Recent Trends in Cardiopulmonary bypass - Pathophysiology - 부천 세종병원 김 재 현 대한흉부외과학회 제 24 차 춘계학술대회 Sejong General Hospital

Recent Trends in Cardiopulmonary bypass

- Pathophysiology -

부천 세종병원 김 재 현

대한흉부외과학회 제대한흉부외과학회 제 2424 차 춘계학술대회차 춘계학술대회Sejong General Hospital

대한흉부외과학회 제 24 차 춘계학술대회Sejong General Hospital

History

o 1953. John Gibbon• the first successful cardiac surgery(ASD repai

r) using a pump-oxygenator

o 1955. John Kirklin• the second successful cardiac surgery(VSD re

pair) using a pump-oxygenator(‘Mayo-Gibbon bypass machine’)


22ndnd Mayo-Gibbon Bypass Mayo-Gibbon Bypass Machine, since 1957Machine, since 1957


Cohn LH. 3rd Edi. Fig 12-1.

Basic CPB Circuit


CPB Circuit in Real Setting


Venous Cannulas


Venous Drainage

o Gravity or Siphonage

o Affected by• CVP, PVR• Height differential• Resistance in cannula, tubing• Absence of air


Tips to controlpoor venous drainage

o Check air-lock and tubing lineo Check venous cannula positiono Control table Heighto Check CVP, PVR – Volume replacem

ent or alpha agonistso Change venous cannula


Assisted Venous Drainage(AVD)

o Kinetic-AVD / Vaccum-AVDo Advantages

• smaller diameter catheter• smaller priming volume

o Drawbacks• risk of aspirating gross or microscopic air• hemolysis• positive pressure in the venous reservoir – air enterin

g to RA (Davila RM. Ann Thorac Surg 2001;71:1369.)


Venous Reservoir


o Open type(ORS)• easier management, larger capacity, easier prime, le

ss expensive• Hemolysis, material-dependent activation, silicon anti

foam compounds, massive air embolism risk(* safety device)

o Closed type(CRS)• soft, collapsible, eliminate blood-gas interface, reduc

e the risk of massive air embolism

Venous Reservoir


Venous Reservoir

o Schönberger JP. Ann Thorac Surg 1995;59:1549.• CABG, ORS(10)/CRS(10), prospective randomized –

decreased systemic blood activation, hemolysis, postop. Blood loss.

o Brown mahoney C. Perfusion 2000;15:467.• CABG, ORS(616)/CRS(1065), retrospective – sepsis

(1%/0%), resp. failure(4%/1%), shorter hospital stay(9.8d/7.5d), less blood product use


Pump


o Nearly occlusiveo Afterload independento Low prime volumeo Low costo No potential for backflowo Shallow sine-wave pulseo Excessive positive and negative pres

sureo Spallation / Tubing ruptureo Risk of massive air embolism

o Nonocclusiveo Afterload sensitiveo Large priming volumeo Higher costo Potential passive backflowo Safe positive and negative press

ureo Adapts to venous returno Superior for right or left heart byp

asso Preferred for long-term bypasso Protects against massive air emb

olism

Roller Vs. Centrifugal


Pumpo Moen O. Ann Thorac Surg 1996;62:1134.

• CABG, R(10 H/10 U)/C(10 H/10 U), prospective randomized – less hemolysis in centrifugal, heparin coating reduces complement, granulocyte, platelet activation.

o Morgan IS. Eur J Cardiothorac Surg 1998;13:526.• pediatric pts, R(23)/C(22), prospective randomized – less blood traum

a, reduced platelet activation, less imflammatory response, better clinical outcomes

o Klein M. Artif Organs 2001;25:300.• Adult OHS pts, R(500)/C(500), prospective randomized – less chest tu

be drainage, transfusion, shorter hospital stay


o Ashraf S. Ann Thorac Surg 1998;66:1958.• CABG, R(21)/C(20), prospective randomized – IL-6, TCC, neutro

phil, elastase ↑, greater systemic inflammatory response

o Baufreton C. Ann Thorac Surg 1999;67:972.• CABG, R(15)/C(14), prospective randomized – greater complem

ent(SC5b-9) and neutrophil(elastase) activation during op., similar inflammatory response(TNF-α, IL-6…)

• *afterload sensitive – inadequate intestinal perfusion during hypothermia – additional inflammatory responses(endotoxin)


Heat Exchanger


Tips on Temperature control

o Gases are more soluble in cold than in warm blood.• Temperature difference ≤ 5~10°C

o Hypothermia increases blood viscosity.• Hemodilution

Hct 25% ( 20% in deep hypothermia)

• During rewarming – packed cells, ultrafiltration

o Heat may cause protein denaturation.• < 40°C


Hemodilutiono DeFoe GR. Ann Thorac Surg 2001;71:769.

