10.5 References

1. Allen TD.

Disorders of sexual differentiation. Urology 1976, 7 (Suppl): 1-32.

2. Androulakakis PA.

Pediatric Urology. Beta Publishing Co: Athens, 1993.

3. Diamond M, Sigmudson HK.

Management of intersexuality. Guidelines for dealing with persons with ambiguous genitalia. Arch Pediatr Adolesc Med 1997; 151:1046-150.

4. Fekete CN, Lortat-Jacob S. Management of the intersex child at birth.

Proceedings of Pediatric Uroendocrinology, ESPU Annual Course, 1996, Paris.

5. Imperato-Mc Ginley J, Peterson RE, Gautier T, Sturla E.

Male pseudohermaphroditism secondary to 5a-reductase deficiency - a model for the role of androgens in both the development of the male phenotype and the evolution of a male gender identity. J Steroid Biochem 1979; 11:637-645.

6. Manuel M, Katayama KP, Jones HW.

The age of occurrence of gonadal tumors in intersex patients with a Y chromosome. Am J Obstet Gynecol 1976; 124: 293-300.

7. Reiner WG.

Sex assignment in the neonate with intersex or inadequate genitalia. Arch Pediatr Adolesc Med 1997; 151: 1051-1052.

8. Rubin RT, Reinisch JM, Haskett RF.

Postnatal gonadal steroid effects on human behavior. Science 1981; 211: 1318-1324.

9. Savage MO, Lowe DG.

Gonadal neoplasia and abnormal sexual differentiation. Clin Endocrinol 1990; 32: 519-533.

10. SohvalAR.

"Mixed" gonadal dysgenesis: a variety of hermaphroditism. Am J Hum Genet 1963; 15: 155-158.

11. Whitaker RH, Williams DM.

Diagnostic assessment of children with ambiguous genitalia. Eur Urol Update Series 1993; 2: 2-7.

11.UR0DYNAMICS

11.1 STANDARDIZATION OF INVESTIGATIONS

11.1.1 Residual urine

Except in infants, the normal bladder will empty completely. Unrepresentative results may be obtained after voiding in unfamiliar surroundings, after voiding on command with a partially filled or overfilled bladder, or in patients with a high-grade VUR. An isolated finding requires confirmation. Residual volumes can be considered clinically significant when they represent on repeated occasions volumes of more than 20 mL, or volumes of >10% of cystometric bladder capacity.

11.1.2 Uroflowmetry

This involves measurement, either sitting or standing, of voided volume, micturition time, average and maximum urine flow rate. The dependence of the urine flow rate on bladder capacity, which in itself is age-dependent, has to be taken into account. Assessment of the maximum urine flow rate is only valid if the bladder is filled to more than half of its total capacity.

11.1.3 Cystometry

Cystometry is the measurement of intravesical and intra-abdominal pressures during storage and voiding phases. The advantage of transurethral access in school children is based on minimal invasiveness and recording of valid measurements. In younger children, the undisturbed assessment of the voiding phase requires a suprapubic measurement catheter equipment (7 Charr, double lumen filling/measurement catheter or a micro-tip catheter).

With a measurement catheter, rectal pressure sensor and two perineal electrodes to obtain muscular action potential from the pelvic floor, the investigation is performed in the supine position. The neutral electrode is applied to the thigh. Before the investigation the measurement catheter, electronic instruments, measurement tubing, pressure transducer and bubble-free filled input are connected; the external pressure transducer is adjusted to the symphyseal level and set to zero against atmospheric pressure. The correct position and function of the measurement equipment are checked by adequate pressure responses on coughing at regular intervals. The examination should be performed at the earliest 4-6 hours after sedation under infusion of isotonic NaCI solution or contrast medicine or dye. Bladder sensations (first desire to void; normal desire to void; strong desire to void; urgency; pain) are recorded; provocation tests (coughing, abdominal pressure rises and voluntary contraction of the external sphincters) are carried out intermittently. If a neuropathic bladder is suspected, provocation with 20 mL of ice water with about 50 mL bladder filling may be carried out. Non-suppressible detrusor contractions are signs of neurogenic disinhibition.

The carbachol test (subcutaneous injection of 0.035 mg of carbachol per kg of body-weight for children) allows differentiation between neurogenic and myogenic detrusor contractility. In neurogenic bladder dysfunction, an intravesical pressure rise of more than 25 стНгО as over-reaction of the bladder denervation to the cholinergic stimulation after 20-30 minutes is recorded. Intact central inhibition prevents the increase in tonus of the detrusor.

The following parameters are determined with filling cystometry: residual urine (mL), maximum bladder capacity (mL), effective bladder capacity (mL), compliance (mL/cmbbO), intravesical pressure (cmhbO), abdominal pressure (стНгО), detrusor pressure (стЬЮ) and first desire to void. With voiding cystometry, the following parameters are determined: opening time (sec), pre-micturition pressure (стЬЮ), opening pressure (cmhbO), maximum voiding pressure (cmhbO), intravesical pressure at maximum urine flow (cmhbO) urine flow (mL/sec), duration of micturition (sec), flow time (sec), maximum urine flow rate (mL/sec), time of flow increase (sec), micturition volume (mL), coefficient of resistance (cmhbO /mL/sec), contraction pressure at maximum urine flow (стНгО), after contraction.