Fontan fenestration closure and event-free survival

The Lifesaving Impact of Transcatheter Interventions in the Early Post-Fontan Palliation Period

Despite advancements in postoperative outcomes after Fontan surgery, there remains a risk of suboptimal outcomes and significant morbidity in the early postoperative period. Anatomical obstructions in the Fontan pathway can lead to prolonged pleural effusion or ascites, cyanosis, and low cardiac output syndrome (LCOS). Transcatheter interventions offer an alternative to early re-surgery for treating these complications. Over a 13-year period, early catheter angiography, performed within 30 days post-index procedure, was administered to 41 patients, identifying anatomical issues that necessitated re-intervention in 39 cases. This led to transcatheter interventions in 37 (10.4%) of the 344 Fontan surgery patients. The median age was 4.8 years (IQR: 4-9.4), and the median weight was 16.5 kg (IQR: 15-25.2), with females comprising 51.4% (19/37) of this group. The primary indications for the procedures were persistent pleural effusion or ascites in 27 patients (66%), LCOS in 8 patients (20%), and cyanosis in 6 patients (14%). Among the 37 undergoing transcatheter intervention, 30 were treated solely with this method and discharged, three died in ICU follow-up, and four required early re-surgery. No procedural mortality was observed. Our findings demonstrate that transcatheter interventions, including stent implantation, balloon angioplasty, and fenestration dilation, are safe and effective in the early post-Fontan period. Therefore, they should be considered an integral part of the management strategy for this patient group.

Impact on clinical outcomes from transcatheter closure of the Fontan fenestration: A systematic review and meta-analysis

BACKGROUND

Meta-analysis of the impact on clinical outcome from transcatheter closure of Fontan fenestration.

METHODS

Cochrane, Embase, MEDLINE, and Open-Gray were searched. Parameters such as changes in oxygen saturation, cavo-pulmonary pressure, maximum heart rate during exercise, exercise duration, and oxygen saturation after fenestration closure were pooled and statistical analysis performed.

RESULTS

Among 922 publications, 12 retrospective observational studies were included. The included studies involved 610 patients, of which 552 patients (90.5%) had a fenestration. Of those patients, 505 patients (91.5%) underwent attempt at trans-catheter closure. When it could be estimated, the pooled overall mean age at trans-catheter fenestration closure was 6.6 ± 7.4 years, and the mean follow-up time was 34.4 ± 10.7 months. There were 32 minor (6.3%) and 20 major (4.0%) complications during or after trans-catheter Fontan fenestration closure. The forest plots demonstrate that following fenestration closure, there was a significant increase in the mean arterial oxygen saturation of 7.9% (95% CI 6.4-9.4%, p < 0.01). There was also a significant increase in the mean cavo-pulmonary pressure of 1.4 mmHg (95% CI 1.0-1.8 mmHg, p < 0.01) following fenestration closure. The exercise parameters reported in 3 studies also favored closing the fenestration as well, yet the exercise duration increase of 1.7 min (95% CI 0.7-2.8 min, p < 0.01) after fenestration closure is probably clinically insignificant.

CONCLUSION

Late closure of a Fontan fenestration has the impact of improving resting oxygen saturation, exercise oxygen saturation, and a modest improvement of exercise duration. These clinical benefits, however, may be at the expense of tolerating slightly higher cavo-pulmonary mean pressures.

Transcatheter closure of extracardiac Fontan conduit fenestration using new promising materials

Fenestration transcatheter closure is widely considered to eliminate persistent right-to-left shunt after Fontan surgeries. Three consecutive children with stage III-palliated univentricular hearts recently underwent successful endovascular fenestration closure using 43 mm/Large Optimus-CVS™ that were implanted using the new Altosa-XL™ PTA balloon catheters (AndraTec GmbH). The procedure was fast with no complication and patients were discharged the following day with complete shunt closure. One-month follow-up confirmed excellent outcomes. This report aims to highlight and discuss the competitive advantages of these promising new materials in this particular intervention.

