Technical Aspects and Development of Transcatheter Aortic Valve Implantation

J Cardiovasc Dev Dis. 2022 Aug 22;9(8):282. doi: 10.3390/jcdd9080282.

ABSTRACT

Aortic stenosis is the most common valve disease requiring surgery or percutaneous treatment. Since the first-in-man implantation in 2002 we have witnessed incredible progress in transcatheter aortic valve implantation (TAVI). In this article, we review the technical aspects of TAVI development with a look at the future. Durability, low thrombogenicity, good hydrodynamics, biocompatibility, low catheter profile, and deployment stability are the attributes of an ideal TAVI device. Two main design types exist-balloon-expandable and self-expanding prostheses. Balloon-expandable prostheses use a cobalt-chromium alloy frame providing high radial strength and radiopacity, while the self-expanding prostheses use a nickel-titanium (Nitinol) alloy frame, which expands to its original shape once unsheathed and heated to the body temperature. The valve is sewn onto the frame and consists of the porcine or bovine pericardium, which is specially treated to prevent calcinations and prolong durability. The lower part of the frame can be covered by polyethylene terephthalate fabric or a pericardial skirt, providing better sealing between the frame and aortic annulus. The main future challenges lie in achieving lower rates of paravalvular leaks and new pacemaker implantations following the procedure, lower delivery system profiles, more precise positioning, longer durability, and a good hemodynamic profile. Patient-specific design and the use of autologous tissue might solve these issues.

PMID:36005446 | PMC:PMC9409777 | DOI:10.3390/jcdd9080282

A New Detergent for the Effective Decellularization of Bovine and Porcine Pericardia

Biomimetics (Basel). 2022 Aug 1;7(3):104. doi: 10.3390/biomimetics7030104.

ABSTRACT

Human and animal pericardia are among the most widely exploited materials suitable to repair damaged tissues in the cardiovascular surgery context. Autologous, xenogeneic (chemically treated) and homologous pericardia are largely utilized, but they do exhibit some crucial drawbacks. Any tissue treated with glutaraldehyde is known to be prone to calcification in vivo, lacks regeneration potential, has limited durability, and can result in cytotoxicity. Moreover, autologous tissues have limited availability. Decellularized biological tissues represent a promising alternative: decellularization removes cellular and nuclear components from native tissues and makes them suitable for repopulation by autologous cells upon implantation into the body. The present work aims to assess the effects of a new detergent, i.e., Tergitol, for decellularizing bovine and porcine pericardia. The decellularization procedure successfully removed cells, while preserving the histoarchitecture of the extracellular matrix. No cytotoxic effect was observed. Therefore, decellularized pericardia showed potential to be used as scaffold for cardiovascular tissue regeneration.

PMID:35997424 | PMC:PMC9397045 | DOI:10.3390/biomimetics7030104

Bovine pericardium leaflet damage during transcatheter aortic valve crimping: a study of the mechanisms

Comput Methods Biomech Biomed Engin. 2022 Aug 11:1-10. doi: 10.1080/10255842.2022.2110378. Online ahead of print.

ABSTRACT

Leaflet damage has been documented to occur while deploying a transcatheter aortic valve (TAV) due to mechanical loads during the crimping procedures. In this study, the impact of compressive stress on folded leaflets was measured to investigate the mechanism of traumatic leaflet tissue damage. Numerical simulation of TAV crimping procedure was adapted to calculate stress magnitude and distribution of leaflets. A 20 mm balloon expanding short stent TAV with 0.25 mm thickness leaflets was used in the simulation. Then the calculated stresses were applied on leaflet material (bovine pericardium) samples by loading experiments. Mechanical properties evaluation combined with histological and microscopy observation were used to investigate the tissue damage. The elastic modulus and the tensile strength of the tissue began to decrease significantly at 2 MPa stress and 2.5 MPa stress, respectively. No significant differences were observed at 0-1.5 MPa stress. When the TAV was crimped to 14 Fr and 12 Fr, the 2 MPa greater areas on leaflets increased from 18.17% to 76.96%. 2 MPa compressive stress might be the threshold value for leaflet damage. The TAV crimping size should be paid attention to avoid the compressive stress higher than 2 MPa.

PMID:35951008 | DOI:10.1080/10255842.2022.2110378

The hybrid crosslinking method improved the stability and anti-calcification properties of the bioprosthetic heart valves

Front Bioeng Biotechnol. 2022 Sep 9;10:1008664. doi: 10.3389/fbioe.2022.1008664. eCollection 2022.

