• neuraxial blocks: epidural
• pediatrics
• complications

Thank you for the opportunity to respond to Dr Haydar’s1 letter. We appreciated that Dr Haydar and his coauthors found our paper2 of interest. He brought up several points, which we agree are worth clarifying.

First, Dr Haydar and his coauthors thought that penile engorgement was a normal physiological process that was not associated with edema formation. Therefore, Dr Haydar and his coauthors claimed our work perpetuated a baseless myth. However, although we cited the view that caudal block might cause edema of the penile tissue, our conclusion was based on the result of meta-analysis but not the view we cited. Additionally, our conclusion was that ‘caudal blocks were not associated with postoperative complications’. Thus, Dr Haydar and his coauthors misunderstood our conclusion.

Second, as with the study of Mr Tanseco, subgroup analysis was performed by the classification of hypospadias.3 In fact, many studies have confirmed that the classification of hypospadias is a risk factor, and our main objective was to estimate the relative complications of caudal block for hypospadias repair in children. Thus, we did not perform subgroup analysis.

Finally, as it is difficult to conduct randomized trials on an area-wide basis, non-randomized studies of the effects of interventions for many public health interventions are the primary source of evidence for any potential impacts from those interventions.4 There are often reasonable concerns about whether conclusions obtained under an ideal state of strict inclusion criteria can be extended to clinical applications. Therefore, systematic reviews of the impact of health-related interventions often include non-randomized studies of the effects of interventions. Comprehensive understanding of the strengths of the evidence is important.4

We have accepted the other suggestion and we appreciate the opportunity to respond to comments of Dr Haydar.