Hanaoka (1986)
The combined spinal-epidural anesthesia is gaining more space and adepts in obstetric analgesia and anesthesia. On this, we are able to associate the advantages of a spinal block with the presence of an epidural catheter for block extension or continuation if and when necessary. Unfortunately, the chances of complications inherent to each technique are also added.
The first association with a spinal epidural anesthesia was first described in 1937 by Soresi. This author, using the needles available at that time, made an epidural puncture and administered part of the anesthetic solution, and afterward, progressed this same needle to the subarachnoid space where it was administered another part of the anesthetic solution. This technique remained forgotten for many years. In 1979, Curelaru used it in a series of 150 patients by the technique of double puncture. Initially, an epidural catheter was passed into a lumbar intervertebral space and then a subarachnoid puncture was performed 1 to 2 spaces above. Again special needles were not described for those punctures. It is worth mentioning that this technique of "double puncture" is still one of the most used for the combined technique to the present. Next, in order to avoid the trauma secondary to a double puncture, Coates in England and, simultaneously, a group of Swedish researchers (Mumtaz, Daz and Kuz) described in 1982, the "needle-through-needle" technique (picture below). On this option of combined block an epidural puncture is performed and the needle is leased in the space. Then, another needle longer than the first is inserted in the subarachnoid space. Again it was not described the use of special needles except for the use of a longer spinal needle than usual.
However, in 1986, Hanaoka came up with the idea of a needle with innovative features for the realization of the combined spinal-epidural. It was a standard Tuohy-Huber needle but, in its turn, had another orifice aligned with its longest longitudinal axis close to its distal end. On this orifice, called "back hole", passed the spinal needle inserted through the interior of the epidural needle (figure below). Thus, the dural puncture was performed at a right angle rather than at angles of approximately 30 degrees as seen in the original "needle-through-needle" technique. This facilitates the subarachnoid puncture, increasing your chance of success. In fact, the concept of the back orifice in the Huber needle tip had already been patented by this inventor in 1953. However, Hanaoka was the first to report the combined technique with the use of needles with these characteristics.