Holmium laser enucleation of the prostate improves the renal insufficiency of benign prostatic hyperplasia with hydronephrosis

Abstract

Background

Hydronephrosis is a serious long-term complication of benign prostatic hyperplasia (BPH), and patients with this condition are prone to suffer from renal insufficiency. This study was performed to evaluate the efficacy of holmium laser enucleation of the prostate (HoLEP) for renal dysfunction in BPH patients with hydronephrosis.

Methods

In this retrospective cohort study, the enrolled 122 patients were divided into two groups according to the type of surgery: HoLEP (n=64) or bipolar plasmakinetic transurethral resection of the prostate (TURP, n=58). Perioperative indicators and follow-up variables were analysed to evaluate the efficacy and durability of HoLEP.

Results

The HoLEP group had a shorter operation time, bladder irrigation time, catheterization duration and hospital stays; less haemoglobin (Hb) and sodium decrease; and greater tissue removal (P<0.01). Improvements in the International Prostate Symptom Score (I-PSS), postvoid residual, maximum urinary flow rate, hydronephrosis and renal dysfunction in the HoLEP group were more evident during the entire follow-up period (P<0.01).

Conclusions

Therefore, by more safely and completely removing the hyperplastic prostate tissue to ensure durable relief of lower urinary tract obstruction, HoLEP can effectively and continuously benefit the recovery of renal function in BPH patients with preoperative hydronephrosis, and it is expected to become the ideal surgical intervention for these patients.

Highlight box.

Key findings

• In benign prostatic hyperplasia (BPH) patients with hydronephrosis, holmium laser enucleation of the prostate (HoLEP) resulted in shorter recovery times, greater tissue removal, and significantly better long-term recovery from both hydronephrosis and renal insufficiency.

What is known and what is new?

• Long-term bladder outlet obstruction from BPH can lead to hydronephrosis and subsequent renal insufficiency. HoLEP is established as a safe, size-independent procedure for BPH.

• The efficacy of HoLEP on pre-existing renal dysfunction caused by BPH-induced hydronephrosis has not been systematically reported. This manuscript adds novel evidence that the more complete and durable removal of prostatic tissue by HoLEP provides better upper urinary tract decompression, leading to superior and sustained recovery of renal function compared with traditional transurethral resection of the prostate (TURP).

What is the implication, and what should change now?

• HoLEP should not be viewed merely as an alternative to TURP but as a potentially superior and preferred first-line surgical intervention for BPH patients with hydronephrosis. Clinical practice should shift towards adopting HoLEP proactively in this patient population to maximize the chances of preserving and improving long-term renal function.

Introduction

Benign prostatic hyperplasia (BPH) is the main reason for dysuria in elderly men, and the continuous progression of this disease results in a series of serious complications. In addition to common complications, such as urinary retention, urinary tract infection, haematuria, and bladder stones, long-term bladder outlet obstruction (BOO) secondary to BPH can lead to upper urinary tract dilatation and hydronephrosis. Previous studies revealed that the incidence of hydronephrosis in BPH patients is approximately 7%, and nearly 33% of these patients suffer from renal insufficiency (1,2). Moreover, renal dysfunction-related complications not only seriously affect quality of life but also pose a corresponding threat to life. Therefore, early and effective intervention for BPH patients with hydronephrosis is critical for preserving renal function and improving long-term outcomes, underscoring its considerable clinical importance.

In recent years, many novel surgical interventions have emerged, leading the surgical treatment for BPH into a new era. Emerging surgeries further improve long-term efficacy, especially the ideal control of disease-related complications, while ensuring safety (3,4). However, there is still no systematic report on effective surgical interventions for BPH complicated with hydronephrosis. As a long-term consequence of BPH, hydronephrosis can be relieved by appropriate surgical treatments that effectively alleviate low urinary tract obstruction, thereby continuously reducing the internal pressure of the upper urinary tract and providing durable protection of renal function.

Many recent studies have confirmed that holmium laser enucleation of the prostate (HoLEP) can remove hyperplastic prostatic tissue more thoroughly than traditional transurethral resection of the prostate (TURP), which is conducive to maintaining durable patency of the lower urinary tract (5-7). Consequently, the recovery of hydronephrosis and renal dysfunction caused by BPH can be maximized. This study analysed and summarized the surgical safety and long-term efficacy of HoLEP for BPH with hydronephrosis, providing an ideal clinical treatment strategy for the protection of renal function in these patients. We present this article in accordance with the STROBE reporting checklist (available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0197/rc).

