VALVULAR CARDIAC SURGERY

1. VALVULAR CARDIAC SURGERY

2. Outline • Heart and Heart Valve A & P • Valvular Pathology • Valvular Diagnostics • Open Heart Patient Preparation • Supplies, Instrumentation, and Equipment • Valve Surgery (aortic, mitral, tricuspid) • Ventricular Aneurysmectomy

3. A & P Your Heart’s Valves

4. Normal Circulation • Blood comes back to heart for reoxygenation via the superior and inferior vena cava entering into the right atrium • Passes through the tricuspid valve into the right ventricle, then through the pulmonic valve into the pulmonary artery • Blood is reoxygenated in the lungs and returns via the pulmonic veins into the left atrium • There it goes through the mitral valve into the left ventricle through the aortic valve pushing oxygenated blood into the coronary ostia as it passes them and throughout the rest of the body where oxygen is needed by all the organs and tissues

5. CARDIAC VALVES • Tricuspid valve lies between the right atrium and right ventricle • Blood returns to the heart through the superior and inferior vena cavae into the right atrium where it passes through the tricuspid valve into the right ventricle where it is pumped through the pulmonic valve into the pulmonary artery to be taken to the lungs for re-oxygenation

6. CARDIAC VALVES • Mitral Valve lies between the left atrium and the left ventricle • Blood returns via the pulmonary veins (after re-oxygenation) into the left atrium, passes through the mitral valve and into the left ventricle, where it is pumped through the aortic valve

7. CARDIAC VALVES • Aortic valve lies between the aorta and the left ventricle • Blood is pumped from the left ventricle through the aorta to the coronary ostia, head vessels, upper and lower extremities, and the abdominal organs, via the aorta

8. Clarification • The aortic and pulmonic are often referred to as semi-lunar, meaning they have three half moon shaped cusps • The mitral and tricuspid are often referred to as atrioventricular valves, as they separate the atria and ventricles • The tricuspid valve is “three-cusped” • The mitral valve is “two-cusped” or bicuspid

9. Mitral Valve • Has two cusps (a posterior and anterior leaflet) • Often referred to as the bicuspid valve • Leaflets are attached and anchored to the endocardial papillary muscles by cords called cordae tendineae • Cordae tendinae keep the valve from prolapsing

10. Cardiac Conduction • Coordinates cardiac conduction • SA Node (sinoatrial) “the pacemaker” • AV Node (atrioventricular) • Bundle of HIS or AV Bundle • Down R/L insulated branched bundles in ventricular septum • Purkinge Fibers non-insulated and feed into R/L ventricles

11. Cardiac Conduction • SA node initiates impulse > atria contract (blood forced into ventricles)> stimulus picked up by AV node > AV Bundle (signal slightly delayed) > brnached bundles > purkinge fibers > ventricles stimulated and contract (blood forces atrioventricular valves to close and semilunar valves to open) • These valves should go one-way

12. Pathology of Valves • Obstruction of the valves is usually caused by stenosis or fusion of the leaflets causing diminished blood flow resulting in poor oxygenation or backup of blood into the respective ventricles • Backup of blood damages the ventricular endocardium and myocardium over time, which can cause ventricular aneurysm (thinning and enlargement of the ventricle) • Can be regurgitant or insufficient due to leaflet damage (may not necessarily be stenosed) • In the case of the mitral valve, damage can be to the cordae tendineae, causing elongation, rupture, or shortening

13. Aortic Stenosis • Calcification of the aortic valve cusps • LV hypertrophy develops as result of restricted blood flow into the aorta • Sx: fatigue, DOE, palpitations, dizziness, fainting, angina (chest pain)

14. Pulmonic Stenosis • Calcification of pulmonic valve cusps • Restricts flow into PA • RV hypertrophy

15. Mitral Regurgitation • Blood flows back (regurgitates) into the LA through the incompetent mitral valve • LV hypertrophy • Sx: fatigue, palpitations, orthopnea (need to sit up to breath), PND (paroxysmal nocturnal dyspnea, after sleeping wakes up needing air)

16. Mitral Stenosis • Calcified mitral valve • Impedes flow of blood into LV • LA hypertrophy or enlargement • Sx: fatigue, palpitations, DOE, orthopnea, PND, pulmonary edema

