Neuroanatomy of the pelvis in an infant with cloacal exstrophy: A detailed microdissection with histology

The internal anatomy of the pelvis in the patient with cloacal exstrophy has not been described in detail previously. We present in detail the pelvic anatomical relationships of a patient with cloacal exstrophy who died 72 days after birth and whose body subsequently was perfused with a formalin-based anatomical fluid. Microdissection of the pelvis with histological confirmation of the identity of structures dissected was performed. The vascular supply to the urinary hemibladders arises from the internal iliac arteries, which pass along the lateral portion of the pelvis and enter each hemibladder. The autonomic innervation to the bladder and corporeal bodies arises from a pelvis plexus that lies on the anterior surface of the sacrum. The innervation to the hemibladders then travels in the midline along the posteroinferior surface of the pelvis before extending laterally to communicate with each hemibladder. Autonomic innervation to the duplicated corporeal bodies arises from the sacral pelvic plexus and travels in the midline to pierce the inferior portion of the pelvic floor posterior and medial to the hemibladders. These nerves than enter the crural region of the corpora. Sensory innervation to the corporeal bodies arises from the sacral trunk and passes posterior to the pelvic floor muscles, traveling just medial to the widely separated ischial spines and then laterally along the corporeal bodies. Illustrations of the anatomy and implications for management of the exstrophy patient are presented.