A newly designed thoracic support vest prevents ... - gd medical AG

A newly designed thoracic support vest
prevents sternum instability after
median sternotomy
1 Wagner FM, 2 Gorlitzer M, 1 Sprathof N, 1 Seiffert M, 2 Folkmann S,
2 Thalmann M, 2 Grabenwoeger M, 1 Reichenspurner H
Depts. for Cardiovascular Surgery
1 2 Universitäres Herzzentrum Hamburg & 2 & Krankenhaus Hietzing, Wien

120
100
80
60
40
20
0
Deep sternal infection: up to 5%
Mortality ~ 25%
Prolonged hospital stay
Estimated additional cost 2.8 times higher
Braxton et al.: Postoperative survival rate after mediastinitis
Observation Period: 4 years - 15.906 patients
97
93 95
78
89
30 days 1 year 4 years
Background
69
Without mediastinitis
With mediastinitis
Occurence:
During hospitalization: 4.7 %
30 days postoperative:
6.8%
90 days postoperative: 9.0%
D.Jonkers, T.Elenbaas, F.Nieman, E.Stobberingh
European Journal of Cardio-thoracic Surgery 23 (2003) 97-102

To test efficacy and acceptance of a newly designed
thorax support vest to prevent sternum instability and
infections post sternotomy
To develop risk score for postoperative sternum
instability and infections
Aim of the Study
Posthorax® sternum vest (Epple Inc., Vienna, Austria)

Vest Concept and Design
Anteroposterior compression
Sternotomy
cushions

Vest Concept and Design
- allows normal breathing
- stopps over-extension of the thorax
Coughing pressure: 400-1200 N = 40-120 kg (1)
Coughing velocity: 28,000 cm/s = 800 kmH (2)
(1) (The Mechanism of Syncope after Coughing, E. P. Sharpey-Schafer)
(2) (Biomechanical Comparison of Median Sternotomy Closures, Losanoff et al, 2004)

- Prospective 2-center study
- Central randomization
- 90 day follow-up
- Number of patients: n=2000 n= 2000 calculated
- Current analysis:
Study Design
all. pats with complete follow-up until Jan.09

600
500
400
300
200
100
0
400
Groups
482
Patients
85
Patients
Vest
No Vest
Refused
Sept. 07 – Jan 09:
n = 967
age 68±13 68±13
years
9,6% refused vest

Patient Risk Profile
% Group Distribution
80
70
60
50
40
30
20
10
0
Male Female Diabetes COPD Perif.vasc.dis MI Complex Surg Perf 100 min+ Perf 200 min+
Vest Group
Non Vest Group
Refused Vest Group

%
70
60
50
40
30
20
10
0
Operative Data
Group Distribution
CABG CABG+BIMA AKE MKE/R AKE+CABG MKE/R+CABG DKE Aneurysm
Vest
Non Vest
Refused Vest

BMI
40
38
36
34
32
30
28
26
24
22
20
18
16
Box Plot of BMI grouped by Gruppe
Vest ref. Vest no Vest
BMI: KW-H(2,875) = 4.4904, p = 0.1059 Gruppe
Euroscore log
20
18
16
14
12
10
8
6
4
2
0
Risk Score Comparison
BMI Age Weight
Euroscore log
Box Plot of Euroscore log grouped by Gruppe
Vest ref. Vest no Vest
Euroscore log: KW-H(2,200) = 0.0706, p Gruppe = 0.9653
Median
25%-75%
Non-Outlier Range
Median
25%-75%
Non-Outlier Range
PreOP: Alter
100
90
80
70
60
50
40
30
20
Box Plot of PreOP: Alter grouped by Gruppe
Vest ref. Vest no Vest
PreOP: Alter: KW-H(2,1007) = 3.6103, p = Gruppe 0.1644
Total Score
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
-2
STS Score
Box Plot of Total Score grouped by Gruppe
Vest ref. Vest no Vest
Total Score: KW-H(2,972) = 6.1426, p = 0.0464 Gruppe
Median
25%-75%
Non-Outlier Range
Outliers
Extremes
Median
25%-75%
Non-Outlier Range
Gewicht
200
180
160
140
120
100
80
60
40
20
Box Plot of Gewicht grouped by Gruppe
Vest ref. Vest no Vest
Gewicht: KW-H(2,873) = 4.3031, p = 0.1163 Gruppe
For each graph:
Median
25%-75%
Non-Outlier Range
Outliers
Extremes
Box left: Vest
Box middle: Refused vest
Box right: No vest

Prevalence of
Wound Complications
Deep sternal infections, superficial infections, dehiscence
%
3,5
3
2,5
2
1,5
1
0,5
0
0,35
3,17
1,41 1,41
0,88
1 - 4 days 5 - 10 days 11 - 15 days 16 - 30 days 31 - 90 days
Post operative days

Results
90 days follow-up
Non vest &
refused group Vest group
Total sternal wound
Complications 6,86 % 0,50 %
Deep sternal wound
complications 4,93 % 0,00 %
Superficial wound
complications 1,41 % 0,50 %
Dehiscence 0,52 % 0,00 %
(no infection)
p < 0,005 Fishers Exact Test

Incidence (%)
º
º
ººCompl
º
Results
90 days follow-up
º
ºº
ºº
p < 0,001 ANOVA group comp.
Refusal reasons:
- Discomfort
- Pain
- breathing obstruction
- aesthetics
Vest carriage:
- 31 ± 10 days

Days OP to Discharge
Box Plot of Days OP to Discharge grouped by Gruppe ohne Ausreißer
24
22
20
18
16
14
12
10
Days OR to Discharge
no Vest ref. Vest Vest
Days OP to Discharge: KW-H(2,909) Gruppe = 1.8076, p = 0.4050
Hospitalization
Mean±SE
Mean±0.95 Conf. Interval
ICU Length of Stay
ICU Aufenthalt
60
50
40
30
20
10
0
Box Plot of ICU Aufenthalt grouped by Gruppe
Vest ref. Vest no Vest
Gruppe
Median Test, Overall Median = 2.00000;
ICU Aufenthalt Independent (grouping) variable: Gruppe
Chi-Square = 5.700729 df = 2 p = .0578
Median
25%-75%
Non-Outlier Range
Outliers
Extremes

Vest acceptance rate >90%, main reason for denial discomfort
The use of the Posthorax® vest reduced sternum wound
complications significantly
Highest incidence of wound complication in refusal group
More than 50% of wound complications occurred after
hospital discharge
Significant reduction of re-operations lead to cost
effectiveness
Summary