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.