Month: May 2024

J Mech Behav Biomed Mater. 2024 Jun;154:106441. doi: 10.1016/j.jmbbm.2024.106441. Epub 2024 Mar 7.

ABSTRACT

Valvular structural deterioration is of particular concern for transcatheter aortic valve replacements due to their suspected shorter longevity and increasing use in younger patient populations. In this work we investigated the mechanical and microstructural changes in commercial TAVR valves composed of both glutaraldehyde fixed bovine and porcine pericardium (GLBP and GLPP) following accelerated wear testing (AWT) as outlined in ISO 5840 standards. This provided greater physiological relevance to the loading compared to previous studies and by utilizing digital image correlation we were able to obtain strain contours for each leaflet pre and post fatigue and identify sites of fatigue damage. The areas of greatest change in mechanical strain for each leaflet were then further probed using biaxial tensile testing, confocal microscopy, and electron microscopy. It was observed that overall strain decreased in the GLPP valves following AWT of 200 million cycles while the GLBP valve showed an increase in overall strain. Biaxial tensile testing showed a statistically significant reduction in stress for GLPP while no significant changes were seen for GLBP. Both confocal and electron microscopy showed a disruption to the gross collagen organization and fibrillar structure, including fragmentation, for GLPP but only the former for GLBP. However, further test data is required to confirm these findings and to provide a better understanding of this fatigue pathway is required such that it can be incorporated into both valve design and selection processes to improve overall longevity for both GLPP and GLBP devices.

PMID:38518510 | DOI:10.1016/j.jmbbm.2024.106441

J Vasc Surg Cases Innov Tech. 2024 Jan 17;10(2):101405. doi: 10.1016/j.jvscit.2023.101405. eCollection 2024 Apr.

ABSTRACT

Fractures and dislocations of the sternoclavicular joint (SCJ) are uncommon, accounting for <5% of all shoulder girdle injuries. They are relatively more common in the pediatric population than in the adult population and can often present concurrently as a posteriorly displaced medial clavicular dislocation with a fracture through the unfused physis. It is especially important to recognize this injury, because its management and potential sequelae are very different from those for fractures of the clavicle shaft. This type of injury frequently requires closed or open operative management because fracture-dislocation of the SCJ can be associated with potentially serious complications such as pneumothorax, brachial plexus injury, vagus nerve injury, tracheal injury, and vascular compromise. Few case reports describe fracture-dislocation of the SCJ resulting in vascular injuries. We describe the case of a 17-year-old boy who sustained a blunt hockey injury resulting in a right physeal fracture-dislocation of the SCJ causing an innominate artery pseudoaneurysm. This was treated with excision of the pseudoaneurysm, bovine pericardial patch angioplasty repair of the innominate artery, and open reduction and internal fixation of the medial clavicular physeal fracture.

PMID:38379617 | PMC:PMC10877183 | DOI:10.1016/j.jvscit.2023.101405

Vasc Endovascular Surg. 2024 Apr 19:15385744241249291. doi: 10.1177/15385744241249291. Online ahead of print.

ABSTRACT

This case report highlights the successful application of a robotic-assisted surgical approach in managing Nutcracker syndrome. The patient, a 36-year-old female presented with severe symptoms and underwent robotic left renal vein transposition after failing conservative management. The procedure was performed through a minimally invasive approach utilizing the Da Vinci robotic system™ which offers enhanced visualization and precision. However, challenges arose during the renal vein anastomosis due to tension and poor flow through the transposition, requiring two revisions with a bovine pericardial patch. Ultimately, an 8 mm ringed PTFE bypass was anastomosed from the distal left renal vein to the Inferior Vena Cava. Despite these challenges, the patient experienced a successful outcome with complete symptom resolution of this complicated pathology.

PMID:38641903 | DOI:10.1177/15385744241249291