Surgical approaches in cardiac surgery:

Median sternotomy

Ministernotomy (aortic valve, asc. aorta …)

Thoracotomy

  - right side (ASD, Mi, Tri, re-do surgery)

  - left side (open arterial duct, CoA, decs. aorta)

Minithoracotomy

   - left side – ischemic heart disease, open arterial duct)

   - right side (IHD)

Transverse sternotomy

Parasternal incision

Incision in the epigastrium

Endoscopic approach (robotic)

Cardiac surgery – types of procedures:

without cardiopulmonary bypass - beating heart surgery

            - congenital heart diseases (open arterial duct, CoA)

           - CABG

           - pericarditis

           - heart injury

           - mitral comissurotomy (history)

with cardiopulmonary bypass (ECC)

Extracorporeal circulation – cardiopulmonary bypass:

1. Pump

2. Oxygenator

3. Heat exchanger

Principles

 - heparinization (2-3 mg/kg)

 - hemodilution

 - hypothermia/normothermia

Myocardial protection:

ischemic cardiac arrest = myocyt injury

→ complete electromechanical arrest

→ cell membrane stabilization

→ myocardial cooling – to achieve metabolic

                                           suppression

Cardioplegic solution

            crystaloid x blood

                warm x cold

Types of delivery

            antegrade

            retrograde

Heart diseases:

Congenital

   - without shunting

   - left to right shunt

   - right to left shunt

Acquired  

   - ischemic heart diseases

   - valve diseases

   - aortic diseases

   - tumors

   - others

Congenital heart diseases:

0,6-0,8% newborns

the most often – ventricle septal defect, atrial septal defect, persistent open arterial duct

main principles of treatment

            - critical defects - early repair

            - others – at the preschool-age surgery

            - radical correction – one step surgery

            - palliative surgery

                   - conection (shunt) between

                     systemic and pulmonary circulation

         - catheter intervention techniques development

            (BAS, ASD and VSD closure, PDA closure, coils, stents, dilation)

Coarctation of the aorta:

5-8 % of CHD

male : female  2-5:1

congenital narrowing of thoracic aorta after the origin of subclavian artery

hypertension in upper part of body

Congenital aortic valve stenosis:

According to localization types of congenital aortic stenosis are subvalvular, valvula and supravalvular.

Target of treatment is reduction of surgery in young age. Due to catheter treatment (baloon dilatation) and AVS surgery is possible to delay AVR to adult.

AVR is made with mechanical prosthesis (rarely with biological in young age) prothesis. In childhood and in young people we kan use so called Ross procedure - replacement aortic valve by autograft of pulmonary valve. During this procedure we remove stenotic aortic valve, after that a pulmonary autograft is harvested and implated in aortic position, we have to reimplant coronary artery ostia.  After that pulmonary valve is replaced with homograft from tissue bank.

Congenital heart diseases with left to right:

↑pulmonary blood flow → RV volume overload → ↑PVR →RV pressure overload

-        VSD

-        ASD

-        patent ductus arteriosus

-        aortopulmonary window

-        anomalous origin of the LCA from the pulmonary artery  

-        AV septal defect (incomplete x complete)

Ventricular septal defect:

most often CHD

- isolated  x   with other CHD

- blood circulation pathophysiology 

  depends on diameter and PVR

Atrial septal defect:

no symptoms x large defect - weariness

symptoms in adult – enlarging RA, RV, RV failure, arythmia

↑ CVP - paradoxical embolism

surgery x catheterization

Persistent open arterial duct:

extracardial connection between pulmonary and systemic circulation

during fetal circulation - ↑prostaglandins (E2, E1) → persistent connection

after birth ↑pO2 a ↓PG (placental removal)

- 5-10%  all congenital heart diseases

- in prematurely born 20-30%

farmacotherapy - ibuprofen - PG inhibitors

cathetrization

surgery - VATS

               - „open surgery“ - thoracotomy  

Congenital heart diseases with right-to-left shunt  -  cyanotic:

- tetralogy of Fallot

- transposition of great arteries

 - VSD with pulmonary atresia

 - total anomalous pulmonary venous return

 - truncus arteriosus

Tetralogy of Fallot:

Four signs of TofF are: pulmonary artery stenosis, RV hypertrophy, VSD+ aorta over the VSD.

Surgical therapy is made during firts year.  Surgery is discision of stenotic pulmonyay valve and closing of VSD.

