Introduction & Objective :
The pelvic anatomy of females with classic bladder exstrophy (CBE) has been discussed anecdotally, but has never been quantified in anticipation of reconstruction. Measuring and understanding the unique female anatomy in CBE is paramount for surgical navigation and reconstructive outcomes. This study presents quantitative measurements about the cervix, vagina, and erectile bodies in unaltered female CBE pelvises.
Three-dimensional reconstruction of pelvic Magnetic Resonance Imaging (Avanto, Siemens, Erlangen, Germany), acquired using T1 and T2 weighted sequences, were performed (Dextroscope, Bracco Imaging S.p.A., Milan, Italy) on 8 females ranging in age from 0.67-12.17 months. Four female CBE patients (mean age 6.8 months) with MRIs before their osteotomy and primary closure were compared to four age matched controls with normal pelvises (mean age 5.8 months). Measurements of the erectile bodies, the cervix, and the vagina were taken.
The mean distance between clitoral halves in CBE females was 1.35cm (mean diastasis 3.9cm), while the mean distance in controls was 0.04 cm. The distance between the anal verge and vagina was larger in CBE females (mean 2.64 cm) than in controls (mean 1.62cm). The total vaginal length in CBE females (mean 1.67cm) was half the length compared to controls (mean 3.39cm). The mean angle between the cervical os axis and the vaginal axis was more acute in females with CBE (121.9 degrees) compared to normals (163.7 degrees). All four controls had anteverted cervical ora, while three of four females with CBE had a retroversion of the cervix, with the other cervix in slight anteversion. The mean clitoral body angle is less in CBE females (88.05 degrees, right; 88.90 degrees, left) than in controls (134.5 degrees, right; 138.75 degrees, left). The average total length of each clitoral body was comparable in CBE females (26mm) and controls (29.1 mm), however the proportion of anteriorly dependent clitoris to pelvic rami associated clitoris was over five times larger in CBE patients (9.56 anterior:posterior) when compared to normals (1.82 anterior:posterior).
Along with quantifying several anecdotal relationships of the cervix and vagina with implications for fertility, this study offers novel observations about the anatomy of the erectile bodies in female exstrophy infants. Most importantly, contrary to the erectile bodies in male CBE patients, females have the majority of the clitoral body anterior to the pelvic attachment.