• 6980 CABG pts, Multi-center trial – The lowest Hct. during CPB increases the risk of hospital mortality, IABP, CPB weaning failure.

o Habib RH. J Thorac Cardiovasc Surg 2003;125:1436.• 5000 OHS, retrospective – Increased hemodilution d

uring CPB was associated with worse periop. vital organ dysfunction, morbidity, increased resource use, greater intermediate-term mortality.


Oxygenator


Oxygenator

o Membrane oxygenator(vs. Bubble)• Safer, less particulate and gaseous microemboli, les

s reactive to blood elements, superior control of blood gases

• Hollow fiber type / Spiral coil type* (prolonged perfusions)

o Membrane Polypropylene(PLP) - 0.3 ~ 0.8 μm Silicon rubber Polymethylpentene(PMP) - 0.05 μm


PMP oxygenator

o PMP(poly-4-methyl-1-pentene) membr.• (Memrana GmbH, Wuppertal, Germany)

o 0.05 μm pore, tight membrane• solution-diffusion, low resistance, low priming volum

e, reduced blood contact

o reduce the risk of gas emboli & plasma leakage


PMP oxygenator

o Hortons. Perfusion 2004;19(1):17.• 2000.7~, 23 ECMO pts(mean wt; 3.56kg) – no oxyge

nator change due to device failure, Longest time 1119hrs(47d)

o Khoshbin E. Perfusion 2007;22:15.• PMP(20:20)/Silicon(20:20), ECMO pts., retrospective

–significant reduction in X-ray signs of inflammation and in time taken to subsidence of X-ray changes(neonate group), delayed inflammatory changes in X-ray(adult group)


Filters


Filters


Filters


Microembolio <500 μm diametero Sources:

• Gas – bubble oxygenator, air entry into the circuit, residual air in the heart, loose purse-string sutures, cardiotomy reservoir, rapid warming, cavitation

• Foreign – atheromatous debris, fat, fibrin clot, cholesterol crystals, calcium particles, muscle fragments, tubing debris, dust, bone wax, silicone antifoam, glue, surgicel, cotton sponge fiber

• Blood – fibrin, free fat, aggregated chylomicrons, denatured proteins, platelet aggregates, platelet-leukocyte aggregates, hemolyzed red cells, transfused blood


Tips tominimize microemboli

o Membrane oxygenator, centrifugal pumpo Cardiotomy reservoir filtero Arterial line filter/bubble trapo Temperature difference < 8~10°Co Prime with CO2 flush; recirculate with saline and filtero Prevent air entry into the circuito Use cell savero Adequate anticoagulationo Epiaortic ultrasound scanningo Consider use of special aortic cannula

Intracardiac irrigation and Deairing


Aortic cannulas


High velocity jets from A. Cannula

o “Sand-blasting effect”• damage the aortic wall• dislodge atheroemboli• produce dissections• disturb flow to nearby vessels• cause cavitation and hemolysis


Breakdown of Atheromatous Plaque

Preop. Postop.

Ann Thorac Surg 2007;84:e17– 8.


Sarns Soft-flow cannula

Baxter RMI dispersion cannula

2217 CABGs – 2.3% stroke, Left side(75%)

Ann Thorac Surg 2001;71:128.

Flow Characteristics of A. Cannulas


Mean Velocities of A. Cannulas

Mean velocities in TEE

----- 318/296/271

(Cm/s)

----- 351/240/171

----- 174/138/90

(P<0.05)

Ann Thorac Surg 2003;75:1919.


EMBOL-X® filtration system

Heparin-coated 120μm polyester mesh net


EMBOL-X® cannulao Banbury MK. Ann Thorac Surg 2003;76:508.

