New Frontiers in Molecular and Imaging Research on Evaluation and Diagnosis of Bladder Outlet Obstruction in Women

Abstract

Purpose Diagnosis of bladder outlet obstruction (BOO) often presents a challenge in female patients. Traditional diagnostic elements such as symptom history and urodynamic data are rarely clear cut in women. Therefore, we sought to review the current literature on diagnosis of female BOO, focusing on new frontiers in the realm of molecular markers and imaging modalities. Recent Findings In addition to fluoroscopy in the setting of videourodynamics, ultrasound and MRI can augment the diagnosis and aid in therapeutic planning in certain etiologies of female BOO. Furthermore, multiple potential biomarkers (i.e. nerve growth factor, prostaglandins, ATP) that have been studied in correlation to BOO in animal models as well as human subjects hold promise for diagnostic applications. Summary These novel techniques may augment standard clinical and urodynamic evaluation of BOO in females. Future directions include further studies of each of these biomarkers in female patients with BOO compared to normal controls to test their feasibility as potential screening tools.

Systematic review of urinary biomarkers of female bladder outlet obstruction (fBOO)

“…In the setting of BOO, a pathologic increase in outlet resistance is recorded, conducting to a more forceful contraction of the detrusor muscle to generate urine flow across the outlet. This dysfunction results in functional and anatomical changes in the detrusor as well as in the neural networks involved in the process (1). Whereas BOO in males is mainly due to benign prostatic hyperplasia (BPH), the causes are more varied in females, being subdivided into anatomic and functional.…”

“…Among anatomic causes, urethral distortion secondary to pelvic organ prolapse (POP), iatrogenic BOO caused by antiincontinence procedures, intrinsic etiologies (strictures, fibrosis, urethral diverticula), should be considered. Functional BOO results from primary bladder neck obstruction (failure of bladder neck relaxation), neurogenic detrusor external sphincter dyssynergia, non-neurogenic dysfunctional voiding (abnormal contraction of periurethral muscle) and Fowler's syndrome (1,5).…”

“…The increased concentration of NGF can reduce the threshold or increase excitability in the afferent fibers leading to increased bladder sensation or overactivity. Expression of NGF is modulated by intervention, being reduced after medical or surgical treatment of the obstruction (1,5).…”

“…Furthermore, the decreases in NGF/Cr levels after treatment correlated with subjective improvement in the symptoms of patients as demonstrated by decreased UDI-6 survey scores and objective improvement as demonstrated by increased flow rates. Therefore, urinary NGF looks like a promising tool for women with suspected anatomic BOO as a diagnostic and an objective assessment of the therapeutic effects of surgical and medical interventions in women with BOO (1,5).…”

“…Diagnosis of bladder outlet obstruction (BOO) in females is often challenging, not only because of the overlap in storage and voiding symptoms in women with various etiologies of lower urinary tract dysfunction but also due to the lack of standardized urodynamic criteria to define the condition (1).…”