Lower urinary tract symptoms (LUTS) in men are commonly associated with benign prostatic obstruction (BPO), a condition that most often arises from benign prostatic hyperplasia [1, 2]. These symptoms, which include urinary frequency, urgency, slow stream, and a sensation of incomplete bladder emptying, can significantly diminish quality of life. Although BPO is widely recognized as the leading cause of male LUTS, a subset of patients experiences similar symptoms due to detrusor underactivity (DU). DU is characterized by a reduced ability of the detrusor muscle to contract sufficiently during voiding [3]. In severe cases, this condition can progress to detrusor acontractility, where the bladder loses its contractile function. While BPO is a well-documented cause of LUTS, it is crucial also to consider other underlying conditions, such as DU, which presents its own unique set of management challenges.

The management of DU presents a significant clinical challenge due to the absence of effective treatments. Pharmacological interventions often fail to provide relief, necessitating that patients with DU frequently rely on self-catheterization to manage their symptoms [4]. This requirement for catheterization represents a considerable burden and is associated with an increased risk of urinary tract infections and a diminished quality of life [5]. Given the lack of effective therapeutic options for DU, there is an urgent need to explore alternative approaches that might improve bladder emptying and alleviate associated symptoms.

One potential avenue for improving outcomes in patients with DU is surgical intervention specifically, the reduction of prostate volume to decrease urethral resistance during micturition [6]. Holmium laser enucleation of the prostate (HoLEP) is a well-established surgical technique used to treat BPO by removing obstructive prostatic tissue [7]. While HoLEP is primarily indicated for patients with BPO, it is hypothesized that reducing prostate size in patients with DU may similarly alleviate bladder outlet obstruction, thereby enhancing bladder emptying and reducing reliance on self-catheterization. This hypothesis is based on the understanding that, even in the presence of DU or acontractile bladder (AcB), a reduction in urethral resistance can lead to improved voiding dynamics [8].

In light of these considerations, this study aims to retrospectively evaluate the efficacy of HoLEP in male patients with LUTS associated with DU or AcB. By analyzing clinical outcomes in this population, we sought to determine whether surgical reduction of prostatic obstruction can provide meaningful therapeutic benefits, including improved voiding efficiency (VE), decreased postvoid residual urine (RU), and a reduced need for self-catheterization. This research has the potential to identify a novel therapeutic strategy for a challenging and underserved patient population, offering hope for improved management of LUTS in the context of DU or AcB.

This retrospective study was conducted on men with prostatic enlargement and urodynamic evidence of impaired or absent detrusor contractility who underwent HoLEP between April 2021 and April 2024. The inclusion criteria were a prostate size of ≥30 mL and urodynamic study (UDS) results indicating DU or AcB. The exclusion criterion was a bladder outlet obstruction index (BOOI) of ≥40.

We did not rely solely on the bladder contractility index (BCI=PdetQmax [detrusor pressure at maximum flow rate]+5 Qmax [maximum flow rate]) to diagnose DU or AcB. DU is characterized by contractions of reduced strength and/or duration, leading to prolonged bladder emptying and/or incomplete emptying within a reasonable timeframe. AcB is defined as the absence of detectable contractions during UDSs, as outlined in the International Continence Society standardization report. In our study, a single urologist diagnosed patients by evaluating their symptoms and UDS results based on these definitions to ensure a comprehensive assessment.

All patients underwent transrectal ultrasonography to assess prostate volume, uroflowmetry (UFM) with postvoid residual (PVR), UDSs, and cystourethroscopy. The UDS included filling and voiding cystometry, and VE was calculated as the ratio of self-voided urine volume (SV) to the sum of SV and PVR based on UFM results. Additional preoperative workup included a medical history assessment, serum prostate-specific antigen (PSA) testing, and the International Prostate Symptom Score (IPSS).