Methods

Study design

We conducted a retrospective cohort study on BPH patients with hydronephrosis undergoing surgical treatment in our department at Huadong Hospital Affiliated to Fudan University between January 2018 and April 2023. All BPH patients suffered acute or severe chronic urinary retention at the first visit and underwent catheterization due to for at least two weeks before the operation, and both preoperative hydronephrosis and renal dysfunction were improved to varying degrees. Patients with a history of chronic kidney disease (CKD); polycystic kidney disease; poorly controlled hypertension or diabetes mellitus [haemoglobin (Hb) A1c >7.0%]; neurogenic bladder dysfunction; psychological disorders; and any other comorbidities that could result in renal dysfunction, urinary tract obstruction or voiding dysfunction, such as urogenital malignancy, urinary tract injury or prior urologic surgery, urolithiasis and urinary tuberculosis, were excluded. The sample size was determined by the number of cases in our hospital during the study period and validated by PASS 15 software (NCSS, LLC, Kaysville, UT, RRID: SCR_019099).

Preoperative data, including age, body mass index (BMI, body weight divided by the square of height), International Prostate Symptom Score (I-PSS), Quality of Life Questionnaire (QoL), prostate volume (PV, length × width × height × 0.52), intravesical prostatic protrusion (IPP, the vertical distance between the base of the bladder neck and the top of the mid-lobe), prostate-specific antigen (PSA) level, hydronephrosis condition (the average dilated distance of bilateral renal pelvises), serum creatinine (SCr) level, estimated glomerular filtration rate [eGFR, 142 × min (SCr/0.9, 1)^−0.302 × max (SCr/0.9, 1)^−1.2 × 0.9938^Age], urine white blood cell (WBC) counts, Hb level and serum sodium (Na⁺) level, were collected and evaluated.

According to the surgical treatment, the patients were divided into the TURP group and the HoLEP group. The TURP group underwent traditional bipolar plasmakinetic TURP with a cutting power of 160 W and a coagulation power of 100 W (SIMAI Co., Ltd., Zhuhai, China). The HoLEP group underwent HoLEP with a power of 90 W (2.0 J, 45 Hz, Lumenis Be Ltd., Yokneam, Israel) via an end-firing 550 µm laser fibre. The two-lobe enucleation technique was used during HoLEP. Tissue morcellation was performed using a DPM-3-A endoscopic morcellation system (Dahua Laser Equipment Co., Ltd., Wuxi, China). Normal saline irrigation was performed in both groups.

Perioperative indicators, such as operation time, continuous bladder irrigation time, catheterization duration, postoperative hospital stays, Hb decrease, Na⁺ decrease, resected tissue weight and resection ratio (resected tissue weight divided by the preoperative prostate weight), as well as postoperative variables, including I-PSS, postvoiding residue (PVR), maximum flow rate (Qmax), PSA level, hydronephrosis condition and renal function during the follow-up, were analysed to evaluate the efficacy and durability of HoLEP in these patients. A variety of efforts, such as rigorous guidelines for data collection, stringent research training, and systemic quality control, were implemented to minimize potential bias, including information bias and selection bias.

This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study protocol was approved by the Ethics Committee of Huadong Hospital Affiliated to Fudan University (No. 2023K137). Individual consent for this retrospective analysis was waived.

Statistical analysis

Quantitative data are expressed as the mean ± standard deviation (SD). An independent samples Student’s t-test was conducted for intergroup comparisons. Two-way repeated-measures analysis of variance (ANOVA) was used to evaluate the follow-up data. Missing data analyses were conducted based on the multivariate imputation by chained equations (MICE) method. The statistical analyses were performed by SPSS Statistics 25.0 (IBM Corp., RRID: SCR_016479). Two-sided P values <0.05 were considered as statistically significant.

Results

A total of 122 patients were enrolled in this study, including 58 patients in the TURP group and 64 patients in the HoLEP group (see Figure 1). Owing to our standardized clinical procedure and uniform follow-up protocols, there were no missing data in either group. Baseline characteristics are presented in Table 1, and no significant between-group differences were observed at baseline (P>0.05).

Figure 1.

