This document discusses the history and evolution of mechanical heart valve substitutes from the 1950s to the present. It describes early ball and cage valves developed by Harken and Starr-Edwards in the 1950s-60s that helped ignite the field of prosthetic heart valves but had limitations. It then covers the development of tilting disc valves including the Bjork-Shiley valve that was later recalled due to failures, and bileaflet valves such as the St. Jude Medical valve made of durable pyrolytic carbon. The document traces the materials, designs and improvements made to mechanical heart valves over decades to increase effectiveness and safety.
The document discusses different types of mechanical heart valves that have been developed over time to replace dysfunctional natural heart valves. It begins by describing the function of natural heart valves and reasons for their replacement. Early mechanical designs like the ball-and-cage valve and tilting disk valves are outlined, followed by modern bileaflet valves. The materials used in heart valves and modes of failure are also covered. Overall the document provides a history of mechanical heart valve design and materials as well as considerations for evaluating prosthetic heart valves.
This document discusses the history and development of coronary stents. It notes that the introduction of angioplasty led to the development of stents to address the problem of restenosis. Early stents were bare metal, but drug-eluting stents were developed to further reduce restenosis rates by preventing neointimal growth. The document covers the various types of stents developed over time including differences in materials, coatings, and platforms. It also discusses the rationale for biodegradable stents which aim to eliminate complications from permanent metal implants.
A 50-year-old man with no comorbidities requires aortic valve replacement. Either a mechanical or bioprosthetic valve could be used. A mechanical valve would require lifelong anticoagulation therapy. It would have a low risk of structural deterioration but higher risks of bleeding, thromboembolism, and reoperation. A bioprosthetic valve would avoid anticoagulation but have a higher risk of structural deterioration requiring reoperation. Long-term outcomes must be considered based on the patient's age, lifestyle, and risk tolerance for anticoagulation versus structural failure.
Prosthetic heart valves have evolved significantly over the past 70 years from early caged ball designs to modern bileaflet valves. Present day valves include mechanical options like the St. Jude bileaflet valve as well as bioprosthetic options derived from animal tissues like the Medtronic Mosaic porcine valve. Complications remain an issue, though designs aim to improve hemodynamics and reduce thrombosis. Future advances may allow reduced anticoagulation needs.
This document describes procedures for aortic valve replacement and repair. It discusses excising the native aortic valve and implanting a prosthetic valve using sutures placed around the annulus. For small annuli, the aortic root can be enlarged using techniques like the Nicks-Nunez or Konno-Rastan methods which involve patching the aortic wall. The document also outlines techniques for reconstructing valves, including patching leaflet perforations or tears.
classification of mechanical valves, types of caged ball valve, single leaflet valve , tilting disc valve, bileaflet valve, ttk chitra valve,ST jude valve, ATS ap valve, On x valve ,carbomedics,
This document discusses the history and types of prosthetic heart valves. It notes that the first successful open heart surgery using cardiopulmonary bypass was in 1953, while the first mechanical replacement valve was implanted in 1960. There are two main types of prosthetic valves - mechanical valves and bioprosthetic valves. Mechanical valves last longer but require lifelong anticoagulation, while bioprosthetic valves do not require anticoagulation but are less durable. Both valve types can lead to complications like thrombosis, bleeding, and structural deterioration over time.
History of cardiac surgery DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG ,DNB CTS SR)DR NIKUNJ SHEKHADA
The document provides a history of cardiac surgery from the 19th century to modern times. It discusses early operations on the heart and pericardium in the 19th century. It then covers the development of anesthesia, vascular surgery, cardiac catheterization, and heart-lung bypass machines, which enabled open-heart surgery. Some key events summarized are the first successful cardiac surgery without complications in 1896, the first use of external heart-lung machines in the 1950s, the first open-heart repair under direct vision in 1952, the first coronary artery bypass surgery in 1960, and the first human heart transplant in 1967. The document also discusses the early development of heart valve surgery and prosthetic heart valves.
The document discusses different types of mechanical heart valves that have been developed over time to replace dysfunctional natural heart valves. It begins by describing the function of natural heart valves and reasons for their replacement. Early mechanical designs like the ball-and-cage valve and tilting disk valves are outlined, followed by modern bileaflet valves. The materials used in heart valves and modes of failure are also covered. Overall the document provides a history of mechanical heart valve design and materials as well as considerations for evaluating prosthetic heart valves.
This document discusses the history and development of coronary stents. It notes that the introduction of angioplasty led to the development of stents to address the problem of restenosis. Early stents were bare metal, but drug-eluting stents were developed to further reduce restenosis rates by preventing neointimal growth. The document covers the various types of stents developed over time including differences in materials, coatings, and platforms. It also discusses the rationale for biodegradable stents which aim to eliminate complications from permanent metal implants.
A 50-year-old man with no comorbidities requires aortic valve replacement. Either a mechanical or bioprosthetic valve could be used. A mechanical valve would require lifelong anticoagulation therapy. It would have a low risk of structural deterioration but higher risks of bleeding, thromboembolism, and reoperation. A bioprosthetic valve would avoid anticoagulation but have a higher risk of structural deterioration requiring reoperation. Long-term outcomes must be considered based on the patient's age, lifestyle, and risk tolerance for anticoagulation versus structural failure.
Prosthetic heart valves have evolved significantly over the past 70 years from early caged ball designs to modern bileaflet valves. Present day valves include mechanical options like the St. Jude bileaflet valve as well as bioprosthetic options derived from animal tissues like the Medtronic Mosaic porcine valve. Complications remain an issue, though designs aim to improve hemodynamics and reduce thrombosis. Future advances may allow reduced anticoagulation needs.
This document describes procedures for aortic valve replacement and repair. It discusses excising the native aortic valve and implanting a prosthetic valve using sutures placed around the annulus. For small annuli, the aortic root can be enlarged using techniques like the Nicks-Nunez or Konno-Rastan methods which involve patching the aortic wall. The document also outlines techniques for reconstructing valves, including patching leaflet perforations or tears.
classification of mechanical valves, types of caged ball valve, single leaflet valve , tilting disc valve, bileaflet valve, ttk chitra valve,ST jude valve, ATS ap valve, On x valve ,carbomedics,
This document discusses the history and types of prosthetic heart valves. It notes that the first successful open heart surgery using cardiopulmonary bypass was in 1953, while the first mechanical replacement valve was implanted in 1960. There are two main types of prosthetic valves - mechanical valves and bioprosthetic valves. Mechanical valves last longer but require lifelong anticoagulation, while bioprosthetic valves do not require anticoagulation but are less durable. Both valve types can lead to complications like thrombosis, bleeding, and structural deterioration over time.
History of cardiac surgery DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG ,DNB CTS SR)DR NIKUNJ SHEKHADA
The document provides a history of cardiac surgery from the 19th century to modern times. It discusses early operations on the heart and pericardium in the 19th century. It then covers the development of anesthesia, vascular surgery, cardiac catheterization, and heart-lung bypass machines, which enabled open-heart surgery. Some key events summarized are the first successful cardiac surgery without complications in 1896, the first use of external heart-lung machines in the 1950s, the first open-heart repair under direct vision in 1952, the first coronary artery bypass surgery in 1960, and the first human heart transplant in 1967. The document also discusses the early development of heart valve surgery and prosthetic heart valves.
Mechanical and bioprosthetic heart valves have evolved significantly since the first prosthetic valve implantation in 1952. Modern bileaflet mechanical valves provide improved central blood flow compared to older caged ball designs. Tissue valves like porcine and pericardial valves do not require lifelong anticoagulation but have limited durability. Prosthetic heart valves are prone to complications like thrombosis, structural deterioration, endocarditis, and paravalvular leak. Careful monitoring and treatment is needed to optimize outcomes.
5 million people in the United States are diagnosed with heart valve disease annually. The four heart valves (mitral, tricuspid, aortic, pulmonary) can develop stenosis or regurgitation. This reduces blood flow and pressures heart function. Current artificial heart valves have limitations like calcification, tissue deterioration requiring replacement, and risk of thromboembolism. Future areas of research include minimally invasive valve replacement techniques, using cells to improve tissue valve biocompatibility and durability, and developing fully tissue engineered living cell valves. The ideal artificial valve would use pyrolytic carbon and expanded PTFE materials with a surface coating to reduce thrombogenicity and lower anticoagulant needs.
1) The document discusses various techniques for balloon mitral valvuloplasty (BMV), including the history of the procedure and details of specific balloon designs.
