Transcatheter closure of extracardiac Fontan conduit fenestration using new promising materials

The long-term effects of the fenestration in patients with extracardiac Fontan circulation-a multicenter Korean cohort study based on national Fontan registry

Introduction

The long-term effects of fenestration in patients with Fontan circulation remain unclear. We aim to evaluate the fenestration impact on early and late outcomes in patients with extracardiac Fontan (ECF) using a propensity score matching analysis.

Methods

We performed an extensive retrospective multicenter clinical data review of the Korean Fontan registry and included 1,233 patients with surgical ECF (779 fenestrated, 454 non-fenestrated). Demographics, baseline, and follow-up data were collected and comprehensively analyzed. Patients were divided into two groups according to the baseline presence or absence of surgical fenestration. Subsequently, patients were sub-divided according to the fenestration status at the last follow-up. Propensity-score matching was performed to account for collected data between the 2 groups using a multistep approach. The primary outcomes were survival and freedom from Fontan failure (FFF). We also looked at postoperative hemodynamics, cardiopulmonary exercise test results, oxygen saturations, and functional status.

Results

After propensity-score matching (454 matched pairs), there was no difference in survival or FFF between the 2 groups. However, ECF patients with baseline fenestration had significantly lower oxygen saturation (p = 0.001) and lower functional status (p < 0.001). Patients with fenestration had significantly longer bypass times, higher postoperative central venous pressure, higher postoperative left atrial pressure, and less prolonged pleural effusion in the early postoperative period. The propensity score matching according to the fenestration status at the last follow-up (148 matched pairs) showed that patients with a persistent fenestration had significantly lower oxygen saturation levels (p < 0.001). However there were no intergroup differences in the functional status, survival and FFF.

Conclusions

Our results showed no long-term benefits of the Fenestration in terms of survival and FFF. Patients with persistent fenestration showed oxygen desaturation but no difference in exercise intolerance was shown between the 2 groups.

Proof of Concept: A New Solution for Low-Profile Transcatheter Implantation of Optimus-L Stents in Small Children

BACKGROUND

There is no stent designed or approved for use in infants. We sought to obtain in vitro and in vivo data on a new concept conceived to implant Optimus-L stents at infant vessel diameters and offer a potential long term stent solution.

METHODS

Nineteen Optimus-L stents were mounted on 8 types of angioplasty balloons with diameters 6, 8, and 10 mm with the use of an injection-moulded hand crimper. We evaluated balloon-stent unit (BSU) stability before insertion and advancement through short Terumo introducers with incremental French size and possibility of side-arm contrast injections. Three types of long sheaths were tested. Stents were inflated to balloon nominal diameters and re-expanded to 18 and 23 mm. Stent recoil, foreshortening, and fracture were evaluated. In vivo implantations were performed afterward.

RESULTS

In vitro: Medtronic Evercross balloons and modified Terumo Destination sheaths were the best combination: BSUs were inserted in 6 F sheaths with possible injections (for 6 and 8 mm balloons), and 7 F sheaths without injections (for the 10 mm balloon). Retrieving BSUs inside the sheath required 1 additional F-size. Boston Scientific Sterling and Balton Lovix balloons, as well as APT Braidin L guiding sheaths showed unsatisfactory performance. Dilation up to 23 mm was possible, and stent shortening was < 24% at 18 mm and < 37% at 23 mm. Recoil was limited, and no stent fractured. In vivo: Optimus-L stents were used to treat 2 infants with aortic coarctation and 2 children with pulmonary artery stenosis with the use of 8 mm balloons and low-profile access.

CONCLUSIONS

Optimus-L stents can be implanted safely in small patients with a low-profile approach. These stents have the potential to achieve adult size while maintaining structural integrity.

Cerebral embolic protection during transcatheter stent expansion of restrictive extra-cardiac Fontan conduit

We report a 20-year-old female patient (76 Kg/164 cm) with an extra-cardiac Fontan circulation who was referred to our institution for exertional dyspnoea and desaturation. The patient was diagnosed with a large calcified thrombus at the level of the Fontan fenestration, protruding inside the lumen of the conduit and reducing the diameter by half with a 3 mmHg pressure gradient. Transcatheter stent expansion of the obstructed extra-cardiac conduit was done with a 48 mm long XXL PTFE-covered Optimus-CVS® under temporary cerebral embolic protection with a TriGUARD-3™ deflection filter device (Keystone Heart). There was no procedural complication and the 3 months clinical outcomes are good.

Multicentre experience with Optimus balloon-expandable cobalt-chromium stents in congenital heart disease interventions

OBJECTIVES

To evaluate bare-metal Optimus and polytetrafluoroethylene (PTFE)-covered Optimus-CVS balloon-expandable, cobalt-chromium, hybrid cell-designed stents in congenital heart disease (CHD) interventions.

METHODS

Retrospective multicentre review of patients with CHD receiving Optimus stents. Stent mechanical behaviour, clinical indications and outcomes were assessed.

