Cloacal Exstrophy: A Histomorphological Analysis of the Bladder Plate and Correlation with Bladder Dynamics

Objective: Physiological outcomes in patients of cloacal exstrophy are governed primarily by neurological innervation and detrusor histomorphology. An evaluation of the bladder plate histomorphology for the presence of neural elements, collagen fibres and smooth muscle components was done and correlation attempted with detrusor physiology. Methods: From three cases of cloacal exstrophy, full thickness biopsies were taken from the bladder plate at the time of single stage total reconstruction and slides stained with hematoxylin and eosin, masson's trichrome and immunohistochemical staining done with S-100, SMA and CD-117. Bladder biopsy taken at the time of cystolithotomy from a child with vesical calculus served as a control. Results: Cloacal exstrophy bladders showed squamous metaplasia, submucosal edema, increased collagen in the muscle layer and poor staining with S-100 (neural elements) and CD-117 (interstitial cells). Whereas the control biopsy showed normal transitional epithelium, good muscle layer with presence of both neural elements (S-100) and interstitial cells (CD-117). Conclusion: Poor muscle layer with increased fibrosis and scarcity of neural elements in the bladder wall may account for the poor compliance of such bladders and explain the incontinence and upper tract deterioration due to high intravesical pressure.