to be the most important etiologic factor, the significant teratogenetic effects related to maternal diabetes are not yet completely understood. Only few cases have been reported in neurological and neurosurgical literature because most authors believe that the neurological deficits associated with sacral agenesis are static and, therefore, myelography and surgical approach are useless. However, sacral agenesis can be surgically treated when dural sac stenosis is evident in presence of progressive neurological deficits. The usefulness of CT in depicting nervous anomalies which may favorably respond to surgical treatment is emphasized, in particular when compared with contrast myelography. CT scan seems able to replace contrast myelography in delineating the intraspinal nervous anomalies, thus avoiding the myelographic risks.