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.