Flow diagram of recruitment in this study. BPH, benign prostatic hyperplasia; HoLEP, holmium laser enucleation of the prostate; TURP, transurethral resection of the prostate.

Table 1. Comparison of the baseline characteristics between the two groups.

Parameters	HoLEP	TURP	P value
Age (years)	71.72±9.52	72.09±8.76	0.82
BMI (kg/m2)	22.23±2.17	22.51±2.28	0.49
I-PSS-S	13.13±0.86	13.10±0.85	0.89
I-PSS-V	18.16±0.78	18.07±1.04	0.60
I-PSS-T	31.28±1.20	31.17±1.53	0.66
QoL	5.47±0.53	5.52±0.50	0.61
PV (mL)	76.52±45.41	67.01±32.04	0.18
IPP (mm)	17.23±7.72	17.66±6.80	0.75
TPSA (ng/mL)	6.24±5.96	8.38±13.68	0.26
Hydronephrosis condition (mm)	26.97±9.74	27.94±12.79	0.64
SCr (μmol/L)	167.47±83.98	164.74±62.38	0.84
eGFR (mL/min/1.73 m2)	46.57±19.69	43.98±17.24	0.44
Hb (g/L)	123.03±17.65	123.47±13.83	0.88
Na+ (mmol/L)	141.90±2.76	142.28±2.84	0.46
Urine WBC (/HP)	24.38±36.55	22.28±35.08	0.75

Data are presented as mean ± standard deviation. BMI, body mass index; eGFR, estimated glomerular filtration rate; Hb, hemoglobin; HoLEP, holmium laser enucleation of the prostate; HP, high power field; I-PSS-S, storage subscore of the International Prostate Symptom Score; I-PSS-T, total score of the International Prostate Symptom Score; I-PSS-V, voiding subscore of the International Prostate Symptom Score; IPP, intravesical prostatic protrusion; Na⁺, serum sodium; PV, prostate volume; QoL, quality of life questionnaire; SCr, serum creatinine; TPSA, total prostate-specific antigen; TURP, transurethral resection of the prostate; WBC, white blood cell.

The comparison of perioperative indicators between the two groups is shown in Table 2. In terms of operation time (96.41±39.97 vs. 116.21±36.70 min, P=0.005), postoperative hospital stays (6.17±1.64 vs. 7.02±1.52 days, P=0.004), Hb decrease (12.75±2.46 vs. 14.16±3.01 g/L, P=0.005) and serum sodium decrease (7.52±2.53 vs. 9.19±3.09 mmol/L, P=0.002), the advantages were more significant in the HoLEP group. Furthermore, the HoLEP group had a shorter continuous bladder irrigation time (35.25±12.07 h vs. 48.00±19.07 h, P<0.001) and catheterization duration (5.53±0.50 vs. 6.09±0.78 days, P<0.001) and greater tissue removal (45.72±37.86 vs. 26.32±19.61 g, P<0.001; 50.13%±12.93% vs. 34.70%±9.50%, P<0.001) than the TURP group.

Table 2. Comparison of the perioperative outcomes between the two groups.

Parameters	HoLEP	TURP	P value
Operation time (min)	96.41±39.97	116.21±36.70	0.005
Continuous bladder irrigation time (hour)	35.25±12.07	48.00±19.07	<0.001
Catheterization duration (day)	5.53±0.50	6.09±0.78	<0.001
Postoperative hospital stays (day)	6.17±1.64	7.02±1.52	0.004
Hemoglobin drop (g/L)	12.75±2.46	14.16±3.01	0.005
Serum sodium decrease (mmol/L)	7.52±2.53	9.19±3.09	0.002
Resected tissue weight (g)	45.72±37.86	26.32±19.61	<0.001
Resection ratio (%)	50.13±12.93	34.70±9.50	<0.001

Data are presented as mean ± standard deviation. HoLEP, holmium laser enucleation of the prostate; TURP, transurethral resection of the prostate.

During the follow-up visits at 1, 6, 12 and 24 months postoperatively, the HoLEP group exhibited greater improvements in BPH-related clinical outcomes (see Figure 2). The HoLEP group showed more evident improvements in I-PSS, PVR, Qmax and PSA during the entire follow-up period (see Figure 2A-2G, P<0.01). Patients in the HoLEP group had better recovery of both hydronephrosis and renal dysfunction (see Figure 2H,2J, P<0.001).

