Hypospadias is among the most common congenital genital malformations in boys and is typically treated through surgical intervention. During pediatric urological surgery, caudal anesthesia, also known as a caudal block, is frequently employed as a regional anesthetic technique. It has proven to be a safe and effective anesthetic approach in children, with a low rate of anesthesia-related complications. However, despite the low incidence of complications directly associated with the caudal block, there is limited and inconclusive evidence regarding its impact on surgical complications. Therefore, this randomized controlled superiority trial aims to evaluate whether the use of caudal anesthesia, compared to the dorsal penile block, is associated with an increased incidence of urethrocutaneous fistulas and glans dehiscence following hypospadias repair.

The rationale for conducting a comprehensive study arises from the limitations inherent in existing literature, primarily due to selection bias and the retrospective nature of current evidence, which fails to clarify whether caudal blocks lead to higher complication rates after hypospadias repair. To fill this knowledge gap and address the clinical uncertainty surrounding this issue, the only effective approach is to randomly assign patients undergoing hypospadias repair to receive either caudal or penile block anesthesia. The purpose of this pilot study is to evaluate the feasibility of a definitive trial and identify any methodological issues that must be resolved before committing significant resources to a full-scale study.

This pilot study will assess the feasibility of conducting a large, definitive, parallel-group, randomized controlled trial (RCT) to determine whether a dorsal penile block results in fewer postoperative complications than a caudal block in boys aged 6 to 48 months undergoing hypospadias repair.

Hypospadias repair will be performed under standardized analgesic administration, and participants may receive fentanyl (1-3 mcg/kg) at the anesthesiologist's discretion. Anesthesia will be induced via inhalation of air/nitrous oxide and sevoflurane. Based on a randomized allocation, patients will receive either a caudal anesthetic block (0.25% bupivacaine, 1 ml/kg, up to a maximum of 10 ml) or a dorsal penile block (bupivacaine without epinephrine, 10-20 ml/kg). All patients will receive antiemetic prophylaxis with dexamethasone (150 mcg/kg), ondansetron (50 mcg/kg), acetaminophen suppository (40 mg/kg), and intravenous morphine (0.02-0.1 mg/kg).

At discharge, patients will be prescribed oral morphine (0.2 mg/kg) every 4 hours as needed, Ditropan (0.2 mg/kg) every 12 hours as needed, Tylenol (15 mg/kg per dose) every 4 hours, or ibuprofen (10 mg/kg per dose) every 6 hours. Parents will administer these medications at their discretion. Trimethoprim (2 mg/kg) will also be prescribed until catheter removal.

Inclusion Criteria:

• Aged between 6 and 48 months
• Distal hypospadias
• Acceptance of participation

Exclusion Criteria:

• Midpenil hypospadias
• Proximal hypospadias
• Prior surgery
• Comorbidity (diabetes, hypertention, cardiac pathology)

participant and outcome assessor