Epidemiology of underactive bladder: Common but underresearched

Detrusor underactivity (DU) or underactive bladder is a common cause of lower urinary tract symptoms (LUTS), but it is still poorly understood and underresearched. Although there has been a proposed definition by International Continence Society in 2002, no widely accepted diagnostic criteria have been established for this entity in clinical practice. Therefore, it has been rare to identify community-based researches on the epidemiology of DU until now. Only certain studies have reported the prevalence of DU in community-dwelling cohorts with significant LUTS using arbitrary urodynamic criteria for DU and these investigations have indicated that DU accounts for 25%–48% and 12%–24% of elderly men and women, respectively. However, these prevalence data based on the urodynamic definition apparently are limited in their extrapolation to the general population. Despite the clinical ambiguity of DU, its clinical effects on quality of life are quite significant, especially in the elderly population. An overall and proper comprehension of epidemiologic studies of DU may be crucial for better insight into DU, relevant decision making, and a more reasonable allocation of health resources. Therefore, researchers should find clues to the solution for the clinical diagnosis of this specific condition of LUTS from contemporary epidemiologic studies and try to develop a possible definition of ‘clinical’ DU from further studies.

Impact of Detrusor Underactivity on Surgical Outcomes of Laser Prostatectomy: Comparison in Serial 12-Month Follow-Up Outcomes Between Potassium-Titanyl-Phosphate Photoselective Vaporization of the Prostate (PVP) and Holmium Laser Enucleation of the Prostate (HoLEP)

OBJECTIVE

To evaluate impacts of preoperative detrusor underactivity (DU) on outcomes of photoselective vaporization of the prostate (PVP) or holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia, and to compare them between the two surgeries.

MATERIALS AND METHODS

A total of 1423 men, who underwent PVP (group A) or HoLEP (group B), were categorized into four groups: A1 (239 without DU), A2 (432 with DU), B1 (329 without DU), and B2 (423 with DU). DU was defined as bladder contractility index of <100. Outcomes were assessed at 1, 3, 6, and 12 months postoperatively using International Prostate Symptom Score (IPSS), uroflowmetry, and prostate-specific antigen. Successful outcome was defined as reductions by ≥50% of total IPSS at 12 months postoperatively.

RESULTS

In all four groups, almost all parameters of IPSS and uroflowmetry improved starting from 1 month. A1 or B1 had greater increases in maximum flow rate than A2 or B2. Decreases of total IPSS in A2 were less than in A1 starting from 1 month after PVP, whereas those in B2 were less than those in B1 as late as 12 months after HoLEP. B2 showed greater improvements in maximum flow rate, subtotal voiding symptom score, bladder voiding efficiency, and total IPSS than A2. In all patients, multivariate regression analysis revealed that the absence of DU, presence of bladder outlet obstruction, and higher baseline total IPSS were independent predictors of successful outcome after surgery, but the type of laser surgery (PVP vs HoLEP) was not.

CONCLUSION

Our data suggest that micturition symptoms, maximum flow rate, bladder voiding efficiency, and quality of life improve starting from the early period after PVP or HoLEP, irrespective of DU. However, patients with DU may have less degree of improvement in micturition after PVP or HoLEP than those without DU.