Observation is important becacuse developing of pulmonary regurgitation in about 25%. And that regurgitatio causes RV , arrhytmhmias, RV dilatation, and then RV failure in future. So the rest of pulmonary valve (after discision) has to be replaced by (biological) valve.

Acquired hear disease:

   - ischemic heart diseases (IHD)

   - valve diseases

   - aortic diseases

   - tumors

   - others

IHD – risk factors, signs, symptoms, therapy:

- hypertension

- diabetes

- obezity

- smoking

- hyperlipoproteinemia

…

- no symptoms

- angina pectoris

- myocardial infarction

- heart failure, sudden death

PREVENTION!!!

- drugs

- percutaneous coronary intervention

- surgical revascularization

- combination

- heart transplantation

IHD – surgical treatment options:

The surgical treatment options are with CP bypass, or without. So called off-pump procedures on beating heart due to several types os stabilization. Stabilizator with vakuum can help us stabilize diferent part of heart. We can open coronary artery , insert intracoronary shut (which help us make operative field clean) and make peripheral anastomosis.

Choice of conduits for coronary artery bypass:

Arterial

  -  LITA (a. thoracica int. l. sin) – 10 years patency 90-95%

  -  RITA

  -  radial artery

  -  a. gastroepiploica dx., a. epigastrica inf.

Venous

  - great saphenous vein – 10 years patency 50-60%

  - short saphenous vein

Anatomy of heart valves:

Basics functional parts of AV valves (mitral and tricuspid) are leaflets attached to annulus, papillary musceles witch chords attached to the leaflets. And also left or right ventricle is important funcitonal parts of AV valves.

In VA valves (mainly aortic), there are no chords, but leaflets are attached to the annulus. And with STJ they are parts of aortic root.

This is important for understanding to function and etiology of disease and it´s important for correction (mainly for reconstruction surgery).

Aortic valve disease – stenosis:

AoS is the most often disease of valves. There are three basic ethiologic types of AoS.

degenerative AS with calcification (in pts with risk factors of atherosclerosis a aging)

congenital - bicuspid valve (for about 2% of population have bicuspid valve). In bicuspid aortic valve degeneration, calcification and stenosis can occur in early age. Also aortic root dilatation in this cohort is more often than in other population.

post-rheumatic aortic stenosis – fusion of leaflets - rare diagnosis (in rare of rheumatic fever) in this part of world  – often with mitral stenosis. But it quite often in i.e. South-East Asia, or arabic countries.

Aortic valve disease – stenosis – indication for surgery:

Important for AoS  indication for surgery are symptoms.

ECHO diagnosis is on first place but for you is important…SYMPTOMS (chest pain, shortness of breathe, syncope)

If there are no symptoms  we detect LV function. If there is LVEF bellow 50% and/or LV dilatation – surgery is indicated. If not, during periodic follow-up we will check the patient LV function.

Aortic valve disease – regurgitation:

acute  x  chronic

Etiology  - post-rheumatic

                 - endocarditis

                 - congenital

                 - degenerative

                 - annulus/root/STJ dilatation

Mitral valve diseases:

Stenosis      Etiology   - post-rheumatic

                                          - degeneration (calcification)

Regurgitation (acute, chronic)

                     Etiology  - myxomatous degeneration (leaflet prolaps, chords rupture…)

                                      - post-rheumatic

                                      - endocarditis

                                      - ischemic (MI, LV dysfunction)

Tricuspid valve disease:

Stenosis

         Etiology - post-rheumatic

                                    - carcinoid syndrom

Regurgitation

         Etiology  - relative…annulus dilatation

                         - endokarditis

Heart valve surgery:

Basic decision-making in heart valve surgery

1. We can spare the valve, repair the valve if it is possible, but there is risk of...

2. On the other side we can replace the valve but there is risk of artefitial valve complication Risk of anticoagulation therapy (in case of mechanical prothesis), risk of thrombebolism, risk of prosthetic endocarditis

Aortic valve sparing surgery – leaflets:

We can make correction on every functional parts of valve. In VA valves on leaflets...

During AVS surgery on leaflets – plication of free edge, replacement of pathologic part of leaflet (calcification) with percardial patch.

Aortic valve sparing surgery – anulus:

In case of annular dilatation we can diminish annulus by special stitch, by annular ring on required diameter.

Aortic valve sparing surgery-root:

In case of root dilatation we can replacemet root by vascular prothesis with sparing of valve. You see replacement dilated aortic root with aortic valve reimplantation into the prosthesis.