All surgeries were performed by a single surgeon to ensure consistency in surgical technique and procedural outcomes. Patients were placed in the dorsal lithotomy position under general anesthesia. Initial dilation was achieved using a 28Fr sound, followed by the insertion of a 26Fr 3-way continuous transurethral resection (TUR) sheath. A Holmium laser with a 550-nm fiber was utilized to incise the urethral mucosa from the upper lateral sides of the verumontanum to the capsule. Incisions were made from the bladder neck to bilateral incisions at the verumontanum, which were then connected transversely above the verumontanum. For the left lobe, dissection was initiated at the 3 o’clock position, and for the right lobe, at the 11 o’clock position, with the adenomas dissected along the capsule towards the bladder neck and excised into the bladder. Hemostasis was achieved by targeting the bleeding points with the laser fiber. A nephroscope was inserted, and morcellation was performed using a morcellator to remove the dissected prostate lobes, ensuring that the bladder was adequately filled to avoid injury. After the procedure, a 24Fr 3-way urethral catheter was inserted. The Foley catheter was removed based on urine color and the patient’s condition on postoperative day 2.

Postoperatively, all patients visited the clinic at 2 weeks and 2 months and then every 3 months for UFM, PVR, and IPSS assessments. The amount of tissue resected, operation time, time to Foley catheter removal, and incidence of failure-to-void were also included in the postoperative data.

The primary outcome was the change in VE in patients with DU or AcB following HoLEP. The secondary outcomes included the differences in VE and changes between the DU and AcB groups. Additionally, we assessed the proportion of patients who transitioned from preoperative Foley indwelling catheterization or clean intermittent catheterization (CIC) to self-voiding postoperatively.

Statistical analyses were conducted using the Mann-Whitney test, with a P-value of less than 0.05 considered statistically significant. Changes in VE were visualized using Python’s Seaborn library, employing the locally weighted scatterplot smoothing (LOWESS) method for trend analysis. VE trends were plotted using Matplotlib.

The median follow-up for the study was 26 weeks (interquartile range [IQR], 9.8–47). Table 1 summarizes the baseline characteristics of the 26 patients who underwent HoLEP. Fourteen male patients were identified as having DU preoperatively. The median age was 76.5 years (IQR, 69.8–81.3 years), and the median PSA level was 1.96 ng/mL (IQR, 1.2–7.7 ng/mL). The median PVR volume was 155 cc (IQR, 45–312.5 mL). Among these 14 patients, 6 (43%) required either an indwelling Foley catheter or CIC preoperatively. The median PVR for catheterized patients was 375 mL (IQR, 192.5–437.5 mL), compared to 75 mL (IQR, 30-180 mL) for noncatheterized patients. The Qmax for catheterized patients was 2 mL/sec (IQR, 0–5.5 mL/sec), while for noncatheterized patients it was 9.5 mL/sec (IQR, 4.0–12.25 mL/sec).

Of the 14 patients, 8 were unable to complete pressure-flow studies (PFSs), preventing the measurement of the BOOI and BCI. For the 6 patients who successfully underwent PFS, the median BOOI was 8.5 (IQR, 3.75–17.0), and the median BCI was 45 (IQR, 32.25–57.0). The highest observed BCI was 104, exceeding the threshold of 100 commonly used to diagnose DU. However, this patient was diagnosed with DU based on their voiding phase pattern and clinical presentation. Among the 6 patients requiring preoperative catheterization, 4 failed PFS. Maximum detrusor pressure (MaxPdet) was measurable in 8 of the 14 patients, with a median value of 39 cm H₂O (IQR, 30.5–49.25 cm H₂O). Twelve patients with AcB had a median age of 74.5 years (IQR, 65.3–79.3 years) and a median PSA level of 7.9 ng/mL (IQR, 2.2–12.5 ng/mL). All AcB patients failed self-voiding during preoperative evaluation. Of these, 11 (92%) required either an indwelling Foley catheter or CIC. All 12 patients failed PFS, could not self-void during preoperative testing, had a RU volume of 170 mL, and failed PFS with a MaxPdet of 41 cm H₂O. Among AcB patients, MaxPdet was measurable in 3 individuals, with values of 33, 41, and 55 cm H₂O, respectively.

