Anatomical Measurements of Pudendal Nerve Block in Children

Investigation of the Distance of the Needle Entry Point From the Anus and the Depth to Reach the Pudendal Nerve in Pudendal Nerve Block Application in Children

This prospective observational study aims to investigate the relationship between anatomical parameters-specifically the distance from the anus to the needle insertion point and the depth required to reach the pudendal nerve-during neurostimulation-guided pudendal nerve block and patients' age, height, and weight in children undergoing penile surgery.

The pudendal nerve originates from the sacral nerve roots Sacral2-Sacral4 and provides sensory and motor innervation to the penile and perineal regions. Effective postoperative analgesia is essential in pediatric penile surgeries. Pudendal nerve block may provide longer-lasting and more effective analgesia compared to caudal or penile blocks.

However, due to age- and size-related anatomical variability in children, data regarding optimal needle insertion distance and depth to reach the pudendal nerve are limited. In this study, neurostimulation will be used to confirm pudendal nerve localization, and anatomical measurements will be analyzed in relation to demographic parameters.

Inclusion Criteria:

• Children aged 1-18 years
• Scheduled for penile surgery (e.g., hypospadias, phimosis)
• Planned to receive neurostimulation-guided pudendal nerve block
• Patient and parents/legal guardians willing to participate under general anesthesia

Exclusion Criteria:

• Patients with incomplete measurement data
• Cases where successful nerve block cannot be performed or nerve stimulation is not detectable at currents ≥1.5 mA
• Patients or parents/legal guardians who refuse pudendal nerve block
• Patients with pelvic deformities or neuromuscular disorders