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.