Figure 2.

Follow-up data of the two groups. *, P<0.05; **, P<0.01; ***, P<0.001. eGFR, estimated glomerular filtration rate; HoLEP, holmium laser enucleation of the prostate; I-PSS-S, storage subscore of the International Prostate Symptom Score; I-PSS-T, total score of the International Prostate Symptom Score; I-PSS-V, voiding subscore of the International Prostate Symptom Score; PVR, postvoiding residue; Qmax, maximum flow rate; QoL, quality of life questionnaire; SCr, serum creatinine; TPSA, total prostate-specific antigen; TURP, transurethral resection of the prostate.

Discussion

Hydronephrosis is a serious complication of BPH, and it is also the main manifestation of disease progression and an important indication for surgical intervention. BPH can cause BOO and lower urinary dysfunction. In the early stage, through the compensation mechanism, the detrusor can still maintain voiding to a certain extent. If the disease progresses continuously, bladder function gradually decompensates, and bladder compliance decreases simultaneously. As progression continues, detrusor hypertrophy may contribute to anatomic obstruction of the uretero-vesical junction (UVJ). Persistent high intravesical pressure during the storage stage due to the substantial PVR results in the functional compression of the UVJ. In addition, sustained high bladder pressure promotes vesicoureteral reflux and ureteral reflux. Given the above mechanisms (8-11), if the obstruction of the lower urinary tract is not relieved, progressive BPH results in hydronephrosis. Subsequently, sustained parenchymal pressure ultimately leads to renal insufficiency (10). Patients with BPH are typically elderly men, and those who progress to hydronephrosis are generally even older. These patients usually have more chronic comorbidities, and superimposed renal dysfunction further increases the complication burden, substantially impairing quality of life and increasing mortality risk to varying degrees. Therefore, it is of great clinical significance to implement timely and effective medical interventions for BPH patients with hydronephrosis.

The technical key to implementing the above surgical intervention is to achieve more complete removal of hyperplastic prostate tissue, thereby maximizing durable lower urinary tract patency. As the historical gold standard for surgical intervention in BPH, TURP can effectively relieve lower urinary tract obstruction due to BPH, but it is associated with many complications, such as transurethral resection syndrome (TURS) and perioperative haemorrhage. Moreover, the incidence of retreatment after TURP is approximately 10–15% within 10 years (12), highlighting limitations in long-term durability. Therefore, there is a clear need to develop more durable and safer surgical approaches for the management of BPH.

The application of HoLEP as a treatment for BPH was first reported in 1998 (13). Working at a wavelength of 2,120 nm, the pulsed holmium laser enables simultaneous tissue cutting and coagulation with a tissue penetration of approximately 0.4 mm. Leveraging these intrinsic characteristics of holmium laser, HoLEP allows the precise identification of the anatomic plane and enucleation of the entire transitional zone (TZ) of the prostate from the surgical capsule. Therefore, HoLEP achieves more complete removal of hyperplastic tissue than traditional TURP and offers efficacy comparable to open simple prostatectomy with less invasiveness. Many previous studies have verified that HoLEP shows obvious advantages in both safety and efficacy as an endoscopic intervention for BPH, with sustained improvement in voiding symptoms. However, the wide adoption and application of HoLEP for BPH is still somewhat limited. One of the most important reasons is the steep learning curve. Consequently, during early implementation, its advantages were less apparent and even accompanied by drawbacks, such as longer operative time than TURP (14,15). More recently, outcomes have improved with ongoing technical refinements and accumulated surgical experience. Habib and colleagues (16,17) reported that HoLEP was associated with a shorter operation duration than TURP (P<0.05). In the current study, the operation time was also significantly shorter in the HoLEP group than in the TURP group (P=0.005). Additionally, many studies have validated that HoLEP shows pronounced advantages in other important perioperative variables, such as bladder irrigation, catheterization duration, hospital stays, Hb decline and tissue removal (P<0.05) (14-18). Our study also likewise demonstrated that HoLEP is still superior to TURP in terms of continuous bladder irrigation time (P<0.001), catheterization duration (P<0.001), postoperative hospital stays (P=0.004), Hb decrease (P=0.005), serum sodium decrease (P=0.002), resected tissue weight (P<0.001) and resection ratio (P<0.001). Similarly, many previous studies have shown the durable efficacy of HoLEP for disease-related manifestations in BPH patients (19-21). Short-term urinary incontinence is common after HoLEP, with an incidence of 24% to 44%, but it resolves in most patients during follow-up (14-18,22,23). The results of our study are consistent with those in the literature. Although the I-PSS and QoL were transiently higher in the HoLEP group at the early stage after surgery, owing to more obvious temporary urge urinary incontinence, in general the I-PSS, QoL, PVR and Qmax all showed obvious improvement in the HoLEP group with ideal durability throughout the entire follow-up period (P<0.01). All these findings further proved the excellent efficacy, safety and durability of HoLEP in the treatment of BPH.

