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Residents’ podcast: Urinary continence recovery after radical prostatectomy

Maria Uloko is a Urology Resident at the University of Minnesota Hospital and Giulia Lane is a Female Pelvic Medicine and Reconstructive Surgery Fellow at the University of Michigan.

In this podcast they discuss the BJUI Article of the Week ‘Investigating the mechanism underlying urinary continence recovery after radical prostatectomy: effectiveness of a longer urethral stump to prevent urinary incontinence‘.

 

Investigating the mechanism underlying urinary continence recovery after radical prostatectomy: effectiveness of a longer urethral stump to prevent urinary incontinence

 

Yoshifumi Kadono*, Takahiro Nohara*, Shohei Kawaguchi*, Renato Naito*, Satoko Urata*, Kazufumi Nakashima*, Masashi Iijima*, Kazuyoshi Shigehara*, Kouji Izumi*, Toshifumi Gabata† and Atsushi Mizokami*

*Department of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan; †Department of Radiology, Kanazawa University School of Medicine, 13‐1 Takara‐machi, Kanazawa, Ishikawa 920‐8640, Japan

Abstract

Objective

To assess the chronological changes in urinary incontinence and urethral function before and after radical prostatectomy (RP), and to compare the findings of pelvic magnetic resonance imaging (MRI) before and after RP to evaluate the anatomical changes.

Patients and Methods

In total, 185 patients were evaluated with regard to the position of the distal end of the membranous urethra (DMU) on a mid‐sagittal MRI slice and urethral sphincter function using the urethral pressure profilometry. The patients also underwent an abdominal leak point pressure test before RP and at 10 days and 12 months after RP. The results were then compared with the chronological changes in urinary incontinence.

Fig. 1 Intraoperative view of the apex of the prostate transection line between the urethra and prostate at the normal (straight line) and long urethral stump (dashed line) positions.

Results

The MRI results showed that the DMU shifted proximally to an average distance of 4 mm at 10 days after RP and returned to the preoperative position at 12 months after RP. Urethral sphincter function also worsened 10 days after RP, with recovery after 12 months. The residual length of the urethral stump and urinary incontinence were significantly associated with the migration length of the DMU at 10 days after RP. The residual length of the urethral stump was a significant predictor of urinary incontinence after RP.

Conclusion

This is the first study to elucidate that the slight vertical repositioning of the membranous urethra after RP causes chronological changes in urinary incontinence. A long urethral residual stump reduces urinary incontinence after RP.

 

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Editorial: Towards an individualized approach for predicting post‐prostatectomy urinary incontinence: the role of nerve preservation and urethral stump length

Traditionally, MRI of the prostate has been mainly applied in the diagnosis and staging of prostate cancer. Kadono et al. [1] used pre‐ and postoperative pelvic MRI to assess the repositioning of the urethra 10 days and 12 months after prostatectomy, hypothesizing that these alterations could correlate with urinary incontinence and urethral function. Recent MRI measurements of anatomical structures of the pelvic floor, such as membranous urethral length and inner levator distance, were found to be independent predictors of early continence recovery at 12 months after prostatectomy [2] A meta‐analysis has also shown a strong correlation between membranous urethral length and continence recovery at 3‐, 6‐ and 12‐month follow‐up [3] Kadono et al. [1] add another metric to the pelvic floor dimensions that may help predict continence. Cranial migration of the lower end of the membranous urethra early after prostatectomy was associated with urinary incontinence and urinary sphincter function, as objectively assessed by urethral pressure profile. Interestingly, return of the membranous urethra to the more distal preoperative position after 12 months was associated with improvement in continence. In a multivariate model, urethral stump length was a strong predictor of continence outcome at 10 days as well as 12 months after prostatectomy. This observation suggests that urethral length may partly improve post-prostatectomy continence through better compression of the membranous urethra in the pelvic floor membrane rather than through transfer of the intra‐abdominal pressure onto the intra‐abdominally located urethra. If confirmed, this observation may imply that more cranial fixation of the bladder neck in a more intra‐abdominal position may not necessarily improve continence after prostatectomy, in line with data from randomized controlled studies comparing median fibrous raphe reconstruction with standard anastomosis that failed to show a benefit [4,5].

Besides anatomical location, innervation of the proximal urethra is important for post-prostatectomy continence [6]. Kadono et al. found that nerve preservation was an independent predictor of early and long‐term continence outcome, with a b value similar to that of urethral stump length at 12‐month follow‐up. To improve post-prostatectomy continence outcome, proper patient selection seems crucial. In the era of personalized medicine, MRI could be a valuable tool to assess preoperatively the risks of postoperative urinary incontinence and counsel patients accordingly. Avoiding prostatectomy in men with short preoperative membranous urethral length may be an important approach for improving outcome, in particular in light of the fact that many attempts to surgically correct anatomical alignment of the pelvic floor have not clearly improved continence outcome. If surgery is considered, nerve preservation should be performed where possible to improve continence.

