ABSTRACT
Background: Intraextracardiac Fontan procedure aimed to combine
the advantages of lateral tunnel and extracardiac conduit modifications
of the original technique. Herein, we present our experience in our
patients with intraextracardiac fenestrated Fontan Procedure.
Methods: A retrospective analysis was performed in order to
evaluate intraextracardiac fenestrated Fontan patients between 2014 and
2021. Seventeen patients were operated on with a mean age and body
weight of 9.1 ± 5.5 years and 28.6 ± 14.6 kg.
Results: Sixteen patients (94%) were palliated as
univentricular physiology with hypoplasia of one of the ventricles. One
patient (6%) with well-developed two ventricles with double outlet
right ventricle and complete atrioventricular septal defect had
straddling of the chordae prohibiting a biventricular repair. All of the
patients had cavopulmonary anastomosis prior to Fontan completion,
except one case. Fenestration was performed in all cases. Postoperative
mean pulmonary artery pressures and arterial oxygen saturation levels at
follow up were 10 ± 2.4 mmHg and 91.3 ± 2.7 %, respectively. Mean
duration of pleural drainage was 5.4 ± 2.3 days. All of the
fenestrations are patent at a mean follow up period of 4.8 ± 7.7 years,
except one case. Any morbidity and mortality were not encountered.
Conclusions: The mid-term results of intraextracardiac
fenestrated Fontan procedure are encouraging. This procedure may improve
the results in a patient population who should be palliated as
univentricular physiology, especially in cases with complex cardiac
anatomy.
INTRODUCTION Fontan procedure (FP) has been performed as the common destination
treatment for patients with single ventricle physiology, since it was
defined in early 1970’s. At first, Dr. Francis Fontan defined this
surgical procedure by performing an atriopulmonary connection in 3
patients with tricuspid atresia, which was the prototype of true single
ventricle morphology (1). Following the first years of FP, many
modifications were defined as well as the indications of this palliative
procedure were extended. Apart from single ventricle morphology, cases
in which a satisfactory septation could not be achieved such as double
outlet right ventricle (DORV) with a remote ventricular septal defect
(VSD), FP was the procedure of choice (2). Probably, there has been no
other palliative surgical procedure other than the Fontan circulation in
the historical development of congenital heart diseases that had
significant modifications with improved results for decades. Moreover,
although FP is a palliative in nature, it is also the obligatory
definitive treatment in cases where one half of the venricles is not
adequately developed to provide a biventricular cardiac pump.
The necessity for improving the results of FP always delighted the
surgeons in order to achieve better long-term results. The major
disadvantage of first generation atriopulmonary FP was the exposure of
the whole atrial tissue to high systemic venous pressure and this
unphysiological status of the right atrium led to significant atrial
hypertrophy and dilatation, leading to supraventricular arrhythmias (2).
Moreover, this type of FP was unsuitable for patients with mitral
atresia, who had a continous left to right shunt at the level of atrial
septum (3). The first important modification of FP was the lateral
tunnel (LT) technique (1988), which primarily aimed to achieve better
hemodynamic results when the energy loss in the enlarged atrium in the
original technique was considered (3,4). The atrial septal flap and
inner right atrial wall were used in combination in order to direct the
blood coming from inferior venae cavae (IVC) to pulmonary vascular bed
in LT technique. A few years later, before the long-term results of LT
technique were not clear yet, Marcelletti et al. introduced the second
important modification, the extracardiac conduit (ECC) Fontan technique
(1990) (5). This was an IVC to pulmonary artery extracardiac conduit in
origin, which aimed to eliminate the disadvantages of LT technique,
especially the atrial wall still being exposed to high systemic venous
pressure same as it occurs in the original atriopulmonary type FP. It
was soon demonstrated in a canine model by Rodefeld and colleagues that
the suture line in LT technique was an adequate substrate for the atrial
rhythm pathways to result in supraventricular arrhythmias (6).
In the same year with the publication of the ECF technique, in 1990, Dr.
Bridges and colleagues from Boston reported the idea of fenestration,
which was initially performed in high-risk candidates of Fontan
circulation (7). Their criteria in order to identify high risk
candidates were mean pulmonary artery pressure (MPAP >
18mmHg), ventricular end-diastolic pressure > 12 mmHg,
atrioventricular (AV) valvar regurgitation, pulmonary artery distortion,
pulmonary vascular resistance > 2 Woods’ units, systemic
ventricular outflow tract obstruction and complex anatomy (7).
Interestingly, they reported the feasibility of transcatheter closure of
the fenestration in the same paper. This idea of fenestration led to
another vast amount of uncertainty, whether to fenestrate or not. It was
agreed that fenestration decreased the postoperative pleural effusion
duration and length of hospital stay but it was bringing up this
advantage with a cost of systemic desaturation (8). Moreover,
maintenance of the fenestration patency was questionable in LT and ECF
techniques (4).
Although described earlier in the development history of FP, the
intra-extracardiac Fontan procedure with fenestration (IECF) was
revisited which aimed to combine the advantages of LT and ECF (4,9,10).
At the early times of ECF, transection of IVC at cavoatrial junction and
primarily suturing the right atrial stump was thought to be innocent
with regard to atrial conduction pathways. This modification improved
the feasibility of the Fontan circulation in cases with heterotaxy
syndromes, provided with a better hemodynamic result, further decreased
the problem of arrhythmia with preserving IVC and right atrial
continuity as well as providing an easy and durable fenestration on the
conduit.
Herein, we aimed to present our experience in patients whom we performed
the intra-extracardiac fenestrated Fontan technique, along with
discussing the advantages over the other modifications.