Alex Kossar

Columbia University | CU · Department of Surgery

Bioprosthetic heart valves (BHVs) largely circumvent the need for long‐term anticoagulation compared with mechanical valves but are increasingly susceptible to deterioration and reduced durability with reoperation rates of ≈10% and 30% at 10 and 15 years, respectively. Structural valve degeneration is a common, unpreventable, and untreatable conseq...

Conjugate gaze deviation is associated with acute ischemic stroke (AIS), although previously only measured on a 2D plane. The current study evaluates 3D imaging efficacy to assess conjugate gaze deviation and correlate direction and strength of deviation to neuro-clinical findings.A retrospective analysis of 519 patients who had CT scans for suspec...

Valvular heart diseases are associated with significant cardiovascular morbidity and mortality, and often require surgical and/or percutaneous repair or replacement. Valve replacement is limited to mechanical and biological prostheses, the latter of which circumvent the need for lifelong anticoagulation but are subject to structural valve degenerat...

Myxomatous mitral valve degeneration (MMVD) is a leading cause of valve repair or replacement secondary to the production of mitral regurgitation, cardiac enlargement, systolic dysfunction, and heart failure. The pathophysiology of myxomatous mitral valve degeneration is complex and incompletely understood, but key features include activation and t...

Background Staphylococcal (SA), Streptococcal (SC), and Enterococcal (EC) left-sided Infective Endocarditis (IE) are associated with poor clinical outcomes. Our primary aim is to compare clinical outcomes of SA, SC, and EC IE patients who undergo valve replacement surgery with patients treated solely with antibiotics. Methods All patients were tre...

Aorto-right ventricular fistulae have been thoroughly documented as a rare but potentially serious complication of surgical aortic valve replacement. The risk factors and pathogenesis contributing to this complication with respect to transcatheter aortic valve replacement (TAVR), however, remain far less characterized. Here we describe a post-TAVR...

Aortic insufficiency (AI) or regurgitation is caused by the malcoaptation of the aortic valve (AV) cusps due to intrinsic abnormalities of the valve itself, a dilatation or geometric distortion of the aortic root, or by some combination thereof. In recent years, there has been an increase in the number of studies suggesting that AI is an active dis...

Background Aortic valve sclerosis is a highly prevalent, poorly characterized asymptomatic manifestation of calcific aortic valve disease, and may represent a therapeutic target for disease mitigation. Methods Human aortic valve cusps and blood were obtained from 333 patients undergoing cardiac surgery (n=236 for severe aortic stenosis, n=35 for as...

Background Bioprosthetic heart valves (BHV) are widely used to treat heart valve disease but are fundamentally limited by structural valve degeneration (SVD). Non-calcific mechanisms of SVD entirely account for approximately 30% of SVD cases and contribute to calcific SVD but remain understudied. Glycation mechanisms have not been previously associ...

The management of bioprosthetic structural valve degeneration requires complex surgical or transcatheter re‐intervention for which many high‐risk patients are not considered candidates. Here, we describe a technique for a direct surgical access valve‐in‐valve implantation in patients with complex bioprosthetic valvulopathy for whom standard surgica...

OBJECTIVES Standard donor lung assessment relies on imaging, challenge gases and subjective interpretation of bronchoscopic findings, palpation and visual assessment. Central gases may not accurately represent true quality of the lungs. We report our experience using selective pulmonary vein gases to corroborate the subjective judgement. METHODS S...

OBJECTIVES End-stage lung disease continues to rise despite the lack of suitable lung donors, limiting the numbers of lung transplants performed each year. Expanded donor criteria, use of donation after cardiac death donors and the advent of ex vivo lung perfusion have resulted only in a slight increase in donor lung utilization. Organ donors with...

Acute kidney injury (AKI) is a significant complication of surgical aortic valve replacement (SAVR). This study sought to describe AKI following SAVR, its risk factors, predictors and effect on long-term survival. We retrospectively reviewed 2169 patients who underwent isolated SAVR between 2000 and 2012. The main end-points were occurrence of AKI,...

Advancements in technology for the treatment of valvularcardiac diseases seek to provide solutions for high risk patients in the form of percutaneous valve insertion for patients with complicated valvular disease not amenable to more traditional options. Within the last decade, cardiac valves designed for percutaneous insertion have emerged rapidly...

Valvular heart disease affects millions of Americans yearly and currently requires surgical intervention to repair or replace damaged or defective valves. Through a close-knit collaboration between physicians, scientists and biomedical engineers, a vast degree of research and development has been aimed towards the optimization of prosthetic heart v...

Valvular heart disease, inherited or acquired, affects more than 5 million Americans yearly. Whereas medical treatment is beneficial in the initial stages of valvular heart disease; surgical correction provides symptomatic relief and long-term survival benefits. Surgical options include either repair or replacement using mechanical or bio-prostheti...

Patients in cardiogenic shock require immediate circulatory support. Outcomes of patients who underwent short-term ventricular assist device (STVAD) implantation in a community hospital (CH) as a bridge to a long-term VAD (LTVAD) were compared with those who received both implants at the same tertiary hospital (TH). Data were retrospectively review...