17. Tricuspid Regurgitation • Blood flows back (regurgitates) into RA due to incompetent tricuspid valve • Sx: engorged pulsating neck veins, liver enlargement, RV hypertrophy, thrill at left sternum

18. Tricuspid Stenosis • Calcification of tricuspid valve • Impedes blood flow into RV • Sx: diminished arterial pulse, jugular venous prominence

19. Valvular Disease • Causes: • CAD and MI • Degenerative disease due to age • Rheumatic heart disease (a complication of bacterial strep) • Congenital disease • Obstruction results in left ventricular myocardial overload due to backflow of blood, which stresses the myocardium over time • IV Drug Abuse • Dental Infections • Lupus • Marfan’s Syndrome • Scleroderma

20. Symptoms of Valvular Disease • Fatigue • Weakness • Dyspnea with or without exertion, stress, or pregnancy • Pulmonary edema • 1° cause rheumatic fever • May go from mild to total disability in 5- 10 years • May be asymptomatic 10-20 years after initial damage to valve

21. Diagnosis • NONINVASIVE • H & P • ECG/EKG • Exercise EKG (stress test) • Echocardiogram (echocardiography is the Gold Standard for diagnosing valvular disease) • Chest x-ray

22. Diagnosis • INVASIVE • Cardiac catheterization ( may be in conjunction with echocardiogram) • Trans-esophageal echocardiogram (usually done preoperatively in the OR suite in conjunction with valve surgery)

23. Anesthesia • General

24. Medications • Warm saline with antibiotic solution • Topical hemostatic agents of choice: surgicel, gelfoam and thrombin, gelfoam/thrombin/antibiotic rolled into balls for sternal bone application, bone wax for sternum with raytex underneath to prevent surgeon from ripping gloves on rough edges • Extra NS for valve rinsing if is a xenograft • Will rinse x 3 in 250cc NS each rinse for 2 minutes each or per manufacturer’s recommendations • Some surgeons may want antibiotic added to 2nd or 3rd rinse

25. Patient Positioning • Supine position • Arms padded and tucked • May want a shoulder roll to elevate the sternum (optional) • Headrest • Pillow under knees (preferable) • Heel pads (preferable)

26. Prep • Begin at anterior thorax prepping outward in a circular motion to the bedline, prep to top of thighs/ bilateral groins, then pubis • With a separate sponge prep both legs to knees to the bedline • Use betadine soap, then paint • May use gel or spray • Should do minimum of two coats of paint

27. PREP • For a CABG and valve replacement, will prep sternum to neck, bedline to bedline, groins, pubis, then each leg circumferentially to ankles or feet (institutional policy)

28. Equipment • Two large tables (back table and Mayfield) • Mayo stand (for saw) • Double ring • Prep tables x 2 • Slush machine/warmer • ECU x 2 • Cell saver • CPB machine • Off-table suction • External Pacing box

29. Instumentation • Open heart Trays • Valve Tray • Suture Guide Holder • Sternal retractor (Ankinney for aortic valve) and (Cosgrove or Korous for mitral or tricuspid) • Finochetti • Sternal saw • Internal defibrillator paddles • Doctor’s specials • Micro instruments needed if CABG done with valve surgery

30. Supplies • Valve Custom Pack (Coronary pack for CABG/Valve) • CV Drape Pack • Gloves • Chest tubes • Suture guide inserts • Valve Sizers for appropriate valve • Appropriate valves of surgeon request in the room • Misc. suture: pericardial suture, cannulation suture, aortic retraction suture (for aortic valve only), valve repair or replacement suture, suture to close aorta or atrium, pacing wires, suture to sew in pacing wires, cutting needles to sew in chest tubes and pacing wires, sternal wires, fascia suture, subcutaneous, subcuticular • Coronary ostia perfusion catheters (auto-inflating, gummy tip, or spencers (for aortic only)

31. Supplies continued • Aortic cannula • Venous cannula (need two for bicaval cannulation-need for mitral valve surgery) • Antegrade cannula (may just use retrograde and place this after aorta closed for aortic valve surgery/is placed for mitral valve surgery) • Retrograde cannula • Medusa • Cardiac insulation pad • Myocardial temperature probe • Extra saline • Three cytals for washing valve if using a xenograft (porcine or bovine)

