Parasacral Ischial Plane block 

This is an easy, fascial plane approach to block the divisions of the Sacral plexus.
Venkataraju A, Narayanan M, Phillips S.
www.sciencedirect.com/science...
Ultrasound localization of the sacral plexus using a parasacral approach.
Ben Ari. et al.
www.ncbi.nlm.nih.gov/pubmed/1...
Preliminary results of a new ultrasound-guided approach to block the sacral plexus: the parasacral parallel shift
Bendtsen et al.
academic.oup.com/bja/article/...
A simple and successful sonographic technique to identify
the sciatic nerve in the parasacral area.
Taha AM
link.springer.com/article/10....