Does urodynamics predict voiding after benign prostatic hyperplasia surgery in patients with detrusor underactivity?

OBJECTIVE: We sought to determine if urodynamic study (UDS) predicted voiding outcomes in men with detrusor underactivity (DU) and benign prostatic enlargement (BPE) who underwent photovaporization of the prostate (PVP). METHODS: Between September 2010 and July 2015, 106 male patients with BPE and DU were identified. All patients underwent PVP. Urinary retention was noted by the preoperative necessity for an indwelling or intermittent catheter. Data collection included comorbidities, quality of life (QoL) scores, prostate volume, prostate-specific antigen (PSA), UDS and perioperative outcomes. UDS parameters included volume at first desire to void, volume at first urge to void, volume of severe urge, volume at capacity, compliance, detrusor contractions, maximum urinary flow rate (Q(max)), and postvoid residual (PVR). RESULTS: A total of 106 men were included in this analysis, who had urinary retention with a Foley catheter or clean intermittent catheterization (CIC) at the time of surgery. At baseline we found patients who voided had a detrusor pressure at Q(max) (P(det)@Q(max)) of 10.05 ± 6.45 cmH(2)O compared to 16.78 ± 12.17 cmH(2)O in those who did not void (p = 0.071). Postoperatively, 96 (90.6%, mean age 76.9 ± 26.2 years) of patients voided successfully while 10 (9.4%, mean age 80.52 ± 9.61 years) of patients remained in urinary retention. Mean baseline Q(max) was 4.895 ± 5.452 mL/s and 2.900 ± 3.356 mL/s (p = 0.087) in those who voided and did not respectively. PVR was 319.23 ± 330.62 mL in those who voided and 276.88 ± 263.27 mL (p = 0.344) in those who did not void. No UDS parameter predicted who would void postoperatively or improvements in QoL. CONCLUSIONS: The patients with DU and BPE might be able to successfully void after undergoing PVP regardless of UDS findings. All men who voided had improved international prostate symptom score and QoL scores compared to baseline and these parameters were durable up to 12 months.