Low bladder contractility linked with deterioration of voiding function post RARP

A recent study has found an association between preoperative low bladder contractility and prolonged deterioration of voiding function in patients undergoing robot-assisted radical prostatectomy (RARP).¹

The findings were presented at the 2021 International Continence Society Annual Meeting in Melbourne, Australia. Discussing the background for the study, first author Junya Hata, PhD, of Fukushima Medical University in Fukushima, Japan, explained that a previous study had found that a lower bladder contractile index (BCI) level was predictive of postoperative detrusor underactivity (DU) at 1 month after RARP.²

“This result suggested that the decrease in reserve capacity of bladder function preoperatively might contribute to the development of postoperative DU in relatively early phase after RARP… However, the long-term prognosis of lower urinary tract function and symptoms including voiding and storage in the patients with lower bladder contractility remained unclear,” the authors wrote in their abstract for the current study.

For the current study, the investigators sought to evaluate the time-dependent change of lower urinary tract function in patients undergoing RARP. A total of 115 patients undergoing RARP underwent urodynamics testing preoperatively. Patients were divided into 2 groups based on BCI level; these were referred to as the preserved group (BCI ≥ 100, 70 patients) and the impaired group (BCI < 100, 45 patients). Maximum flow rate (Qmax), voiding volume, postvoiding residual volume, International Prostate Symptom Score (IPSS), quality of life score, and Overactive Bladder Symptom Score were assessed at 1, 3, 6, 9, and 12 months post RARP. Univariate and multivariate logistic regression analyses were performed using patient parameters including age, body mass index, prostate weight, diabetes, and LDL cholesterol.

“No significant differences in patient characteristics were observed between the preserved and impaired groups,” Hata reported. IPSS voiding score was significantly higher in the preserved group vs the impaired group (6.1 ± 5.2 vs 2.9 ± 3.2, respectively; P = .01).

“Qmax at 1, 3, 6, 9, and 12 months and voiding volume at 3 months were significantly lower in the impaired group than in the preserved group. This suggests that preoperative lower bladder contractility was associated with prolonged deterioration of voiding function,” Hata said.

In addition, IPSS voiding score at 1, 3, 6, 9, and 12 months was significantly lower in the impaired group compared with the preserved group. “This suggests that preoperative lower bladder contractility was associated with prolonged deterioration of voiding symptoms,” Hata said.

Logistic regression analysis of patient parameters related to preoperative low bladder contractility before RARP identified LDL cholesterol as a predictive factor for low bladder contractility.

“In conclusion, preoperative lower bladder contractility was associated with prolonged deterioration of voiding function. It was suggested that dyslipidemia might be associated with decrease in bladder contractility,” Hata said.

References

1. Hata J, Hasegawa A, Harigane Y, et al. Long-term prognosis of lower urinary tract function after robot-assisted radical prostatectomy in patients with preoperative low bladder contractility. Paper presented at: 2021 International Continence Society Annual Meeting; October 14-October 17; Melbourne, Australia. Abstract 5

2. Hata J, Onagi A, Tanji R, et al. Prevalence and predictors of postoperative detrusor underactivity after robot-assisted radical prostatectomy: A prospective observational study. Int J Urol. 2021;28(7):734-740. doi:10.1111/iju.14549