In the present study, we observed that the prevalence of post-TURP LUTS is not rare; moreover, a preoperative voiding efficiency of less than 75.48% could predict the postoperative medication with α-1 adrenergic antagonists. The findings of the present study could be helpful in preoperative patient counseling.
Post-TURP LUTS is a bothersome situation for patients, resulting in prolonged medication postoperatively.5 A possible pathophysiology of persistent LUTS after TURP is due to residual prostatic tissue or bladder neck dysfunction. Another possible pathophysiology is chronic bladder outlet resistance due to prostatic obstruction.6–8 This chronic resistance induces detrusor muscle hypertrophy over time, leading to a low compliance and small capacity of the urinary bladder.9 Urinary bladder distention due to chronic obstruction also results in ischemic injury to the urinary bladder, which in turn causes bladder wall thickening.10 These changes happen not only at a macrolevel but also at a molecular level.11 Collagen types I and III of the detrusor muscle become upregulated at the transcriptional level. Muscarinic receptors CHRM2 and CHRM3 also become overexpressed, leading to detrusor overactivity. The progression may be reversed by TURP at the early stage but not in the late stage.5
Post-TURP LUTS involves storage and voiding symptoms, both of which could be treated with α-1 adrenergic antagonists.12 These antagonists could inhibit α-1 adrenergic receptors (ARs) in the residual prostatic tissue and bladder neck to relax the smooth muscle and alleviate post-TURP voiding symptoms.5 However, α-1 ARs are also expressed in the body of the urinary bladder, and the blockage of these receptors could cause the relaxation of the detrusor muscles.13 The upregulation of the expression of α-1 ARs in the presence of bladder outlet obstruction was observed by Bouchelouche et al.14; therefore, α-1 adrenergic antagonists may have a role in controlling post-TURP storage symptoms. Moreover, a recent study revealed that α-1 adrenergic antagonists could increase the perfusion of the lower urinary tract and maximize bladder capacity, which could improve chronic ischemic injury due to prolonged bladder outlet obstruction, even after relief with TURP.15
A cohort study in Canada recruiting 58,000 patients revealed that 27% of the patients were under α-1 adrenergic antagonists after a 90-day washout period after TURP.16 Although the rate of post-TURP α-1 adrenergic antagonist usage was lower than that in our study (27% vs. 41%), the absolute reduction rates of α-1 adrenergic antagonist usage before and after TURP were similar (35% and 42%, respectively). Moreover, approximately one-third of the patients in the Canadian cohort study were prescribed with post-TURP medications other than α-1 adrenergic antagonists, including 5α-reductase inhibitors, anticholinergics, or beta-3 agonists. Another retrospective study comparing the effects of different transurethral prostate procedures on medication discontinuation revealed a 74.4% reduction of α-1 adrenergic antagonist usage after TURP, which was higher than those observed in our study and the Canadian cohort study.17 The variable duration of bladder outlet obstruction before TURP and the extent of prostate resection may account for the differences in the discontinuation rates of α-1 adrenergic antagonists among these studies. The earlier the stage at which patients undergo TURP for bladder outlet obstruction, the higher the chance that bladder function could be preserved and, therefore, the lower the prevalence of post-TURP LUTS. The extent of prostate resection during TURP varies among urologists, and patients and should be balanced between the resolution of LUTS and development of surgical complications, such as ejaculation dysfunction, erectile dysfunction, and incontinence.
We found that a preoperative voiding efficiency of less than 75.48% is a predictive factor of continuous α-1 adrenergic antagonist usage after TURP. Similarly, a study involving the GreenLight laser vaporization of the prostate also reported that a preoperative voiding efficiency of greater than 75% is a predictor of surgery success.18 Patients with a preoperative voiding efficiency of greater than 75% had significantly higher improvements in the Qmax and International Prostate Symptom Scores than those whose voiding efficiency was less than 75%. Voiding efficiency, compared with PVR, exhibits less intraindividual variation in predicting the severity of bladder outlet obstruction and capacity of bladder compensation in clinical settings.19 Other parameters, such as bladder outlet obstruction index (BOOI) and bladder contractility index (BCI), could also help determine the bladder function in the presence of bladder outlet obstruction. Combining voiding efficiency with BOOI and BCI would be optimal for the evaluation of the lower urinary tract function of patients with BPO.20 However, not every patient can undergo this painful, inconvenient, and invasive pressure flow examination to obtain BOOI and BCI before TURP. In the present study, we provided a simple and noninvasive parameter to predict the post-TURP α-1 adrenergic antagonist usage, which would be useful in preoperative evaluation and patient counseling.
Advanced age was also found to be associated with poor TURP outcomes in other studies. Campbell et al. found that advanced age could predict post-TURP usage of anticholinergics or beta-3 agonists.16 Another Italian cohort study revealed that the younger age was associated with better surgical outcomes.21 It is reasonable that the older the patients’ age, the longer the duration of bladder outlet obstruction and the higher the possibility of bladder decompensation even after treatment with TURP. A similar trend was also found in our study, although it was not of statistical significance, which may be due to the small sample size.
The present study has a few limitations. First, this was a retrospective study. Some important clinical information was missing during data collection, such as preoperative urodynamic study or loss to follow-up postoperatively. Second, the sample size of this study was not large enough. Some possible predictive factors, such as age, were not of statistical significance. Third, the surgeries were not performed by a single urologist, and some operator-associated factors were difficult to identify. Nevertheless, a preoperative voiding efficiency of less than 75.48% remains not only a strong but also a simple and noninvasive predictive factor of post-TURP α-1 adrenergic antagonist usage. A prospective study recruiting more patients undergoing TURP and other transurethral prostate procedures would help identify more preoperative predictors of post-TURP LUTS, which would be useful in preoperative evaluation and patient counseling.