ABSTRACT

The bioprosthetic heart valves (BHVs) are the best option for the treatment of valvular heart disease. Glutaraldehyde (Glut) is commonly used as the golden standard reagent for the crosslinking of BHVs. However, the obvious defects of Glut, including residual aldehyde toxicity, degradation and calcification, increase the probability of valve failure in vivo and motivated the exploration of alternatives. Thus, the aim of this study is to develop a non-glutaraldehyde hybrid cross-linking method composed of Neomycin Trisulfate, Polyethylene glycol diglycidyl ether and Tannic acid as a substitute for Glut, which was proven to reduce calcification, degradation, inflammation of the biomaterial. Evaluations of the crosslinked bovine pericardial included histological and ultrastructural characterization, biomechanical performance, biocompatibility and structural stability test, and in vivo anti-inflammation and anti-calcification assay by subcutaneous implantation in juvenile Sprague Dawley rats. The results revealed that the hybrid crosslinked bovine pericardial were superior to Glut crosslinked biomaterial in terms of better hydrophilicity, thermodynamics stability, hemocompatibility and cytocompatibility, higher Young’s Modulus, better stability and resistance to enzymatic hydrolysis, and lower inflammation, degradation and calcification levels in subcutaneous implants. Considering all above performances, it indicates that the hybrid cross-linking method is appropriate to replace Glut as the method for BHV preparation, and particularly this hybrid crosslinked biomaterials may be a promising candidate for next-generation BHVs.

PMID:36159659 | PMC:PMC9500414 | DOI:10.3389/fbioe.2022.1008664

Mitral Valve Replacement: A Review of Current Practices and Considerations in Low and High-Risk Patients

Curr Probl Cardiol. 2022 Sep 22:101413. doi: 10.1016/j.cpcardiol.2022.101413. Online ahead of print.

ABSTRACT

Mitral Regurgitation (MR) is the most common form of severe valvular disease occurring in developed countries, being caused either primarily on its own or secondary to cardiac disease. Surgical intervention is required for the correction of MR, which could include the replacement or repair of the affected valve. Transcatheter Mitral Valve Replacement (TMVR) in selected patients is of increasing importance, especially after the success of Transcatheter Aortic Valve Replacement (TAVR). TMVR can be divided into three types i.e., valve-in-valve (ViV) for severe mitral valve disease, valve-in-ring (ViR) for failed surgical repairs, and valve-in-mitral annular calcifications (ViMAC) for mitral valvular disease with severe mitral annular calcifications and poor surgical criteria. The FDA approved Mitral ViV for patients with a high surgical risk in 2017, while ViR and ViMAC are still currently under consideration. The SAPIEN M3 valve is relatively new with a trans-septal system, with a success rate of 86%, and no mortality in a 30-day outcome. The Cardiovalve is a bovine pericardium device that has a dual nitinol frame with a custom surgical design to facilitate TMVR. The AHEAD trial will evaluate whether the device is safe to use in a clinical setting and how effective it is for reducing MR in these patients. The trial consists of 30 patients in which the first 5 patients showed 100% technical success and a reduction of MR. This evolution of modern medicine has assisted in many different countries, including Pakistan where there is a higher prevalence of MR and hence, a greater need to apply TMVR in clinical practice.

PMID:36155202 | DOI:10.1016/j.cpcardiol.2022.101413

Pulmonary Artery Root Replacement for Leiomyosarcoma: A Viable Thoracic Oncovascular Operation

Cureus. 2022 May 4;14(5):e24734. doi: 10.7759/cureus.24734. eCollection 2022 May.

ABSTRACT

Leiomyosarcoma of the pulmonary artery is a rare but potentially fatal disease. Due to its rarity, the treatment algorithm is not well-established. While there may be a role for both chemotherapy and radiotherapy, surgical management is the most definitive method. Unfortunately, when the disease process is advanced, surgery may not be curative. However, it may still be a palliative treatment option. In this case report, we present a patient who suffered from respiratory symptoms that were initially attributed to pulmonary embolism (PE). However, upon the diagnosis of pulmonary artery leiomyosarcoma (PAL), surgery intervention was undertaken and resulted in an improved quality of life for the patient.

PMID:35673312 | PMC:PMC9165929 | DOI:10.7759/cureus.24734

Aneurysmal degeneration of the hood of a cryopreserved vein allograft two years after thrombosis

J Vasc Surg Cases Innov Tech. 2022 May 3;8(2):300-304. doi: 10.1016/j.jvscit.2022.04.002. eCollection 2022 Jun.

