Comparative Functional Outcomes of Bipolar TURP and Bladder Neck Incision in Male Bladder Outlet Obstruction

Abstract

Objectives

Patients who underwent either transurethral resection of the prostate (TURP) or bladder neck incision (BNI) for bladder outlet obstruction (BOO) were evaluated in this study. The aim was to compare the perioperative characteristics and postoperative outcomes of the two surgical approaches.

Methods

Data from 74 patients who underwent surgical treatment for bladder outlet obstruction (BOO) between January and December 2025 were assessed. The study population consisted of 33 patients treated with TURP and 41 patients treated with BNI. Demographic characteristics, prostate volume, and operative time were recorded for all participants. Uroflowmetry parameters, including maximum flow rate (Qmax), average flow rate (Qavg), and post-void residual urine volume (PVR), were evaluated preoperatively and at 6 months postoperatively. Statistical analyses were performed using Student’s t-test or the Mann–Whitney U test.

Results

Patients in the TURP group were older and had significantly larger prostate volumes than those in the BNI group (both p<0.001). Procedure duration was also longer among patients who underwent TURP. Preoperative PVR values were higher in the TURP group, whereas preoperative Qmax, Qavg, and voided volume did not differ significantly between the groups. Patients treated with BNI demonstrated higher Qmax, Qavg, and voided volume values at 6 months postoperatively, while PVR was lower than that in the TURP group.

Conclusion

Postoperative voiding test results were more favorable in the BNI group than in the TURP group. This difference may be related to patient age and the underlying cause of bladder outlet obstruction. These factors should be considered when planning treatment and counseling patients.

Bladder outlet obstruction (BOO) is a common condition in men and becomes more frequent with age. The most common causes are benign prostatic hyperplasia (BPH) and bladder neck obstruction (BNO).^[1] In patients with severe LUTS, recurrent urinary retention, or obstruction-related complications, surgical management may become necessary.^[2] Bipolar transurethral resection of the prostate (TURP) is one of the most commonly used surgical treatments for BOO caused by BPH.^[3] In patients with bladder neck obstruction who have a normal-sized prostate and do not respond to medical treatment, bladder neck incision (BNI) is often performed.

TURP and BNI are widely used in the management of BOO. There are few clinical studies comparing their functional outcomes. However, there is limited evidence regarding how the underlying etiology affects surgical outcomes. Patients with BNO are generally younger and often present with LUTS that can be difficult to distinguish from those associated with BPH. Despite this clinical similarity, symptom relief with medical treatment is usually less satisfactory in patients with BNO.^[4–6]

In younger men, BNO may be overlooked because prostate enlargement is usually absent, and LUTS are often attributed to other conditions, such as urinary tract infections.^[7,8] In patients with a normal-sized prostate who do not respond to medical treatment, BNO should also be considered. If uroflowmetry suggests obstruction, cystoscopy or urodynamic evaluation can be used to support the diagnosis.^[9]

The present study compared demographic characteristics, perioperative parameters, and postoperative functional outcomes between patients who underwent bipolar TURP for BPH and those treated with BNI for BNO.

Methods

A total of 74 male patients who underwent surgical treatment for bladder outlet obstruction between January and December 2025 were included in this retrospective cohort study. The study was approved by the Mudanya University Ethics Committee (No. 2026-3/20; Date: March 02, 2026) and was conducted in accordance with the Declaration of Helsinki. Informed consent was obtained from all participants.

Between January and December 2025, 45 patients underwent bipolar TURP for BPH, and 42 underwent BNI for BNO. After applying the predefined exclusion criteria, 12 patients were excluded from the BPH group (2 due to prostatitis, 2 due to previous lower urinary tract surgery, 3 due to urethral stricture, 1 due to prostate cancer, 1 due to neurogenic bladder dysfunction with a post-void residual urine volume >300 mL, and 3 due to irregular follow-up). One patient was excluded from the BNO group because of irregular follow-up. Consequently, 33 patients in the BPH group and 41 patients in the BNO group were included in the final analysis.

Patient Groups

The study population consisted of two groups:

• Group 1 (BNO): patients treated with BNI (n=41)

• Group 2 (BPH): patients treated with bipolar TURP (n=33)

Data Collection

The recorded variables included:

• Age and body mass index (BMI)

• Prostate volume measured by transabdominal ultrasonography

• Uroflowmetry parameters, including maximum flow rate (Qmax), average flow rate (Qavg), voided volume, and post-void residual urine volume (PVR)

Uroflowmetry and PVR assessments were performed before surgery and repeated 6 months postoperatively.

Inclusion Criteria

• Complete uroflowmetry and imaging data available

• Regular postoperative follow-up

• Complete clinical records

Exclusion Criteria

• Prostatitis

• Prostate cancer

• Neurogenic bladder dysfunction or PVR >300 mL

• Prior lower urinary tract surgery

• Urethral stricture

• Irregular follow-up

Patients in the BNO group were diagnosed based on cystoscopic findings demonstrating a narrowed and obstructive bladder neck in the absence of urethral stricture or previous lower urinary tract surgery.