Persisting and reoccurring cyanosis after Fontan operation is associated with increased late mortality

OBJECTIVES

The Fontan operation aims at reducing cyanosis and cardiac volume overload in patients with complex univentricular heart malformations. However, persisting or reoccurring cyanosis is frequently observed. We sought to systematically determine the prevalence and clinical consequences of persisting and secondary cyanosis after Fontan operation.

METHODS

A total of 331 Fontan patients, operated between 1984 and 2016 with a median postoperative follow-up of 7.9 (interquartile range 2.6-15.8) years, were studied retrospectively. Cyanosis was defined as transcutaneous oxygen saturation ≤93% at rest measured by pulse oximetry. Prevalence of cyanosis was analysed at 3 different time points (t1 = post-Fontan operation, t2 = post-Fontan cardiac catheterization, t3 = last follow-up) and the association of cyanosis with mortality was examined.

RESULTS

Prevalence of cyanosis was 50% at t1 and 39% at t3. Fenestration was patent in 71% and 33% of all cyanotic patients at t1 and t3, respectively. In patients with clinical indication for catheterization (t2; n = 178/331), prevalence of cyanosis was 72%. At t2, patent fenestration (33%), veno-venous collaterals (24%) or both (32%) were present. Thirty-six (11%) patients died during follow-up. In a time-varying multivariable Cox regression analysis, cyanosis was the strongest predictor for late mortality (P < 0.001, hazard ratio 12.2, 95% confidence interval 3.7-40.5).

CONCLUSIONS

Prevalence of cyanosis was considerable during long-term follow-up after Fontan operation and-as a surrogate parameter for unfavourable Fontan haemodynamics-is associated with increased late mortality. Accordingly, particular attention should be directed towards the persistence or reoccurrence of cyanosis during follow-up since it may indicate haemodynamic attrition and development of Fontan failure.

Venous Properties in a Fontan Patient with Successful Remission of Protein-Losing Enteropathy

We present the case of a 1-year-old boy who developed protein-losing enteropathy (PLE) within 2 months of a fenestrated Fontan procedure. His fenestration rapidly closed despite bilateral pulmonary stenosis (BPS). Subsequent to PLE onset, both fenestration and the bilateral pulmonary artery were reconstructed, and the patient's PLE had been in remission, with additive use of medications, for more than 2 years. Notably, although fenestration closed again and central venous pressure (CVP) reduction was minimal, the surrogates of venous return resistance were markedly suppressed as shown by increased blood volume, reduced estimated mean circulatory filling pressure, and suppressed CVP augmentation against a contrast agent. Taken together, dynamic characteristics of venous stagnation, rather than the absolute value of CVP, were ameliorated by the pulmonary reconstruction and use of medications, suggesting a significant role of venous property in the physiology of PLE. In addition, simultaneous measures of CVP and ventricular end-diastolic pressure during the abdominal compression procedure suggested a limited therapeutic role of fenestration against PLE in this patient.

Use of institutional criteria for transcatheter device closure of Fontan fenestration - Midterm outcomes

Background:

There are no established criteria to decide suitability for Fontan fenestration closure. Our institution has the following criteria: an unobstructed Fontan pathway with no significant decompressing venovenous collaterals, baseline Fontan pressure ≤15 mmHg, baseline cardiac index ≥2 L/min/m², and a decrease in cardiac index ≤20% with test occlusion of the fenestration.

Objective:

The objective of the study was to review midterm outcomes following device closure of Fontan fenestration using institutional criteria.

Materials and Methods:

A retrospective review was performed of patients who underwent catheterization with prior fenestrated Fontan procedure between May 2005 and January 2015. Patients were classified as those who underwent successful closure (A), had closure deferred due to failure to meet criteria (B), or were not referred for closure (C).

