Objectives: Closure of ducts with severe pulmonary arterial hypertension (PAH) with duct occluders (DO) risks aortic embolization since they lack pulmonary retention skirt. In such instances, more expensive muscular ventricular septal occluders(mVSO) with bilateral skirts are preferred.
Methods: We reviewed patients with large ducts with pulmonary artery to aortic systolic pressure ratio of more than 0.7 who underwent transcatheter closure. If clinical, radiological and echocardiographic findings suggest higher pulmonary vascular resistance(PVR), oxygen hemodynamics and test balloon occlusion were performed. Otherwise only room air hemodynamics were studied. The DO size was chosen 1-2 mm above the duct diameter.
Results: 17 patients with median age of 12 months (1.5-120 months) and median weight of 6.2 kg (2.6-21 kg) had large ducts (mean 7.2+/-3.7 mm; range 4-20 mm). All except one were aged under 24 months. 13 patients weighed below 5th centile. 13 patients had large left to right shunt and hyperkinetic PAH. Four patients with borderline hemodynamics had acceptable data on oxygen study and test balloon occlusion. One 2-year-old patient with 8 mm duct and basal PVR of 15 wood units with right heart failure had favourable data on oxygen and test occlusion; underwent device closure with 10 mm mVSO. All others with PVR less than or equal to 10 wood units were closed with DO (5x4mm - 24x22mm). There were no device embolizations.
Conclusions: Closure of most ducts with severe PAH can safely be performed with appropriately chosen DO. mVSO can be reserved only in markedly elevated but reversible PVR.