The purpose of this study was to introduce a new feasible and effective intraoperative localization technique for small peripheral pulmonary nodules in hybrid operating room.
Category: General
Surgical correction of total anomalous pulmonary venous return in an adult patient
Total anomalous pulmonary venous return (TAPVR) is rare congenital heart disease. Most TAPVRs require surgical corrections in the neonatal period and survival to adulthood without surgical correction is extrem… Read More
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
A case report of an unusual mycotic pseudoaneurysm of the ascending aorta
Mycotic pseudoaneurysms of the ascending aorta are a rare and devastating complication of previous cardiac surgery.
Successful treatment with femoro-femoral venovenous extracorporeal membrane oxygenation in traumatic tracheal injury: a case report
Traumatic tracheal injury is a rare type of trauma. In this type of injury, catastrophes may occur owing to a failure to secure the patient’s airway. Extracorporeal membrane oxygenation (ECMO) is rescue therap… Read More
Is cardiopulmonary bypass standby still required for laser lead extractions?
Over the last two decades there has been an increase in the number of cardiac implantable electronic devices and consequently, there has also been an increased need for lead extractions. Fibrotic attachments d… Read More
Minimising chemical crosslinking for stabilising collagen in acellular bovine pericardium: Mechanistic insights via structural characterisations
Acta Biomater. 2022 Aug 30:S1742-7061(22)00540-2. doi: 10.1016/j.actbio.2022.08.057. Online ahead of print.
ABSTRACT
Chemically crosslinked acellular bovine pericardium (ABP) has been widely used in clinical practice as bioprostheses. To ensure its consistency and durability, crosslinkers are used in excess, with stability guided by indicators including the hydrothermal denaturation temperature, the enzymatic resistance and the degree of crosslinking. Yet, understanding of the intermolecular structure in collagen fibrils which imparts the intrinsic stability of the ABPs is lacking, and the discrepancies in the stability criteria in varied conditions are poorly explained. In this study, synchrotron small-angle X-ray scattering (SAXS) in combination with thermal and colorimetric methods are employed to investigate the changes in the structure and the stability of ABPs during crosslinking using glutaraldehyde (GA) or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) at different concentrations. Based on the findings, a mechanism is proposed to explicate the crosslinking effects on collagen structure and the relationship between the structure and each stability indicator. At low crosslinker concentrations, the telopeptidyl-helical linkages are preferred, which cause rearrangements in the intermolecular structure of collagen, and efficiently contribute to its stabilities. Excess crosslinking is revealed by a revert trend in structural changes and the plateauing of the stabilities, assigning to the helical-helical linkages and monovalent bindings. The former would improve thermal stability but not collagenase resistance, whereas the latter have negligible effects. Overall, this study provides a mechanistic understanding of the chemical crosslinking of ABPs, which will contribute to the future development of more efficient and economically viable strategies to produce bioprostheses. STATEMENT OF SIGNIFICANCE: Chemical crosslinking imparts suitable properties to acellular bovine pericardium (ABP) for clinical applications, yet the understanding is lacking on the structure-stability relationship especially under different crosslinking conditions. Structural evidence in this study differentiates the binding sites during crosslinking in collagen fibrils at different crosslinker concentrations, highlighting the excess usage in the conventional crosslinking treatments. The mechanism based on the structure of collagen also successfully explains the dissimilarity in hydrothermal and enzymatic stabilities with varied crosslinking conditions. Future researches focusing on developing biomaterials via chemical crosslinking of ABPs would benefit from this study, for its contribution to the better understanding of the relationship of collagen structure and functions.
PMID:36049624 | DOI:10.1016/j.actbio.2022.08.057
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