2) Key balloons described are the Inoue balloon, Accura balloon, JOMIVA balloon, and the double balloon and multi-track techniques.
3) Complications of BMV discussed include balloon rupture and strategies to prevent it, such as avoiding overinflation and slow inflation to reduce rapid stretching of balloon layers.
1) Minimally invasive cardiac surgery techniques have advanced with smaller cannulas, improved visualization tools, and robotic assistance, allowing for reduced trauma through smaller incisions.
2) Three case studies presented patients undergoing minimally invasive aortic valve replacement, mitral valve repair, and atrial septal defect repair who had short, uncomplicated hospital stays.
3) The evidence shows minimally invasive mitral valve surgery has equal outcomes to sternotomy with less post-operative pain and faster recovery, though longer bypass times, with long-term results also equivalent. It is well-suited for high-risk and re-operative patients.
Diagnostic catheters for coronary angiography Aswin Rm
Overview of diagnostic catheters used in coronary angiography
Guide catheters not included
History of coronary catheters
Radial techniques and catheters
This document discusses aortic valve stenosis, including its anatomy, function, causes, pathophysiology, classification, signs and symptoms, diagnostic evaluation, and treatment options. Key points include:
- Aortic stenosis is caused by calcification and stiffening of the aortic valve leaflets, restricting their opening and increasing the pressure gradient between the left ventricle and aorta.
- It can be congenital due to a bicuspid aortic valve or acquired from degeneration, rheumatic fever, or radiation exposure.
- Symptoms include angina, syncope, and dyspnea as the left ventricle hypertrophies and diastolic function declines in response to the increased
interventional cardiology, Guiding catheters, wires, and balloons equipment...salman habeeb
This document provides an overview of guiding catheters, guide wires, and balloons which are core equipment used in percutaneous coronary interventions (PCI). It describes the design characteristics, advantages, and disadvantages of over-the-wire and rapid exchange balloon catheters. Key attributes of balloons like entry, tracking, and compliance are defined. Guiding catheters are discussed in terms of size, shape, and selection for accessing different coronary arteries. Finally, guide wire features such as core material, coating, and tip design are reviewed alongside common wire types used in various clinical scenarios.
This document discusses the materials, design, development process, testing, and clinical use of the TTK Chitra heart valve. The key components of the valve are a frame made of cobalt chromium alloy, a tilting disc made of ultra-high molecular weight polyethylene, and a sewing ring made of polyethylene terephthalate. Extensive testing was required to develop a durable and biocompatible valve design. Over 55,000 valves have now been implanted and clinical studies show acceptable safety and effectiveness for the TTK Chitra heart valve.
Tavi,Transcatheter Aortic Valve Replacement, TAVI,TAVR,Dr.Hasan Mahmud
Transcatheter aortic valve implantation (TAVI) has been developed as an alternative to surgical aortic valve replacement for high-risk patients. TAVI involves threading a collapsible valve through blood vessels and implanting it to replace the diseased valve. Over 30,000 high-risk patients with severe aortic stenosis have undergone TAVI, based on evidence from studies showing it is safer than surgery for this group. TAVI indications may expand as longer-term data on outcomes becomes available and the procedure requires a multidisciplinary team approach and dedicated training.
This document discusses thoracic endografts and future goals for their design. It describes the challenges of treating the thoracic aorta including its pulsatile blood flow, curved anatomy, and diverse pathologies. Current endograft designs aim to provide easy deployment, exclude lesions with a good seal and fixation, be durable and conformable, and be biocompatible. Design considerations include sufficient landing zones, radial pressure of stent frames, proximal bare metal stents, and deployment methods. Future areas of research include hybrid procedures, tapered endografts, new materials, and computational modeling of blood flow to improve endograft performance.
This document discusses different designs of coronary stents. It begins by providing background on the development of coronary stents and their approval for use. It then describes some of the earliest stent designs, including the Gianturco-Roubin coil stent and the Palmaz-Schatz slotted tube stent. The document goes on to discuss various aspects of stent design that can impact performance, such as the geometric configuration, materials used, coatings, and drug-eluting capabilities. Key design considerations like strut thickness, number of struts, and mechanical properties are also reviewed.
This document discusses the intra-aortic balloon pump (IABP), including its history, principles of function, indications, anatomy, techniques of insertion and removal, and key contributors. The IABP provides temporary left ventricular support by mechanically displacing blood within the aorta. It was first developed in the 1950s and used successfully in 1967. The document outlines the physiology effects of IABP therapy in increasing myocardial oxygen supply and decreasing demand. Common indications for IABP include cardiogenic shock and high-risk coronary interventions. The document reviews IABP device components, insertion techniques, optimal catheter positioning, and complications.
This document discusses balloon aortic valvuloplasty (BAV) as a treatment for aortic stenosis. It can be performed via either a retrograde or antegrade approach. The retrograde approach involves crossing the aortic valve from the femoral artery, while the antegrade approach involves transseptal catheterization from the femoral vein. Key steps for both approaches include rapid ventricular pacing to stabilize the heart during balloon inflation. The goals of BAV are to increase the aortic valve area and reduce pressure gradients. Complications can include hypotension, aortic regurgitation, and embolization of calcium deposits. BAV provides symptomatic relief but is usually not curative, as restenosis may occur.
1) Cardiac surgery has evolved significantly from the late 19th century. Early operations on the pericardium took place in the early 19th century but were rarely successful.
2) A major breakthrough was the first successful open-heart surgery performed by John Gibbon in 1953 using the first heart-lung machine. This allowed for direct visualization and repair of cardiac structures.
3) The development of cardiopulmonary bypass by Lillehei in 1954 and the use of mechanical pumps by Kirklin further advanced cardiac surgery by allowing for longer, more complex procedures.
4) Milestones since then include the first coronary artery bypass by Favaloro in 1967, innovations in heart valve surgery and replacement,
The first successful open heart surgery using cardiopulmonary bypass was performed by Dr. Clarence Dennis in 1951 in Minnesota using open cardiotomy and bypass on dogs. The first on a human was by Dr. John Gibbon in 1953 in Philadelphia to correct an atrial septal defect. In 1954, the only place performing open heart surgery was the University of Minnesota using cross-circulation techniques. By 1955-1956, two centers performed open heart surgery - the University of Minnesota and the Mayo Clinic, with the Mayo Clinic using Gibbon's screen oxygenator and the University of Minnesota using DeWall's simpler, disposable bubble oxygenator.
I. A coronary stent is a mesh tube placed in arteries to treat heart disease and keep arteries open. It is implanted via angioplasty.
II. Stents are implanted by threading a balloon catheter into the heart and inflating the balloon to expand the stent against the artery wall.
III. While generally safe, potential risks of stents include blood clots, infection, and re-narrowing of the artery known as restenosis.
This document provides a history and overview of prosthetic heart valves. It discusses the timeline of key prosthetic valve designs from 1954 to present day. The main types of prosthetic valves covered are mechanical valves (ball & cage, tilting disc, bileaflet) and bioprosthetic/tissue valves (homograft, heterograft such as porcine). Newer technologies like stentless, percutaneous, and sutureless valves are also summarized. Valve characteristics like durability, thrombogenicity, and hemodynamics are compared for different valve types.
Evolution of valves, Identification & Key Features | IACTS SCORE 2020IACTSWeb
This presentation is a guide to the historical evolution, modifications and lessons learned in the development of heart valves. It clearly depicts how clinical indications for valve surgery has changed over the years and illustrates the identification of prosthesis and analysis of key features in images, at a time when patients present with malfunctioning valves for reoperations.
This is courtesy of Dr. Vinayak Shukla, MS, MCh, FIACS. He presently serves as Professor and Unit Chief of Cardiothoracic and Vascular Surgery at Christian Medical College and Hospital, Vellore - home to one among the first implants in Asia.
This presentation is part of a video which belongs to the lecture series of IACTS SCORE 2020 held at the Sri Sathya Sai Institute of Higher Medical Sciences Whitefield, Bengaluru between 7th and 8th March, 2020.
Mechanical and bioprosthetic heart valves have evolved significantly since the first prosthetic valve implantation in 1952. Modern bileaflet mechanical valves provide improved central blood flow compared to older caged ball designs. Tissue valves like porcine and pericardial valves do not require lifelong anticoagulation but have limited durability. Prosthetic heart valves are prone to complications like thrombosis, structural deterioration, endocarditis, and paravalvular leak. Careful monitoring and treatment is needed to optimize outcomes.