ABSTRACT

Cryopreserved vein allografts are used as alternative conduits for infrainguinal bypass but are prone to aneurysmal degeneration. A 60-year-old man presented with a pulsatile, tender right groin mass 2 years after thrombosis of a cryopreserved vein jump graft emanating from a prosthetic axillary to profunda bypass. Intraoperatively, the aneurysm was consistent with isolated dilatation of the hood of the thrombosed cryopreserved vein graft. This was excised and repaired with bovine pericardial patch angioplasty. The patient recovered with no recurrence for 2 years. Aneurysmal degeneration of the cryopreserved vein allograft can occur even after graft thrombosis.

PMID:35669278 | PMC:PMC9166410 | DOI:10.1016/j.jvscit.2022.04.002

Outcomes of aortic root enlargement during isolated aortic valve replacement

J Card Surg. 2022 Aug;37(8):2389-2394. doi: 10.1111/jocs.16645. Epub 2022 May 22.

ABSTRACT

OBJECTIVES: Aortic root enlargement (ARE) lowers the risk of patient prosthesis mismatch after surgical aortic valve replacement (SAVR) in patients with small annular size. Whether ARE is associated with increased operative mortality is controversial. This study compares the early and intermediate outcomes in patients undergoing SAVR with and without ARE.

METHODS: All patients undergoing isolated SAVR with and without ARE from 2015 to 2020 were analyzed. Propensity-matching was used to adjust for possible confounding variables. Kaplan-Meier analysis and log-rank test were used to estimate and compare overall outcomes and survival in the study cohorts.

RESULTS: Among 868 isolated SAVRs, ARE was performed in 54 (6.2%) patients. Before matching, mean age was similar but female sex (67.4% vs. 29.6%; SD: -0.82) and previous AVR (18.9% vs. 3.9%; SD: -0.48) were more common in patients undergoing SAVR + ARE versus SAVR alone. A bovine pericardial patch was used for 81.5% (44 of 54) of ARE, with a Dacron patch in the rest. After propensity matching, the average cardiopulmonary bypass (138.2 ± 34.9 vs. 102.9 ± 33.0 min; p < 0.01) and cross-clamp times (113.8 ± 26.7 vs. 83.0 ± 28.4 min; p < 0.01) were longer in the SAVR + ARE group. There were no significant differences in postoperative stroke, new-onset dialysis, pacemaker placement, reoperation for bleeding, length of hospital stay, or 30-day readmission. Thirty-day mortality (0% vs. 0.6%, p = 1.0) and 5-year survival (96.3% vs. 95.7%, p = 0.86) were also similar.

CONCLUSIONS: ARE during surgical AVR can be safely performed without an increase in complications with excellent early and intermediate-term survival.

PMID:35598292 | DOI:10.1111/jocs.16645

Repair of Gerbode defect and aortic neocuspidization by using bovine pericardium in aortic valve endocarditis

Turk Gogus Kalp Damar Cerrahisi Derg. 2022 Apr 27;30(2):264-266. doi: 10.5606/tgkdc.dergisi.2022.22797. eCollection 2022 Apr.

ABSTRACT

Aortic valve endocarditis may be destructive and cause an acquired Gerbode-type defect. The use of biological material in the closure of the Gerbode defect and reconstruction of the aortic valve is essential for both early and long-term survival. Herein, we present a 62-year-old male patient whose Gerbode defect was repaired with bovine pericardium. Additionally, the aortic valve was reconstructed by using bovine pericardium with Ozaki neocuspidization technique.

PMID:36168582 | PMC:PMC9473595 | DOI:10.5606/tgkdc.dergisi.2022.22797

Insertion of durable left ventricular assist device with repair of ischemic ventricular septal rupture

J Card Surg. 2022 Nov;37(11):3896-3898. doi: 10.1111/jocs.16952. Epub 2022 Sep 18.

ABSTRACT

BACKGROUND: A 63-year-old male who presented with acute anterior wall myocardial infarction with ischemic ventricular septal defect (VSD) required veno-arterial extracorporeal membrane oxygenation support due to a profoundly reduced left ventricular function.

METHOD AND RESULS: The VSD was closed with a large bovine pericardial patches. Another Dacron patch was used to close the defect on the anterior wall. The inflow cannula of the left ventricular assist device (LVAD) was sewn to the Dacron patch to secure hemostasis and to maintain the cavity in the left ventricle. The Dacron patch beneath the inflow cuff was then incised, then the LVAD was connected.

CONCLUSIONS: we described a case of concomitant insertion of durable LVAD and repair of ischemic VSD utilizing multiple patches.

PMID:36116061 | DOI:10.1111/jocs.16952