Unifocalization
After initiation of the program a catch up of patients to be treated was
seen, reflected by a higher age at first surgery and the age at
correction. During the first 5 years the mean age at first
unifocalization was 5.9 years (range 3 months -14 years) and after this
period the mean age was 1.8 years (range 1 month -16 years with only one
older patient of 16 who came to our hospital from abroad). Thirty-nine
consecutive patients with PA, VSD and SPCA’s were entered in the
protocol. In these 39 patients, in 13 patients a central shunt was the
first procedure followed by 66 unifocalization procedures in which 129
collateral arteries were treated either with unifocalization or
ligation. In 7 patients a collateral artery was closed by a
percutaneously placed device.
In 50 unifocalization procedures a modified Blalock Taussig shunt was
placed with a tube diameter 5 – 10 mm, depending on the size of the
patient, in later procedures a 5 mm tube prosthesis was most commonly
used.
Based on several reports and our own clinical experience of the behavior
of SPCA’s we tend towards more intrapulmonary anastomoses to avoid long
segments of remaining SPCA tissue which could lead to stenosis or
dilatation.[10, 11]
In one patient the modified Blalock-Taussig shunt was obstructed two
weeks after unifocalization and the patient died after a reoperation in
which the modified Blalock-Taussig shunt was replaced. One other patient
died in hospital 3 months after unifocalization with an unknown cause.
The median time between the first and second unifocalization was 8
months (range 2 weeks - 48 months), this second unifocalization was
considered indicated in 27 patients. In twelve patients a second
surgical unifocalization was not necessary. Four patients had SPCA’s
mainly on one side. Five patients received a coil closing a SPCA at the
contralateral side after unifocalization at the other side. After the
first unifocalization on one side one patient had still incomplete
vascularization of both lungs and progressive pulmonary hypertension and
was consequently treated with a central aorto-pulmonary shunt at the
other side. One patient died before the second unifocalization probably
due to pulmonary infection with an RS virus 3 months after
unifocalization.
After unifocalization 20 additional procedures were needed. Apart from
the coil closure of SPCA’s several other interventions were performed.
In 4 patients a perigraft seroma around the modified Blalock-Taussig
shunt was removed.[12] In one patient the modified Blalock-Taussig
shunt was incorrectly placed on the pulmonary vein, this was revised 2
weeks later. In 2 patients a modified Blalock-Taussig shunt and in 2
patients a central shunt was placed additionally because of cyanosis
after the second unifocalization. In one patient a transannular patch
was placed between the RVOT and the pulmonary trunk later followed by
balloon dilatation and stent implantation in the left pulmonary artery.
In two patients balloon dilatation of the modified Blalock-Taussig shunt
was performed in one also with stent implantation. Two patients
underwent revision of a central shunt with augmentation of the pulmonary
artery, one with stent implantation and the other with balloon
dilatation of the left pulmonary artery. One patient underwent revision
of the modified Blalock-Taussig shunt because of shunt occlusion. One
patient underwent a sliding plasty of the distal trachea for stenosis
with complete tracheal rings.