Recent reports suggest reopening of the patent ductus arteriosus (PDA) afte
r complete occlusion with three-loop Gianturco coils. We hypothesize that f
ive-loop coils may produce a larger thrombus than three-loop coils, which w
ill result in no or less probability of recanalization of PDA during follow
-up. This study is designed to test this hypothesis. Follow-up echocardiogr
aphic and Doppler data of 30 patients who underwent five-loop coil occlusio
n of small to medium-sized PDA during a 33-month period ending December 199
8 were examined. Thirty patients had no residual shunt an echo Doppler stud
y on the day following the procedure and were followed for 6 to 30 months (
median, 12) after coil implantation. At the last follow-up study, none of t
he patients had a residual shunt and left atrial size decreased. Careful pu
lsed, continuous wave, and color Doppler interrogation of left/main pulmona
ry artery junction and proximal descending aorta did not reveal any evidenc
e far obstruction. The follow-up data suggest that complete occlusion of sm
all- to medium-sized PDAs is feasible with five-loop coils without evidence
for recanalization at a mean follow-up of 12 months. Much longer (2 to 5 y
ears) follow-up data may be necessary to confirm these observations. We spe
culate that a greater degree of thrombosis is produced within the ductus by
the five-loop coils, which in turn may be responsible for lack of shunt re
currence. We recommend use of five-loop instead of three-loop coils for tra
nscatheter occlusion of small- to medium-sized PDAs. (C) 2000 Wiley-Liss, I
nc.