5 million people in the United States are diagnosed with heart valve disease annually. The four heart valves (mitral, tricuspid, aortic, pulmonary) can develop stenosis or regurgitation. This reduces blood flow and pressures heart function. Current artificial heart valves have limitations like calcification, tissue deterioration requiring replacement, and risk of thromboembolism. Future areas of research include minimally invasive valve replacement techniques, using cells to improve tissue valve biocompatibility and durability, and developing fully tissue engineered living cell valves. The ideal artificial valve would use pyrolytic carbon and expanded PTFE materials with a surface coating to reduce thrombogenicity and lower anticoagulant needs.
1) The document discusses various techniques for balloon mitral valvuloplasty (BMV), including the history of the procedure and details of specific balloon designs.
2) Key balloons described are the Inoue balloon, Accura balloon, JOMIVA balloon, and the double balloon and multi-track techniques.
3) Complications of BMV discussed include balloon rupture and strategies to prevent it, such as avoiding overinflation and slow inflation to reduce rapid stretching of balloon layers.
1) Minimally invasive cardiac surgery techniques have advanced with smaller cannulas, improved visualization tools, and robotic assistance, allowing for reduced trauma through smaller incisions.
2) Three case studies presented patients undergoing minimally invasive aortic valve replacement, mitral valve repair, and atrial septal defect repair who had short, uncomplicated hospital stays.
3) The evidence shows minimally invasive mitral valve surgery has equal outcomes to sternotomy with less post-operative pain and faster recovery, though longer bypass times, with long-term results also equivalent. It is well-suited for high-risk and re-operative patients.
Diagnostic catheters for coronary angiography Aswin Rm
Overview of diagnostic catheters used in coronary angiography
Guide catheters not included
History of coronary catheters
Radial techniques and catheters
This document discusses aortic valve stenosis, including its anatomy, function, causes, pathophysiology, classification, signs and symptoms, diagnostic evaluation, and treatment options. Key points include:
- Aortic stenosis is caused by calcification and stiffening of the aortic valve leaflets, restricting their opening and increasing the pressure gradient between the left ventricle and aorta.
- It can be congenital due to a bicuspid aortic valve or acquired from degeneration, rheumatic fever, or radiation exposure.
- Symptoms include angina, syncope, and dyspnea as the left ventricle hypertrophies and diastolic function declines in response to the increased
interventional cardiology, Guiding catheters, wires, and balloons equipment...salman habeeb
This document provides an overview of guiding catheters, guide wires, and balloons which are core equipment used in percutaneous coronary interventions (PCI). It describes the design characteristics, advantages, and disadvantages of over-the-wire and rapid exchange balloon catheters. Key attributes of balloons like entry, tracking, and compliance are defined. Guiding catheters are discussed in terms of size, shape, and selection for accessing different coronary arteries. Finally, guide wire features such as core material, coating, and tip design are reviewed alongside common wire types used in various clinical scenarios.
This document discusses the materials, design, development process, testing, and clinical use of the TTK Chitra heart valve. The key components of the valve are a frame made of cobalt chromium alloy, a tilting disc made of ultra-high molecular weight polyethylene, and a sewing ring made of polyethylene terephthalate. Extensive testing was required to develop a durable and biocompatible valve design. Over 55,000 valves have now been implanted and clinical studies show acceptable safety and effectiveness for the TTK Chitra heart valve.
Tavi,Transcatheter Aortic Valve Replacement, TAVI,TAVR,Dr.Hasan Mahmud
Transcatheter aortic valve implantation (TAVI) has been developed as an alternative to surgical aortic valve replacement for high-risk patients. TAVI involves threading a collapsible valve through blood vessels and implanting it to replace the diseased valve. Over 30,000 high-risk patients with severe aortic stenosis have undergone TAVI, based on evidence from studies showing it is safer than surgery for this group. TAVI indications may expand as longer-term data on outcomes becomes available and the procedure requires a multidisciplinary team approach and dedicated training.
This document discusses thoracic endografts and future goals for their design. It describes the challenges of treating the thoracic aorta including its pulsatile blood flow, curved anatomy, and diverse pathologies. Current endograft designs aim to provide easy deployment, exclude lesions with a good seal and fixation, be durable and conformable, and be biocompatible. Design considerations include sufficient landing zones, radial pressure of stent frames, proximal bare metal stents, and deployment methods. Future areas of research include hybrid procedures, tapered endografts, new materials, and computational modeling of blood flow to improve endograft performance.
This document discusses different designs of coronary stents. It begins by providing background on the development of coronary stents and their approval for use. It then describes some of the earliest stent designs, including the Gianturco-Roubin coil stent and the Palmaz-Schatz slotted tube stent. The document goes on to discuss various aspects of stent design that can impact performance, such as the geometric configuration, materials used, coatings, and drug-eluting capabilities. Key design considerations like strut thickness, number of struts, and mechanical properties are also reviewed.
This document discusses the intra-aortic balloon pump (IABP), including its history, principles of function, indications, anatomy, techniques of insertion and removal, and key contributors. The IABP provides temporary left ventricular support by mechanically displacing blood within the aorta. It was first developed in the 1950s and used successfully in 1967. The document outlines the physiology effects of IABP therapy in increasing myocardial oxygen supply and decreasing demand. Common indications for IABP include cardiogenic shock and high-risk coronary interventions. The document reviews IABP device components, insertion techniques, optimal catheter positioning, and complications.
This document discusses balloon aortic valvuloplasty (BAV) as a treatment for aortic stenosis. It can be performed via either a retrograde or antegrade approach. The retrograde approach involves crossing the aortic valve from the femoral artery, while the antegrade approach involves transseptal catheterization from the femoral vein. Key steps for both approaches include rapid ventricular pacing to stabilize the heart during balloon inflation. The goals of BAV are to increase the aortic valve area and reduce pressure gradients. Complications can include hypotension, aortic regurgitation, and embolization of calcium deposits. BAV provides symptomatic relief but is usually not curative, as restenosis may occur.
1) Cardiac surgery has evolved significantly from the late 19th century. Early operations on the pericardium took place in the early 19th century but were rarely successful.
2) A major breakthrough was the first successful open-heart surgery performed by John Gibbon in 1953 using the first heart-lung machine. This allowed for direct visualization and repair of cardiac structures.
3) The development of cardiopulmonary bypass by Lillehei in 1954 and the use of mechanical pumps by Kirklin further advanced cardiac surgery by allowing for longer, more complex procedures.
4) Milestones since then include the first coronary artery bypass by Favaloro in 1967, innovations in heart valve surgery and replacement,
The first successful open heart surgery using cardiopulmonary bypass was performed by Dr. Clarence Dennis in 1951 in Minnesota using open cardiotomy and bypass on dogs. The first on a human was by Dr. John Gibbon in 1953 in Philadelphia to correct an atrial septal defect. In 1954, the only place performing open heart surgery was the University of Minnesota using cross-circulation techniques. By 1955-1956, two centers performed open heart surgery - the University of Minnesota and the Mayo Clinic, with the Mayo Clinic using Gibbon's screen oxygenator and the University of Minnesota using DeWall's simpler, disposable bubble oxygenator.
I. A coronary stent is a mesh tube placed in arteries to treat heart disease and keep arteries open. It is implanted via angioplasty.
II. Stents are implanted by threading a balloon catheter into the heart and inflating the balloon to expand the stent against the artery wall.
III. While generally safe, potential risks of stents include blood clots, infection, and re-narrowing of the artery known as restenosis.
This document provides a history and overview of prosthetic heart valves. It discusses the timeline of key prosthetic valve designs from 1954 to present day. The main types of prosthetic valves covered are mechanical valves (ball & cage, tilting disc, bileaflet) and bioprosthetic/tissue valves (homograft, heterograft such as porcine). Newer technologies like stentless, percutaneous, and sutureless valves are also summarized. Valve characteristics like durability, thrombogenicity, and hemodynamics are compared for different valve types.
Evolution of valves, Identification & Key Features | IACTS SCORE 2020IACTSWeb
This presentation is a guide to the historical evolution, modifications and lessons learned in the development of heart valves. It clearly depicts how clinical indications for valve surgery has changed over the years and illustrates the identification of prosthesis and analysis of key features in images, at a time when patients present with malfunctioning valves for reoperations.