RESULTS

183 stents (49.2% XXL/15-ZIG, 33.3% XL/12-ZIG, 17.5% L/9-ZIG) were implanted (98.9% success rate, 2.3% serious procedural complication rate) in 170 patients (57.6% men, 64.1% adults), median age 23.6 years (IQR, 15.2-39.2) and weight 63.5 kg (IQR, 47-75.7). Indications were right ventricular outflow tract stand-alone stenting or before revalvulation (62.4%), aortic coarctation treatment (15.3%), Fontan-circuit fenestration closure (12.4%) and miscellaneous (10%). 86/170 (50.6%) patients had PTFE-covered stenting (50% prophylactic). In 86/170 (50.6%) patients with stenotic lesions, median percentage of achieved stent expansion was 93.4% (IQR, 85.5%-97.7%), median gradient decreased from 28 mm Hg (IQR, 19-41) to 5 mm Hg (IQR, 1-9) (p<0.001), median vessel diameters increased from 13 mm (IQR, 7.9-17) to 18.9 mm (IQR, 15.2-22) (p<0.001) and percentage of vessel expansion was 45.2% (IQR, 19.8%-91.3%). In 30/36 (83.3%) patients with graft, median dilation of 2 mm (IQR, 2-5) above nominal diameter was achieved. Median stent shortening was 10.9% (IQR, 6.1-15.1) and was associated only with expansion diameter (OR: 0.66, 95% CI: 0.38 to 0.93). No clinically relevant fracture, stent embolisation or dysfunction occurred on a median follow-up of 9 (IQR, 4-14) months.

CONCLUSIONS

Optimus stents are effective tools for transcatheter treatment of simple and complex CHD. Optimus stents' reliable mechanical behaviour and particular covering design can promote widespread use.

Long-term outcomes of transcatheter Potts shunt in children with suprasystemic pulmonary arterial hypertension

BACKGROUND

Transcatheter Potts shunt (TPS) is a palliation alternative for children with severe pulmonary arterial hypertension (PAH). Debates on the long-term outcomes remain unsolved.

OBJECTIVES

To evaluate long-term clinical and procedural outcomes of TPS intervention.

METHODS

Single-center retrospective data review of children with severe PAH who had TPS between 2009 and 2018. Patients who died per-operatively and early post-procedure were excluded. Long-term outcomes of survivors were evaluated.

RESULTS

Out of 13 identified patients (53.8% males), 7 had endovascular stenting of probe/patent arterial ducts, while 6 individuals had aorta-to-pulmonary radiofrequency perforation and covered stent placement. Compared to baseline, the overall clinical condition significantly improved at discharge (p < 0.001) and stayed better at the last visit (p < 0.05) despite frequent clinical worsening events across follow-up. Improvement in functional class across follow-up was significant (p < 0.001). There was, however, no significant improvement in other disease markers (TPASE, 6MWD z-scores, and NT-proBNP levels) or reduction in PAH medications. The median follow-up was 77.4 months (IQR, 70.7-113.4). Survival was 100% at 1 year and 92.3% at 6 years. Freedom from reinterventions was 77% at 1 year and 21% at 6 years. Nine (69.2%) patients had stent reinterventions at a median of 25 months (IQR, 9.5-56) postoperative. Balloon dilatation and restenting were performed in 53.8% and 46.2% of patients, respectively. High-pressure post-dilatation of implanted stents was performed in 53.8% of patients during TPS intervention for incomplete stent expansion and/or residual pressure gradient and was associated with higher rates of reinterventions (p = 0.021). Stent malfunctioning was present in 46.2% of patients at last follow-up. Two patients are listed for heart-lung transplantation.

CONCLUSION

Survivors of TPS procedures experience significant improvement in functional class that can be durable. Clinical worsening and stent malfunctioning are frequent morbid events indicating recurrent transcatheter reinterventions throughout follow-up. Six-year survival is, however, satisfactory.

Transcatheter interventions in patients with a Fontan circulation: Current practice and future developments

The Fontan operation represents the last of multiple steps that are offered a wide range of congenital cardiac lesions with a single ventricle (SV) physiology. Nowadays this surgical program consists of a total cavopulmonary connection (TCPC), by anastomosing systemic veins to the pulmonary arteries (PAs), excluding the right-sided circulation from the heart. As a result of imaging, surgical, percutaneous, and critical care improvements, survival in this population has steadily increased. However, the Fontan physiology chronically increases systemic venous pressure causing systemic venous congestion and decreased cardiac output, exposing patients to the failure of the Fontan circulation (FC), which is associated with a wide variety of clinical complications such as liver disease, cyanosis, thromboembolism, protein-losing enteropathy (PLE), plastic bronchitis (PB), and renal dysfunction, ultimately resulting in an increased risk of exercise intolerance, arrhythmias, and premature death. The pathophysiology of the failing Fontan is complex and multifactorial; i.e., caused by the single ventricle dysfunction (diastolic/systolic failure, arrhythmias, AV valve regurgitation, etc.) or caused by the specific circulation (conduits, pulmonary vessels, etc.). The treatment is still challenging and may include multiple options and tools. Among the possible options, today, interventional catheterization is a reliable option, through which different procedures can target various failing elements of the FC. In this review, we aim to provide an overview of indications, techniques, and results of transcatheter options to treat cavopulmonary stenosis, collaterals, impaired lymphatic drainage, and the management of the fenestration, as well as to explore the recent advancements and clinical applications of transcatheter cavopulmonary connections, percutaneous valvular treatments, and to discuss the future perspectives of percutaneous therapies in the Fontan population.