• EmbolX(645)/control(644), multi-center(22) trial – emboli(96.8%), more than moderate risk pts. - renal Cx(14%/24%), Composite endpoint(24%/36%)

o Horvath KA. Heart Surg Forum 2005;8:E161.• EmbolX(2297), multi-center(39) trial – emboli(98%), high risk pt

s.(No. 8.5/5.8, SA 6.6/4.0mm2), fibrous atheroma(79%), platelets/fibrin(44%), thrombus(8%), foreign(2%)

o Leyh RG. Eur J Cardiothorac Surg 2002;21:100.• 60/M, Redo MVR in endocarditis pt. – Acute type A dissection


Dual-stream baffle cannula(CobraTM catheter)


Ascending a. cannulation

o Site selection• mannual palpation, TEE• epiaortic ultrasonic scanning *

o Complications• Difficult insertion, bleeding, tear, malposition, athero

matous emboli, injury to aortic back wall, problems with cerebral perfusion, aortic dissection, late bleeding and false aneurysm.


Aortic dissection

o 0.01~ 0.1% of a. cannulationso Clues

• adventitia discoloration• arterial line pressure increase• sharp reduction in venous return

o Management• Prompt a. cannulation site change – HCA - repair or r

eplacemento Survival rate

• 66~85%(early recognition), 50%(late discovery)


MBC 드라마

‘ 뉴하트’


Circuit coatings

o To increase biocompatability• ↓: SIR(systemic inflammatory response) -Compleme

nt activation, granulocyte activation, platelet adhesion, cytokine release

• ↑: platelet function, clinical outcomes(pulmonary function)

o Coating materials• Heparin coating(ionic or covalent)• PMEA(poly-2-methylethylacrylate)• Triblock copolymer


Heparin Coating Circuit

o Ranucci MR. Ann Thorac Surg 1999;67:994.• High risk OHS pts, H(442)/U(444), Multi-center(12) randomize

d, full heparin – ICU & hospital stay ↓, severely impaired clinical outcomes ↓, protective effect on lung and kidney function

o McCarthy PM. Ann Thorac Surg 1999;67:1268.• Redo-operation pts, H(173)/U(177), prospective randomized, fu

ll haparin – major bleeding(1.2%/5.4%), protection from reoperation for bleeding


Summaryo Assisted venous drainage

• smaller cannula and smaller priming volumeo Closed reservoir system

• less hemolysis and systemic blood activationo Centifugal pump

• less blood trauma and sytemic inflammatory response(normothrmic condition)

o Hemodilution• increase morbidity and motality

o PMP oxygenator• reduced blood contact, increased durability

o Circuit coating• Increase biocompatibility


Miniaturized CPB

o Alternative method of OPCAB

o Choices• MECC®(Jostra AG, Germany)• Carmeda coating(Medtronic, USA)• CorX®(Cardiovention Inc., USA)• Synergy mini-bypass system(Cobe)


MECC®

Components• PMP oxygenator(Quadrox D®)• Centrifugal pump(Rotaflow®) • Heparin coated short lines(Bioline®)• Integral heat exchanger• KAVD / No venous reservoir

o Closed circuit →+vent→ Semiclosed o Heparin: 150 IU/kgo Warm high potassium blood cardioplegia(Calafio

re formula)o Mild hypothermia


MECC®

system


MECC®

o Characteristics• Hemodilution ↓(priming vol. 450~500cc), for

eign surface area ↓, air-blood interface xo Drawbacks

• Air entry and lock, volume control – close observation

• Distal anastomosis in CABG – bloody field


MECC®

o Wiesenack C. Artif Organs 2004;28:1082.• CABG, MECC(485)/Control(485), retrospective – intraop. lactate

↓, postop. Complication, blood usage ↓

o Remandi JP. Am Heart J 2006;151:198.e1.• CABG, MECC(200)/control(200), prospective randomized – LCO

S(0.66%/4%), CRP ↓, transfusion(6%/12.8%), BUN/Cr ↓• 450 MECC cases (150 AVRs, 5 Mitral ops, 4 redo.) – air entry

(3)

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Recent Trends in Cardiopulmonary bypass - Pathophysiology - 부천 세종병원 김 재 현 대한흉부외과학회 제 24 차 춘계학술대회 Sejong General Hospital