This is courtesy of Dr. Vinayak Shukla, MS, MCh, FIACS. He presently serves as Professor and Unit Chief of Cardiothoracic and Vascular Surgery at Christian Medical College and Hospital, Vellore - home to one among the first implants in Asia.
This presentation is part of a video which belongs to the lecture series of IACTS SCORE 2020 held at the Sri Sathya Sai Institute of Higher Medical Sciences Whitefield, Bengaluru between 7th and 8th March, 2020.
prostheticvalvesthepastpresentandfuture-itammiraju-140413095625-phpapp01 (1).pdfSittie Ali
Prosthetic heart valves have evolved significantly over the past 70 years from early caged ball designs to modern bileaflet valves. Present day valves include mechanical options like the St. Jude bileaflet valve as well as bioprosthetic options derived from animal tissues like the Medtronic Mosaic porcine valve. Complications remain an issue, though designs aim to improve hemodynamics and reduce thrombosis. Future advances may allow reduced anticoagulation needs.
1. The document discusses the history and evolution of prosthetic heart valves from the first mechanical valve designed in 1954 to current bioprosthetic and transcatheter valves.
2. Key events and innovators discussed include the first successful aortic valve replacement in 1960 by Dwight Harken and the development of the Starr-Edwards ball-in-cage valve in the 1960s.
3. The major types of prosthetic heart valves covered are mechanical valves (ball-in-cage, tilting disk, bileaflet), bioprosthetic valves (homograft, autograft, heterograft), and newer transcatheter valves.
This document summarizes different types of artificial heart valves, including ball valves, disk valves, and tissue valves. It describes early valve designs like the Starr-Edwards ball valve and discusses both advantages and disadvantages of different valve materials and designs. Key valve types summarized are the Hancock and Carpentier-Edwards porcine and pericardial valves, which are commonly used tissue valves today. Guidelines for anticoagulation and prevention of bacterial endocarditis in patients with artificial heart valves are also briefly outlined.
The document discusses different types of mechanical heart valves that have been developed over time to replace dysfunctional natural heart valves. It describes early valve designs like the ball-and-cage Starr-Edwards valve and the tilting disc Bjork-Shiley valve. More modern bileaflet valves are also discussed. The key materials used in heart valves include metals for strength as well as pyrolytic carbon and polymers which are durable and promote blood compatibility. Researchers continue working to improve valve lifespan, reduce risk of blood clots, and develop less invasive implantation methods.
Echocardiographic recognition, function and dysfunction of prosthetic heart v...soumenprasad
The document discusses echocardiographic recognition, function, and dysfunction of prosthetic heart valves. It begins by classifying prosthetic heart valves into mechanical valves, which are made of non-biological materials, and tissue (bioprosthetic) valves, which are made from human or animal tissue. It then describes the echocardiographic evaluation of normal functioning prosthetic heart valves and provides guidance on assessing prosthetic valves in the aortic, mitral, pulmonary, and tricuspid positions. The document concludes by discussing potential prosthetic valve dysfunction and limitations of echocardiography for assessment.
This document provides a history of heart valve substitutes, beginning with the first implantation of homografts in the 1950s-1960s and moving to the development of xenograft valves fixed with glutaraldehyde in the 1960s-1970s. It discusses the work of Carpentier in developing low-pressure fixation and mechanical protection of valves. Various generations of bioprosthetic valves are summarized, including advances in fixation methods and anti-mineralization treatments. Stentless valves are introduced, providing improved hemodynamics over stented valves but requiring more complex implantation.
The document discusses oxyacetylene welding (OAW). OAW uses oxygen and acetylene gases to produce a high-temperature flame. It requires manually controlling the torch. Equipment includes cylinders storing oxygen and acetylene at high pressures, regulators to reduce pressure, and hoses. Safety devices like flashback arrestors are used. The document also covers cylinder transportation, flame types, welding procedures, and quiz questions/answers on OAW topics.
This document summarizes the history and evolution of hip replacement surgery. It discusses early attempts at hip replacement in the 1840s using wooden blocks. Modern hip replacement surgery began in the 1920s with mould arthroplasty to reshape damaged bone. A variety of materials were then tested for the joint replacement components, including glass, plastics, alloys. Key developments included the first total hip replacement using stainless steel in 1938, the introduction of polyethylene and metal-on-metal designs in the 1960s, and the first ceramic-on-ceramic design in 1970. The document outlines different bearing material options for modern hip replacements and their advantages and disadvantages.
The document discusses oxyacetylene welding (OAW). OAW uses oxygen and acetylene gases to produce a high-temperature flame for welding. It involves manually controlling the torch and adding filler rods. The equipment needed includes oxygen and acetylene gas cylinders, regulators to reduce pressure, hoses to carry gases, and torches. Safety devices like flashback arrestors are also discussed. The document provides details on cylinder storage, transportation, valves, regulators, pressures, and starting procedures. It describes flame types and settings used for different materials and thicknesses.
This document provides an overview of well testing equipment and procedures used by Power Well Service Groups and Halliburton to evaluate oil and gas reservoirs. It begins by expressing appreciation for the companies providing well testing presentation materials. It then covers various types of well testing equipment like drill stem testing tools and surface testing packages. The remainder of the document discusses objectives and details of drill stem testing and describes components of typical open hole and cased hole drill stem testing systems. It also covers surface well testing facilities, data acquisition systems, reporting formats, and emergency shutdown systems.
The evolution of shoulder arthroplasty has progressed through several generations of prosthesis designs from the late 19th century to present day. Early designs in the 1890s-1950s aimed to replicate the native anatomy but had high failure rates due to issues like wear, loosening, and infection. Modular designs in the 1980s improved positioning and sizing but still did not fully restore anatomy. Current third generation prostheses from the 1990s onward are anatomically designed with variable sizes and offsets to more closely mimic the native joint mechanics and center of rotation. Reverse total shoulder arthroplasty, developed in the 1970s-1990s, has also improved through lateralized and inferiorly tilted component designs to maximize deltoid function for patients with rotator c
This document discusses the history and evolution of spine instrumentation. It describes various instrumentation techniques for the cervical, thoracic, and lumbar spine, including Harrington rods, Luque rods, Cotrel-Dubousset systems, pedicle screws, and lateral mass screws. Key developments include the introduction of segmental fixation, hooks and wires, pedicle screws, and dynamic stabilization systems. Placement techniques are outlined for lateral mass screws, pedicle screws, and laminar hooks.
This document provides an overview of screws in orthopedic surgery. It discusses the history of screw development from ancient times through modern innovations in materials. The anatomy of a screw is described in detail, including the head, shaft, thread, tip, and special features like pitch, diameter, and cannulation. Different types of screws are compared based on their properties and intended uses in cortical versus cancellous bone. Special screw designs like Herbert screws, lag screws, and dynamic hip screws are also briefly mentioned.
This document provides an overview of the history and development of x-ray tubes. It describes how early x-ray tubes evolved from Crookes tubes used in the late 1800s to the modern rotating anode x-ray tube. The key components of modern x-ray tubes are discussed, including the cathode, anode, housing, and high voltage connections. Different types of x-ray tubes such as those used for mammography, radiotherapy, and CT are also covered. The document concludes with sections on x-ray tube ratings, common causes of tube failure, and tips for proper care of x-ray tubes.
The document discusses gas welding using oxyacetylene, including descriptions of the equipment such as oxygen and acetylene cylinders, regulators, hoses, check valves and flashback arrestors. It also covers topics like cylinder transportation, regulator pressure settings, startup procedures, and the different types of oxyacetylene flames including neutral, carburizing, and oxidizing flames.
Similar to Mechanical heart valve substitutes (20)
This document discusses weaning from mechanical ventilation. It defines key terms like liberation, extubation, spontaneous breathing trials (SBT), and weaning success and failure. It describes the process of conducting an SBT to assess readiness for extubation. Factors that can lead to weaning failure like respiratory load, cardiac load, neuromuscular issues, and psychological factors are reviewed. Finally, it discusses using different ventilator modes like pressure support ventilation to aid in more difficult weaning cases.
Tracheostomy is an artificial opening created in the trachea in the neck to allow access to the lower airway. It has major indications for preventing laryngeal damage from prolonged intubation, managing secretions, and providing stable airway access for prolonged mechanical ventilation. The techniques include open surgical and percutaneous dilatational tracheostomy. Early tracheostomy within 7 days of cardiac surgery has been shown to improve outcomes compared to late tracheostomy by reducing atrial fibrillation, kidney dysfunction, ICU stay, and hospital stay with no increase in mortality or infections. Complications can occur during surgery or post-operatively including hemorrhage, pneumothorax, nerve injury, and infections. Care involves tube
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3. Surgical options include repair of associated defects while maintaining discordance, or an anatomic repair to place the morphological left ventricle as the systemic ventricle. The approach depends on the severity of lesions and individual patient factors.