Table 1 also presents the operative characteristics of both groups. The median prostate volume and resected tissue weight for the DU group were 48.6 mL (IQR, 37.3–73.4 mL) and 22.5 g (IQR, 8.5–38.8 g), respectively. For the AcB group, these values were 68 mL (IQR, 48.7–89.5 mL) and 32 g (IQR, 17.3–49.5 g), respectively. The median operation time was 62.5 minutes (IQR, 46–89.3 minutes) for the DU group and 86.5 minutes (IQR, 58.5–135 minutes) for the AcB group. Regarding the duration from symptom onset to surgery, the median was 4.3 years (IQR, 0.9–10 years) for the DU group and 0.8 years (IQR, 0.1–7.5 years) for the AcB group.

Postoperatively, 5 patients in the DU group required temporary Foley catheterization or CIC. Of these, one patient failed to self-void on the day following surgery and subsequently had a Foley catheter inserted prior to discharge, which was removed during an outpatient visit one week later. Three patients presented to the Emergency Department (ED) with acute urinary retention (AUR) within 5 days postoperatively, necessitating Foley catheter insertion or CIC; one of these patients required hospital admission for treatment of concurrent acute pyelonephritis. The remaining patient developed AUR at 1 month after operation and underwent Foley catheter insertion, which was removed 1 week later. None of the 5 patients required Foley catheterization for more than 1 week. In the AcB group, no patients required postoperative catheterization or CIC. Ultimately, all patients in both groups were able to void spontaneously without catheterization.

Each group, DU and AcB, had 1 patient who experienced postoperative complications. In the DU group, 1 patient presented to the ED on postoperative day 9 with hematuria and AUR. This patient underwent hematoma evacuation and transurethral coagulation. His VE improved from 35% preoperatively to 46.4% at 2.5 months postoperatively. In the AcB group, one patient developed a bulbous urethral stricture post-surgery and subsequently underwent internal urethrotomy 6 months later. This patient’s VE improved from 0% preoperatively to 68.1% at 10 months postoperatively.

Postoperative UFM results demonstrated significant improvement compared to preoperative data following HoLEP surgery (Table 2). VE increased by 81.3%, while PVR volume decreased from 325 mL to 45 mL, representing a reduction of 280 mL. Furthermore, Qmax increased from 0 mL/sec to 14.4 mL/sec. Fig. 1 illustrates the VE trend for all patients during the follow-up period using the LOWESS method. VE increased sharply up to 1 month after surgery and then plateaued at approximately 80%. Regarding the IPSS score, there were significant improvements in the voiding symptom score (-9.5) and QoL score (-3), while the storage symptom score remained unchanged (Table 2). Table 3 presents the results for the DU group and the AcB group, respectively. Both groups exhibited notable improvements in VE, PVR, and Qmax. Specifically, in the DU group, VE increased by 47.8%, PVR volume decreased by 116.5 mL, and Qmax increased by 5.8 mL/sec. In the AcB group, VE increased by 78%, PVR decreased by 351 mL, and patients who were previously unable to perform self-voiding demonstrated an increase in Qmax, with a median value reaching 16.3 mL/sec. Fig. 1 also presents the VE trends for the DU group and the AcB group, respectively. The graphs indicate that both groups showed improvements in voiding function, with no significant differences between them.

The management of LUTS in male patients with DU or AcB remains a significant clinical challenge due to the limited efficacy of pharmacological treatments [9, 10]. In this retrospective study, we explored the outcomes of HoLEP in patients with impaired detrusor contractility. Our findings demonstrate that surgical reduction of bladder outlet resistance, even in the context of DU or AcB, can lead to meaningful improvements in VE, PVR, and the need for catheterization. This suggests that timely intervention may promote functional recovery in select cases.

