Comment
About 4-11% of ASD are SV ASD defects [1]. The surgical closure of this type of defect can be particularly prone to residual ASD, due to their location [2]. In these cases, a percutaneous closure of the residual defect is unfeasible, due to their particular position. Therefore, a surgical procedure is always deemed necessary.
Minimally invasive techniques adopted to treat simple CHD are constantly evolving in the current era. This allowed to minimize surgical trauma while maintaining functional results [3]. The introduction of peripheral cannulation for CPB has further minimized the surgical access and expanded the spectrum of CHD that can be addressed with these techniques [4].
In our patients, the combination of a minimally invasive right axillary thoracotomy with total peripheral CPB and IVF allowed us to obtain a successful surgical result with a reduction in surgical trauma (due to minimal mediastinal tissue dissection e.g. no need for aortic cross-clamping, unsnared IVC) and a good aesthetic result (particularly important in female patients). Furthermore, in cases when a reintervention is required (like the cases presented here), it allowed us to avoid a resternotomy thus reducing the potential sources of bleeding both at the re-entry of the thoracic cavity and during the dissection of the tissues.
The establishment of a CPB with central cannulation without snaring of the IVC has already been described in the literature for the treatment of CHD with potentially complicated venous drainage. This was mainly performed for extra-cardiac Fontan procedures, demonstrating great feasibility with adequate venous drainage and no reduction in flow or circulatory arrest [5].
In our cases, peripheral cannulation of the femoral vein, with the tip of the cannula held below the junction of the right atrium and an unsnared IVC, allowed us to perform an uncomplicated CPB (e.g. no air locks) and to obtain a complete visualization of the defect and a definitive closure. In fact, IVC snaring can sometimes cause potential edge distortion of an SV ASD, especially in case with very low extension, making it difficult to visualize it.
This technique has provided excellent results at our center and it is now considered the gold-standard practice also in all patients with a large ostium secundum type ASD with inferior extension towards the IVC or with an inferior SV ASD. From 2008 to 2019, 12 patients were treated at first operation with a RPLMT and unsnared IVC without intraoperative and long-term complications.
Although limited, our experience shows that the combination of a minimally invasive approach with partial or total peripheral cannulation and unsnaring of the IVC has proven to be safe and effective. This technique allows an optimal visualization of the intracardiac anatomy in cases where a proper identification of the edges of the ASD is required.