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This document discusses various laboratory tests used to monitor coagulation, including clotting time, prothrombin time and INR, activated partial thromboplastin time, fibrinogen level, fibrin degradation products, D-dimer, and tests for monitoring anticoagulants like heparin. It provides details on what each test measures, its normal range and clinical uses, and potential causes of abnormal results. It also discusses limitations and factors that can influence certain tests, as well as newer techniques for individualized monitoring and dosing of heparin.
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Evolution of management stratergy for TGAIndia CTVS
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3. HARKEN’s -TEN COMMANDMENTS
The IDEAL prosthesis MUST
1. technically practical to insert.
2. inserted in a physiological site (generally the normal anatomic site).
3. capable of permanent fixation
4. chemically inert and not damage blood elements.
5. offer no resistance to physiological flows.
Ann Thorac Surg 1989;48:18-19
4. HARKEN’s -TEN COMMANDMENTS
6. close promptly (less than 0.05 second).
7. remain closed during the appropriate phase of the cardiac cycle.
8. not propagate emboli.
9. have lasting physical and geometric features.
10 It must not annoy the patient.
Ann Thorac Surg
1989;48:18-19
7. EVOLUTION OF PROSTHETIC HEART
VALVES
• 1950’s : Idea of prosthetic
heart valve consisting of cage
with mobile spherical poppet
• Resembled a bottle stopper.
9. HUFNAGEL’S BALL AND CAGE DEVICE
• No anticoagulation was used
• Drawbacks:
– Mortality
– cumbersome insertion during brief cross‐clamp period
– Valve noise : hollow nylon ball coated with silicone
rubber
– Poor hemodynamics
– embolization and thrombosis
10. DR. JUDSON CHESTERMAN-1955
• First ball valve implantation in
mitral position
• Cage and poppet device :
Perspex
• Fixed to outside of heart with
two buttons attached to device
• Patient died 14 hours after
surgery
12. DWIGHT EMARY HARKEN- 1960
• Double cage-ball valve
• Cage : stainless steel
• Lucite ball- changed to silicone-
rubber
• sewing ring Ivalon or Teflon
backing.
• Placed subcoronary location
• Two survivors among first seven
patients
13. STARR-EDWARDS BALL VALVE-1960
• "The need exists and it will eventually be
met. That is the law that all nature
follows.“-Lowell Edward
• Our job is not to design a valve identical
to nature‘s,not to see how close we can
come to duplicating a natural
phenomenon, but to overcome the
clinical problem of the diseased heart
valve. If we can do this with a valve
similar to the natural one-fine. But we
must evaluate on the basis of function
rather than form.—Albert Starr
(Tex Heart Inst J
14. DEVELOPMENT OF STARR-EDWARDS
BALL VALVE
• Bileaflet valve : silicone-
rubber leaflets hinged on a
central crossbar made of
solid Teflon
•Teflon cloth margin for
fixation.
•Thrombus formation
originate at suture line and
grow by direct extension
onto leaflets. (Tex Heart Inst J
15. DEVELOPMENT OF STARR-EDWARDS BALL
VALVE
• Adopted idea of ball and cage
valve from Ellis and Bulbulian
• Cage : Lucite cage
(methacrylate)thick struts
• Ball : compression moulded
Silicone elastomer rubber
• Sewing ring : Knitted teflon
• 1960 in mitral position
16. DEVELOPMENT OF STARR-EDWARDS BALL
VALVE
• First successful human
implantation: Philip
Admunson on September 21,
1960
• He had undergone 2 previous
commissurotomies and was
in NYHA functional class IV
• Admunson survived for 15
years after the implantation
18. SE model 6120/1260
• Heat cured ball – disapperance of ball variance
• Thrombo embolic problem: extending cloth of sewing ring
to edge of inflow orifice(decreasing amount of metal
exposed)
• Lowering of cage
• Barium sulfate impregnated silastic ball to make radio-
opaque.
• Teflon and polypropylene sewing ring.
19. DRAWBACK OF STARR-EDWARDS
BALL VALVE
• Ball variance.
– Hollow stellite-21 balls
– Heat cured silicone rubber balls
• High profile
• Difficult implantation in small ventricles and
small aortic root
• Inherently high gradients
20. DRAWBACK OF STARR-EDWARDS BALL
VALVE
• Less favorable thromboembolic profiles
• Wear and tear of cloth
• Edwards Lifesciences (Irvine, CA) discontinued
production of the Starr-Edwards valve in 2007.
21. MAGOVERN-CROMIE BALL VALVE-1962
• Sutureless valve
• Ball-Silicone rubber
with barium
• cage-titanium
• 25-year experi- ence
– 728 patients between
1962 and 1988
– ball variance occurred in
14 patients (2%)
23. DEBAKEY-SURGITOOL CAGED BALL
VALVE,1967
• hollow pyrolytic carbon
poppet
• first use of new carbon
material developed by Dr
Jack Bokros
• Drawback:
• strut wear and strut
fracture
24. DR JACK BOKROS
• Invented pyrolytic carbon :
Pyrolyte
• Exceptional
biocompatibility (highly
thromboresistant)
• Founded Medical Carbon
Research Institute ,Austin
• silicone-free pyrolytic
carbon: On-X Valve.
25. PYROLYTIC CARBON
• Isotropic form of carbon.
• distorted lattice structure with random unassociated carbon
atoms
• Formed by pyrolysis of hydrocarbon gas creating random
crystallization
• Excellent stability, strength, wear resistance, fatigue resistance
and biocompatibility
• Originally developed for the encapsulation of nuclear fuel rods
26. NINA STARR BRAUNWALD -1960
• Flexible polyurethane-
Dacron fabric mitral
valve prosthesis with
attached Teflon-tape
chordae ten- doneae
• 44 year old female with
mitral regurgitation
Nina Starr
Braunwald (1928–
1992)
27. BRAUNWALD-CUTTER BALL VALVE,1968
• Cloth covered caged ball valve
• Struts : knit Dacron tubing
• Inflow ring : ultrathin polypropylene
mesh fabric
• Drawbacks:
– fabric wear
– silicone poppet abrasion in aortic valves
leading to poppet escape.
28.
29.
30. NONTILTING DISC VALVES
• Closing component was a poppet that was held in a cage
(open position) or obturated the ring (closed position)
• Differed in material of disc, housing, ring and cage
design.
• Advantages:
– low-profile design
– easier implantation
– very little opening resistance
– very short closure delay (and therefore very little
regurgitation)
37. TILTING DISC VALVES
• Designed on principle of tilting disc : differences
in disc housing and angle of tilting
• Tilting angle : eventual diagnostics of valve failure
• Discs are radio-opaque , fluoroscopy imaging
– normal mobility
– restricted range of motion
– complete occluder blockade.
38. LILLEHEI-CRUZ-KASTER TILTING DISC
VALVE, 1963
• Free-floating disc tilting on
edge of orifice ring
• Good hemodynamic qualities
• Disadvantage: Area of stasis
between open disc & aortic
wall
39. BJORK-SHILEY FLAT DISC VALVE-1969
• Flat occluder disc
• Disc : Delrin(POM=polyoxymethylene);
Pyrolyte disc
• Stellite housing
• Disc tilting up to 60°
• Inlet and outlet struts welded to flange
•
• Early failures of inlet strut welds eliminated
with change to welding process.
41. BJORK-SHILEY CONVEXO-CONCAVE
TILTING DISC VALVE-1976
Advantages:
• Decreased thromboembolic complications by 50 %
• superior hemodynamic characteristics
• valve completely open with half flow required with
straight disc
• much more rapid reaction on closure resulting in
reduced regurgitation
42. BJORK-SHILEY CONVEXO-CONCAVE TILTING
DISC VALVE-1976
• 1986: Removed from market due to serious safety
concerns.
• outlet strut fracture causing death in 2/3rd of patients
• After recall, not all Bjork Shiley valves were removed
from patients
• 1991 : class action lawsuit filed against Pfizer
• 1992: lawsuit settled, with Pfizer expecting to pay
between $155 and $205 million total.