However, there is no systematic report on the improvement of renal function after HoLEP for BPH with hydronephrosis. As mentioned above, HoLEP can remove hyperplastic prostate tissues more thoroughly, so we believe that it can significantly and durably ensure the patency of the lower urinary tract after surgery for BPH with preoperative hydronephrosis, which helps to reduce intravesical pressure, alleviate compression of the UVJ, and decrease vesicoureteral reflux and ureteral reflux. Collectively, these changes will promote the relief of hydronephrosis and the recovery of renal function in these patients. This study also showed greater tissue removal in the HoLEP group (P<0.001), and the significant decline in PSA further validated the ideal efficacy of the resection (P<0.01). The evaluation of follow-up data of hydronephrosis and renal function demonstrated greater clinical improvements in the HoLEP group at 24 months postoperatively (P<0.001). These results suggest that HoLEP provides sustained improvement in hydronephrosis in patients and lays a solid foundation for renal function recovery. Therefore, the application of HoLEP is of great significance for maintaining a good quality of life and durably improving renal insufficiency for BPH with hydronephrosis, and it is expected to be the preferred surgery for these patients.

Although the findings are encouraging, there are still some limitations in this study. Limited by study duration and available resources, the sample size was relatively small. It is a retrospective single-center study, so there are potential selection biases and information biases. Furthermore, bipolar plasmakinetic TURP and HoLEP were performed by different surgeon, which may introduce inter-operator heterogeneity. Additionally, more comprehensive evaluations of renal function were not carried out, such as assessments of kidney injury molecule-1 (KIM-1) and N-acetyl-β-D-glucosaminidase (NAG) for acute kidney injury and retinol-binding protein (RBP) for chronic kidney injury. Moreover, the assessment of hydronephrosis and renal dysfunction did not include intravenous pyelography (IVP), glomerular filtration rate detected by single photon emission computed tomography (SPECT) or other auxiliary examinations. A follow-up urodynamic study (UDS) after the operation was not performed, resulting in a lack of objective data to document UDS changes supporting postoperative improvements. Therefore, the conclusions should to be further confirmed by more comprehensive multicentre, large-sample randomized controlled studies.

In recent years, novel energy platforms have been introduced into surgical practice, and their application to transurethral enucleation of the prostate is expected to further enhance the enucleation efficiency and haemostatic control. Compared with traditional open simple prostatectomy, robot-assisted simple prostatectomy has demonstrated comparable resection efficiency with reduced invasiveness. In parallel, advances in the understanding of detailed prostatic surgical anatomy have enabled more precise enucleation, aiming to achieve efficient removal of hyperplastic tissue while preserving urinary continence. In addition, the development and clinical adoption of novel drugs for lower urinary tract symptoms may complement surgical therapy, providing more durable lower urinary tract patency and renal function protection for patients with BPH complicated by hydronephrosis. This progress will significantly enhance patients’ quality of life and mitigate the burden of long-term complications.

Conclusions

Compared with traditional bipolar plasmakinetic TURP, HoLEP achieves safer and more complete removal of hyperplastic prostate tissue, thereby ensuring durable relief of lower urinary tract obstruction. Consequently, HoLEP supports sustained recovery of renal function in BPH patients with preoperative hydronephrosis, and may be an optimal surgical option for these patients.

Supplementary

The article’s supplementary files as

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of Huadong Hospital Affiliated to Fudan University (No. 2023K137) and individual consent for this retrospective analysis was waived.

Data Sharing Statement

Available at https://tau.amegroups.com/article/view/10.21037/tau-2026-0197/dss

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DOI: 10.21037/tau-2026-0197