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\begin{document}

\title{Minimally invasive congenital cardiac surgery with unsnared inferior
vena cava}



\author[1]{Alvise Guariento}%
\author[1]{Claudia Cattapan}%
\author[1]{Francesco Bertelli}%
\author[1]{Vladimiro Vida}%
\affil[1]{University of Padua}%


\vspace{-1em}



  
  \date{May 21, 2024}


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\selectlanguage{english}
\begin{abstract}
Here we report two cases of residual atrial septal defect (ASD) with
inferior extension towards the inferior vena cava (inferior sinus
venosus type). In both cases, patients underwent surgical repair of
their ASD in childhood. However, signs of persistent hemodynamic right
ventricular overload were detected at the last follow-up and a residual
ASD was demonstrated. Both underwent successful minimally invasive
surgical closure of the ASD by combining a right postero-lateral
mini-thoracotomy (sub-axillary approach) and total peripheral
cardiopulmonary bypass, avoiding snaring of the inferior vena cava. This
allowed an optimal visualization of the residual intra-cardiac shunt and
its subsequent closure.%
\end{abstract}%



\sloppy


\textbf{Keywords:}

\begin{itemize}
\tightlist
\item
  Congenital heart disease
\item
  Minimally invasive surgery
\item
  Surgical strategies
\end{itemize}

\textbf{TEXT}

\textbf{Introduction}

Atrial septal defects (ASD) can be found in different sites of the
interatrial septum depending on their embryological origin. Sinus
venosus ASD (SV ASD) are interatrial defects morphologically adjacent to
the outlet of the superior (SVC) or inferior vena cava (IVC) {[}1{]}.
Surgical closure of this type of defects is sometimes challenging due to
a difficult surgical exposure (e.g. extension into the inferior vena
cava orifice) or misidentification of contiguous structures (e.g. an
enlarged Eustachian valve). For this reason, the need for reoperation
for a residual ASD is not a rare event {[}2{]}.

Over the past decade, surgical correction of less severe congenital
heart disease (CHD) such as ASD has been increasingly performed through
minimally invasive less traumatic surgical approaches {[}3, 4{]}. In
particular, the advantage of total or partial peripheral cardiopulmonary
bypass (CPB) includes the possibility of avoiding IVC snaring during
CPB. This proved particularly important for the visualization of SV ASD
with inferior extension towards the IVC orifice.

\textbf{Technique}

In the current study, we report the cases of two female patients who
underwent surgical re-intervention for residual SV ASD after initial
repair in childhood (at the age of 4 years for Patient 1 and 10 months
for Patient 2). Both index procedures were uneventful, and patients were
discharged in good clinical conditions with no suspicion of residual
intra-cardiac defects.

At follow-up, patients were asymptomatic. However, persistent right
ventricular dilation with a significant residual ASD located at the
junction between the right atrium and IVC was demonstrated. Both
patients were scheduled for elective surgery considering that a
percutaneous approach was not deemed feasible.

At the time of surgery, at the age of 32 years for patient 1 and 20
years for Patient 2, after surgical cannulation of the femoral vessels
and percutaneous cannulation of the internal jugular vein, a peripheral
CPB was started. A right postero-lateral mini-thoracotomy (or
sub-axillary approach) was performed through a 4 cm incision in the
fourth intercostal space just below the corner of the right scapula.
Right lung exclusion was achieved in order to gain better surgical
exposure.

After isolation of the mediastinal structures, with the aid of induced
ventricular fibrillation (IVF), a right atriotomy was performed. While
the SVC was snared before opening the atrium, the IVC was left unsnared
to allow optimal visualization of the residual intra-cardiac shunt
(Figure 1, Video 1). The residual ASD was closed with a heterologous
pericardial patch (Figure 2). Total CPB time was 98 minutes for Patient
1 and 63 minutes for Patient 2. IVF time was 75 minutes and 24 minutes,
respectively. The ventricular fibrillation was converted to sinus rhythm
by direct current cardioversion shock in both, and the left cavities
were cautiously deaired.

Surgical results were carefully reviewed by 2D-transesophageal
echocardiography and confirmed through a bubble test. The postoperative
course was uneventful, and patients were discharged home on
postoperative day 7 (Patient 1) and 6 (Patient 2).

\textbf{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.

\textbf{REFERENCES}

{[}1{]} Geva T, Martins JD, Wald RM. Atrial septal defects. Lancet. 2014
May 31;383(9932):1921-32.

{[}2{]} Banka P, Bacha E, Powell AJ, Benavidez OJ, Geva T. Outcomes of
inferior sinus venosus defect repair. J Thorac Cardiovasc Surg
2011;142:517--22.

{[}3{]} Vida VL, Padalino MA, Bhattarai A, Stellin G. Right
posterior-lateral minithoracotomy access for treating congenital heart
disease. Ann Thorac Surg 2011;92:2278--80.

{[}4{]} Vida VL, Tessari C, Putzu A, Tiberio I, Guariento A, Gallo M, et
al. The peripheral cannulation technique in minimally invasive
congenital cardiac surgery. Int J Artif Organs Wichtig Publishing Srl
2016;39:300--3.

{[}5{]} Corno AF, Horisberger J, David J, Segesser LK Von. Right atrial
surgery with unsnared inferior vena cava. Eur J Cardio-thoracic Surg
2004;26:219--20.

\textbf{Figure legend}

\textbf{Figure 1.} Graphic representations (A) and intraoperative view
(B) of a residual inferior SV ASD. The IVC was left unsnared to allow
optimal visualization of the residual intra-cardiac shunt. IVC: inferior
vena cava, SV ASD: sinus venosus atrial septal defect.

\textbf{Figure 2.} Graphic representations (A) and intraoperative view
(B) of residual ASD closure with a heterologous pericardial patch. IVC:
inferior vena cava, SV ASD: sinus venosus atrial septal defect.



\textbf{Video legend}

\textbf{Video 1.} Video showing the surgical closure of a residual
inferior sinus venosus atrial septal defect by combining a right
postero-lateral mini-thoracotomy and a total cardio-pulmonary bypass,
avoiding snaring of the inferior vena cava.\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-1/Figure-1}

\end{center}
\end{figure}\selectlanguage{english}
\begin{figure}[H]
\begin{center}
\includegraphics[width=0.70\columnwidth]{figures/Figure-2/Figure-2}

\end{center}
\end{figure}

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