Renal transplantation in young boys with posterior urethral valves: preliminary report

Kidney transplants in patients with bladder augmentation: correlation and evolution

OBJECTIVE

To review the literature, analyse the evolution of kidney transplants (KT) in patients with bladder augmentation (BA) and investigate the relation between BA and KT.

MATERIALS AND METHODS

Six patients with a history of severe lower urinary tract dysfunction and BA, received a KT at our Unit between 1993 and 2003. Three had moderate renal failure at the moment of the BA. The remaining three had end stage renal failure.

RESULTS

With a follow-up of 7 years (mean) we have a patient survival of 100% and a graft survival of 83%. No complications occurred between the BA and the KT. The few KT complications were not related to BA.

CONCLUSION

When a bladder dysfunction is present, it should be treated before KT. In noncompliant bladders, BA is the best treatment. This can be done to try to avoid end stage renal failure or only to prepare the lower urinary tract for reception of the transplant. The presence of a BA did not worsen the evolution of the KT.

[Posterior urethral valve: determining factors of long-term results]

Posterior urethral valves (PUV) is the most common congenital urine flow impairment in boys. Long-term prognosis involves: renal function impaired in 30 to 50% of PUV and leading to hyperdiuresis, low GFR and acidosis; bladder urodynamics impaired in 75% of PUV with abnormal urine storage, abnormal micturition and vesicoureteric reflux. Incontinence and recurrent urinary tract infections commonly reflect bladder and renal failures; abnormal bladder outlet leads to incontinence and abnormal ejaculation. The roles of antenatal treatments (vesico-amniotic shunts), neonatal treatments (resuscitation and endoscopic treatment of PUV) and long-term treatments (urinary diversions, bladder augmentation, alpha blockers, anticholinergic, dialysis and renal transplant) in the long-term outcomes of PUV are reviewed.

Mercapto-acetyltriglycine (MAG 3) renography and indirect radionuclide cystography in posterior urethral valves

OBJECTIVE

To assess dynamic isotope renography with 99mTc-labelled mercapto-acetyltriglycine (MAG 3) in conjunction with indirect radionucleide cystography (IRC) in the follow-up of boys with posterior urethral valves.

PATIENTS AND METHODS

Fifty-one boys (95 renal units; mean age = 89 months, range 65-118) with previously treated posterior urethral vales underwent MAG 3 renography followed by IRC. Glomerular filtration rate (GFR) was estimated from the plasma clearance of 51Cr-ethylenediamine tetra-acetic acid following single intravenous injection. Renographic parameters noted were renal function based on the quality of renal visualization and background activity as well as renal drainage and the appearance of isotope in ureter and bladder. Following the dynamic 20 min MAG 3 renogram the child was allowed to leave the department and to return when he wished to void. IRC was then performed. Diuretics were not administered.

RESULTS

Initial drainage from 30 kidneys was normal, in 36 drainage was delayed and in 25 drainage did not occur during the renogram phase. In four kidneys function was so poor as to preclude assessment. After the IRC, drainage was noted in 17 of 25 units which had not drained during the renogram, six units did not drain and in two drainage was equivocal due to the presence of vesico-ureteric reflux. The quality of the scan was good or very good in 42 patients (mean GFR = 92 ml/min/1.73 m2 SA) and moderate or poor in nine patients (median GFR = 20 ml/min/1.73 m2 SA) (P < 0.001). A residual urine was noted following micturition in 35 boys; this was due to incomplete bladder emptying in 14 and to immediate secondary refilling from dilated upper tracts in the remainder.

CONCLUSION

IRC in conjunction with traditional dynamic renography using MAG 3 provides valuable additional information about upper tract drainage. The necessity for diuresis renography is obviated in the majority of patients. IRC also allows an excellent non-invasive, physiological assessment of both upper and lower urinary tract function which is superior to conventional single examination techniques. We recommend the use of MAG 3 with IRC in the routine follow-up of boys with posterior urethral valves.