44. LILLEHEI-KASTER TILTING DISC
PROSTHESIS, 1970
• Pivot point moved forward to cord
measuring one-third of
circumference of orifice.
• Lateral guides replaced cage of Cruz
valve.
• Seating : titanium
• Disc : Pyrolyte.
• Disc opening = 80° and closing = 18°
45. OMNISCIENCE-1978 AND
OMNICARBON-1984
• Omniscience valve:
– two tabs as catch mechanism.
– titanium housing ,Pyrolyte disc.
• Omnicarbon Valve
– disc and housing -pyrolytic
carbon.
– disc opens up to 80° and closes
at 12°, thus achieving the tilting
range of 68°.
46. MEDTRONIC-HALL-KASTER TILTING
DISC, 1977
• Titanium housing
• Pyrolytic carbon disc with a
small central perforation.
• Disc slides over a guidewire
through its central perforation
to tilt open
• opens up to 75° (aortic valve)
and 70° (mitral valve)
47.
48. TTK CHITRA VALVE
• Distributed by TTK (Tiruvellore Thattai
Krishnamachari) pharma Chennai
• The first human implant was December 6,
1990 at Sree Chitra Tirunal Institute for
Medical Sciences and Technology, Trivandrum
Marthanda Varma Sankaran
Valiathan
51. Kalke-Lillehei Bileafet Valve
• Based on configuration of Indian tidal floodgates
• peripheral hinging leaflets and central opening.
• Implanted on May 20, 1968, woman with advanced
rheumatic mitral disease.
• She developed low cardiac output and died 48
hours postoperatively.
52. St. Jude Medical Heart Valve-1977
• Pyrolytic carbon over graphite substrate for
housing and leaflets
• Opening angle = 85o : central near laminar flow
• SJM Standard series
• SJM Masters series
• SJM HP (hemodynamic plus, since 1992)
• SJM Regent (since 1998)
55. SJM Masters HP(Hemodynamic Plus)
• Sewing cuff reduced-> supra-annular
placement
• Increased EOA
• Minimizes interference with subvalvular
structures in mitral position.
• Aortic and Mitral sizes: 17 to 27 mm.
56. SJM REGENT
• Supra-annular placement only for aortic position(size 19-27
mm)
• Significantly larger EOAs
– Less gradient even in valve sizes as small as 19 mm
– Renders root enlargement practically unnecessary
• Low-implant height
• Flexi cuff and Standard cuff
57. ATS (Advancing The Standard) MEDICAL
MECHANICAL HEART VALVE
• Pyrolytic carbon over graphite
substrate for housing and leaflets
• opening angle is 85o.
• Open pivot :decrease blood stasis
and thrombus formation near
hinge
• Standard series
• Advanced Performance series
59. Medtronic Open Pivot Mechanical
Valve
• Originally developed and owned by ATS Medical,Inc,
(Minneapolis, MN)
• Open pivot design
– Eliminates shallow recessess in hinge area where clots may
form
– Continous gentle flow of blood across valve-> low
hemolysis,low level of clotting
– Continous passive washing of valve
60. ON-X MECHANICAL PROSTHESIS -1996
• Housing: pure, non-silicon
carbide alloyed pyrolytic-carbon
• Leaflets : pyrolytic carbon-coated
over tungsten-loaded graphite
substrate
• curved housing in flow geometry
and an orifice diameter-to-
housing height ratio to minimize
vena contracta phenomenon and
facilitate laminar blood flow.
• opening angle 90o
65. TERMINOLOGY & PARAMETERS
• Valve size :outer diameter of the valve housing
(TAD - tissue annulus diameter)
• Internal orifice diameter (IOD) of the valve is
smaller than labeled valve size
• ESRD (external sewing ring diameter) larger
than TAD
69. PATIENT–PROSTHESIS MISMATCH
(PPM).
• First described in 1978 by Rahimtoola
• “Mismatch can be considered to be present when the effective
prosthetic valve area, after insertion into the patient, is less than
that of a normal human valve”
• Smaller than expected effective orifice area (EOA) in relation to
the patient's body surface area (BSA) will result in higher
transvalvar gradients.
Circulation vol 58 ,No
1,July 1978
70. PATIENT–PROSTHESIS MISMATCH (PPM).
• Aim : Implant a valve large enough to avoid hemodynamically
significant patient–prosthesis mismatch (PPM).
• Aortic position -IEOA of implanted valve should be > 0.85
cm2/m2.
• Mitral position- IEOA of implanted valve should be > 1.2
cm2/m2.
• Severe patient–prosthesis mismatch occurs
– IEOA <0.65 cm2/m2 in aortic position
– IEOA <0.9 cm/m2 in mitral position
71. PERFORMANCE INDEX (PI)
– Better indicator of hydraulic function efficiency of
particular prosthesis
– Ratio of effective orifice area (EOA) to sewing ring area
– Size-independent measure of valve’s resistance
characteristics
– Bileaflet valves typically have higher PI’s than tilted-disc
models, which in turn have higher PI’s than caged-ball
model
72. GOOD HEMODYNAMICS
• minimal resistance to forward blood flow
• only trivial regurgitant backflow as the occluder closes
• minimal turbulence and stasis in vivo during physiologic
flow conditions
• durable enough to last a lifetime
• constructed of biomaterials that are nonantigenic,
nontoxic, nonimmunogenic, nondegradable, and
noncarcinogenic.
• low incidence of thromboembolism.
73. HEMODYNAMICS
Factors determining opening resistance to blood flow
• orifice diameter
• size, shape, and weight of occluder
• opening angle
• orientation of leaflet or disk occluders with respect
to plane of annular orifice for any given annular size
76. HEMODYNAMICS
Thrombosis:
• Areas of perivalvular blood stagnation and
turbulence
• increase platelet aggregation
• activation of the coagulation proteins
• thrombus formation.
77. HEMODYNAMICS
Dynamic regurgitation
• sum of closing volume and leakage volume
Closing volume
• function of EOA and time needed for closure.
• Closure time is influenced by difference between the
opening and closing angles of occluder and valve ring.
78. HEMODYNAMICS
Leakage volume(washing jets)
• inherent to design of valve
• depends on amount of time valve remains in closed
position
• small amount of regurgitant volume can be beneficial by
• minimizing stasis and reducing platelet aggregation
• decreases incidence of valve thrombosis and valve-
related thromboembolism
79. Hemodynamics: Ball and cage valves
• Minimal leakage
• Leakage volumes - indicate pathologic process
• Annular area for flow creates turbulenece
• Cage may contact ventricular wall during contraction
• Partial obstruction by ball in aortic position
• Increase risk of hemolysis and thromboembolic
complications
80. Hemodynamics : Tilting disc valve
• Less obstruction to flow
• Gradient of 6- 7 mm Hg
• Opening angle high- less
gradient, more
regurgitation
• Opening angle low- more
gradient and less
regurgitation
81. Hemodynamics : Bileaflet valve
• more uniform central, and laminar flow
• less turbulence
• decreased transvalvular pressure gradients
• favorable hemodynamics in smaller sizes makes it
especially useful in children.
• large EOA for each valve size at the expense of
greater regurgitant volumes, especially at low heart
rate
85. valve housing Sewing ring leaflets Opening
angle
Implantatio
n
ROTATABLE
SJM PYROLYTIC
CARBON
COATED
GRAPHITE
SUBSTRATE
POLYESTER/
PTFE
PYROLYTIC
CARBON
COATED
GRAPHITE
SUBSTRATE
850 Masters:
intraannular
HP and
Regent:
supra
annular
YES
MEDTRONIC 100%
PYROLYTIC
CARBON
with
titanium
strengthnin
g band
Double-
velour
POLYESTER
Cuff marker
present
PYROLYTIC
CARBON
COATED
GRAPHITE
SUBSTRATE,
20%
tungsten
impregnate
d
850 Standard:
intra
annular
AP: supra
annular
yes
On-X GRAPHITE
SUBSTRATE
coated with
On-X
carbon-pure
unalloyed
PTFE
mounted
using
titanium
retaining
rings and 5-
On-X
CARBON
COATED
GRAPHITE
SUBSTRATE,
10%
900 Mitral:
supra
annular
Aortic(19-
25mm):intra
supra-
yes
86.
87. MORBIDITY AND MORTALITY
GUIDELINES
• The councils of the Society of Thoracic Surgeons
(STS) and the American Association of Thoracic
Surgery (AATS) formulated the Ad Hoc Liaison
Committee for Standardizing Definitions of
Prosthetic Heart Valve Morbidity.