Historically, DU has been associated with poor outcomes following deobstructive surgery, as reduced detrusor contractility is believed to limit the bladder’s ability to expel urine effectively [11]. However, our study demonstrates that patients with DU and AcB, when managed with HoLEP, experience substantial improvements in voiding function. Specifically, VE increased by 47.8% in the DU group and by 78% in the AcB group postoperatively. These findings support the hypothesis that reducing prostate size and alleviating bladder outlet obstruction (BOO) can improve voiding dynamics, even in cases where detrusor function is compromised.

Patients with DU and elevated PVR volume may require CIC, an indwelling Foley catheter, or cystostomy to achieve adequate bladder emptying. In this study, all patients who required catheterization preoperatively were able to achieve self-voiding postoperatively. Based on these findings, deobstructive surgery may be considered a viable treatment option for patients with DU requiring catheterization.

One of the key insights from this study is the potential for bladder recovery in patients with detrusor acontractility, a condition traditionally considered irreversible [12]. Although AcB is often viewed as the end stage of bladder dysfunction, our results suggest that timely surgical intervention can lead to significant improvements in voiding function, as evidenced by the increase in VE and the reduction in PVR among AcB patients. This finding challenges the prevailing notion that DU and AcB are permanent states of dysfunction and supports the idea that the bladder may retain some capacity for functional recovery if outlet resistance is adequately addressed.

Several previous studies have reported reduced efficacy of deobstructive surgery in patients with DU, particularly when vaporization or transurethral resection of the prostate was used as the primary intervention [13-15]. In contrast, HoLEP has emerged as a more effective alternative for patients with impaired detrusor contractility [16-18]. Our study supports this growing body of evidence, indicating that HoLEP can produce favorable outcomes even in challenging patient populations with DU or AcB. The sharp increase in VE observed during the first month after surgery suggests that early postoperative improvements in bladder function are attainable, with sustained benefits over time.

It is also important to note that while all patients in both the DU and AcB groups were able to void spontaneously by the end of the follow-up period, 5 patients with DU required temporary catheterization for up to 1 week postoperatively. This finding suggests that, although HoLEP can lead to significant improvements in voiding function, patients with DU may require additional postoperative support before achieving self-voiding. The use of catheterization in this group is not necessarily indicative of treatment failure; rather, it may reflect the time required for the bladder to adapt to the reduced outlet resistance.

The underlying mechanism by which surgical intervention leads to improved outcomes in patients with DU or AcB remains a topic of debate. One possible explanation is that reducing outlet resistance allows for more efficient voiding despite weakened detrusor contractions. Additionally, some degree of bladder recovery may occur as a result of the decreased workload on the detrusor muscle following HoLEP. Previous studies have demonstrated that bladder function can improve after the surgical correction of BOO, even in the presence of DU [6, 19-21], which supports the idea that the bladder retains some degree of plasticity and potential for recovery.

Our study has several limitations that should be acknowledged. Although we excluded patients with a BOOI greater than 40 to minimize selection bias and focus on prominent DU or AcB patients, there were limitations due to the retrospective nature of the study and the relatively small sample size. Additionally, while the follow-up period was sufficient to capture early postoperative outcomes, longer-term studies are needed to assess whether the observed improvements in voiding function are sustained over time.

This study demonstrates that HoLEP effectively improves VE and reduces PVR urine in male patients with DU or AcB. Postoperative outcomes revealed significant improvements in voiding dynamics, with a substantial proportion of patients achieving spontaneous voiding despite impaired detrusor contractility. These findings suggest that deobstructive surgery can play a crucial role in the management of DU and AcB, challenging the traditional notion that these conditions are irreversible. Further studies with extended follow-up are warranted to validate these findings and assess long-term outcomes.