Groin surgery was changed to a laparoscopic technique; recruitable patients ceased.

For surgery in the region of the lower abdominal wall the administration of local anesthetic drugs in the epidural space via the caudal route is the preferentially used technique since several decades.

The transversus abdominis plane (TAP) block features the advantages of a peripheral nerve blockade. The aim of this study is to evaluate potential differences in the effectiveness of postoperative analgesia and to test the hypotheses that the duration of pain relieve ist prolonged after a TAP block when compared with an epidural technique.

Caudal block (CB) is the gold standard technique for analgesia in children undergoing surgical interventions in the groin.

Although the efficacy and the safety of this technique is high, nonetheless, there are several caveats such as unwarranted motor blockade of the lower limbs and disturbances of the bladder function, potentially resulting in delayed demission in the ambulatory setting. The effect of the blockade wears off within 4-5h post-block, making the administration of additional pain medication necessary.

Peripheral nerve blockades (PNB) are an alternative to CB and have a prolonged duration of the analgesic effect. More recently, an alternative method to block neural structures which innervate lower abdominal wall has been described; the transverse abdominal plane block. The ultrasound guided technique improves the safety of margin. However, although this new technique seems to offer substantial advantages so far only experience from small case series are available. In particular, the TAP block has not been compared in a systematic trial with the "gold standard", the caudal block.

Inclusion Criteria:

• Male and female children aged 2 - 8 years
• physical status classification system (ASA) score I or II
• Undergoing surgical interventions in the groin (hernia repair, funiculocele ectomy)

Exclusion Criteria:

• Hypersensitivity to Levobupivacaine