Valve repair in atrio-ventricular valves (Mi,Tri):

- leaflets

- anulus

- chords

- papillary muscles - limited

- left/right ventricle - limited

Mitral valve reconstruction surgery – leaflets:

But we can correct leaflets - pathologic part (if there is i.e. prolaps) can be cut of and edges are sewn together.

Mitral valve reconstruction surgery – chords:

If the problems is on chords – we can replaced prolonged or ruptured chords by new gore-tex chords implant.

Mitral valve reconstruction surgery – anulus:

Almost in all cases of mitral valve reconstructions annulus diameter is decreased and shape is remodelated with special anuloplasty ring.

Valve replacement – mechanical:

If the valve sparing or reconstruction is impossible, than we replace the valve.

We can use mechanical: type of bileaflet mechanical valvel is used nowadays.

Valve replacement – biological:

Second possibility are biological valves – porcine or from bovine pericardium.  New valve are also so called suturesless.

In special indication we can use allograft (homograft) from tissue bank. We can use that homograft for example in case of endokarditis to avoid placement of any prosthetic material

Mechanical vs. biological valves:

Mechanical

            - advantages - long-term durability

            - disadvantages - need of anticoagulation

Biological

            - advantages - no anticoagulation

            - disadvantages - limited durability

Complications after valve replacement:

- thrombembolism

- bleeding

- valve dysfunction (pannus, thrombus)

- prosthetic endokarditis

TAVI – transcatheter aortic valve implantation:

Modern trend in valve replacement (especially in aortic valve replacement) is co called TAVI – trancatheter aortic valve implantation. Transfemoral – from groin, catheter with baloon and valve, or transapical  - from small thoracotomy, open the pericardiom and across the LV apex, on beating heart without C-P bypass.

Aortic diseases – aortic aneurysm:

ascending, arch, descending, thoracoabdominal ≥ 55mm

risk factors - hypertension,  bicuspid valve, Marfan syndrom, Ehlers-Danlos syndrom, Loeys-Dietz syndrom, inflammatory aortic disease (aortitis)

symptoms – no symptoms OR chest pain, hoarseness, cough, shortness of breath

Dg - ECHO, CT, MRI

therapy – prevention of rupture/dissection

                  aortic replacement with vascular prosthesis, TEVAR (thoracic      

                  endovascular aortic repair)

Ascending aorta aneurysm:

graft replacement– W/, W/O aortic valve replacement , aortic valve sparing procedures

PEARS (personalised external aortic root support)

-        prophylactic surgery on the aortic root and AA to prevent further growth in aortic aneurysms

Aortic arch aneurysm:

Aortic arch surgery is one of the most technically demanding procedures in cardiac surgery, in which protection brain (hypothermia) is necessary for patient safety.

Epiaortic vessels are reimplanted or redirected with special types of vascular grafts – trifurcated graft...

Descending aorta aneurysm:

In descending aorta aneurysm dilated aorta is replaced with vascular graft. Surgical approach is thoracotomy. Also endovascular aortic repair with stengraft implanted from groin is possible. Catheter from groin through femoral artery is inserted, catheter with spaciela covered stent – called stentgraft

Thoracoabdominal aneurysm – surgery:

For thoracoabdominal aneurysm surgery we use long incision thoracofrenolaparotomy.  Aorta is replacent with special graft. All branches have to be reimplanated (intercostal spinal cord arteries, celiac trunk, mesenteric arteries, renal arteries)

For catheter endovascular repair with branched grafts special stengraft are individualy prepared according to CT scans. Implantation is challenging procedure.

Aortic dissection:

tear in the inner wall of the aorta causes blood to flow between the layers of the wall of the aorta and force the layers apart → true and false lumen

- acute (< 2 weeks) OR chronic

During acute dissection tunica media of aortic wall is splited. So there is  weaking of the wall and increases risk of rupture.

On the other hand flow in the banches of aorta can be impaired. There is danger of i.e. pericardial tamponade (in case of rupture to pericardium) or risk of malperfusion according to localization – myocardial, brain, visceral extremity malperfusion

Aortic dissection – risk factors:

hypertension

connective tissue disorders (Marfan, Ehlers-Danlos, Turner)

degenerative or inflamatory disease of aortic wall

iatrogenic injury

atherosclerosis

bicuspid aortic valve

aortic dilatation

trauma

polycystic kidney disease

coarctation of the aorta

Aortic dissection – classification:

There are two basic types of classification…De Bakey

And frequently used Stanford classification – type A – dissection of ascending aorta (also possible going on descending) and type B – only descending aorta (after the origin of left subclavian artery) is suffered from aortic dissection.