• The initial report of this committee was issued in
1988 with an update in 1996
• The report strictly defines types of morbidity and
mortality that can occur after valvular surgery.
88. Early Mortality
• Early mortality is to be reported as all-cause
mortality at 30, 60, or 90 days and depicted by
actuarial estimates (with number remaining at
risk and confidence intervals [CIs]) or as
simple percentages, regardless of the patient’s
location, be it home or in a health care facility
89. STRUCTURAL VALVE DETERIORATION
• Includes dysfunction or deterioration
involving the operated valve (exclusive of
infection or thrombosis), as determined by
reoperation, autopsy, or clinical
investigation.
90. STRUCTURAL VALVE DETERIORATION
changes intrinsic to the valve:
• such as wear, fracture, poppet escape, calcification,
leaflet tear, stent creep
• suture line disruption of components of a prosthetic
valve
• new chordal rupture, leaflet disruption, or leaflet
retraction of a re- paired valve.
91. NONSTRUCTURAL DYSFUNCTION
• abnormality not intrinsic to the valve itself
that results in stenosis or regurgitation of
the operated valve or hemolysis.
• do not directly involve valve components
yet result in dysfunction
92. NONSTRUCTURAL DYSFUNCTION
• entrapment by pannus, tissue, or suture
• paravalvular leak
• inappropriate sizing or positioning
• residual leak or obstruction after valve
implantation or repair
• clinically important intravascular hemolytic
anemia
93. VALVE THROMBOSIS
• any thrombus not caused by infection attached to or
near an operated valve that occludes part of the blood
flow path, interferes with valve function, or is sufficiently
large to warrant treatment.
• Valve thrombus found at autopsy in a patient whose
cause of death was not valve related or found at
operation for an unrelated indication should also be
counted as valve thrombosis.
94. EMBOLISM
• Embolism is any embolic event that occurs in
the absence of infection after the immediate
perioperative period.
• Embolism may be manifested by a neurologic
event or a noncerebral embolic event.
95. BLEEDING EVENT
• A bleeding event is any episode of major
internal or external bleeding that causes
death, hospitalization, or permanent injury
(eg, vision loss) or necessitates transfusion.
96. OPERATED VALVE ENDOCARDITIS
• Operated valve endocarditis is any infection
involving a valve on which an operation has
been performed.
• Positive blood cultures are not required for the
diagnosis of operated valve endocarditis.
97. OPERATED VALVE ENDOCARDITIS
The diagnosis is based on one of the following criteria:
• (1) reoperation with evidence of abscess, paravalvular leak, pus,
or vegetation confirmed as secondary to infection by histologic
or bacteriologic studies
• (2) autopsy findings of abscess, pus, or vegetation involving a
repaired or replaced valve
• (3) in the absence of reoperation or autopsy, meeting of the
Duke Criteria for endocarditis
98. Morbidity data
• Rate for nonstructural dysfunction of mechanical valves
– 0.2 to 0.8 (events/ patient-years) for the aortic position
– 0.3 to 1.4 (events/patient-years) for the mitral position
• Rate of thrombosis of mechanical valves
– 0 to 0.2 (events/patient-years) in the aortic position
– 0.4 to 0.8 (events/patient-years) for the mitral position
99. Morbidity data
Rate of thromboembolism
• 1.4 to 2.5 (events/patient-years) for the aortic position
• 1.8 to 3.6 (events/patient-years) for the mitral position
Rate of bleeding event
• 0.8 to 2.5 (events/patient-years) for the aortic position
• 1.2 to 2.2 (events/patient-years) for the mitral position
Rates for prosthetic valve endocarditis
• 0.4 to 0.7 (events/patient-years) for both the aortic and mitral
positions.
Editor's Notes
In principle, his device resembled a bottle stopper (002) for which a patent
was obtained by JB Williams2 in 1858.
Harvard Medical School, Boston, Massachusetts USA
During the sixties, a number of innovative designs were pieced together for experimental as well as clinical application.
The development of the original ball-and-cage valve design can be attributed to the bottle stopper for which a patent
was obtained by JB Williams in 1858.
The problem of mitral regurgitation also received zealous attention from several quarters. ,
CITY GENERAL HOSPTIAL, SHEFFIELD, ENGLAND
when poppet got twisted out of position
JOHN H GIBBON
Philadelphia 6 May 1953 successfully performed cardiopulmonary bypass for open-heart closure of ASD
introduction of cardiopulmonary bypass opened the era of implanting valve prostheses in their native positions
Dr Harken working with Mr W. C. Birtwell from Davol Rubber Company, Rhode Island, started the modern era of prosthetic valve replacement
following excision of the diseased cusps.
concerned that the ball could intrude into the aortic wall. Thus, he designed his valve with a second outer concentric cage.
Both the patients required successive valve replacement, one at 3 years for perivalvular leak and another at 22 years for bacterial endocarditis. The ball valve removed after 22 years had no deterioration
Their first design was a silicone rubber bileaflet valve. This approach proved to be unsuccessful.
Ball variance : gross abnormality with cracks and fracture manifesting as loss of substance,loss of spherical shape,yellowish discolouration due to absorption of lipids.
PyC is generally deposited as a structural coating over a substrate pre-form
It is usually formed in a fluidized bed furnace
Americal thoracic surgeon In 1960, at the age of 32, she led the operative team at the U.S. National Institutes of Health (NIH) that implanted the first successful artificial mitral human heart valve replacement
The valve had two leaflets. Teflon chordae attached to the device were brought out through the ventricular muscle and secured outside the heart at the time of implantation
Due to these drawbacks, the non-tilting disc valves fell into dis use and were replaced by modern tilting disc valves.
first commercially available prosthetic valve with sewing ring configurations dedicated for intra-annular, (177) supra-annular (178) and subannular placement. (179) The aortic valve was available only for intra-annular implantation.
The convex-concave shape of the disc is of significant advantage, not only decreasing thromboembolic com- plications by 5 0 % , but with its superior hemodynamic characteristics, it will keep the valve completely open with half the flow required with a straight disc. It also has a much more rapid reaction on closure resulting in reduced regurgitation. The 70-degree opening angle of the monostrut valve also decreases the in vivo gradient by an average 15% across valve sizes 2 1-33 mm as com- pared to the spherical disc valve.
The convex-concave shape of the disc is of significant advantage, not only decreasing thromboembolic com- plications by 5 0 % , but with its superior hemodynamic characteristics, it will keep the valve completely open with half the flow required with a straight disc. It also has a much more rapid reaction on closure resulting in reduced regurgitation. The 70-degree opening angle of the monostrut valve also decreases the in vivo gradient by an average 15% across valve sizes 2 1-33 mm as com- pared to the spherical disc valve.
It was manufactured first by Shiley Laboratories, then later by Pfizer after that company purchased Shiley.
fracturing at the place where it was welded onto the metal valve ring
Eventually, 619 of the 80,000 convexo-concave valves implanted fractured in this way, with the patient dying in two-thirds of those cases.
Because of the risk associated with removal surgery, which included an approximated death rate of about five percent, patients with weak or defective heart valves did not undergo the
removal surgery, leaving the potentially defective heart valves implanted.
on behalf of patients who had received the implant and were concerned it might fracture.
The lawsuit alleged Pfizer Inc hid potential defects from patients.
Pfizer agreed to create a fund to pay patients for a cardiac consultation and further agreed to set aside funds for research to identify which patients had a significant risk of having the
heart valve fracture.
orifice ring and integral struts are constructed from a single piece of cobalt–chromium alloy to give it a weld-free mechanism.
The 70-degree opening angle of the monostrut valve also decreases the in vivo gradient by an average 15% across valve sizes 2 1-33 mm as com- pared to the spherical disc valve.
Leaflet motion is by rotation and translation.
The aortic and mitral valves differ in their sewing ring configuration
To eliminate the area of stasis behind the open Cruz valve ,kaster
e Omniscience valve was introduced in 1978 to replace the Lillehei-Kaster valve.
Karl Victor Hall, MD (1917 to present) was the chairman of the Department of Surgery at the Rikshospitalet in Oslo, Norway. As a cardiac surgeon, Dr Hall used the available valves of the time until the mid-1970s, when he sensed that improvements could be made in the tilting disc concept.
