Transversus abdominis plane block (TAPB) has emerged as a safe and effective regional anesthesia technique for providing postoperative lower abdominal analgesia. Complications associated with TAPB are very rare and pose a lower overall risk to the patient receiving a TAPB versus a caudal block, which is considered the gold standard for pediatric lower abdominal regional anesthesia. Our study hypothesis was that TAPB would be equivalent to caudal block initially in providing postoperative pain control but would show improved pain relief beyond the anticipated caudal duration.

The study design was a double-blinded randomized controlled trial. A minimum of 44 children between the ages of 1 and 9 undergoing bilateral ureteral reimplantation surgery through a low transverse incision will be enrolled. Narcotic requirement, pain scores (FLACC/FACES), episodes of nausea/vomiting, and anti-spasmodic requirement will be recorded in the PACU and at 6 hour intervals through 24 hours from the time of the block placement.

Inclusion Criteria:

• Patients aged 1 to 9 years old scheduled for intravesicular ureteral reimplantation surgery

Exclusion Criteria:

1. Coagulation status or anatomic variations precluded safe placement of either TAPB or caudal epidural,
2. there was a preexisting chronic pain disorder,
3. there was a history of constipation that persisted despite appropriate treatment and that may have impacted postoperative pain assessments,
4. additional procedures were planned via a separate incision at the time of the ureteral reimplantation, 5) there was a contraindication to receiving the medications described in the protocol.