Analgesic Efficacy of Ultrasound-guided Single Shot Subcostal Transversus Abdominis Plane (TAP) Block After Laparoscopic Gastric Bypass.

Obesity surgery is expensive, although highly competitive to the cost of obesity related disease. An important step would be to reorganize obesity surgery into a day surgical procedure. Some reports already exist in the literature but the number of publications are sparse, and the description of the condition of the patient is limited. Our primary aim, therefore, is to investigate the influence transverses abdominis plane block has on pain after laparoscopic gastric bypass.

The benefits of adequate postoperative analgesia are clear, and include a reduction in the postoperative stress response, reduction in postoperative morbidity and in certain types of surgery, improved surgical outcome. The benefits of utilizing regional analgesic techniques compared to systemic analgesics include reduction in pain intensity, decreased incidence of side effects from systemic analgesics and improved patient comfort. Effective pain control thereby accelerates recovery from surgery.

A substantial component of the pain experienced by patients after abdominal surgery is derived from the abdominal wall incision.

The Transversus Abdominis Plane (TAP) Block was first described in 2001 in a letter by Dr. Rafi. McDonnell et al have developed and tested the block and describes it as a landmark technique. TAP Block involves blocking the sensory afferent nerves that supply the anterior abdominal wall including the skin, muscles and the parietal peritoneum. Hebbard et al subsequently described an ultrasound guided technique for the TAP block which they named the Posterior TAP block. The posterior TAP block provides analgesia on the lower abdominal wall. Hebbard also described another ultrasound-guided technique called the Oblique Sub costal TAP block which provides analgesia for surgery on the upper abdominal wall.

There is some debate over the extent of sensory blockade achieved by TAP block. Nerves supplying the anterior abdominal wall are derived from T16 to L1 and pass through this plane before supplying the anterior abdominal wall. Earlier studies showed a T7-L1 spread of the block after a single posterior TAP injection, while some newer studies revealed that the block failed to spread above T10 so was suitable only for lower abdominal procedures. In contrast the oblique sub costal TAP block can provide an effective analgesia after surgery that involves dermatome T6 to T10, in other word provide analgesia for surgery on the upper abdominal wall.