Results:

There were 42 patients in Group A, 10 in Group B, and 150 in Group C. The mean Fontan pressure increased from 13.1 ± 2.1 to 14.5 ± 2.1mmHg in Group A and 14.6 ± 1.5 to 15.7 ± 2.2 mmHg in Group B (P = not significant). With test occlusion, cardiac index fell by 18.12% ± 15.68% in Group A and 33.75% ± 14.98% in Group B (P = 0.019). At a median of 46 month follow-up, oxygen saturation increased significantly from 85.15% ± 6.29% at baseline to 94.6% ± 4.43% (P < 0.001) in Group A but with no statistically significant difference in the rates of plastic bronchitis, protein-losing enteropathy, stroke, or heart transplantation between the three groups.

Conclusions:

Using institutional criteria, transcatheter device closure of Fontan fenestration was followed by significant increase in oxygen saturations and no statistically significant difference in morbidity or mortality between closure and nonclosure groups.

Extracardiac Fontan Fenestration Device Closure with Amplatzer Vascular Plug II and Septal Occluder: Procedure Results and Medium-Term Follow-Up

The objective of this study was to determine medium-term morbidity and mortality of patients who have undergone device closure of an extracardiac Fontan fenestration with an Amplatzer Vascular Plug II (AVPII) or Septal Occluder (ASO). A secondary objective was to compare medium-term morbidity and mortality between these patients and other fenestrated Fontan patients. A retrospective chart review was performed on patients who underwent an extracardiac fenestrated Fontan procedure between 1992 and 2015 at Cardinal Glennon Children's Medical Center. Procedural and follow-up data were obtained and compared between those who underwent fenestration closure and those who did not. Additional outcome measures included whether the fenestration had spontaneously closed, morbidity and mortality, oxygen saturations, and hemodynamics pre- and post-closure. Fifty-nine of 118 patients (50%) with a fenestrated Fontan underwent 60 device closures of the fenestration. Thirty-two (53%) of these were with the AVPII and 28 (47%) with the ASO. There was one device embolization. At a median follow-up of 3.9 years, five patients suffered morbidity, including 2 with arrhythmias, 1 with plastic bronchitis, 1 with protein losing enteropathy, and 1 with stroke. There were no cardiopulmonary deaths in this group. Twenty-three of 118 patients (19%) had spontaneous closure. There was no difference in morbidity and mortality between patients who underwent percutaneous fenestration closure and those who either had spontaneous closure or a persistently patent fenestration. Device closure of Fontan fenestrations is a safe and effective procedure with minimal morbidity and mortality comparable to other patients with fenestrations.

Fenestration in the Fontan circulation as a strategy for chronic cardioprotection

Background

Fenestration in the Fontan circulation potentially liberates patients from factors leading to cardiovascular remodelling, through stable haemodynamics with attenuated venous congestion. We hypothesised that a fenestrated Fontan procedure would possess chronic haemodynamic advantages beyond the preload preservation.

Methods

We enrolled 35 patients with fenestrated Fontan with a constructed pressure–volume relationship under dobutamine (DOB) infusion and/or transient fenestration occlusion (TFO). Despite the use of antiplatelets and anticoagulants, natural closure of fenestration was confirmed in 11 patients. Cardiovascular properties in patients with patent fenestration (P-F) were compared with those in patients with naturally closed fenestration (NC-F). To further delineate the roles of fenestration, paired analysis in patients with P-F was performed under DOB or rapid atrial pacing with/without TFO.

Results

As compared with P-F, patients with NC-F had a higher heart rate (HR), smaller ventricular end-diastolic area, better ejection fraction and higher central venous pressure, with higher pulmonary resistance. While this was similarly observed after DOB infusion, DOB markedly augmented diastolic and systolic ventricular stiffness in patients with NC-F compared with patients with P-F. As a mirror image of the relationship between patients with P-F and NC-F, TFO markedly reduced preload, suppressed cardiac output, and augmented afterload and diastolic stiffness. Importantly, rapid atrial pacing compromised these haemodynamic advantages of fenestration.

Conclusions

As compared with patients with NC-F, patients with P-F had robust haemodynamics with secured preload reserve, reduced afterload and a suppressed beta-adrenergic response, along with a lower HR at baseline, although these advantages had been overshadowed, or worsened, by an increased HR.

