Effect of Caudal Block on Urethrocutaneous Fistula After Distal Hypospadias Repair

The Effect of Caudal Block on the İncidence of Urethrocutaneous Fistula After Distal Hypospadias Repair: A Multicentre, Randomized Controlled Trial

Hypospadias is one of the most common congenital urogenital anomalies in males, occurring in approximately 1 in every 200-300 male births. It is characterized by abnormal positioning of the urethral meatus on the ventral surface of the penis. Surgical repair is the standard treatment; however, urethrocutaneous fistula formation remains one of the most frequent and clinically significant postoperative complications, potentially requiring reoperation and causing considerable distress to both the patient and the family.

Caudal nerve block is a widely used regional anesthesia technique in pediatric lower abdominal and genitourinary surgery, valued for its high analgesic efficacy, relative ease of application, and low complication profile. However, emerging evidence suggests that caudal block may be associated with an increased incidence of postoperative complications following hypospadias repair, including fistula formation and wound edema. Notably, Kundra et al. (2012) reported a fistula rate of 19.2% in patients who received caudal block, compared to 0% in those who received penile block, raising important questions about the routine use of caudal block in hypospadias surgery.

This prospective, multicenter, randomized controlled trial aims to evaluate the effect of caudal block on the incidence of urethrocutaneous fistula following distal hypospadias repair. A total of 80 male patients aged 6-60 months will be randomized 1:1 to either receive general anesthesia with caudal block or general anesthesia alone. The primary outcome is the incidence of urethrocutaneous fistula. Secondary outcomes include perioperative opioid consumption, postoperative pain scores, analgesic duration, and other surgical complications such as wound dehiscence and urethral stricture. Patients will be followed up for 3-6 months postoperatively. The study will be conducted across four centers in Turkey. Results are expected to provide evidence-based guidance on the role of caudal block in pediatric hypospadias repair.

This is a prospective, multicenter, randomized controlled trial. Eighty male patients aged 6-60 months undergoing distal hypospadias repair will be enrolled across four centers: Dicle University Faculty of Medicine Hospital, Istanbul Başakşehir Çam ve Sakura City Hospital, Diyarbakır Gazi Yaşargil Training and Research Hospital, and Mardin Training and Research Hospital. Patients will be randomized 1:1 using a simple randomization method with sealed envelope allocation into two groups: Group 1 (caudal block + general anesthesia) and Group 2 (general anesthesia alone). Demographic and clinical data, anesthesia and surgery duration, intraoperative and postoperative analgesic use, pain scores, length of hospital stay, and postoperative complications will be recorded. Patients will be followed for 3-6 months postoperatively for fistula formation, wound dehiscence, and urethral stricture. Statistical analysis will be performed using SPSS v22.0; Student t-test, Mann-Whitney U test, Kruskal-Wallis test, and chi-square test will be applied as appropriate. A p value ≤ 0.05 will be considered statistically significant.

Inclusion Criteria:

• Male patients aged 6-60 months
• Diagnosed with distal hypospadias
• Scheduled for elective hypospadias repair
• Written informed consent obtained from parent or legal guardian

Exclusion Criteria:

• Age < 6 months or > 60 months
• Proximal or non-distal hypospadias
• Previous hypospadias repair
• Skin lesions at the epidural/caudal injection site
• Coagulopathy
• Known allergy to anesthetic agents, particularly bupivacaine hydrochloride
• Spinal anomalies
• Chronic granulomatous disease
• Diabetes mellitus
• Patients receiving corticosteroid therapy
• Refusal of informed consent by parent or guardian