Expectant approach of treating
PDA at a later time, only when signs indicate hemodynamic
significance, allows for possible spontaneous closure.
It carries the advantage of minimizing the risk of exposure
of preterm infants to the hazards of therapy but the disadvantage
of late intervention such as lower success rate
and increased exposure of preterm infants to the hazards of
BioMed Research International 5
HS-PDA. One of the challenges of expectant symptomatic
approach is to clearly define a HS-PDA as discussed earlier.
Gersony et al. [113] randomized 421 preterm infants with
HS-PDA into three groups of intervention: conservative with
indomethacin, conservative then back-up indomethacin, and
conservative then surgery. They found that administration of
indomethacin concurrentwith or as back-up to usual medical
therapy at the time of diagnosis resulted in a significant
increase in the rate of ductal closure compared to conservative
treatment. Althoughmortality did not differ significantly,
infants given indomethacin as a back-up to conservative
therapy had a lower incidence of bleeding than those to
whom indomethacin was given with initial conservative
therapy.They concluded that administration of indomethacin
only when conservative treatment fails appears to be the
preferable approach for the management of symptomatic
PDA in preterm infants.
Only one clinical trial has compared late indomethacin
therapy with continued medical management without
indomethacin and found a significant decrease in the rate
of mechanical ventilation with a trend toward decreasing
NEC and ROP in the indomethacin-treated group. However,
the sample size of this trial was too small to make any firm
As the available evidence does not support prophylactic
or presymptomatic approach for PDA, expectant symptomatic
intervention for HS-PDA seems to be the most
reasonable approach of care. Further studies are needed
to evaluate the validity of expectant symptomatic therapy
compared to conservative treatment.