PROSTHETIC VALVES-perioperative echo evaluation.pptx

seminar presentation on prosthetic valves perioeprative evaluation , mainly transesophageal echo point of view for cardiac anaesthesiologists

1. PROSTHETIC VALVES : PERIOPERATIVE TEE EVALUATION PRESESNTER : DR RAJESH MUNIGIAL SENIOR RESIDENT DEPT. OF CARDIAC ANAESTHESIA JNMC , BELGAUM , KARNATAKA

2. History Epidemic RHD 20 th century Initial attempts : manual reconstruction , decalcification Multiple animal implants in 1954 First orthotopic implantation of a ball and cage prosthetic valve in the mitral position in 1960 by Albert Starr9 and then in the aortic position in 1962 by Harken Hufnagel valve in descending aorta position

3. Introduction: Prosthetic valves can be grouped into 2 broad categories: Mechanical ( bileaflet , tilting disc, caged ball) or Bioprosthetic/tissue (stented, unstented, homografts ). The choice of prosthesis balances the (1) need for anticoagulation, (2) durability, and (3) valve function. Despite improving patient survival and quality of life, prosthetic valve implantation is palliative, not curative.

4. Surgical implantation involves selecting the correct (1) prosthesis size and height, (2) valve orientation, and (3) insertion level (valvular or supravalvular). Interrupted sutures are used to secure the valve sewing ring to surrounding tissue. Intraoperative TEE during prosthetic valve surgery, a SCA/AHA class I indication , determines baseline prosthetic valve function, detects any issues which require immediate reintervention, and monitors cardiac function.

5. Valve orientation Correct valve orientation of the mechanical valve is important for optimal function and to prevent complications. • Mitral Position : orientate valve to minimize disc entrapment by submitral chordae. Anti-anatomic : This is the typical implantation for single disc valves and bileaflet valves with pivot points at 90° to the native MV commissures. The open leaflets are best seen in ME 120° view. Anatomic : Unusual to orientate the pivot points with the native MV commissures. Leaflet opening is best seen in 0° view.

6. • Aortic Position : orientate valve with one pivot between the LCC and RCC to allow for smooth opening of valve discs without obstructing the coronary arteries. Leaflet opening is best seen in the TG views. • Mechanical valves are seldom implanted in the tricuspid or pulmonic position, as there is insufficient pressure to open and close the valve.

7. Mechanical tilting disc Single disc + eccentric strut/hinge • Opening angle 60–70° • 2 antegrade orifices (major, minor) • 2–3 washing jets Medtronic-Hall : large central + small peripheral jets Bjork-Shiley : small peripheral jets

8. TEE evaluation immediately after valve placement Valve leaflet /occlude morphology and mobility Valve sewing ring integrity and motion Trans prosthetic gradients Effective orifice area ( EOA/DVI) Patient prosthetic mismatch Regurgitation ( physiologic vs pathologic , location & severity) LV size and systolic function Pulmonary artery pressure

9. Assess collateral damage Mitral regurgitation from a misplaced suture through the anterior mitral valve leaflet after aortic valve replacement 2. Aortic regurgitation from a misplaced suture through an aortic valve cusp after mitral valve replacement 3. Coronary obstruction after aortic valve replacement manifested by right or left ventricular dysfunction 4. Left circumflex coronary artery injury or obstruction after mitral valve replacement manifested by left ventricular segmental wall motion abnormality 5. Ventricular or atrial septal defect after mitral or aortic valve replacement 6. Left ventricular outflow tract obstruction after mitral valve replacement

10. Bioprosthetic valves : • 3 stents or struts • Constructed of bovine pericardium (CE) or porcine heterograft (Hancock) • 3 leaflets • Smaller orifice than stentless valve • Sized to aortic annulus • Central gap in pericardial valve

