Percutaneous left atrial appendage closure with a novel self-modelizing device: A pre-clinical feasibility study

Park, Jai‐Wun; Sherif, Mohammad; Zintl, Konstantin; Lam, Yat‐Yin; Goedde, Martin; Scharnweber, Tim; Jung, F.; Franke, Ralf P; Brachmann, Johannes

doi:10.1016/j.ijcard.2014.09.194

Cited by 13 publications

(4 citation statements)

References 22 publications

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“…Therefore, EC seeding as a means of creating a hemocompatible surface of cardiovascular implants is a strategy to render thrombogenic surfaces hemocompatible . In vivo, the luminal surfaces of cardiovascular devices are often lined only sparsely with endothelial cells. − Thus, the blood-contacting surface remains unhealed and covered with a layer of compacted plasma proteins only, a so-called pseudointima. Cardiovascular devices therefore can fail, in part, due to thrombosis resulting from the lack of endothelium .…”

Section: Introductionmentioning

confidence: 99%

Response of Endothelial Cells to Gelatin-Based Hydrogels

Krüger‐Genge

Hauser

Neffe

et al. 2021

ACS Biomater. Sci. Eng.

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The establishment of confluent endothelial cell (EC) monolayers on implanted materials has been identified as a concept to avoid thrombus formation but is a continuous challenge in cardiovascular device engineering. Here, material properties of gelatin-based hydrogels obtained by reacting gelatin with varying amounts of lysine diisocyanate ethyl ester were correlated with the functional state of hydrogel contacting venous EC (HUVEC) and HUVEC’s ability to form a monolayer on these hydrogels. The density of adherent HUVEC on the softest hydrogel at 37 °C (G’ = 1.02 kPa, E = 1.1 ± 0.3 kPa) was significantly lower (125 mm–1) than on the stiffer hydrogels (920 mm–1; G’ = 2.515 and 5.02 kPa, E = 4.8 ± 0.8 and 10.3 ± 1.2 kPa). This was accompanied by increased matrix metalloprotease activity (9 pmol·min–2 compared to 0.6 pmol·min–2) and stress fiber formation, while cell-to-cell contacts were comparable. Likewise, release of eicosanoids (e.g., prostacyclin release of 1.7 vs 0.2 pg·mL–1·cell–1) and the pro-inflammatory cytokine MCP-1 (8 vs <1.5 pg·mL–1·cell–1) was higher on the softer than on the stiffer hydrogels. The expressions of pro-inflammatory markers COX-2, COX-1, and RAGE were slightly increased on all hydrogels on day 2 (up to 200% of the control), indicating a weak inflammation; however, the levels dropped to below the control from day 6. The study revealed that hydrogels with higher moduli approached the status of a functionally confluent HUVEC monolayer. The results indicate the promising potential especially of the discussed gelatin-based hydrogels with higher G’ as biomaterials for implants foreseen for the venous system.

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Section: Introductionmentioning

confidence: 99%

Response of Endothelial Cells to Gelatin-Based Hydrogels

Krüger‐Genge

Hauser

Neffe

et al. 2021

ACS Biomater. Sci. Eng.

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“…It is broader than humans’ LAA but still has a narrow junction with the rest of the atrium ( Ho, et al, 2002 ), which makes it a good candidate for LAA surgical research. The swine model has been widely used in both LAA procedure evaluation and ischemic stroke studies ( Park et al, 2014 ; Reinthaler et al, 2021 ; Taha et al, 2022 ). Using this model, we validated the novel concept of LAA inversion.…”

Section: Discussionmentioning

confidence: 99%

Safety and feasibility of left atrial appendage inversion in swine: A proof-of-concept study for potential therapy to prevent embolic stroke

Wang

Wang²,

Guo³

et al. 2023

Front. Bioeng. Biotechnol.

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Objective: Left atrial appendage (LAA) occlusion or exclusion has been used in patients with atrial fibrillation to prevent stroke, but the techniques and devices have shortcomings. This study aims to validate the safety and feasibility of a novel LAA inversion procedure.Methods: LAA inversion procedures were done in six pigs. Before the procedure and at 8 weeks postoperatively, heart rate, blood pressure, and electrocardiogram (ECG) were recorded. The serum concentration of atrial natriuretic peptide (ANP) was measured. The LAA was observed and measured by transesophageal echocardiogram (TEE) and intracardiac echocardiogram (ICE). At 8 weeks after LAA inversion, the animal was euthanized. The heart was collected for morphology and histology, including hematoxylin-eosin, Masson trichrome, and immunofluorescence staining.Results: TEE and ICE showed that LAA was inverted, and the inversion was maintained during the 8-week study duration. Food intake, body weight gain, heart rate, blood pressure, ECG, and serum ANP level were comparable before and after the procedure. Morphology and histological staining showed that there was no obvious inflammation or thrombus. Tissue remodeling and fibrosis were observed at the LAA inverted site.Conclusion: The inversion of LAA effectively eliminates the dead space of LAA and thus may reduce the risk of embolic stroke. The novel procedure is safe and feasible, but the efficacy in reducing embolization remains to be demonstrated in future studies.

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“…The CLAAS system was also evaluated in a well-accepted canine model for assessing LAAO devices [15][16][17][18][19][20][21]. The acute canine studies demonstrated that the device could be successfully deployed providing complete LAA seal using standard clinical techniques.…”

Section: Discussionmentioning

confidence: 99%

Preclinical Assessment of a Novel Conformable Foam‐Based Left Atrial Appendage Closure Device

Sommer

Lamport²,

Melanson³

et al. 2021

BioMed Research International

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Background. Left atrial appendage (LAA) occlusion has been established as an alternative to systemic anticoagulation for stroke prevention in patients with atrial fibrillation; however, limitations of current devices have slowed adoption. We present preclinical evaluations of a novel device, the Conformal Left Atrial Appendage Seal (CLAAS). Methods. An in vitro assessment of conformability was conducted to evaluate the two CLAAS devices (regular 27 mm and large 35 mm) and a Watchman 2.5 (27 mm). Devices were placed within silicone tubes and compressed in a vise submerged in a water bath at 37°C. Changes in device diameter and visual seal were noted. Acute ( n = 1 ) and chronic 60-day ( n = 6 ) canine studies with gross and histologic assessment were performed. Results. Conformability bench tests demonstrated that the regular CLAAS implant was able to seal oval orifices from 20 × 30 mm to 15 × 33 mm and the large from 30 × 35 mm to 20 × 40 mm . As the CLAAS implant was compressed in the minor diameter, it increased in the major diameter, thereby filling the oval space, whereas the Watchman 2.5 showed gaps and maintained its round configuration when compressed in one direction. Seven devices were successfully implanted in the canine model with complete seal without thrombus. Histologic examination showed complete neointima covering with minimal inflammation at 60 days. Conclusions. Preclinical testing demonstrated the conformability of the CLAAS implant and its ability to seal the LAA. Clinical studies are ongoing to characterize the utility of the CLAAS implant in the treatment of patients with atrial fibrillation.

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Percutaneous left atrial appendage closure with a novel self-modelizing device: A pre-clinical feasibility study

Cited by 13 publications

References 22 publications

Response of Endothelial Cells to Gelatin-Based Hydrogels

Response of Endothelial Cells to Gelatin-Based Hydrogels

Safety and feasibility of left atrial appendage inversion in swine: A proof-of-concept study for potential therapy to prevent embolic stroke

Preclinical Assessment of a Novel Conformable Foam‐Based Left Atrial Appendage Closure Device

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