NEUROUROLOGY & FEMALE UROLOGY

Is There A Role For Periurethral Collagen Injection In The Management Of Urodynamically Proven Mixed Urinary Incontinence?
Poon CI, Zimmern PE
Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
Urology. 2006; 67: 725-9; discussion 729-30

• Objectives: To investigate the effectiveness of periurethral collagen injection (PCI) in patients presenting with symptoms of mixed urinary incontinence (MUI) and urodynamically demonstrated sphincter deficiency and detrusor overactivity.
• Methods: A retrospective review was performed on all patients undergoing PCI from February 1999 to February 2003, during which those with MUI were treated with PCI as first-line therapy. The inclusion criteria were MUI symptoms, detrusor overactivity on urodynamic study, stress urinary incontinence due to sphincter deficiency (determined from physical examination, stress test, urodynamic study with Valsalva leak point pressure, and cystography findings, without urethral hypermobility). The primary outcome measures were the Urogenital Distress Inventory (UDI), Incontinence Impact Questionnaire, and quality-of-life score and the need for anticholinergic medications or additional surgery. Comparisons were performed using the Wilcoxon signed ranks test and paired t test.
• Results: Of the 56 patients who underwent PCI, 43 presented with symptoms of MUI, and 16 of these (29%) had both detrusor overactivity and stress urinary incontinence on urodynamic study. The mean follow-up after PCI (without additional PCI) was 18 months (range 6 to 39). The mean age was 65 years (range 40 to 84). The mean Valsalva leak point pressure was 54 +/- 40 cm H2O (range 18 to 146). Ten patients had undergone previous anti-incontinence procedures, and anticholinergic medications had failed in six. The questionnaire scores, indicating severe MUI/poor quality of life before PCI, improved after PCI: UDI question 1, 2.3 +/- 0.8 versus 1.3 +/- 1.0 (P = 0.021); UDI question 2, 2.1 +/- 1.2 versus 1.4 +/- 1.0 (P = 0.068); UDI question 3, 2.9 +/- 0.4 versus 1.8 +/- 1.2 (P = 0.010); and quality-of-life question, 8.6 +/- 2.1 versus 5.2 +/- 3.5 (P = 0.026). The mean injected volume/patient was 8.5 cm3 (range 5 to 17) within a mean of 1.9 treatments (range 1 to 3). Four patients continued taking anticholinergic medications and one proceeded to sling placement.
• Conclusions: The use of PCI as the primary/initial intervention in patients with MUI may be the preferred approach, particularly in patients with an elevated risk of anticholinergic medication side effects or when voiding dynamics preclude sling placement.
  
  
• Editorial Comment
  The authors describe a retrospective review involving the performance of periurethral collagen injection for patients plagued with mixed urinary incontinence. The detrusor overactivity was diagnosed on urodynamics as an increase in detrusor pressure and/or a sensation of urgency with or without incontinence during the filling phase of the study.
  The authors found a significant improvement in both the symptoms of stress urinary incontinence and overactive bladder (urinary frequency and urinary urge incontinence). These findings somewhat echo those found by McGuire & Savastano (1) from greater than 2 decades ago. This mirror success rate does give some merit to the argument of detrusor overactivity having a definite urethral component in its etiology. Based on the findings of these authors, injectable therapy seems to be a very reasonable option for patients with mixed urinary urge incontinence and has a higher success than those patients tried with pharmacologic therapy alone.

Reference
1. McGuire EJ, Savastano JA: Stress incontinence and detrusor instability/urge incontinence. Neurourol. Urodyn. 1985; 4: 313-6.

Dr. Steven P. Petrou
Associate Professor of Urology
Chief of Surgery, St. Luke’s Hospital
Associate Dean, Mayo School of Graduate Medical Education
Jacksonville, Florida, USA