Complications in Valvular Heart Surgery

Complications in Valvular Heart

Surgeryนพ.ณัฐพล อารยวุฒกิลุศูนยโ์รคหัวใจโรงพยาบาล

ลำาปาง

Technique related complications

• Massive bleeding require reoperation

• Heart block• Stroke• Perioperative MI• Valve dysfunction• Incomplete correction

Valve related complication

• Thromboembolism and Bleeding

• Endocarditis• Structural deterioration• Prosthetic valve thrombosis • Prosthetic-Patient Mismatch

Serious bleeding

• Mediastinal bleeding requiring reoperation 5-11%

Serious mediastinal bleeding

• Infant 6 kg– 70 cc in first hour– 60 cc in second

hour– 50 cc in third hour– Total 130 cc by

fourth hour– Total 150 cc by fifth

hour

• Adult 50 kg– 500 cc in first hour– 400 cc in second

hour– 300 cc in third hour– Total 1000 cc by

fourth hour– Total 1200 cc by

fifth hour

Preoperative precautions

• Aspirins– Should be stopped 1 week prior to surgery

• Clopidogrel and ticlopidine– Should be stopped at least 1 week prior to

surgery• NSAIDs

– Should be stopped 1 day before surgery• Warfarin

– Should be discontinued 3 days before surgery

Predisposing comorbid metabolic abnormalities

• Uremia– Plt dysfunction/impaired vWf action– Plt transfusion usually not effective– Adequately dialyzed preoperatively– FFP , Cryoprecipitate and DDAVP are

considered

Predisposing comorbid metabolic abnormalitiesAcute liver dysfunction• Impaired synthesis

function of factor 2,7 9 10 • Fibrinogen and platelets

may be low• Increased fibrinolysis

process• Preop vitamin K , FFP and

platelets must be transfused to correct or normalize PT and platelet counts

DIC eg IE pt.• Elevated D-dimers,

thrombocytopenia, prolonged PT/PTT

• In adequated heparinization during CPB leading to thrombosis in the oxygenator of the pump

How to prevent postoperative bleeding

• Strict avoidance of hypertension• Aware of heparin rebound ( up to about 6 hrs.

postop)• Anti fibrinolytic drugs

– Tranexamic acid• Load 2.5-100 mg per kg over 30 mins• Continuous infusion 1-4 mg/kg/hr over 1-12

hr.– Desmopressin(DDAVP)

• Vasopressin analogue, increase factor 8 and von Willibrand’s factor

• IV 0.3 microgram per kg

Left Ventricular Rupture

• Left ventricular rupture– Major lethal complication of MVR– Mortality ~ 75%– Risk factors

• Female sex, advanced age,small left ventricle, previous operation

• Extensive retraction of papillary muscle, inadvertent injury to annulus, too large prosthesis, impingement by a valve strut and deep sutures to the myocardium

Left Ventricular Rupture

Ann Thorac Surg 46 Nov 1988

LV Rupture Type 1

LV Rupture Type 2

LV Rupture Type 3

Repair LV rupture

Repair LV rupture

Heart Block• Heart block requiring a permanent

pacemaker ~1% following AVR and MVR

Heart Block• Heart block requiring a permanent

pacemaker ~2-7% following TVR

Stroke

• Incidence*

–4.8% in aortic valve surgery–8.8% in mitral valve surgery–9.7% in double valve surgery

*Ann Thorac 2003;Feb 75(2) 472-8

*Ann Thorac 2003;Feb 75(2) 472-8

Stroke• Aortic plaque*

– Intraop palpation can detect around 50%

– TEE – better than manual palpation but less sensitive in the mid and distal ascending Aorta

– Epiaortic U/S – sensitivity 96.8%*Chest 2005; 127:60-65

Stroke• Left Atrial clot• Air

– Cardiac vent + Aortic root vent– Intraoperative CO2 blowing 6-8 L/min– Inversion of the left atrial

appendage/obliterate LAA– Tilting of the table from side to side with

inflation of the lungs to dislodge any pulmonary vein bubbles

– TEE

Stroke• Valve position (mitral versus aortic),

adequacy of anticoagulation, presence of atrial fibrillation, and patient comorbidities.

• Interestingly, the risk of thromboembolism appears equal regardless of whether the prosthesis is a mechanical or bioprosthetic valve.

Perioperative MI

Perioperative MI

Perioperative MI• (TEE) was invaluable in confirming

the diagnosis in the setting of acute ventricular fibrillation and new left bundle branch block.

• Iatrogenic injury to coronary arteries is a known complication of aortic valve surgery, and was the likely source of the ischemia and resultant arrhythmia.