Assessment of Late Thromboembolic Complications Post-Fontan Procedure in Relation to Different Antithrombotic Regimens: 30-Years' Follow-up Experience

Background: The current CHEST guidelines recommend the use of antithrombotic therapy, either aspirin or warfarin, as a primary thromboembolic complications (TECs) prophylaxis in patients who undergo Fontan procedure, without specification on drug selection or duration of therapy. Objective: To investigate the incidence rate of late TECs, occurring after 1-year post-Fontan procedure and to assess the difference in rate of late TECs between warfarin and aspirin. Methods: A retrospective cohort study included patients who had Fontan procedures between 1985-2010 at our institution. Patients were stratified according to the antithrombotic regimen-warfarin, aspirin, or no therapy-at the time of TECs. Results: We screened 499 patients who underwent Fontan procedures; 431 procedures met the inclusion criteria. Over a median follow-up of 13.6 years (IQR= 8.7), freedom from late TECs at 5, 10, 15, and 20 years was 97.54%, 96.90%, 90.78%, and 88.07%, respectively. There was no difference in late TEC incidence rates per 1000 patient-years between warfarin and aspirin: 7.82 and 5.83 events, respectively; rate ratio= 1.34 (95% CI= 0.68-2.60). Warfarin was associated with a higher major bleeding incidence rate per 1000 patient-years: 3.70 versus 2.91 events with aspirin; rate ratio= 1.27 (95% CI= 0.49 to 3.29). Conclusion and Relevance: The incidence rate of late clinical TECs post-Fontan procedure in our population is low. Warfarin was not superior to aspirin for prevention of late TECs. Yet warfarin was associated with a higher rate of bleeding. This finding suggests a simpler antithrombotic regimen for prevention of TEC after 1-year post-Fontan procedure.

A computational study of the Fontan circulation with fenestration or hepatic vein exclusion

Fontan patients may undergo additional surgical modifications to mitigate complications like protein-losing enteropathy, liver cirrhosis, and other issues in their splanchnic circulation. Recent case reports show promise for several types of modifications, but the subtle effects of these surgeries on the circulation are not well understood. In this paper, we employ mathematical modeling of blood flow to systematically quantify the impact of these surgical changes on extracardiac Fontan hemodynamics. We investigate two modifications: (1) the fenestrated Fontan and (2) the Fontan with hepatic vein exclusion. Closed-loop hemodynamic models are used, which consist of one-dimensional networks for the major vessels and zero-dimensional models for the heart and organ beds. Numerical results suggest the hepatic vein exclusion has the greatest overall impact on the hemodynamics, followed by the largest sized fenestration. In particular, the hepatic vein exclusion drastically lowers portal venous pressure while the fenestration decreases pulmonary artery pressure. Both modifications increase flow to the intestines, a finding consistent with their utility in clinical practice for combating complications in the splanchnic circulation.

[Comparison between patients undergoing Fontan operation with or without cardiopulmonary bypass]

Fontan operation is the final palliative stage of patients with univentricular hearts. Cardiopulmonary bypass (CPB) decreases ventricular performance and increases pulmonary artery pressures in the post operative recovery period. It seems that Fontan operation performed without CPB decreases short term morbidity and intra hospitalary length of stay.

OBJETIVE

Compare outcome in Fontan patients who have undergone surgery with or without CPB.

METHOD

This is a retrospective review of patients undergoing Fontan operation from january 2009 to december 2012. Patients were grouped according to CPB use and comparative analyses were done.

RESULTS

Ten patients were operated without CPB use. There was a discrepancy between age in both groups, being younger in the no CPB group. Around 80% of patients in both groups had a staged procedure. A 18mm graft was used in half of the cases; a fenestration was created in all cases. Length of stay was equal in both groups, there was less need of pharmacologic support and nitric oxide use in patients without CPB use. No deaths were reported also in this group. At folllow up, most patients had a class i functional status.

CONCLUSIONS

In our experience, Fontan operation without CPB has similar outcomes compared with CPB use.

