There is ongoing debate concerning the optimal investigations for patients who suffer from post-prostatectomy incontinence (PPI). The exact indications for the use of standard urodynamics (SUDS) for the investigation of male stress urinary incontinence (SUI) vary across guidelines (1, 2, 3). There is little to no mention of the role video-UDS (VUDS) has in the evaluation of PPI. 

The aim of this study is to explore the role of SUDS and VUDS in the investigation of PPI and to determine if they have an impact on its management.

This is a retrospective chart review of a UDS database of male patients with PPI between 2012 and 2023 in a single high volume tertiary centre. UDS was performed in every patient with PPI when surgical treatment was being considered. Clinical and urodynamic diagnoses were compared. Management of all patients who underwent UDS was analysed. Urethrocystoscopic and fluoroscopic findings of patients with urethral stricture seen on VUDS were compared. Statistical analysis was performed using Excel version 16.83.

A total of 256 patients had VUDS for PPI during the time frame. 

Clinical diagnoses
All patients had a clinical diagnosis of SUI. Of those with available data, there was a concomitant clinical diagnosis of overactive bladder (OAB) and underactive bladder (UAB) in 74 (33.9%) and 2 (0.9%) patients, respectively (Table 1). 

Urodynamic diagnoses
There was urodynamic stress urinary incontinence (USI) in 227 (88.7%) patients. UDS revealed detrusor overactivity (DO) and/or detrusor overactivity incontinence (DOI) in 145 (56.9%) patients. There was detrusor underactivity (DUA) in 80 (31.3%) patients. 11 (4.3%) patients had impaired compliance. Urethral pressure profile (UPP) was performed in 136 patients. The average maximum urethral closure pressure (MUCP) was 40.3 cmH2O (range 0, 100) and the average urethral functional length was 10.1 mm (range 2, 27). VUDS identified de novo urethral narrowing in 13 patients (5.1%) and recurrence of stricture in 5 patients (2.0%). None of the patients had vesicoureteral reflux (VUR) (Table 1). 


Comparison of clinical and urodynamic diagnoses
Both patients with clinical diagnosis of UAB had confirmation of DUA on UDS. DO/DOI was confirmed in 54 (24.9%) patients with a clinical diagnosis of OAB. DO/DOI was not demonstrated in 35 (16.1%) of patients who had a clinical diagnosis of OAB, but USI was present in 85.7% of them. There was also discovery of DO/DOI in 70 (32.3%) in patients without a clinical diagnosis of OAB, and 11 (5.1%) of these patients did not have SUI (Table 2). 

Urethral stricture
There were 20 patients with a known urethral stricture that had been previously treated with either urethral dilation or urethrotomy. Of those with available fluoroscopy details, VUDS showed recurrence of stricture in five patients (27.8%), whereas 13 (72.2%) had normal imaging. Four of the five patients with stricture on VUDS underwent confirmatory flexible urethrocystoscopy. Three of them had a normal urethrocystoscopy and underwent artificial urinary sphincter (AUS) insertion. One patient had confirmation of a stricture that was subsequently treated with urethral dilation. This patient decided not to proceed with AUS insertion after management of his stricture. 

10 of 13 patients with de novo urethral narrowing on VUDS had a subsequent flexible urethrocystoscopy. Stricture was confirmed in two patients. One of them only underwent urethral dilation without surgery for PPI (patient preference), whereas the other had AUS insertion after management and stabilization of the stricture. Among the 8 patients who had a normal urethrocystoscopy, six proceeded with AUS implantation, and the other two opted for conservative management even though they were eligible for surgery.

Management
178 patients had implantation of an AUS, four patients had insertion of a male sling, and 74 did not have surgery for SUI. 23 of the latter (31.1%) had treatment for DO/DOI instead (conservative measures, medications, intradetrusor Botox injections and/or sacral neuromodulation). There was no AUS or male sling insertion in patients without a diagnosis of USI [29 patients (39.2%)]. 15 (51.7%) of the patients without USI had DO/DOI on UDS.

Our study demonstrates that UDS is important in the investigation of PPI and that it can assist in clinical decision making. Indeed, 12.8% of patients did not have USI, and DO/DOI was responsible for the symptoms in slightly more than half of these patients. UDS potentially avoided unnecessary surgery in these patients. 

In addition, there appears to be a weak correlation between clinical diagnosis of OAB and demonstration of DO/DOI on UDS. Indeed, DO/DOI was confirmed in only 24.9% of patients with a clinical diagnosis of OAB, whereas the majority of these patients had USI.  

To our knowledge, this is one of the first studies that explores the role of VUDS for the evaluation of PPI. VUDS did not identify patients with high-risk features, such as VUR, and urethral narrowing was observed in only a minority of patients. Most of the patients with a suspicion of urethral stricture on VUDS (whether recurrent or de novo) underwent subsequent urethrocystoscopy to confirm this diagnosis. The majority of urethrocystoscopies showed normal urethras and absence of stricture. Although our study demonstrated that there is a weak correlation between cystoscopic and VUDS with regards to urethral stricture diagnosis, it did suggest that VUDS would be a more appropriate investigation compared to performing SUDS with urethrocystoscopy. This is because performing the latter combination in every patient increases cost and instrumentation into the urethra. 

In light of these results, we believe that UDS has a crucial impact on the management of PPI and should be included in the investigation of every patient with PPI in whom surgery is being considered. According to most guidelines, UDS is currently recommended when the diagnosis of SUI is unclear, to help with patient counselling and for the identification of factors that would predict a poor outcome (1, 2, 3). These factors include DO, DU, and low bladder compliance. Our study clearly demonstrates that there is a weak correlation between clinical and urodynamic diagnoses in PPI, and therefore UDS should be used in all patients rather than on a case by case basis. 

Given that the presence of a urethral stricture has an impact on the management of PPI, we recommend performing VUDS in every patient contemplating surgery for PPI. If VUDS is not available or the patient has a contra-indication to VUDS, then SUDS with flexible urethrocystoscopy would be an acceptable alternative, although it would not be able to assess for reflux especially in those patients with poorly compliant bladders. 

This is one of the largest studies that evaluates the role of UDS for PPI, but it does have some limitations. Although the data was collected prospectively, this is a retrospective study, and it is therefore subject to recall bias. A prospective, multi-center study would be needed to further confirm the findings demonstrated in our study. There should also be further exploration of the role of UPPs in the evaluation of PPI.

UDS is a valuable diagnostic tool for the assessment of PPI and has an important impact on the management of male SUI prior to surgery. VUDS seems to be more advantageous compared to SUDS, although in centres where it is not available, SUDS with flexible cystoscopy can be an alternative. Guidelines should be updated with this information.

Gacci M, Sakalis VI, Karavitakis M, Cornu JN, Gratzke C, Herrmann TRW, et al. European Association of Urology Guidelines on Male Urinary Incontinence. Eur Urol. 2022;82(4):387-98.
Sandhu JS, Breyer B, Comiter C, Eastham JA, Gomez C, Kirages DJ, et al. Incontinence after Prostate Treatment: AUA/SUFU Guideline. J Urol. 2019;202(2):369-78.
Bhatt NR, Pavithran A, Ilie C, Smith L, Doherty R. Post-prostatectomy incontinence: a guideline of guidelines. BJU Int. 2023.