32. Valve Replacement Options • Mechanical • Biological • Diseased valve excised and replaced

33. Valve Replacement Options (Aortic and Mitral) • 1. Mechanical: • St. Jude or Starr-Edwards valve only conduit/valve available for aortic • Durable • Used primarily in young patients • Patient requires long-term anticoagulant therapy (not for elderly) • Complications: emboli and bleeding from other injury due to anticoagulant therapy

35. Valve Replacement Options (Aortic or Mitral) • 2. Heterograft/Xenograft • Biologic • May be bovine or porcine • Bovine pericardium is the new rage • Old porcine has a duration of 15 years • Bovine pericardial are thought to last longer/research inconclusive due to recent development • No anticoagulant therapy needed

37. Valve Replacement Option (Aortic) • 3. Aortic Stentless • Biologic • Porcine • Durability good over age of 60 • No anticoagulant therapy needed

39. Valve Replacement Options (Aortic, Mitral, Pulmonic) • 4. Allograft/Homograft • Biologic • Cadaver from organ donor • Will measure annulus size with TEE • Will choose graft before incision made or as opening chest • Time will be required for proper thawing procedure to be implemented to prevent damage to the graft • Long term • Limited availability

40. Valve Replacement Option (Aortic) • 5. Autograft (ROSS Procedure) • Requires expert valve surgeon • Excision of patient’s pulmonic valve to be used as the patient’s new aortic valve • A pulmonic allograft will be used to replace excised pulmonic valve • Long term • Limited availability of pulmonic allograft

42. Valve Repair Options • Annuloplasty rings • Mitral annuloplasty rings • Tricuspid annuloplasty rings

43. Replacement verses Repair • Aortic and Mitral are replaced • Tricuspid in extreme situations can be replaced with a mitral valve • Mitral and tricuspid usually repaired with annuloplasty rings • Mitral may have to be replaced if attempted repair is unsuccessful

44. Annuloplasty Rings • Used for repairing of the mitral or tricuspid valves • Mitral rings are a near to complete circle • Tricuspid rings are an incomplete circle or half-circle • Sizers are half moon shaped and have T or M on them (will come with a malleable handle-bend it slightly for ease of sizing) • Are differentiated between by T or M on the tag (remove the Minnie-Pearl tag before passing it to the surgeon) • Provide reduction of the dilated annulus • Often the tricuspid function will return to normal with the repair of the mitral

47. Valve Repair/Replacement Procedure • Incision with #10 blade • Cautery • May use curved mayo scissors to ream under the xiphoid to loosen the fascia from the sternum • Sternal saw • Bone wax or gelfoam powder mixed with saline or thrombin to make soft balls to spread on sternum • Wet laps folded in half (should have been soaked in antibiotic NS and wrung out) • Sternal retractor • Cautery and debakeys to open/dissect the pericardium • Pericardial sutures (may use pop-off silk or neurolon)

48. Valve Repair/Replacement Procedure • Dissect aorta from pulmonary artery to provide room to place aortic cross-clamp • Purse-string cannulation stitches for aortic cannula (x2), venous cannula, and retrograde cannula, each is rommeled • Heparin is administered by anesthesia at surgeon prompt • Cannulas are placed, aortic first, stab blade (#11), aortic cannula, heavy tie or umbilical tape, tube clamp, bowl and scissors to cut aortic pump line, hook to CPB tubing, make sew cannula to patient/drape or clamp with non-penetrating towel clip • Venous cannula placed, metz, cannula (some surgeons may use a satinsky to clamp the atrial appendage before incising it), heavy tie or umbilical tape, tube clamp or not and hook to venous line from CPB machine • Surgeon will say to perfusion, “Go on bypass”

49. Valve Repair/Replacement Procedure • Hypothermia will begin by perfusion who can cool the blood he is circulating • Cross Clamp will be placed across the aorta • Cardiac insulation pad may be placed • Myocardial temp probe may be placed near the apex of the left ventricle • Ice may be applied to the heart as well

50. Aortic Valve Replacement • AORTIC • Once temperature is where surgeon wants it, he will take a metz and cut the aorta open above the aortic valve and below the aortic cross clamp • He may want stay sutures or retraction sutures • He may continue to perfuse the heart with cardioplegia fluid directly into the coronary ostia via the medusa and coronary perfusion cannula that is attached (his/her preference)