Surgical Technique

All operations were performed by the same surgeon. In patients with BPH, bipolar TURP was performed using a 26 Fr bipolar resectoscope. Resection extended from the bladder neck to the verumontanum, and the resected specimens were submitted for histopathological evaluation. In patients with BNO, transurethral bladder neck incisions were made at the 5 and 7 o’clock positions. A 20 Fr three-way Foley catheter was inserted after surgery and removed on the second postoperative day.

Statistical Analysis

Continuous variables are presented as mean±standard deviation (SD). Data distribution was evaluated for normality before statistical testing. Comparisons between groups were made using Student’s t-test or the Mann–Whitney U test, depending on the distribution of the data. All analyses were conducted using MedCalc Statistical Software (MedCalc Software Ltd., Mariakerke, Belgium). A two-sided p value of <0.05 was considered statistically significant.

Artificial Intelligence Assistance

ChatGPT (OpenAI, GPT-5.5) was used solely to improve the English language and readability of the manuscript. The AI tool was not used for study design, data collection, statistical analysis, interpretation of results, or scientific conclusions. All AI-assisted content was reviewed and approved by the authors, who take full responsibility for the final manuscript.

Results

A total of 74 patients were included in this study.

Patients in the BPH group were significantly older than those in the BNO group (72.1±6.5 vs. 55.7±14.0 years, p<0.001). Height, weight, and BMI were comparable between the groups (Table 1).

Table 1.

Comparison of demographic and perioperative characteristics between the study groups

Parameters	Group 1 (BNO, n=41)	Group 2 (BPH, n=33)	p
Age (years)	55.7±14.0	72.1±6.5	<0.001*
Height (cm)	165.8±7.1	165.9±6.6	0.845
Weight (kg)	81.3±17.9	80.0±15.0	0.501
BMI (kg/m2)	30.0±7.2	29.4±5.9	0.518
Prostate volume (mL)	32.7±13.5	87.3±38.8	<0.001*
Operative time (min)	25.2±7.5	44.8±22.4	<0.001*

Data are presented as mean±standard deviation. Group comparisons were performed using Student’s t-test. A p-value <0.05 was considered statistically significant (*). BNO: Bladder neck obstruction; BPH: Benign prostatic hyperplasia; BMI: Body mass index; mL: milliliter; min: minutes.

Prostate volume was significantly higher in the BPH group (p<0.001). Procedure duration was also longer in the BPH group than in the BNO group (44.8±22.4 vs. 25.2±7.5 minutes, p<0.001) (Table 1).

Preoperative uroflowmetry findings were similar between the groups, with the exception of PVR, which was significantly higher in the BPH group (p<0.001).

At the 6-month follow-up, functional outcomes differed significantly between the groups:

• Qmax and Qavg were higher in the BNO group (p=0.002 and p=0.003, respectively) (Table 2).

• Voided volume was also higher in the BNO group (p<0.001).

• Lower PVR values were observed in the BNO group (p<0.001).

Table 2.

Comparison of preoperative and postoperative uroflowmetry parameters between the study groups

Parameters	Group 1 (BNO, n=41)	Group 2 (BPH, n=33)	p
Preoperative Qmax (mL/s)	10.5±2.8	9.3±3.9	0.120
Preoperative Qavg (mL/s)	5.6±1.4	5.5±2.4	0.806
Preoperative voided volume (mL)	293.9±123.8	253.8±97.5	0.122
Preoperative PVR (mL)	59.0±21.6	111.2±9.1	<0.001*
Postoperative Qmax (mL/s)	19.9±5.7	14.9±6.8	0.002*
Postoperative Qavg (mL/s)	12.1±3.6	9.0±3.9	0.003*
Postoperative voided volume (mL)	351.7±112.5	260.1±66.6	<0.001*
Postoperative PVR (mL)	26.8±9.6	48.3±9.5	<0.001*

Data are presented as mean±standard deviation. Group comparisons were performed using Student’s t-test. A p-value <0.05 was considered statistically significant (*). BNO: Bladder neck obstruction; BPH: Benign prostatic hyperplasia; Qmax: Maximum urinary flow rate; Qavg: Average urinary flow rate; PVR: Post-void residual volume; mL/s: milliliters per second; mL: milliliters.

Overall, patients with BNO had better postoperative functional outcomes than patients with BPH (Table 2).

No capsular perforation was observed in either group. No intraoperative bleeding requiring blood transfusion occurred. No cases of urethral stricture were encountered during the 6-month follow-up.

Because the study was retrospective, sexual function outcomes, including retrograde ejaculation, were not systematically evaluated.

Discussion

In this study, patients who underwent TURP or BNI for BOO were evaluated. Uroflowmetry parameters improved in both groups at 6 months postoperatively. However, patients treated with BNI had higher Qmax, Qavg, and voided volume values, as well as lower PVR values, compared with those who underwent TURP. Overall, postoperative functional outcomes were more favorable in the BNI group (Table 2).