To accomplish his goal, Dr Hall needed financial help and scientific support. Arne Woien, a friend, physicist, and businessman, came to his aid. As prosthetic heart valve expertise was not available in Norway, Mr Woien suggested that they contact Mr Robert Kaster, who had returned to Minneapolis from New York. In 1974, Medtronic, Inc, of Minneapolis distributed the Lillehei- Kaster valve. Mr Woien was the Medtronic European representative. It was through this connection that Mr Woien and Mr Kaster met.
Doctor Hall, Mr Woien, and Mr Kaster worked to- gether to develop a satisfactory design,
Valve washing was improved by a relatively larger minor orifice and a disc that lifted out of the housing and rotated with opening. It had a moderately high profile in the open position and a low transvalvular gradient. Occluder impingement was possible because its position at the equator of the valve housing made it susceptible to obstruction from retained valve elements, sutures cut too long, or pannus. Loss of structural integrity, however, was never reported. The valve could be rotated after implan- tation to achieve the desired orientation. Several studies reported a low incidence of valve-related morbidity and mortality.
Medtronic discontinued manu- facturing the valve in September of 2009, removing the last of the tilting disc prosthesis available for clinical use.
Tilting Disc
– pivoted eccentrically in the metallic frame.
– MADE FROM ULTRA HMW POLY ETHYLENE •
The sewing ring – POLYETHYLENE TEREPTHALATE (PET) – fitted snugly around the frame – used to suture the valve in the intended position in the heart.
FRAME: COBALT CHROMIUM tungsten ALLOY( HAYNES 25) •
The frame and the disc are hydro dynamically designed to reduce drag and inertia and polished to minimize the chances of clotting.
Bhagavant Kalke, MD, began work in Dr Lillehei’s Min- neapolis laboratory in 1964 and continued with Dr Lille- hei after their move to Cornell Medical School in 1967. Doctor Kalke’s
Later he placed the pivot sites for the two rigid leaflets at the equator of the annular ring.
bileaflet design positioned the leaflets to open with their hinging axis toward the periphery of the metal annulus. As this did not work well, the pivot axis was moved to the diameter of the retaining ring. A single wire guard placed 90 degrees from the main hinging axis of the leaflets and extending over the leaflets aided the control of leaflet excursion
reduced sewing ring significant enlargement of EOA(effective orifice area)
avoiding PPM(patient-prosthesis mismatch) in patients with small aortic annulus and large body-surface area.
Its two pyrolytic carbon semilunar lea ets open up to 85° and close at 30°, which yields a tilting range of 55°. e valve mechanism has remained unchanged since its release, but a rotatable sewing cu was added and other ring re nements were developed. e The primary facilitator of the development of the St. Jude Medical valve was Mr Manny Villafana, founder of Car- diac Pacemakers, Inc. In 1976, Xinon (Chris) Posis, an industrial engineer, designed a prototype of a bileaflet valve with the pivots near the periphery and a central opening. Mr Posis obtained additional suggestions for his design from Dr Demetre Nicoloff, a cardiovascular sur- geon at the University of Minnesota. Posis and Nicoloff showed their prototype valve to Manny Villafana who felt the peripheral hinges would not be suitable. Subse- quently, Mr Posis along with another engineer, Donald Hanson, redesigned the valve with the hinge mechanism located near the central axis of the housing. It was Mr Villafana’s idea that the entire valve be fabricated of Jack Bokros’ pyrolytic carbon, which had been widely adapted for most monoleaflet valves in the 1970s. Working with Jack Bokros, the engineers Posis and Hanson modified the initial pivot mechanism and came up with the con- cept of a leaflet-tab rotating in a “butterfly recess” in the inner wall of the housing. Doctor Nicoloff implanted the first St. Jude valve on October 3, 1977.
It was suggested by Mr Villafana that they call their new valve the Nicoloff valve. Doctor Nicoloff declined. At that time, Mr Villafana’s son was recovering from a serious illness. The St Jude valve was proposed as a name by Mr Villafana. Church liturgy teaches that St Jude Thaddeus is the patron saint of difficult cases.
In the original prosthesis, the housing could not be rotated. The prosthesis has been altered in the Masters (Fig. 40b) series to rotate within the sewing ring and provide radio-opacity of the annular-rotating mechanism
In the standard cuff St. Jude Medical mechanical prosthesis, part of the cuff fabric is intra-annular, whereas in the HP Series prosthesis this fabric has shifted to an entirely supra-annular position. The St. Jude Medical Regent™ prosthesis shifts the carbon rim from intra-annular to entirely supra-annular.
introduced and are designed to optimize hemodynamics.
in patients with small aortic annulus and large body-surface area.
standard SJM model size (21 mm) had an e ective ori ce area (EOA) of only 1.51 cm2, the type HP 2.03 cm2, and the latest model, Regent, 2.47 cm2. Nonetheless, even a “small-size” SJM Regent 19-mm valve has an EOA of 1.84 cm2, i.e., su cient enough to prevent a signi cant patient–prosthesis mismatch in a patient with a body-surface area of 2 m2.
allowing for an increase in orifice size for a given tissue annulus diameter..
redesigned sewing cuff to facilitate supra-annular placement, allowing for an increase in orifice size for a given tissue annulus diameter..
Minimizes interference with subvalvular structures in the mitral position.
St. Jude Medical heart valves are MR conditional
Renders root enlargement practically unnecessary
Significant reduction in left ventricular (LV) mass
Low-implant height
FlexCuff has a flanged and more pliable sewing ring that easily conforms to annulus.
even a “small-size” SJM Regent 19-mm valve has an EOA of 1.84 cm2, i.e., sufficient enough to prevent a signi cant patient–prosthesis mismatch in a patient with a body-surface area of 2 m2.
Due to lack of silicon doping in valves carbon construction
Increased EOA ,decreases ability of retained valve tissue to interfere with opening and closing
Allows the valve to wash itself
e whole arti cial valve diameter is then larger for several millimeters (the thickness of the sewing ring is added), i.e., the external sewing ring diameter (ESRD).
valve housing and its sewing ring oc- clude an important portion of the patient’s valve orifice; therefore,
much larger ori ce area and therefore better hemodynamic parameters can be implanted into a given annulus.
valve housing and its sewing ring oc- clude an important portion of the patient’s valve orifice; therefore,
much larger ori ce area and therefore better hemodynamic parameters can be implanted into a given annulus.
larger EOAs, reduced transprosthetic gradients
EOA measure of how much the prosthesis impedes blood flow through the valve. A higher EOA corresponds to a smaller energy loss. The performance index (PI) normalizes the EOA by valve size and is a size-independent measure of the valve’s resistance characteristics. Bileaflet valves typically have higher PI’s than tilted-disc models, which in turn have higher PI’s than caged-ball models
Indeed, it is generally superior in newer compared with older generations of prostheses, in mechanical compared with stented bioprosthetic valves,16 in stentless compared with stented bioprosthetic valves,17,18 and in supraannular compared with intra-annular stented bioprostheses.
Least resistance to transvalvular blood flow is provided by a large ratio of orifice to total annular area.
A wide opening angle improves the effective orifice area and results in decreased pressure gradients
With an increasing orifice diameter- more energy is lost across the valve as more backflow passes through the valve
is a feature of all prosthetic valves
that passes through valve while it is closed.
Ball valve allowed
in the ball-and-cage design, and in contrast to other mechanical valves, the
The central ball occluder causes lateralization of forward flow and results in turbulence and cavitation
three different flow areas through the valve orifice
at any annulus diameter size and cardiac output compared with the caged-ball and single leaflet tilting valves
Low-profile prostheses simplify the surgical implant.
The lowest profile is that of the bileaflet valve,
The increased flow orifice of the bileaflet valve is clearly shown as compared to ball valves and tilting disc valves
SJM: double-velour knitted polyester fibre in polyester cuff allows rapid,controlled endothelial ingrowth over entire sewing cuff
Polyester sewing cuff have suture markers for valve orientation/placement of sutures
he calculation of events per patient-year(s) is the number of incident cases divided by the amount of person-time at risk. The calculation can be accomplished by adding the number of patients in the group and multiplying that number times the years that patients are in a study in order to calculate the patient-years (denominator). Then divide the number of events (numerator) by the denominator.
Example: 100 patients are followed for 2 years. In this case, there are 200 patient-years of follow-up.
If there were 8 myocardial infarctions in the group, the rate would be 8 MIs per 200 patient years or 4 MIs per 100 patient-years.