Valve Dysfunction• Sutures loop around the struts• Free ends of the sutures must be

short and placed properly to avoid being caught in the closing prosthetic leaflets

• Subvalvular tissue

Valve Dysfunction• Periprosthetic leakage

–Usually there is no different between mechanical and bioprosthetic valve

Predisposing factors

• annular calcification• Infection• PPM• Excessive tension on suture or

annulus• Incorrect / insufficient number of

sutures

Incomplete Correction

• Residual regurgitation• Stenosis • SAM (Systolic anterior

motion)

Systolic Anterior Motion

• Adverse outcome after valve repair• Anterior leaflet obstruct LVOT• Etiology

– Increased redundancy in leaflet tissue– Small annuloplasty ring

Systolic Anterior Motion

Systolic Anterior Motion

• Treatment Medical Rx if parameter of repair is good– Avoid inotropic drug except for norepinephrine– Maintain adequate preloadSurgical Rx – Posterior leaflet sliding procedure – Slightly oversized the annuloplasty ring– Use Alfieri stitch to A1/P1– Implant Gortex suture to reduce height of

anterior leaflet

Thromboembolism and Bleeding

• Major causes of thromboembolism– Interrupted anticoagulant or inadequate

INR• High risk group*:

– Prior embolic complications– AF– Left atrial thrombus– Recent operation ( first operative year )– Operation before the mid 1970s

Thromboembolism

• MVR – more common due to AF and large LA• AF – important factor for

thromboembolism• Multiple valve replacement higher

embolic rate

Anticoagulant-related Hemorrhage

• Incidence - 1%-4% per person year - same rate in MVR and AVR - Risk: increase in INR > 4.0

Prosthetic Valve Endocarditis

• Early - within 2 months - incidence 1% per patient/year - mortality 50%-70% - highly destructive process valve ring abscess &

paravalvular leaks and conduction disturbances

Prosthetic Valve Endocarditis

• Early PVE has higher mortality rate ( 75% VS 43% ) due to–Predominance of nonstreptococcal

mechanisms–More debilitated patients– Involve freshly implanted,

nonendothelialized valve and sewing ring

Prosthetic Valve Endocarditis

• Late - more than 2 months - Source of infection : Dental and

Genitourinary tract - Mechanical sewing cuff - Bioprosthesis cusps(leaflets) less at sewing cuff paravalvular leaks

rare

Prosthetic Valve Endocarditis

• Indication for Surgery• Early prosthetic valve endocarditis (first 2 mo) • Heart failure with prosthetic valve dysfn • Evidence of perivalvular extension• Persistent infection after 7-10 d of adequate ATBs• Recurrent emboli despite appropriate ATBs• Infections due to organisms with poor response

ATBs• Obstructive vegetation

Structural Deterioration

• Bioprosthetic Valve Failure - freedom from valve deterioration for the

two most commonly used bioprosthesis valve ( Carpentier-Edward and Hancock ) is between 60% and 80% at 10 years and drops sharply to 45% at 14 years

- Mitral valve higher rate of failure

Prosthetic valve thrombosis

• Any obstruction of a prosthesis by non infective thrombotic material

• Incidence: 0.5-8% in Lt. sided mechanical Valve 20% in tricuspid position• Thrombosis 77%• Pannus 10.7%• Pannus + Thrombosis 11.6%• Mitral position more frequent than aortic position

Prosthetic valve thrombosis

• Obstructive PVT abnormal dyspnea, heart failure• Non-obstructive PVT embolic episode• Echo findings:

– Abnormal movement of prosthesis– Paraprosthetic thrombus– Abnormal transprosthetic flow– Mitral gradient > 8 mmHg, effective area < 1.3 cm2

– Aortic mean gradient > 40 mmHgHeart 2007;93:137-142

Prosthetic valve thrombosis

• Surgery Mortality: 4% in pt with FC I-III 17.5% in pt with FC IV• Thrombolysis: success 82% mortality 10% systemic emboli 12.5% bleeding 2-5%

J.Heart Valve Dis Vol.14. No.5. Sep 2005

Prosthetic valve thrombosis

• Emergency operation is reasonable for patients with a thrombosed left-sided prosthetic valve and NYHA functional class III-IV or a large clot burden (IIa level C)

• Fibrinolytic therapy is reasonable for thrombosed right-sided prosthetic heart valves with NYHA class III-IV or a large clot burden (IIa level C)

ACC/AHA Practice Guidelines 2006

Prosthetic valve thrombosis

• Fibrinolytic Rx may be considered as a first-line Rx for patients with a thrombosed left-sided prosthetic valve, NYHA class I-II, and a small clot burden (IIb level B)

• Fibrinolytic Rx may be considered as a first-line Rx for patients with a thrombosed left-sided prosthetic valve, NYHA class III-IV or a large clot burden if Sx is high risk or not available (IIb level C)

ACC/AHA Practice Guidelines 2006

Prosthetic valve thrombosis

• Intravenous UFH as an alternative to fibrinolytic therapy may be considered for patients with a thrombosed valve who are in NYHA class I-II and have a small clot burden (IIb level C)

ACC/AHA Practice Guidelines 2006

Which type of valve to be selected

• Risks of anticoagulant-related bleeding

• Risks of structural failure• Risk of reoperation• Underlying medical or surgical

problems

Prosthetic-Patient Mismatch

• Prevention - Implant another type of

prosthesis with large EOA such as stentless valve

- Enlarge the aortic root

Thank you for

your attention