Closure of Fontan fenestration with the use of covered stents: short- and mid-term results in a cohort of 50 patients

OBJECTIVE

The use of covered stents to close fenestration in total cavopulmonary connection is presented.

METHODS

We retrospectively reviewed data of all patients undergoing the procedure of a covered stent to close fenestration of total cavopulmonary connection between 2005 and 2012.

RESULTS

A total of 50 patients met the inclusion criteria. Median age and weight were 7.7 years and 20 kg, respectively. Median interval between Fontan completion and fenestration closure was 13 months. The femoral vein was used in 42 patients and the jugular vein in eight patients. Of the patients, seven received two stents. Covered stents were CP stents in 42 patients and Atrium Advanta V12 in eight patients. BIB balloons were used in 24 patients and simple balloons in 18 patients. Simultaneous occlusion of venous collaterals was observed in five patients. Median procedural and fluoroscopy times were 49 and 8 minutes, respectively. Mean central venous pressure rose from 10 to 12 mmHg. Mean oxygen saturation increased from 88% to 96%. Full occlusion was confirmed in 47 patients. The remaining had residual shunts: two patients had intracardiac Fontan, and one patient had a stent that could not be fully opened. Following the procedure, five patients had local bleeding, and three delayed discharge 48 hours after the procedure. There was no thromboembolic event after a mean follow-up of 49 months.

CONCLUSION

Covered stent is a good option to close fenestration in extracardiac total cavopulmonary connection. It is safe, easily achievable with low fluoroscopy time, with very low risk of complication or failure. Good results are sustainable when excluding patients with none circular pathway.

Effect of Fontan fenestration on regional venous oxygen saturation during exercise: further insights into Fontan fenestration closure

Fontan fenestration closure is a topic of great debate. The body of data regarding the risks and benefits of fenestration closure is limited yet growing. Previous studies have demonstrated that Fontan patients have less exercise capacity than those with normal cardiovascular anatomy. Differences also have been noted within various subgroups of Fontan patients such as whether Fontan is fenestrated or not. This study aimed to compare trends in regional oxygen saturations using near-infrared spectroscopy (NIRS) in patients with Fontan circulations during ramping exercise to further delineate differences between patients with and without a fenestration. It was hypothesized that Fontan patients with fenestrations have better exercise times, higher absolute regional oxygen venous saturations, and smaller arteriovenous differences than Fontan patients without fenestrations. For this study, 50 consecutive Fontan patients and 51 consecutive patients with normal cardiovascular anatomy were recruited. Placement of NIRS probes was performed to obtain regional oxygen saturations from the brain and the kidney. Readings were obtained at 1-min intervals during rest, exercise, and recovery. A standard Bruce protocol was used with a 5-min recovery period. Absolute regional tissue oxygenation values (rSO2) and arterial-venous oxygen saturation differences (AVDO2) calculated as arterial oxygen saturation (SPO2)--rSO2 for normal versus Fontan patients and for fenestrated versus unfenestrated Fontan patients were compared using independent t tests. When normal and Fontan patients were compared, the Fontan patients had a significantly shorter duration of exercise (9.3 vs 13.2 min; p < 0.001). No statistically significant difference in rSO2 change or AVDO2 was evident at the time of peak exercise, at 2 min into the recovery, or at 5 min into the recovery. A small oxygen debt also was paid back to the brain in the Fontan patients after exercise, as evidenced by a narrower AVDO2 than at baseline. The comparison of Fontan patients with and without fenestration showed no statistically significant difference in exercise time, rSO2 change, or AVDO2. The Fontan patients were noted to have shorter exercise times than the normal patients and also appeared to have an alteration in postexertional regional blood flow. However, when the various Fontan subtypes were compared by presence or absence of a fenestration, no significant differences were noted with regard to change in regional oxygen saturation or arteriovenous oxygen saturation. Thus, for patients with Fontan physiology, closure of the fenestration does not seem to have an impact on the dynamics of regional oxygen extraction during exercise or recovery.