Evolution of the transversus abdominis plane block and its role in postoperative analgesia.

Since it was first described by Rafi in 2001, the transversus abdominis plane (TAP) block can be best described as a peripheral nerve block to the anterior abdominal wall (T6 to L1). The TAP block is specifically a local anesthetic injection into the fascial plane superficial to the transversus abdominis muscle and deep to the internal oblique muscle. The TAP block has been a subject of controversy with regard to utility, to indications, and more fundamentally, how best to place the block and its precise mechanism of action. The evolution of thinking with regard to this block, or more correctly family of interrelated blocks, includes knowledge of underlying anatomy, as well as an appreciation of its varied approaches. The TAP block affords excellent analgesia for abdominal procedures. In summary, the TAP block affords effective analgesia with opioid sparing effects, technical simplicity, and long duration of action. Some disadvantages include the need for bilateral block for midline incisions and absence of effectiveness for visceral pain.