Transcatheter Closure of Persistent Left Sided Superior Vena Cava Draining into Left Atrium—Importance of Balloon Test Occlusion
- Volume 21 - Issue 7 - July, 2009
- Posted on: 7/14/09
- 0 Comments
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There have been several other reports of closure of PLSVC by percutaneous methods. Percutaneous occlusion of PLSVC has been reported in 2 adolescents with late cyanosis post Fontan procedure.14 In 1 case, a PLSVC draining into the coronary sinus, which communicated freely with the left atrium through an atrial septectomy, was closed using a 10–12 Amplatzer Duct Occluder. The second case was that of a patient with a PLSVC to the left atrial roof, which was not ligated at the time of surgery.14 In a patient with worsening dyspnea, Kougias et al described positioning of coils in a covered stent placed in the proximal innominate vein and the contiguous part of the PLSVC.15 This stent was intentionally restricted in its mid portion with the use of sutures prepared ex vivo for the purpose of “trapping” the coils. We do not favor this approach, as it is unnecessarily complicated, requiring multiple steps both before and during percutaneous intervention. Troost reported closure of a PLSVC draining into the left atrium in a patient with a frontal cerebral abscess using an Amplatzer ASD occluder.5 Both reports were able to confirm the presence of collaterals to the RSVC post procedure with angiograms. We believe documentation of collaterals from the PLSVC to the RSVC is an important step that should be performed before attempting definitive percutaneous repair.
Another anatomic feature that is important to note is that PLSVC usually receives the hemiazygous vein before penetrating the pericardium and entering the heart.11 It is important to look for the hemiazygous vein and place the closure device distal to the hemiazygous connection so that any residual right-to-left shunting from the left-sided abdominal organs can be avoided.
Finally, we chose a PI-VSD occluder — in preference to the standard muscular VSD occluder — as the PI-VSD occluder has a larger disc diameter relative to the waist. By oversizing the device (20 mm device in a 17 mm residual waist), we ensured adequate occlusion of the distensible venous structure and effective anchoring of the device. This minimized the risk of distal embolization into the left heart chambers. Another appropriate device that was not available at the time of this procedure would be the Amplatzer Vascular Plug II with a range in diameter from 3–22 mm. Once expanded, the 360-degree of vessel wall apposition creates a secure fit in the target vessel.
Exclusion of cardiac sources of systemic emboli remains an important element of management of patients with cryptogenic stroke. While identification of intracardiac defects such as patent foramen ovale is crucial, additional sources of paradoxical emboli such as pulmonary AV malformations and persistent left-sided SVC should also be sought. Percutaneous closure of a PLSVC can be safely achieved using presently available implants. Recognition of the potential anatomical variants in this population, awareness of the need for appropriate collateral flow, including the role of test occlusion, and the implications of device occlusion in terms of venous drainage of upper and lower body organs are essential.
Acknowledgement. We wish to acknowledge the contributions of Dr. Nicholas Collins for his constructive comments and review of the final manuscript.