GUIDELINES FOR THE USE OF

NEGATIVE PRESSURE WOUND THERAPY (NPWT)

FOLLOWING CARDIAC SURGERY

Dr. Ammar Mustafa

Head of Wound Care Service

Heart Hospital, Doha, Qatar

EWMA Meeting, Copenhagen, Denmark, May 2013

INTRODUCTION

Postoperative wound complications post cardiac surgery, deep sternal infections in particular, are associated with increased morbidity and mortality.

Negative Pressure Wound

Therapy (NPWT) is a well

established modality in the

management of infected

sternal wounds. However, it is a

relatively new modality of

treatment for clean and closed

surgical incisions.

INCISION MANAGEMENT SYSTEM (PREVENA)

Definition:

Powered Negative Pressure dressing

designed for clean & closed surgical

incisions in patients at risk for developing

post-operative wound complications.

Mechanisms of action:

1. Holding incision edges together

reduces chance of wound dehiscence.

2. Promoting wound tissue perfusion

& improving lymph flow.

3. Redistributing skin strain

reduces lateral tension.

4. Reducing hematoma, seroma & edema

via Negative Pressure suction.

5. Protecting the surgical site from infection

wound interface layer contains silver

which reduces microbial colonization of

the wound.

METHODOLOGY

We utilized NPWT over a period of 6 months in the treatment of sternotomy incisions in patients considered high risk for complications such as surgical site infection and wound dehiscence.

There are no specific clinical indications in the literature for the use of NPWT for clean closed sternotomy wounds following Cardiac Surgery.

We have looked at our 6 months experience with this type of dressing to check if we can define some indications.

GUIDELINES

1. Obesity (BMI > 30 kg/square meter).

2. Uncontrolled diabetes (HbA1c > 8%).

3. Bilateral Internal Mammary Arteries harvesting.

4. Heavy smoking and COPD.

5. Fragile substance of sternal bone .

6. Delayed primary closure of sternal wounds.

7. Secondary closure of sternal wounds.

8. Repeat median sternotomies for “Redo” operations.

DISCUSSION

NPWT has been applied to 47 patients with one or more of the above criteria immediately after closure of sternotomy wounds.

The dressing was removed after 6-7 days. The primary end point was the development of wound complications within 30 days.

Only 1 patient developed sternal wound infection (2.1%) compared to 5 patients (10.6%) from a similar control group of 47 patients with no postoperative NPWT.

We have also used NPWT (Prevena) after secondary closure of 3 thigh wounds that had to have haematomas evacuated at the sites of long saphenous vein harvesting for Coronary Artery Bypass Grafting (CABG) with good results.

CASE PRESENTATION: 1- MORBID OBESITY

History:

43 year old (morbidly obese)

gentleman (BMI of 52).

He had resection of a huge

Thymoma through Median

Sternotomy incision.

Procedure:

ZipFix System of sternal closure has

been used because of the high BMI.

NPWT (Prevena) has been used for

7 days.

Result:

No wound problems.

CASE PRESENTATION: 2- FRAGILE STERNUM

History:

74 years old diabetic gentleman

with severe Aortic Stenosis.

He underwent Biological Aortic

Valve Replacement. His sternal

bone was fragile.

Procedure:

His sternum was closed using

Modified Robicsek technique.

NPWT (Prevena) was applied for

7 days.

Result:

Good wound healing, stable

sternum and no complications.

CASE PRESENTATION: 3- DELAYED STERNAL CLOSURE

History:

52 years old gentleman with severe 3 vessel

Coronary Artery Disease, poorly controlled

diabetes and morbid obesity.

He had CABG with good wound healing

initially but he was readmitted with

Mechanical Dehiscence of the lower half of

the sternum after one month.

Procedure:

Modified Robicsek closure of Pseudoarthrosis

of the lower half of the sternum. NPWT

(Prevena) for 2 weeks.

Superficial wound infection treated with IV

antibiotics for 2 weeks.

Result:

Good wound healing subsequently.

CASE PRESENTATION: 4- SECONDARY STERNAL CLOSURE

History:

72 years old diabetic lady with poor left

ventricular function. CABG for 3 vessel

Coronary Artery Disease with Bilateral

Internal Mammary Arteries harvesting.

Hemodynamic instability upon sternal

closure. Therefore the chest was left open

(covered with dressing) for 48 hours for the

myocardial edema to subside.

Procedure:

Sternum was then closed with wound

tension sutures and good hemodynamics.

NPWT (Prevena) was applied for 7 days.

Result:

Excellent wound healing result.

CASE PRESENTATION: 5- INFECTED THIGH HEMATOMA

History:

58 year old obese and diabetic lady she

developped an infected left thigh

hematoma post CABG at the site of long

saphenous vein harvesting.

Procedure:

Evacuation of the hematoma PLUS

V.A.C. therapy & Antibiotics for 2 weeks.

CASE PRESENTATION: 5- INFECTED THIGH HEMATOMA

After 2 weeks:

Space filled with granulation tissue and

Infection cleared.

Procedure:

Secondary wound closure PLUS

Prevena dressing for one week.

Result:

Good healing with no wound complications.