Caudal ‘duplication’ or ‘split’ syndrome: Is there a misnomer?

‘Caudal duplication syndrome’ was coined to describe the apparent duplication of organs derived from the hindgut, the neural tube and the adjacent mesoderm. Review of the anatomy suggests that the word ‘duplication’ may be a misnomer. This paper describes the management of 2 girls with caudal duplication syndrome who underwent multistage reconstructive surgery. Both had a large omphalocele and a severe diastasis of the pubic symphysis. The first patient also had an apparent duplication of the vulva, the perineum and the anus to either side of a wide midline. Each vulva contained a urethra, a hemi-clitoris with ipsilateral labium minor, and a hemi-vagina with hemi-uterus. The second child had an infrapubic sequestrated appendico-cecal duplication lying between two hemi-bladders each with ipsilateral ureter and urethra. The everted duplication split the single vulva longitudinally in the midline as far as the fourchette. To each side were a hemi-clitoris, and a hemi-vagina with hemi-uterus and ipsilateral fallopian tube. Analysis of our patients' anatomy and a literature review indicates for the most part ‘hemi’ organs on either side and suggests that the term ‘duplication’ is a misnomer such that caudal ‘split’ syndrome may be a more appropriate title.