Urodynamic studies are considered the reference standard to diagnose bladder outlet obstruction. However, the procedure is invasive, expensive, and time-consuming. The purpose of this study was to evaluate a new minimally invasive urodynamic assessment model and compare the results with those of conventional urodynamic evaluation.

The study included 50 male patients who presented with lower urinary tract symptoms. Their mean age was 62 years (range 34 to 82). After undergoing a conventional urodynamic study, they underwent the minimally invasive evaluation. The urethral device is a conical apparatus that adapts to the urethral meatus and fossa navicularis. The isometric bladder pressure and interrupted flow were recorded. The results of the conventional assessment were classified according to the Abrams-Griffiths number and a logistic regression fit was applied to the minimally invasive method.

Only two variables demonstrated the predictive capacity: the isometric pressure and interrupted flow. In addition to selecting the relevant variables, logistic regression analysis is a more adequate model that provides a binary result of obstructed and unobstructed, used to predict the normal and equivocal categories of the Abrams-Griffiths classification, and taken as the reference standard. The sensitivity and specificity of the new method was 67% and 79%, respectively.

The urethral device proved to be simple and easy to use. The minimally invasive method was able to detect most patients with bladder outlet obstruction; thus, the conventional urodynamic assessment could be avoided. We consider this method to have a place as a first-line noninvasive examination.