Henk G. van der Poel and Nikos Grivas

Department of Urology, Netherlands Cancer Institute, Amsterdam, The Netherlands

References

  1. Kadono Y, Nohara T, Kawaguchi S et al. Investigating the mechanism underlying urinary continence recovery after radical prostatectomy: effectiveness of a longer urethral stump to prevent urinary incontinence. BJU Int 2018. 37: 463–9
  2. Grivas N, van der Roest R, Schouten D et al. Quantitative assessment of fascia preservation improves the prediction of membranous urethral length and inner levator distance on continence outcome after robot-assisted radical prostatectomy. Neurourol Urodyn 2018; 37: 417–25
  3. Mungovan SF, Sandhu JS , Akin O, Smart NA, Graham PL, Patel MI. Preoperative membranous urethral length measurement and continence recovery  following radical prostatectomy: a systematic review and meta-analysis. Eur Urol 2017; 71: 368–78
  4. Joshi N, de Blok W, van Muilekom E, van der Poel H. Impact of posterior musculofascial reconstruction on early continence after robot-assisted laparoscopic radical prostatectomy: results of a prospective parallel group trial. Eur Urol 2010; 58: 84–9
  5. Menon M, Muhletaler F, Campos M, Peabody JO. Assessment of early continence after reconstruction of the periprostatic tissues in patients undergoing computer assisted (robotic) prostatectomy: results of a 2 group parallel randomized controlled trial. J Urol 2008; 180: 1018–23
  6. van der Poel HG, de Blok W, Joshi N, van Muilekom E. Preservation of lateral prostatic fascia is associated with urine continence after robotic-assisted prostatectomy. Eur Urol 2009; 55: 892–900Dearnaley DP, Jovic G, Syndikus I et al. The. Lancet Oncol 2014; 15:464–73

 

Video: Urinary continence recovery after radical prostatectomy

Investigating the mechanism underlying urinary continence recovery after radical prostatectomy: effectiveness of a longer urethral stump to prevent urinary incontinence

Abstract

Objective

To assess the chronological changes in urinary incontinence and urethral function before and after radical prostatectomy (RP), and to compare the findings of pelvic magnetic resonance imaging (MRI) before and after RP to evaluate the anatomical changes.

Patients and Methods

In total, 185 patients were evaluated with regard to the position of the distal end of the membranous urethra (DMU) on a mid‐sagittal MRI slice and urethral sphincter function using the urethral pressure profilometry. The patients also underwent an abdominal leak point pressure test before RP and at 10 days and 12 months after RP. The results were then compared with the chronological changes in urinary incontinence.

Results

The MRI results showed that the DMU shifted proximally to an average distance of 4 mm at 10 days after RP and returned to the preoperative position at 12 months after RP. Urethral sphincter function also worsened 10 days after RP, with recovery after 12 months. The residual length of the urethral stump and urinary incontinence were significantly associated with the migration length of the DMU at 10 days after RP. The residual length of the urethral stump was a significant predictor of urinary incontinence after RP.

Conclusion

This is the first study to elucidate that the slight vertical repositioning of the membranous urethra after RP causes chronological changes in urinary incontinence. A long urethral residual stump reduces urinary incontinence after RP.

 

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Article of the week: Effectiveness of a longer urethral stump to prevent urinary incontinence after radical prostatectomy

Every Week, the Editor-in-Chief selects an Article of the Week from the current issue of BJUI. The abstract is reproduced below and you can click on the button to read the full article, which is freely available to all readers for at least 30 days from the time of this post.

In addition to the article itself, there is an accompanying editorial written by a prominent member of the urological community. This blog is intended to provoke comment and discussion and we invite you to use the comment tools at the bottom of each post to join the conversation.

Finally, the third post under the Article of the Week heading on the homepage will consist of additional material or media. This week we feature both a video and a podcast discussing the paper.

If you only have time to read one article this week, it should be this one.

Investigating the mechanism underlying urinary continence recovery after radical prostatectomy: effectiveness of a longer urethral stump to prevent urinary incontinence

Yoshifumi Kadono*, Takahiro Nohara*, Shohei Kawaguchi*, Renato Naito*, Satoko Urata*, Kazufumi Nakashima*, Masashi Iijima*, Kazuyoshi Shigehara*, Kouji Izumi*, Toshifumi Gabata† and Atsushi Mizokami*

*Department of Integrative Cancer Therapy and Urology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan; †Department of Radiology, Kanazawa University School of Medicine, 13‐1 Takara‐machi, Kanazawa, Ishikawa 920‐8640, Japan

Abstract

Objective

To assess the chronological changes in urinary incontinence and urethral function before and after radical prostatectomy (RP), and to compare the findings of pelvic magnetic resonance imaging (MRI) before and after RP to evaluate the anatomical changes.

Patients and Methods

In total, 185 patients were evaluated with regard to the position of the distal end of the membranous urethra (DMU) on a mid‐sagittal MRI slice and urethral sphincter function using the urethral pressure profilometry. The patients also underwent an abdominal leak point pressure test before RP and at 10 days and 12 months after RP. The results were then compared with the chronological changes in urinary incontinence.

Fig. 1 Intraoperative view of the apex of the prostate transection line between the urethra and prostate at (A) the normal and (B) long urethral stump positions.

Results

The MRI results showed that the DMU shifted proximally to an average distance of 4 mm at 10 days after RP and returned to the preoperative position at 12 months after RP. Urethral sphincter function also worsened 10 days after RP, with recovery after 12 months. The residual length of the urethral stump and urinary incontinence were significantly associated with the migration length of the DMU at 10 days after RP. The residual length of the urethral stump was a significant predictor of urinary incontinence after RP.

Conclusion

This is the first study to elucidate that the slight vertical repositioning of the membranous urethra after RP causes chronological changes in urinary incontinence. A long urethral residual stump reduces urinary incontinence after RP.

 

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