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Functional Failure: Incontinence despite adequate
Urethral and Bladder Neck Support
Despite the restoration of adequate bladder neck and
urethral support many patients have persistent post-
operative urinary incontinence. This may occur as a
result of intrinsic sphincteric deficiency, fistula,
urinary obstruction or persistent or de novo urgency and
urge incontinence.
Intrinsic
Sphincteric deficiency
In the absence of significant urgency, frequency,
urgency incontinence and elevated post – void residuals
which is suggestive of obstruction, the most likely
cause of persistent or recurrent incontinence in the
setting of good anatomic support is intrinsic
sphincteric deficiency (ISD). ISD may occur as a result
of the surgery or may have been a preexisting but
unrecognized preoperative condition.
ISD is often secondary to atrophy of the urethral mucosa
and the submucosal spongy tissue of the sphincteric unit
or damage to the fibromuscular urethral envelope. This
leads to inadequate coaptation of the urethra despite
good muscular support in many instances. One could
compare this situation to that of a new faucet with a
bad washer. The application of unlimited or infinite
closure pressure will still not create a satisfactory
seal if the washer is faulty. If one changes the washer
, however, only minimal pressure is required to stop the
leakage.
As discussed above, ISD may occur as a result of intra
operative damage to the urethra. This may occur during
any procedure where the sutures are accidentally placed
into or through the urethral wall . The MMK procedure
involves the placement of several sutures perilously
close to the urethral wall. Inexperienced surgeons may
inadvertently place these sutures through the urethral
envelope resulting in fibrosis of the spongy submucosal
tissue and the development of ISD.
Patients may also have pre–existing ISD as a result of
previous urethral surgery, pelvic radiotherapy and poor
estrogenization. ISD may also occur in association with
or independent of anatomic hypermobility. As discussed
above, this is an important diagnostic point, as
patients with significant ISD will not do well with
simple bladder neck suspension. ISD in the setting of
good anatomic support is the main indication for the use
of periurethral bulking agents such as collagen. They
increase the bulk of the inner urethral layer (submucosal
tissues) thereby improving urethral coaptation and
continence. |
