Covered Stent for Superior Sinus Venosus Atrial Septal Defect

Sinus venosus atrial septal defect continued to be the surgeon’s domain even when transcatheter device closure of secundum atrial septal defect became commonplace. Transcatheter closure of superior sinus venosus ASD has become a feasible alternative to surgical closure in selected patients over the past decade [1]. A single center study of covered stent for superior sinus venosus ASD had 100 patients during the period from May 2015 to October 2023 [2]. I was quite happy to see that it was from Institute of Cardio Vascular Diseases, Madras Medical Mission, Chennai, India which I had the opportunity to visit a couple of times in the past. Median age of patients was 35 years, with a range from 4-69 years. Children were included if their superior vena caval diameter was 16mm or more. Authors noted an overall procedural success rate of 97%. Recent modifications increased patient inclusions and decreased complication rates. The procedure has also been simplified.

Initial evaluation included transthoracic echocardiography, transesophageal echocardiography and computed tomography. TEE looked for extension of the superior SVASD towards the fossa ovalis. Significant caudal extension of the defect manifested as vertical dimension in bicaval view larger than the transverse cavoatrial diameter. CT could locate right upper pulmonary vein in relation to cavoatrial junction and identify high draining pulmonary veins. Those with significant caudal extension and those without large high draining additional pulmonary veins were considered for balloon interrogation. Cases found suitable after balloon interrogation underwent closure of the superior sinus venosus ASD with covered stents. Additional uncovered stents at upper part may be considered in case of high draining veins. After a successful procedure, along with complete closure of the defect, there was redirection of right upper pulmonary vein to the left atrium. Right upper pulmonary vein pressure should not be beyond 2 mm Hg above left atrial pressure after a successful procedure. Total of 126 covered stents and 25 bare stents were used in the 100 patients. A few patients with additional secundum ASD underwent simultaneous device closure of the defect.

There were no in-hospital deaths. Some of the complications were caudal migration of the stent, fabric leak, transient caval obstruction and jailing of left innominate vein. Couple of patients developed brief generalized tonic-clonic seizures from cerebral venous hypertension during balloon occlusion, which recovered quickly, without sequelae. One elderly person with systemic hypertension, moderate pulmonary hypertension and heart failure who needed overlapping covered stent for fabric leak developed subarachnoid hemorrhage. Even with gradual neurological recovery, he died of pneumonia after 3 weeks at another institution. 17.5% had mild residual shunt, which decreased to 5.4% at one year follow up. Dual antiplatelet therapy were given routinely and continued beyond one year in occasional patient with other indications. Asymptomatic thrombi were seen in four patients on surveillance.

References

1. Callahan R, Gillespie MJ. Transcatheter Superior Sinus Venosus Defect Closure: Experience Increases Patient Eligibility. J Am Coll Cardiol. 2024 Jun 4;83(22):2193-2195. doi: 10.1016/j.jacc.2024.04.017. PMID: 38811096.
2. Sagar P, Sivakumar K, Thejaswi P, Rajendran M. Transcatheter Covered Stent Exclusion of Superior Sinus Venosus Defects. J Am Coll Cardiol. 2024 Jun 4;83(22):2179-2192. doi: 10.1016/j.jacc.2024.03.417. PMID: 38811095.