Mid Term Results of Fenestrated Intra-Extracardiac Fontan Procedure: Insights, Experiences and Expectations

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.

Catheter ablation of macroreentrant atrial tachycardias following transconduit puncture access in a patient after total cavopulmonary connection with an extracardiac conduit

We present the case of a 23-year-old male diagnosed with a complex congenital heart disease (with single ventricle physiology) which necessitated many surgical interventions including total cavopulmonary connection. The patient presents with recurrent (almost daily) highly symptomatic atrial tachycardia with rapid ventricular rate and poor haemodynamic tolerance. Due to failure of antiarrhythmic drug therapy the patient was referred for catheter ablation. Atrial access was provided following transconduit puncture with a standard transseptal set. Crossing to the atrium with the transseptal introducer was not successful due to resistance from the conduit and the atrial wall. Therefore, balloon dilation of the puncture using a cutting balloon was carried out which resulted in easy crossing to the atrium with a steerable transseptal introducer. Several atrial tachyarrhythmias were induced two of which allowed mapping demonstrating a macroreentrant tachycardia dependent on the cavoannular isthmus as well as a complex fi gure-of-eight circuit involving right pulmonary veins and the right atrial appendage. Linear lesions transecting the critical isthmuses of the two circuits were delivered which rendered the patient noninducible. During a 9-month follow-up period the patient remained arrhythmia free.

Usefulness of a Radiofrequency Transseptal Needle in the Second Puncture of Fontan Extracardiac Conduit

We performed a second puncture of the extracardiac conduit in an 11-year-old Fontan patient to assess the patency of the stent previously deployed in the left pulmonary vein. For the first puncture, a mechanical Brockenbrough needle was selected to puncture the Gore-Tex conduit, an electrical insulator. For the second puncture, the location of that previous hole was detected as an indentation covered with atrial tissue, which is an electrical conductor. The second puncture was performed safely using a radiofrequency transseptal needle.

Dobutamine stress testing for the evaluation of atrial and diastolic ventricular function in Fontan patients

ObjectiveTo assess the atrial and ventricular diastolic function response to dobutamine stress in Fontan patients, and to relate these measurements to exercise capacity and events during the follow-up.MethodsWe performed a secondary analysis of a cross-sectional multicentre study of Fontan patients with intra-atrial lateral tunnel (ILT) or extracardiac conduit (ECC) modification. Subjects underwent cardiac MRI during rest and low-dose dobutamine stress, and cardiopulmonary exercise testing. Atrial and diastolic ventricular function parameters were derived from volume-time curves.Medical records were abstracted for a composite end-point of death, listing for transplant, arrhythmia and reintervention. Spearman’s r correlation tests and Cox proportional hazards models were used to assess the relation between the dobutamine response for atrial and diastolic ventricular function and outcomes, including exercise capacity.ResultsWe included 57 patients (26 ECC; 31 ILT) aged 12.8 (IQR (10.3–15.5)) years. During dobutamine stress atrial cyclic volume change increased (3.0 (0.4–5.9) mL/m2, p<0.001), as did early (1.9 (−1.6 to 3.6) mL/m2, p=0.001) and late emptying volume (2.2 (0.2–4.4) mL/m2, p<0.001).Ventricular early filling decreased (−1.6 (−5.7 to 0.7) mL/m2,p=0.046) and ventricular late filling increased (1.0 (−0.4 to 3.4) mL/m2,p<0.001) while stroke volume remained similar.Only for patients with the ECC modification, atrial early emptying volume increase correlated with peak oxygen uptake (ρ=0.66,p=0.002). No other parameter related to exercise capacity.During a median 7.1-year follow-up, 22 patients reached the composite endpoint. No parameter predicted events during the follow-up.ConclusionsDobutamine stress augmented atrial reservoir and pump function for Fontan patients. Atrial early emptying reserve related to exercise capacity in ECC patients. No other atrial or diastolic ventricular function parameter related to outcomes.

Technical modifications for transplant in the failing Fontan

Introduction: Heart transplant after Fontan completion poses a unique surgical challenge. Twenty patients are presented, stressing the technical hints performed in the five anastomoses to match the graft in the recipient. Methods: Data are collected from 20 Fontan patients between 2013 and 2019. Age (13 years), weight (37 kg.), and time interval between Fontan and transplant (7 years) are presented as median. Extracardiac conduit (size 18/20) was implanted in 15 patients, whereas atrio-pulmonary connection was performed in 4 and lateral tunnel in 1. Six patients developed protein-losing enteropathy. Seventeen stents had been previously deployed. Results: The five anastomoses underwent some changes. Left atrium once, aorta 9 times, superior vena cava 7 times, pulmonary branches 15 times, and inferior vena cava 12 times. Follow-up was complete for a median of 42 months (range 6–84). Two patients died. ECMO was needed in six cases for pulmonary hypertension. Four patients had collateral vessels occluded in the cath lab, and stents were placed in superior vena cava (1) and aorta (1) post-transplant. Protein-losing enteropathy was resolved in five patients. Interestingly, one patient was on a systemic assist device before transplant (Levitronix) and right assistance (ECMO) afterwards. Conclusions: Transplant in Fontan patients is actually challenging. Hints in every of the five proposed anastomoses must be anticipated, including stents removal. Extra tissue from the donor (innominate vein, aortic arch, and pericardium) is strongly advisable. ECMO for right ventricular dysfunction was needed in nearly one-third of the cases. Overall results can match other transplant cohorts.