Anatomical Characteristic Of The Hypospadiac Penis And Clinical Application:a Preliminary Study

PurposeHypospadias is a common congenital anomaly affecting the male urogenital system. The current repair techniques are of high incidence of complications. Successful repair depends on an accurate anatomical understanding of the hypospadiac penis, but little work on it has been reported. We explored the anatomical characteristics of the hypospadiac penis, and designed penile skin flap according to our findings, so as to find out reliable local skin flaps for urethroplasty and wound coverage in hypospadias surgery, and to reduce the incidence of complications such as urethral fistula and stricture.Methods1. By morphological and histopathological observation, and Doppler examination, anatomical anomalies of the hypospadiac penis were studied from blood supply variation and tissue displacement. Surgical procedures for hypospadias repair were modified based on the findings. Penile skin flaps for urethroplasty and wound coverage were designed according to characteristics of cutaneous blood supply of the penis, and were compared with other local flaps of their oxyhemoglobin saturation variation after the flaps were harvested. The two branches of the divergent corpus spongiosum were replaced and reunited at the ventral aspect of the neourethra. The results of modified surgery were compared with the traditional surgery.2. Congenital hypospadiac human penile specimens are hardly available. For better study on the anatomical variation of the hypospadiac penis, we established the rabbit model of congenital hypospadias by feeding the pregnant rabbits finasteride. Morphological study of the anatomical characteristics of their penis was carried out. Modified repair procedures were performed on their penis, and the surgical outcome was compared with the traditional procedures. We also observed the oxyhemoglobin saturation variation of the rabbit penile skin flap.Results1. Morphological anomalies of hypospadiac penis were characterized by abnormal appearances of prepuce, penile skin, the glans penis, and urethral meatus, with or without frenulum absence and chordee. Number and severity of the anomalies varied in accordance with hypospadias classification. These deformities have important impact on the choice of surgical procedure. The potential abnormalities includ divergent corpus spongiosum and variation of cutaneous blood supply. The divergent corpus spongiosum is closely related to the superficial skin. Various penile skin flaps that were designed according to characteristics of the abnormal penile cutaneous blood supply have similar oxyhemoglobin saturation variation. Properly application of the divergent corpus spongiosum can reduce the incidence of complications such as urethrocutaneous fistula.2. We succeeded in establishing the rabbit model of congenital hypospadias. The cutaneous blood supply of the hypospadiac penis was slightly different from normality. The corpus spongiosum was ectopic and hypoplastic. Different penile skin flap designs have different impacts on oxyhemoglobin saturation. Corpus spongioplasty provides effective protection for the reconstructed urethra.ConclusionExcept for morphological anomalies, potential anatomic variation was found in hypospadiac penis. The former determines which procedure to choose, while the latter has a major influence on the result of the selected procedure. Accurate anatomical understandings of the hypospadiac penis, which can be revealed by anatomical and histopathological studies, as well as Doppler flowmeter, contribute to improving success rate of hypospadias repair surgery.