Abstract
A case of profound sistemic oxigen desaturation after atrial septostomy in a patient with primitive pulmonary hypertension is reported. A new method to correct such severe complication of atrial septostomy is described, consisting in a graded reduction of the right to left atrial shunt by deployment of a manually perforated atrial septal closure device.
1
Introduction
Pulmonary arterial hypertension is characterized by a progressive increase in pulmonary vascular resistance eventually leading to right-heart failure. Treatment consists of pulmonary vasodilator therapy, long-term oxygen therapy, anticoagulation, and lung transplantation, or, at times, heart–lung transplantation . In recent years, percutaneous balloon atrial septostomy (BAS) has been established as a palliative treatment or bridge to transplantation in patients with severe right-heart failure refractory to conventional therapy .
BAS is a percutaneous intervention consisting of a puncture of the interatrial septum followed by repetitive balloon dilatation of the created atrial septal defect to a diameter leading to right-to-left shunt. BAS aims at creating a “safety valve” by unloading the right heart and increasing left ventricular preload and output, peripheral perfusion, net oxygen tissue delivery, exercise tolerance, and prognosis. The net balance between systemic blood desaturation and increase of perfusion generally results in a better tissue perfusion with the consequent clinical improvement. However, this balance is not always predictable and can occasionally result in profound hypoxemia and tissue damage.
Although the use of fenestrated occluder devices has been reported in stable patients with pulmonary hypertension , the following presents the use of a fenestrated occluder device in the setting of life-threatening hemodynamic instability and hypoxemia in a patient who developed overwhelming right-to-left shunting after BAS.
2
Case report
A 35-year-old male with end-stage pulmonary hypertension causing NYHA Class IV heart failure resistant to medical therapy was scheduled for BAS to improve his clinical status.
The procedure was successfully performed with a 10-mm-diameter balloon ( Figs. 1 and 2 ), but the patient showed profound systemic blood desaturation (from 89% to 75%) resistant to mask high flow oxygen therapy. Subsequently, the patient developed sustained ventricular tachycardia rapidly degenerating into ventricular fibrillation requiring external electrical cardioversion to restore sinus rhythm. Due to residual severe hemodynamic instability, the patient was assisted with extracorporeal membrane oxygenation (ECMO). During the following days, weaning from ECMO was not possible due to profound desaturation caused by attempts to reduce the pump output to 2 l/min. On the assumption that the BAS-induced right-to-left interatrial shunt was excessive, a new procedure for shunt reduction was scheduled. Under transesophageal echo monitoring, a high support exchange wire was positioned into the left superior pulmonary vein through the previous septostomy hole and a 10-French Mullins catheter was inserted into the left atrium. Then, a 13-mm Amplatzer (AGA Medical, Golden Valley, MN, USA) device was manually perforated by a sheath inner dilator, passing through the Dacron structure of the prosthesis ( Fig. 3 ). The mesh surrounding the hole was sutured to avoid any interference with blood flow ( Fig. 4 ), and the hole was then enlarged to 5 mm by inflating a 5×20-mm coronary balloon ( Fig. 5 ). The device was delivered to the interatrial septum through the Mullins sheath and released as usual securing the interatrial septum between both discs identical to closure of an atrial septal defect or patent foramen ovale ( Fig. 6 ). Transesophageal echocardiography confirmed a good position of the closure device and demonstrated the desired residual but now smaller right-to-left shunt via the orifice in the Amplatzer device previously created by the sheath dilator and the coronary balloon as described ( Figs. 7 and 8 ). Systemic saturation increased from 75% to 84%.
