II. INVESTIGATIONS
BIOLOGIC INVESTIGATIONS (Table 5 &
7)
Leucocytosis and microcytic anaemia were noted respectively in
63% and 79% of our cases. Uraemia was noted in 12 patients (57%) with BUN
greater than 45 mg% and hyperkaliemia in 5 patients (56%).
Urine cultures were requested for in all patients but results
were available in 19. 7 cultures were sterile and of the 12 in which pathogens
were identified, E. coli was the
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POSTERIOR URETHRAL VALVES IN CHILDREN: A review of 28
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most frequent (26%) followed by Pseudomonas
aeroginosa (11%). In COULIBALY's series (18) E. coli was also the
most frequent pathogen followed by Pseudomonas aeroginosa, and no
pathogens in 26%. No pathogens were identified in 37% of our patients. In the
series reported by FALL et al (20) the most frequent pathogen was Pseudomonas
(50%) followed by Klebsiella (38%).
ULTRASONOGRAPHY (Table 8)
In all our patients, the mothers had undergone at least one
prenatal ultrasonographic examination, but no case was diagnosed antenatally.
Diagnosis of PUV could be made as early as 16-18 weeks of gestation (19). The
major benefit of antenatal ultrasonography is to allow early diagnosis of
urinary tract malformations before post-natal infection worsens the
prognosis3)
In the post-natal period transperineal voiding ultrasound is
non-invasive and useful in diagnosing PUV. With a posterior urethral diameter
of at least 6 mm during voiding as a criterion for transperineal ultrasound
diagnosis of obstruction, sensitivity is 100%, specificity 89% and a positive
predictive value of 89% (12).
In our series 18 patients had results of ultrasound
examinations available. Bilateral ureterohydronephrosis was noted in 94%,
trabeculated bladder wall (67%) and a dilated posterior urethra in 72% of the
patients.
In 3 of our patients, diagnosed on ultrasound in the first
month, no further radiological investigations were done because of severe
sepsis and uraemia. They all underwent emergent vesicostomies.
VOIDING CYSTOURETHROGRAMS (Table 9)
Apart from the 3 patients mentioned above, all our patients
had VCUG, but results at diagnosis were available only in 18, vesico-ureteral
reflux was present in 5 patients (28%); bilateral in 4 (22%) and unilateral (on
the right) in 1 case (6%). COULIBALY et al found 13.51 % (bilateral) and 24%
(unilateral). It is reported (11) that reflux may present in up to 60% of the
patients with PUV and that, when unilateral, it is most often
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on the left and associated with a poorly functioning or
non-functioning kidney and persists despite surgery. However if on the right it
is associated with a functioning kidney and resolves in most patients (11).
Direct evidence of valves was noted in 7 patients (39%) and present as filling
defects in the posterior urethra. Hutch's diverticulum which is a paraureteral
diverticulum was noted in 2 patients. One patient developed urosepsis after a
retrograde urethrocystography and was treated.
INTRAVENOUS PYELOGRAPHY (Table 10)
This was done in 6 patients and showed bilateral
uretero-hydronephrosis in 5 (83%), late secretion in 1 (17%), non-functional
left kidney in 1 (17%). COULIBALY et al (18) found 80% of their cases with
upper tract dilatation and 20% with non-functioning kidneys.
SCINTIGRAPHY (Table 11)
Radionuclide evaluation is superior to IVP in evaluating renal
functions and gives reproducible information about total and differential renal
function, but it does not provide a sensitive and accurate illustration of the
anatomic changes in the kidney .(40). Two patients benefited from this
examination (one in France and one in Britain). In one there was strong
suspicion of bilateral renal dysplasia.
BLADDER URODYNAMICS (Table 12)
Bladder urodynamics are necessary in evaluating the
bladder-sphincter complex and will help in the diagnosis of bladder dysfunction
(41). The same two patients benefited from this examination.
Reduced bladder compliance was noted in one who had
incontinence.
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