Survival of untreated pts with type A aortic dissection:

- 50 % (36–72 %) of untreated pts with acute type A dissection die within 48 hours 

- mortality rate 1 % / hour

- the survival rate without treatment at 1 month is approximately 5%

- after 3 weeks die approx. 90 %

Aortic dissection – symptoms:

PAIN!!!

-        pre-shock symptoms (sweating, hypotension, tachycardia)

-        malperfusion (peripheral or splanchnic ischemia)

CAVE:

ALWAYS CONSIDER AORTIC DISSECTION IN CASE OF ISCHEMIC EXTREMITY !

-        neurological signs (stroke)

-        no another symptoms (some patients are only complaining chest pain)

Aortic dissection – diagnosis:

WITHOUT DELAY !!!

ECHO

CT-angio

(MR)

Aortic dissection – therapy:

Initial

           analgetics

           ANTIHYPERTENSIVE THERAPY (vasodilatation, betablockers)

Definitive

           type A - surgery !!!

           type B - no surgery

                        - intervention (stentgraft) :

                             rupture

                             malperfusion

                             pain

                             progresive dilatation >10mm/30 days

                             failure of hypertension treatment management

Aortic dissection – surgery:

Acording to range the type of surgical procedures is made.

-        Ascending aorta replacement with tubular vascular prothesis with or without aortic valve

-        replacement ascending aorta and part of aortic arch (so called hemiarch procedures)

We can replace also aortic arch with origin of aortic braches or with redirection of supraaortic vessels. We can use special graft with conected stentgraft. In case of dissection also on descending aorta cathether intervention after surgery is indicateted using so called stentgraft.

Aortic dissection therapeutic results:

Prognosis without surgery

type A - within 48 hours of the event - 50% mortality

             - survival rate at 1 month is approximately 5%

Surgery

                                                                     survival

                             early mortality       1 year            5 years  

Type A                     10-25%                     91%              75%

Type B                      20-50%                    93%               82%

stentgrafts               5-10%     

Conservative (no surgery) therapy

Type B                      10-20%

Heart transplantation:

The world's first human-to-human heart transplant was performed by South African cardiac surgeon Christiaan Barnard utilizing the techniques developed by American surgeons Norman Shumway and Richard Lower.^[Patient received this transplant on December 3, 1967, in Cape Town, South Africa. However patient died 18 days later from pneumonia.

The next big breakthrough came in 1983 when cyclosporine entered widespread usage. This drug enabled much smaller amounts of corticosteroids to prevent rejection.

indications

    terminal heart failure

    (coronary artery disease, valve disease, cardiomyopathy)

contraindications

    fixed pulmonary hypertension

    neoplasms

    active alcohol or drug abuse

    age over 65 years (individual assessment)

potential relative contraindications

    active infection, pulmonary embolism, active peptic ulcer disease

liver, kidney failure – 2 or 3 organs transplantation

Heart failure – etiology:

The main etiology of heart failure are CAD and CMP. Both around 45%.

The others are valve disease, congenital heart disease, reHTx

Heart transplantation - surgical technique:

Actually mainly bicaval technique is used which was introduced into clinical practice 30 years ago (early 90‘s). Bicaval technique is characterized by two arterial, one left atrial, and two caval anastomoses, leaving the right atrium intact and leaving only a small posterior part of recipient’s left atrial tissue between the pulmonary veins.

Heart transplantation - what happens next?

therapy:

     - immunosupression: CNI (cyclosporine, tacrolimus) + mycopfenolate + steroids

     - side effects: nephrotoxicity, diabetes, hypertension, infection, dyslipidemia,

                              bone marrow suppression,neoplasms, osteoporosis

complications after Htx:

      - RV failure, rejection, infection, cardiac allograft vasculopathy,

        complications of immunosuppressive therapy

follow-up after Htx:

      - transplant center (biopsy, level of immunosupression, coronarography – OCT)

Mechanical circulatory support:

Modern and quickly developing part of cardiac surgery is MCS. In case of heart failure heart function is supported and replaced by any type of mechanical pump.

Acording duration of support we distinguish...short-term, long-term, permanenet.

Some patients need left-, right or biventricular support.

Short term pumps are usually extracorporeal and long term are usually implantable.

Acording to flow we can distinguish pulsatile or non-pulsatile flow (patient has no pulse)!!!

