446 Structural study of gubernaculum testis in fetuses with Prune Belly Syndrome

Eur Urol Suppl 2014;13;e446 Print!

Freitas Costa S., Silva Costa W., Sampaio F.J., Favorito L.A.

State University of Rio de Janeiro, Dept. of Anatomy, Rio de Janeiro, Brazil

INTRODUCTION & OBJECTIVES: Prune-Belly syndrome (PBS) is a disorder characterized by deficiency of the abdominal muscles,

malformations of the urinary tract and bilateral cryptorchidism. The gubernaculum seems to be the most important anatomical structure in

the process of testicular migration. The objective of this paper is to study the structure of gubernaculum testis in fetuses with PBS.

MATERIAL & METHODS: We studied 6 gubernaculums obtained from 3 male fetuses with PBS and 14 gubernaculums obtained from 7

male fetuses without anomalies. The gestational age of the fetuses was determined in weeks post conception (WPC), according to the foot-

length criterion. After the measurements, the fetuses were carefully dissected with the aid of a stereoscopic lens with 16/25X magnification.

The abdomen and pelvis were opened to identify and expose the urogenital organs. The gubernaculum was dissected and embedded in

paraffin, from which 5µm thick sections were obtained and stained with Masson trichrome (to quantify connective tissue and smooth muscle

cells - SMC); Weigert Resorcin Fucsin (to observe elastic fibres) and Picro-Sirius Red with polarization to observe collagen. The images

were captured with Olympus BX51 microscopy and Olympus DP70 camera. The Stereological analysis was done with the software Image

Pro and Image J, using a grid to determine volumetric densities (Vv) (FIGURE). Means were statistically compared using the ANOVA and

Unpaired T test (p<0.05).

RESULTS: The PBS fetus ranging in age from 17 to 31WPC and weighted between 240 and 2150g. The fetus from the control group

ranging in age from 12 to 35 WPC and weighted between 430 and 2860g. The 3 fetuses with PBS had abdominal testis and in the control

group 12 testes (85.71%) were abdominal and 2 testes (14.29%) were scrotal. Quantitative analysis documented that there are no

differences in Vv of SMC in PBS gubernaculum (14.93% to 22.72%, mean=15.70%), when compared to control group (12.94% to 18.87%,

mean=19%), p=0.12. Picro-Sirius Red with polarization photomicrographs presented a difference in colors between the groups. This

difference could suggest changes in the collagen fiber organization of PBS gubernaculum. The analysis showed predominance of green in

PBS fetal gubernaculums, suggesting collagen type III presence and a predominance of red in gubernaculum of control group, suggesting

collagen type I presence in this group. Quantitative analysis documented that elastic fibers were significantly smaller (p=0.002) in PBS

gubernaculum (10.25% to 19.4%, mean=14.06%) when compared to gubernaculum of control group (18.2% to 27.8%, mean=24.6%)

CONCLUSIONS: The gubernaculum in PBS had alterations in concentrations of collagen and elastic fibres. These structural alterations

could be one of the factors involved in cryptorchidism in Prune Belly Syndrome.