Incontinent diversion is no longer considered an acceptable alternative to reconstruction in the pediatric population.
The goals of urinary reconstruction are to preserve the upper urinary tract, attain socially acceptable continence, and maximize the child's ease of care and potential for self-care.
Four components of balanced urinary tract function must be achieved to ensure long-term success with urinary reconstruction.
Adequate bladder (reservoir) capacity and sufficient compliance to provide low-pressure storage.
Adequate bladder outlet resistance to maintain urinary continence.
A convenient, reliable mechanism for bladder (reservoir) emptying.
Unobstructed and nonrefluxing sterile upper tract drainage of urine into the bladder (reservoir) is desirable in order to protect the upper tracts.
Conceptual Approach to Urinary Tract Reconstruction and Preoperative Evaluation
There are 4 components to balanced urinary tract function that must be achieved in order to ensure long-term success with urinary reconstruction. The first component is that of adequate bladder (reservoir) capacity and sufficient compliance to provide low-pressure storage. The maintenance of storage pressures below 35 to 40 cm H2O will optimize upper-tract preservation. Optimal bladder capacity should allow a 4-hour catheterization or voiding interval during the day, and an 8-hour interval at night without reaching excessive pressure or precipitating incontinence.
The second component is that of adequate bladder outlet resistance to maintain urinary continence. Third, there must be a convenient, reliable mechanism for bladder (reservoir) emptying. Ideally, this should be achieved by spontaneous voiding, otherwise intermittent catheterization is necessary. The native urethra may represent an acceptable conduit for this maneuver, although should its catheterization prove excessively difficult or uncomfortable (preventing patient compliance), an alternative catheterizable conduit may be necessary. Fourth, unobstructed and nonrefluxing sterile upper-tract drainage of urine into the bladder (reservoir) is desirable in order to protect the upper tracts.
When contemplating urinary tract reconstruction, meticulous preoperative evaluation is critical. It is essential to tailor the reconstruction to the individual needs of the patient. Renal function is assessed by measurement of serum creatinine and glomerular filtration rate. Anatomy is assessed by intravenous urography or ultrasound, contrast voiding cystourethrography, and careful preoperative endoscopic evaluation. Evaluation of bladder and sphincteric function is of paramount importance. Here, detailed urodynamic investigation, as well as upright cystography to evaluate the competence of the bladder neck, are performed. A careful history, physical examination, and counseling of the patient and family allow an assessment of the patient's intellect, dexterity, and potential for self-care. After this assessment is completed, an exhaustive trial of nonoperative therapy is undertaken. This trial may include the use of pharmacologic agents (anticholinergics, sympathomimetics, or sympatholytics) in an attempt to achieve safe intravesical pressure from the perspectives of upper-tract preservation and continence. This trial of therapy may also include intermittent catheterization, which may result in sufficient stabilization of the urinary tract, thereby avoiding any surgical reconstruction. Moreover, this important therapeutic modality indicates the need for urinary tract reconstruction where ...