Mechanical circulatory support – indication:

Postcardiotomy cardiogenic shock

         unsuccessful weaning from extracorporeal circulation  

         malignant ventricular arrythmias     

         low cardiac output syndrom

Other etiology of cardiogenic shock

        after acute myocardial infarction, after PCI, myocarditis…

Chronic heart failure

        pts on waiting list for heart transplantation

Acute rejection after HTx

Heart failure (primary graft non-function) after HTx

Patients with contraindications for heart transplantation

Intraaortic baloon counterpulsation:

The intra-aortic balloon conterpulsation (IABP) isn‘t really pump but mechanical device that increases myocardial oxygen perfusion and indirectly increases cardiac output due to afterload reduction. Balloon in descendiang aorta approximately 2 centimeters distally from the left subclavian artery inflates and deflates, actively deflates in systole and inflates in diastole. Systolic deflation decreases afterload and indirectly increases forward flow from the heart. Diastolic inflation increases blood flow to the coronary arteries by retrograde flow. Inflation and deflation is usully synchronic to electrocardiogram.

Short-term MCS – Centrimag:

For short term mechanical circulatory support we use extracorporeal (nonimplantable) pump called Centrimag.

Blood from LA-outside pump- aorta – LVAD

RA—outside pump- pulmonary artery - RVAD

BiVAD

Short-term MCS – ECMO:

Most used short term MCS is ECMO. This device pumps blood, oxygenation.

There are VV configuration in respiratory failure. We will talk abou VA configuration – as circulatory an also respiratory support.

Usually from groin – inflow cannula through the femoral vein to RA, outflow to femoral artery (subclavian artery, aorta...).

main adventages are:Transportable device, quick setup which allow quick circulation restoration.

MCS – HeartWare HVAD:

More than 10 years ago for long term support we started with implantable pump with nonpulsatile axial flow. Heart mate II. Only one driveline goes throw skin out of human body. Driveline is connected to controller and two bateries. Next LVAD generation is HeartWare HVAD. Centrifungal pump with inflow part, which insert into the LV cavitu throug the LV apex. Outlow part with prosthesis usually is usually anastomosed on ascending aorta.

MCS – HEARTMATE 3:

Now we use the newest type of LVAD- Heartmate 3. Costruction is similar to Heartware HVAD

Total artificial heart – Syncardia:

The SynCardia total artificial heart (TAH) currently provides option for patients with biventricular failure who are not candidates for isolated left ventricular (LV) assist device placement. It is pneumatic pump.

During implantation left and right ventricles are removed ant the TAH is conected with inflow part to right and left atrium a with outflow graft to pulmonary artery and ascending aorta.

TAH is asserted as BTT for pts on wainting list for Htx.

Total artificial heart – Carmat:

New type of TAH is Carmat. It is electrohydraulic pump (without any noise) with biological valve and membrane from bovine pericardium inside.

Carmat is the first auto-regulating artificial heart able to mimic the natural physiology of the human heart.

MCS – future:

When we talk about MCS. We can talk aso about the future. The future can be in miniaturization – mainly external components,

 in wireless technology – without driveline. In telemonitoring.

All pts with MCS need AKT. There is the question if the MCS future wil be w/o anticoagulation.

Infective endokarditis:

Despite improvements in its management, IE remains associated with high mortality

and severe complications.

Low-grade (but repeated) bacteraemia occurs more frequently during daily routine activities - toothbrushing, flossing or chewing - more frequently in patients with poor dental health

Most case – control studies did not report an association between invasive dental procedures and the occurrence of IE risk of IE following dental procedures is very low

Take-home message:

- the most often used approach in cardiac surgery is median sternotomy

- arterial grafts have better long-term patency than venous grafts in coronary revascularization

- valve repair (if it’s possible) is better than valve replacement

- acute aortic dissection type A is life-threatening condition with high mortality without surgery

Learning target

- basic principles in cardiac surgery

- cardiac surgery in congenital heart diseases

- cardiac surgery in acquired heart diseases

- cardiac surgery in heart failure – heart transplantation, mechanical circulatory support

References:

Commented presentations on IS.MUNI are integral part of this education text

Heart valve surgery, Jan Dominik, Pavel Žáček, Grada, 2008, ISBN 978-80-247-2712-7

Heart Transplantation, James K Kirklin, ISBN-13: 978-0443076558

https://www.ctsnet.org/perspectives-cardiothoracic-surgery-scts-ionescu-university

https://www.ctsnet.org/perspectives-cardiothoracic-surgery-scts-ionescu-university-volume-ii

https://www.ctsnet.org/perspectives-cardiothoracic-surgery-scts-ionescu-university-volume-iii