A study of lower urinary tract anatomy and selected pathology in boys

Abstract

New technology for the examination of the lower urinary tract has resulted in higher quality information being available for study of congenital anomalies of the male urethra. The standard of the radiological images and the improved procurement techniques, together with the ability to easily view and record the urethra endoscopically, have allowed our understanding of urethral pathology to be reconsidered. Also, the availability of sophisticated perineal ultrasound, allows for a pre-emptive diagnosis of bladder neck and urethral obstruction so that an antegrade cystourethrogram can be appropriately performed, allowing the urethra to be viewed before any alteration of the anatomy. Combined with modifications of the conduct of endoscopy, recordings of the undisturbed anatomy have been able to be produced. This new information has indicated the need for re-evaluation of the method of dissection of the autopsy specimens and the need for new interpretations of the data; the development of new concepts has also been aided by the prenatal diagnosis of urinary outflow obstructive disease and the earlier presentation for treatment of the post-natal cases, which has strengthened the evidence of the congenital naturo of the pathology. All of the diseases studied in this thesis have been reassessed because of the facility to review video recordings of the pathology, while reviewing the cystourethrograms, and the opportunity to compare the findings in the abnormal urethra with those of a large number of prospectively recorded normal urethras. With the background of data collected in London, pertaining to obstruction in the posterior urethra, the video recording system was established for all my cases in Adelaide. The information obtained has provided proof of a case of primary bladder neck obstruction, further insight into classification of obstruction of the posterior urethra, variability of the degree of obstruction from case to case and the relationship of the external sphincter to the obstructive membrane. Pathology of the more distal urethra has been differentiated from that of the posterior urethra, with the adoption of the term, Cobb's collar. The association of Cobb's collar to cystic lesions of Cowper's glands (syringoceles) has been assessed and a modified concept presented, suggesting that it is Cobb's collar, rather than a flat plate external sphincter, that syringoceles are closely related to. The information on the outcome of transplantation in the urethral obstruction patients pertains to the secondary effects of congenital urethral obstruction. The detailed investigation of the cases of urethritis was undertaken as part of the study, to highlight the need to differentiate between congenital and acquired urethral pathology. The clinical significance of the work is in the conceptual relocation of the proximal extent of the external sphincter in relation to syringoceles and posterior urethral obstruction, a new approach to intervention for urethritis in adolescents and raising concern about the long-term impact of outlet obstruction on bladder function. From the academic perspective, the data provide new information on which to base embryological studies, plus, hopefully, a stimulus to others to undertake meticulous video recording to allow the hypotheses to be further tested.