[Comparison of Analgesic Efficacy between Posterior and Lateral Transversus Abdominis Plane Block Techniques for...

Posterior transversus abdominis plane (TAP) block has been considered as a useful technique for lower abdominal postoperative analgesia, but in ultrasound-guided block, its efficacy and usability are still unknown. We prospectively compared the analgesic efficacy among posterior and lateral TAP block and with control group in laparoscopic gynecological surgery.

29 patients were randomly assigned to a study group. Ultrasound-guided TAP block was performed before the operation. In the posterior group (n =10), a needle was inserted from posterior to the middle axillary line, and its tip was centrally positioned at the origin of the transversus abdominis muscle. In the lateral group (n=10), a needle was inserted from the middle axillary line, and the tip was peripherally positioned at the surface of the transversus abdominis muscle. Visual analog scale (VAS), the use frequency of fentanyl rescue dose, and the period of time until initial rescue use after the operation were measured.

In posterior group, pain scores both at rest and on movement were significantly lower than other groups at early phase (P<0.05). The number of uses of the fentanyl rescue dose was smaller in posterior group than in control group in the first 6 postoperative hours (1±1.2 vs 3±1.5, P<0.05).

Ultrasound-guided posterior TAP block could become a more useful tool for postoperative analgesia. We presumed that its additional effect is caused from reduction of visceral pain related to sympathetic nerve block.