RESULTS
Patients’ characteristics: 27 patients underwent 30 cardiac catheterization procedures (10 diagnostic and 20 interventional). The median age at the time of cardiac catheterization was 15 months ranging from 15 days to 20 years. The median time from cardiac surgery was 3 days ranging from 0 day (same day of surgery) to 32 days. Out of 30 procedures, six procedures were performed for 6 patients immediately after surgery (3 interventional and 3 diagnostic), 18 procedures (including the 6 procedures done immediately after surgery) were performed in the 1st week post-surgery (8 diagnostic, 10 interventions) and 20 procedures were performed in the 1st 2 weeks post-surgery (9 diagnostic, 11 interventions). The median weight at time of cardiac catheterization was 8.2 kg, (3.4 – 53 kg). Fourteen (14) procedures were performed in patients with single ventricle physiology and 10 procedures in conotruncal anomalies. Two genetic syndromes were identified in this cohort one was DiGeorge and the other was William syndrome. Twenty-three (23) procedures were performed while patients were on mechanical ventilation and inotropic support; the median time for mechanical ventilation was 23 days (2-89 days). Eleven procedures were done for 11 patients on ECMO support, the median duration for ECMO were 5 days, range (2-7 days), Table (1). There was no significant difference between patients underwent diagnostic cardiac catheterization and those underwent interventional procedure regarding age, weight, diagnosis, time from surgery, mechanical ventilation, vasoactive inotropic score or ECMO support (table 1).
Indication for cardiac catheterization: Inability to wean from ECMO /cardiopulmonary support (CPS) and cyanosis were the most frequent indications. There was no significant difference between diagnostic group and interventional group regarding the indication for cardiac catheterization (Table 2).
Catheterization procedures: For the intervention group angioplasty through stenting was performed in 10 procedures, 6 of them were for pulmonary artery branches (Fig. 1), 2 for right ventricular outflow tract (RVOT), one for coronary artery and one for pulmonary venous baffle. The success rate in stenting group was 90% (one patient with pulmonary atresia –VSD that underwent surgical repair developed embolized left pulmonary artery stent in the conduit that required redo surgery for retrieval of the stent and fenestration of the VSD patch). Angioplasty through ballooning was performed in 2 procedures; one for stenosis of pulmonary venous confluence -left atrial connection after repair of total anomalous pulmonary venous connection (TAPVC) that failed to decrease the pressure gradient or heart failure symptoms and required a redo surgery, the other was for a kink in a modified Blalock Thomas Taussig (BTT) shunt that was successful with improvement of oxygen saturation after the procedure. In all angioplasty procedures the median balloon size to stenosis diameter ratio was 2.5 (1.8-3). Occlusion was performed in 8 procedures (2 for MAPCAS, 2 for Fontan fenestrations, 1 for pulmonary arteriovenous malformation, 1 for modified Blalock Taussig (BT) shunt (Fig. 1), 1for aorta to right ventricular outflow tract (AO to RVOT) fistula (Fig. 2) and 1 for missed antegrade pulmonary flow in Fontan patient) (Table 4), the success rate in occlusion procedures was 100%.
Outcome: Out of total 30 procedures there were no complications during transportation of patients from operating room or PICU to the cardiac catheterization laboratory. Three procedures had complications during cardiac catheterization namely; cardiac arrest that required cardiopulmonary resuscitation, embolization of stent in the RV-PA conduit during stenting of stenotic branch pulmonary artery and post procedural arterial thrombosis of the femoral artery that improved on Heparin infusion. All complications were reported in the interventional group. No reported mortality during procedures.
Seven (7) patients required redo surgery in the form of arch repair (1 patient), pulmonary venous baffle augmentation (2 patients), VSD fenestration (3 patients), and Fontan fenestration (1 patient). The median duration of hospital stay was 20 days (2-330 days) and for pediatric intensive care unit (PICU) stay was 16 days (1-99 days). There was no significant difference between the diagnostic group and interventional group regarding PICU stay, hospital stay, need for redo surgery, and occurrence of complications during procedure (table 3). No mortality was reported in catheterization laboratory.
Regarding survival, the overall survival till the time of the study was 51.8% (14 out of 27 patients). Survival to discharge was 55.5% (15 out of 27 patients, 1 patient died one year after the procedure from infective endocarditis).
Procedures performed on ECMO support: 11 procedures were performed for 11 patients on ECMO support (4 diagnostic and 7 interventions), 8 patients (72.7%) successfully disconnected from ECMO support, 5 (45.4%) survived to discharge and 4 (36.3%) thereafter (1 died 1 year after procedure with infective endocarditis). Kaplan Meier univariate analysis demonstrated that patients performed cardiac catheterization on ECMO support had less survival than others (Fig. 3).