A randomised controlled trial comparing intra- uterine vesico- amniotic shunting vs. not shunting in the treatment of congenital bladder outflow obstruction.

Congenital lower urinary tract (often bladder outflow) obstruction (LUTO) is
usually identifiable using ultrasound. Its natural history is associated with
a high prevalence of chronic renal impairment in infancy and childhood. If
associated with oligohydramnios of early-onset there is a significant risk of
pulmonary hypoplasia, with perinatal mortality of up to 50% within the early
neonatal period (first week of life). Even if oligohydramnion has not yet
developed, there is a significant risk of renal impairment, secondary to
obstruction. In utero, percutaneous vesicoamniotic shunting bypasses the
congenital urethral obstruction to potentially improve fetal outcome. To date,
there are no large prospective studies assessing the risks and benefits of this
intervention to either mother or baby.

Objective
A high-quality multi-centre randomised controlled trial (RCT) with the
following objectives:
Primary objective:
• To determine if intrauterine vesico-amniotic shunting for fetal bladder
outflow
obstruction, compared to conservative, non-interventional care improves
pre-natal
and perinatal mortality and renal function
Secondary objectives:
• To determine if shunting for fetal bladder outflow obstruction improves
perinatal
morbidity
• To determine if improvement in outcomes is related to prognostic assessment at
diagnosis, and if possible, derive a prognostic risk index.
• To determine the safety and long-term efficacy of shunting

Following an ultrasound diagnosis of fetal bladder outflow obstruction,
eligibility and
baseline characteristics will be confirmed by standard assessments of renal
function, a
detailed ultrasound examination to exclude other co-existing anomalies and fetal
karyotyping. Eligible mothers will receive an explanation of the diagnosis,
prognosis, and
treatment options for the condition and rationale for the trial. If the mother
consents to
participation, the fetus will be randomised to receive either a fetal
vesico-amniotic shunt or
continue with conservative management without a shunt. A minimum of 200
pregnancies
will be randomised from at least 18 (UK) centres. The primary outcome measures
are
perinatal mortality and serum creatinine at 6 weeks of age. Secondary outcome
measures
include bladder and renal function, termination and miscarriage rates and
resource usage.
Initial follow-up of secondary outcomes will continue to one year of age.
Long-term followup
of continence is planned at five years.

Vesico- amniotic shunting.

There are no extra risks then in usual care of patients with LUTO, when
patients participate in the PLUTO- trial.