11. Stentless valve No stent Porcine aortic heterograft 3 leaflets Larger orifice than stented valve(particularly useful in patients with a native aortic valve annulus less than 20 mm in diameter) Only implanted in aortic position Sized to sinotubular junction Implantation of the stentless valve within the native aortic root increases the thickness of the vessel wall at the region of overlap and makes paravalvular regurgitation possible (mild AR 25%)

12. TEE findings in stentless valve Little acoustic shadowing • 3 leaflets similar to native AV • Implantation involves valve (SPV) or valve + root ( FreeStyle ) • Thickened aortic root • Trace valvular AI • Small pressure gradient • Paravalvular leaks are not possible

13. AORTIC VALVE PROSTHESIS 2D: assess valve opening and closing Doppler: Color : laminar/turbulent/regurgitation(valvular/paravalvular) CW spectral : flow dependant , avoid being too close to prosthesis NORMAL : triangular , early peaking and short acceleration time (<80ms) Obstructed : rounded , mid peaking , AT > 100ms , AT/ET>0.4s HIGH GRADIENT : small size , PPM , INCREASED STROKE VOLUME and obstruction

14. Associated coronary blood flow and LV function to be assessed

15. MITRAL VALVE PROSTHESIS

16. PATIENT PROSTHESIS MISMATCH PPM occurs if the prosthesis-effective orifice area (EOA) is too small for the patient’s size, resulting in abnormally high transvalvular pressure gradients. PPM may be less relevant in obese patients. Well studied with AVR and can occur with MVR: PPM MVR if ≤1.2–1.3 cm2/m2 occurs in 39-71% of patients suspect if persisting pulmonary hypertension When PPM is present after AVR patients have reduced short- and long-term survival, particularly if there is LV dysfunction.

17. Avoidance of PPM may necessitate AVR implantation that is: after patch root enlargement in the supra-annular position tilted from the standard intra-valvular position

18. Pressure recovery Pressure recovery is a hydrodynamic phenomenon observed in high-velocity flow profiles through narrow orifices. It is based on the principle of conservation of energy. In the chamber proximal to stenosis, there is a buildup of pressure (potential energy). As blood exits the stenotic valve, the velocity increases (kinetic energy) with a simultaneous drop in pressure (potential energy). Farther distally, the velocity of blood decreases with a simultaneous rise in pressure, known as pressure recovery (PR)

19. Usually PR is only significant in valves in the aortic position and in patients with an aorta <3 cm in diameter. The phenomenon of PR sometimes can be responsible for discordance between the Doppler-derived and cardiac catheterization–derived peak transvalvular gradients

20. Prosthetic valve dysfunction

21. Valve regurgitation

22. Stuck leaflet Bileaflet or tilting disc valves Caused by: subvalvular apparatus, sutures Identified by: Immobile leaflet: stuck open, closed, or in between, Check in multiple views Turbulent or no flow through valve Partially open has regurgitation

23. Hematoma Blood or edema (arrow) may collect around the suture line during valve insertion. This typically resolves in days. This early finding is important to document; should the patient become febrile, it should not be confused with an abscess.

24. Paravalvular leak Incomplete seal between sewing ring / annulus • Incidence: AVR (1–17%), MVR (up to 30%) • Risk factors: annular calcium • Difficult to quantify regurgitation, as an eccentric jet • Trivial leaks common, resolve after protamine • If uncorrected, may cause hemolysis , dehiscence

25. Thrombus : Inadequate anticoagulation : Acute thrombosis , stenosis or regurgitation Pannus : subacute condition , fibrous structure , echodense Hemolysis Endocarditis LVOT obstruction

26. References Perioperative two-dimensional transesophageal echocardiography- Annette Vegas Practical approach to transesophageal echocardiography – Albert C Perrino Intraoperative Echocardiographic Assessment of Prosthetic Valves: A Practical Approach.Mahmood , Faraz et al.Journal of Cardiothoracic and Vascular Anesthesia , Volume 32, Issue 2, 823 - 837

27. Thank you