Blunt Traumatic Aortic Rupture and the Aortic Response to High - - PowerPoint PPT Presentation

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Blunt Traumatic Aortic Rupture and the Aortic Response to High - - PowerPoint PPT Presentation

Oct 28, 2023 500 likes •685 views

Blunt Traumatic Aortic Rupture and the Aortic Response to High Speed Impact MARK COHEN AND LYES KADEM Blunt Traumatic Aortic Rupture (BTAR) In North America, approximately 19% of all auto accident fatalities are caused by BTAR. Second

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SLIDE 1

Blunt Traumatic Aortic Rupture and the Aortic Response to High Speed Impact

MARK COHEN AND LYES KADEM

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SLIDE 2

Blunt Traumatic Aortic Rupture (BTAR)

▪ In North America, approximately 19% of all auto accident fatalities are caused by BTAR. ▪ Second in fatalities only to Cranial Trauma, BTAR is a condition characterized by the rupture of the aorta and subsequent internal haemorrhaging due to high-speed impacts. ▪ Due to the difficulty in diagnosing this condition, patients who have been in auto accidents and who seem otherwise healthy, may die days after the fact. ▪ While the general cause for BTAR is understood to be high-speed impact, the physiological causes are scarcely understood due to the clinical and ethical constraints of human testing for such a condition. ▪ As such, we have no definitive answer to the mechanism of action of BTAR, though we do have a few theories.

▪ Aortic Stretching ▪ Shearing and Bending stresses due to aortic flexing over the pulmonary artery. ▪ Aortic “water hammer” effect ▪ Osseous Pinch

Source: Branchereau and Jacobs, Vascular Emergencies

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SLIDE 3

OSCAR

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SLIDE 4

The System

Signal generation and acquisition using LabView 3D Printed Rib Cage Aorta with Pressure Probe

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SLIDE 5

Test Parameters

20 40 60 80 100 120 140 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

Pressure (mmHg) Time (s)

Normal Pressure Waveform

  • Pulsatile Flow – Normal Pressure (120/80

mmHg)

  • Pulsatile Flow – High Pressure (160/120

mmHg)

  • Pulsatile Flow – Low Pressure (90/50

mmHg)

  • Continuous Flow – Normal Pressure (115

mmHg)

  • No Flow (gauge pressure 0 mmHg)
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SLIDE 6

Test Procedure

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SLIDE 7

Acceleration Profile

A similar acceleration profile was observed for all tests (±2g).

  • 35
  • 30
  • 25
  • 20
  • 15
  • 10
  • 5

5 10 2 4 6 8 10 12 14

Acceleration (g) Time (s)

Normal Pressure - Peak at Diastole - Acceleration Waveform

Acceleration Profile

Ma Max G-Force: e:

  • 28.39g

.39g

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SLIDE 8

Results – Pressure Probe in the Descending Aorta

50 100 150 200 250 300 1 2 3 4 5 6 7 8 9 10

Time (s)

OSCAR PRESSURE WAVEFORM AT 100% SPEED

Before Impact After Impact Impact

Pressure (mmHg)

▪ The waveform shows a pressure spike to 250 mmHg at the moment of impact, and then a return to normal after approximately 4 seconds.

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SLIDE 9

50 100 150 200 250 300 350 400 1 2 3 4 5 6 7 8 9

Pressure (mmHg) Time (s)

Normal Pressure Waveform - Peak at Diastole

Pressure Profile Systole Point

Ma Max Pressu essure: e: 326.34 .34 mmHg mmHg

Results – Pressure Probe in the Ascending Aorta

▪ The waveform shows a pressure spike to 326.34mmHg at the moment of impact, and then a return to normal after approximately 4 seconds.

After Impact Before Impact Impact

Avera erage e Press essure Betwee een n 2nd and 3rd Peaks ks 150.53 mmHg

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SLIDE 10

Results – Pressure Comparison

50 100 150 200 250 300 350 400 1 2 3 4 5 6 7 8 9 10

Pressure (mmHg) Time (s)

Comparison of Pressure Waveforms – Impact at Diastole

Normal Pressure Profile High Pressure Profile Low Pressure Profile

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SLIDE 11

Results

Test Max Pressure Mean

  • Std. Dev. Max-S.S. Systole Mean Std. Dev. Max-S.S. Diastole Mean Std. Dev.

Normal Pressure - Impact at Diastole 326 312 24 196 183 15 266 233 21 Normal Pressure - Impact at Systole 298 175 224 High Pressure - Impact at Diastole 334 168 216 High Pressure - Impact at Systole 336 170 217 Low Pressure - Impact at Diastole 274 182 224 Low Pressure - Impact at Systole 304 206 252

▪ The results below show the maximum pressure at impact, and the difference between the maximum pressure at impact and the steady state values for systolic/diastolic pressure.

Test Max Pressure Max-Avg Continuous Flow - 115mmHg 310 195 No Flow 217 217

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SLIDE 12

Results – No Flow vs. Normal Flow Peaks

Test Impac act Peak Seco cond ndar ary Peak Tertiar ary Peak Mean n Std. . Dev. Normal mal 326 181 190 No Flow 217 74 88 Δ(Nor

  • rmal

mal-No

  • Flow)
  • w)

109 107 102 106 3.73

50 100 150 200 250 300 350 1 2 3

Pressure (mmHg) Peak Number

No Flow vs. Normal Flow

Normal Pressure Peaks No Flow Pressure Peaks Overlap of No Flow on Normal

  • 50

50 100 150 200 250 300 350

  • 1

1 3 5 7 9 11 13 15

Pressure (mmHg) Time (s)

No Flow and Normal Pressure - Impact at Diastole

No Flow Pressure Profile Normal Pressure Profile Shifted No Flow

Max Pressure (no flow): 217.10 mmHg Max Pressure (normal): 326.34 mmHg

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SLIDE 13

50 100 150 200 250 300 350 2 3 4 5 6 7 8 9

Pressure (mmHg) Time (s)

Normal Pressure Waveform - Impact at Diastole

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SLIDE 14

Discussion

▪ Pressure Loss During Acceleration Phase

▪ Change in Hydrostatic Pressure and Convective Acceleration

▪ Pressure Differential Due to Aortic Volume

▪ Peak at High Pressure

(Wikipedia) A Wiggers diagram, showing the cardiac cycle events occurring in the left side

  • f the heart. (Wikipedia)
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SLIDE 15

What’s Next?

▪ Continued Testing to Have a Larger Sample Size ▪ Particle Image Velocimetry

▪ Straight Tube Aortae

▪ Modification to Allow for Different Aorta Placements

▪ Deformation Measurements

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SLIDE 16

Thank You