Pressure/Flow Study in BPH

Bae, Ug Soo; Lee, Heon Chun; Park, Jae Shin; Kim, Kap Byung

Abstract

BPH is found in 50% of males over the age of 50 and there is increase in incidence with age. But some patients with BPH do not induce bladder outlet obstruction and some patients with prostatism are not caused by bladder outlet obstruction. So, urodynamic study including pressure/flow study was performed in 45 males with prostatism to evaluate the degree of obstruction, and we measured maximal intravesical pressure, maximal detrusor pressure, prostatic urethral length, residual urine, minimal urethral resistance and pressure/flow plots. The 45 males were divided into 3 groups by maximal flow rate(MFR)(A: MFR>=15, B: 10<=MER<=15, C: MFR<10) and there was significant difference between each group only in minimal urethral resistance(P<0.05). The result of pressure/flow plots of A group showed that 93% (13/14) was nonobstructive pattern and the rest one was obstructive pattern which was caused by detrusor hyperreflexia. In B group. we could know the degree of obstruction in 58%(7/12) only with minimal urethral resistance and we could decide the degree of obstruction with pressure/flow plots in rest 5 cases whose minimal urethral resistances were between 0.43 and 0.65 unit. The result of pressure/flow plots of C group showed that 89%(17/19) was obstructive pattern and the rest 2 cases were nonobstructive patterns which were caused by detrusor hyporeflexia. In conclusion, with pressure/flow plots and minimal urethral resistance, we can decide the degree of obstruction in patients with prostatism especially whose MFR are between 10 and 15 ml/sec.