In this study, patients in the BNI group were younger and had smaller prostate volumes than those in the TURP group (Table 1). Similar findings have been reported in previous studies, in which TURP was mainly performed in patients with larger prostates, whereas BNI was more commonly used in younger patients with smaller prostates. In younger men with normal-sized prostates, LUTS are often attributed to overactive bladder.^[10,11] However, in patients with persistent symptoms despite medical treatment, BOO should also be considered. In such cases, uroflowmetry can provide useful additional information.

Delayed diagnosis and treatment of BOO may result in irreversible complications. One of the main findings of this study is that the results should not be viewed as a direct comparison between TURP and BNI. The two procedures were performed in different patient populations based on clinical indications. The better postoperative outcomes observed in the BNI group may be related to younger age, smaller prostate volume, and a lower degree of obstruction. Therefore, the results of this study appear to support the importance of appropriate patient selection when choosing a surgical approach, without favoring either treatment.

The findings of this study indicate that BNO remains an underrecognized cause of LUTS in younger patients with normal-sized prostates.^[12,13] In daily practice, BPH is often considered first when evaluating men with LUTS. However, this may result in delayed diagnosis of less common conditions such as BNO.^[14] The favorable postoperative outcomes observed in the BNO group suggest that surgical treatment may provide clinical improvement in these patients.

Patients in the TURP group were older and had larger prostate volumes and higher preoperative PVR values. These findings suggest a greater degree of BOO in this group. Age-related reductions in detrusor contractility may also have affected voiding function.^[15] In contrast, the younger age and better-preserved detrusor function of patients in the BNI group may have contributed to their better uroflowmetry results. However, the significant improvement in urinary flow rates observed in the TURP group indicates that TURP remains an effective treatment for BPH.^[16]

The shorter procedure duration in the BNI group is another important finding of this study (Table 1). This may be related to the less invasive nature of the procedure. In patients with comorbidities, a shorter operative time may help reduce perioperative complications. In addition, these findings support the use of BNI as a practical and less invasive treatment option in appropriately selected patients with BNO.^[17,18]

Our findings suggest that patients with BOO should be evaluated on an individual basis. In addition to prostate size and age-adjusted PSA levels, the severity of LUTS, response to medical treatment, and uroflowmetry findings should also be taken into account. Both anatomical and functional factors should be assessed during evaluation.^[19] In younger patients with a normal-sized prostate, severe LUTS, or a poor response to treatment, BNO should also be considered.^[20]

BNO should be considered an important cause of lower urinary tract symptoms, particularly in younger patients with a normal-sized prostate and a poor response to medical treatment. Patients with previous lower urinary tract surgery were excluded from the present study to avoid potential confounding from secondary causes of bladder outlet obstruction.^[21,22] The difficulty of diagnosing BNO in young patients with LUTS and a normal-sized prostate highlights the clinical importance of this condition. Particularly in patients who do not respond adequately to alpha-blocker therapy, the underlying pathology may not be prostate enlargement but rather a functional or anatomical obstruction of the bladder neck.^[23] From a clinical perspective, early diagnosis of BNO can prevent prolonged ineffective medical treatment and allow for timely surgical intervention.

Limitations

This study has several limitations. It was conducted at a single center and included a relatively small number of patients. Although all operations were performed by a single surgeon, which may limit the generalizability of the findings, this also increased procedural consistency. The follow-up period was limited to 6 months; therefore, long-term functional outcomes could not be evaluated. In addition, the exclusion of patients with comorbid conditions and the lack of sexual function assessment may have influenced postoperative outcomes. Retrograde ejaculation and other sexual function parameters were not assessed because of the retrospective study design. The absence of urodynamic testing did not allow for objective classification of BNO. However, the diagnosis was based on cystoscopic findings and clinical evaluation. The clinical improvement observed after surgery supports the diagnosis.

Conclusion

Bipolar TURP is a commonly used surgical treatment for patients with BPH and enlarged prostate volume. BNI is an effective treatment option for BNO in younger patients with a normal-sized prostate. The differences observed between the groups in this study may be related to patient age, etiological factors, and the severity of obstruction rather than to the superiority of one surgical method over another.

Disclosures

Ethics Approval

Ethics committee approval for this study was obtained from the Mudanya University (Approval no: 2026-3/20; date: March 02, 2026)

Informed consent

Informed consent was obtained from all participants.

Conflict of Interest

The authors declare that there is no conflict of interest.

Financial Disclosure

This study received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Use of AI for Writing Assistance

ChatGPT (OpenAI, GPT-5.5) was used solely to improve the English language and readability of the manuscript. The AI tool was not used for study design, data collection, statistical analysis, interpretation of results, or scientific conclusions. All AI-assisted content was reviewed and approved by the authors, who take full responsibility for the final manuscript.

Authorship Contributions

Concept – S.Y., N.A.; Design – S.Y., N.A.; Supervision – S.Y., N.A.; Materials − N.A.; Data collection &/or processing – S.Y., M.K.; Analysis and/or interpretation – S.G.; Literature search – S.Y., N.A., S.G.; Writing – S.Y., M.K., B.V.; Critical review – S.Y., M.K., N.A., B.V., S.G.

Peer-review

Externally peer-reviewed.