Continuous ultrasound-guided sacral intervertebral block for postoperative analgesia in neonates.

A sacrococcygeal teratoma and a sacral agenesis represent a contraindication to a caudal block. We report two cases where the optimal use of ultrasound helped place a sacral intervertebral catheter in two neonates. Radiological and ultrasound studies of the sacrum and spine should be available before performing the procedure.