Artificial Urinary Sphincters, Stents, Slings & Meshes Flashcards
Define genuine stress incontinence
Loss of urine which occurs when bladder pressure exceeds urethral pressure in the absence of detrusor activity
Causes of genuine stress incontinence
- raised abdominal pressure (coughing)
- incompetent bladder neck or hypermobile urethra
- intrinsic sphincter deficiency
RF of genuine stress incontinence in males
- post prostatectomy
- > 1% post TURP
- 5% post retropubic prostatectomy for BPH
- 10% post prostatectomy for prostate cancer
RF for genuine stress incontinence in females
- multiparity (vaginal delivery)
- obesity
- pelvic surgery
- oestrogen withdrawal
RF for genuine stress incontinence in both males and females
LMN nerve injury = sphincter denervation
- spinal cord injury below T12
- nerve damage following spinal surgery
- sacral nerve damage following tumour removal
- spina bifida
- MS
Medical management options for genuine stress incontinence
- pelvic floor exercises
- electrical stimulation
- biofeedback of pelvic floor contraction
Surgical management options for genuine stress incontinence
- slings/pubovaginal/autologous/TVT
- injectables (collagen, macroplastique)
- open procedures (vagino-obturator, burch colposuspension)
- artificial urinary sphincter
What does an artificial urinary stent comprise of?
- pressure regulating balloon
- urethral cuff
- pump
What are artificial urinary sphincters made from?
- silicone rubber
What are some examples of artificial urinary sphincters?
- AMS AS-800
- Flowsecure AUS
AMS AS-800 Design Features
- individual parts filled and joined in theatre (modular assembly)
- different balloon sizes for each pressure regulation
- cuff formed as a flat piece
- different size cuffs for each patient
- deactivation button on pump
(urethral cuff + pressure regulating balloon + pump)
Flowsecure AUS Design Features
- one piece = no assembly
- stress relief facility for conditional occlusion
- circular cuff to reduce creasing
- one size urethra cuff
- adjustable pressure regulation through self sealing port in pump
(urethral cuff + pressure reg balloon + stress relief reservoir + pump & self sealing port)
Function of AUS devices
- deflation
- re-inflation
- conditional occlusion
(see lecture diagram)
Contra-indications for AUS devices
- unmanaged detrusor instability
- previous radiotherapy of the lower urinary tract
- problems affecting manual dexterity or motivation (may prevent patient operating device)
- acute UTI (may get post-op complications)
- open surgical procedure risks regarding medical history
- known sensitivity to silicone rubber
How to insert a Flowsecure AUS?
- excise urethra through perineal
- make an abdominal incision and pass trocar through perineal incision
- device is prefilled on sterile field and prepared for implantation
- clamp tube just below regulating balloon with protected forceps, gently squeeze fluid out of cuff with fingers and clamp just below stress relief balloon so fluid cannot return
- remove stylet from trocar and pass the deflated cuff through it to the perineal site
- remove trocar downwards over cuff at perineal site leaving the pump and balloon protruding from abdominal incision above
- place cuff around urethra loop until it is a comfortable fit but not too tight
- apply glue and single stitches at top, middle and bottom of belt to ensure a secure fix
- place balloons in abdominal pouches
- place pump in scrotum
- at a later date, device is pressurised by injecting sterile saline through self-sealing port in the base of the control pump
Differences between Flowsecure and AMS-AS 800?
- Flowsecure one piece assembly so quicker + simpler implantation vs. AMS tedious assembly which may introduce infection
- pressure can be adjusted without need for surgical revision in Flowsecure vs. AMS pressure only increased by surgical revision of pressure balloon
- Flowsecure stress relief facility provides conditional occlusion so device may be able to run at a lower pressure vs. AMS pressure must be set to high to maintain continence even during stress perods
How is sterile saline injected?
- scrotal area prepared under aseptic technique
- 25G short needle filled with sterile saline
- self sealing port in base of pump located
- pump sterile saline into pump
- remove needle and redistribute fluid by pumping device
How to assess continence?
- 7 day voiding and leakage diary
- ICIQ (Quality of Life Questionnaire)
- Measurement of intake/voiding/leakage (pad weighing)
- continence index
How to calculate continence index?
= 100 x Voided volume/ (Leaked volume + voided volume)
Potential Complications with AUS
- recurrent incontinence
- infection
- mechanical failure
How may you get recurrent incontinence? How should it be managed?
- pressure may not be high enough
- may need to carry out additional pressurisation (flowsecure)
- may need to re-operate and replace balloon for higher pressure one
- urethral atrophy
- infection
- mechanical failure
Why may you get infection? How should it be managed?
- acquired at surgery
- may need to remove device and replace
How to manage mechanical failure?
- if spontaneous = device removal and replacement
- if flowsecure = whole device replaced
- if AS-800 = modular components replaced
How to image AUS devices?
AS-800 = fill with radio-opaque solution then x-ray image Flowsecure = MRI or US
Difference in pressure-volume characteristics of Flow secure vs. AMS AS 800
Flow secure = at low volumes pressure ranges 50-70
AMS AS 800 = at higher volumes pressure reaches 50-80
Flowsecure can run at lower pressures but AMS needed to run at higher pressures to maintain continence
Clinical Trial of Flowsecure
- male patients with urodynamically proven stress incontinence = previous Tx with conservative methods/augmentation with injection not excluded/ unctonrolled detrusor actviity not excluded
- pre-op, pressurisation, 3/6 and 12 month visits (urine analysis and culture, cystometrogram and flow rate, stress tests and 7 day voiding and leakage diary)
- additional pressurisation procedures as neccessary based on patient symtpoms
