Lessons From The Computer Model
and How We Do Root Replacement
Ehud Raanani, MD
Cardiac Surgery
Leviev Cardiothoracic and Vascular Center
Sheba Medical Center
“Sackler” School of Medicine, Tel Aviv University
Outline
• Lessons from the computer model
• How we replace the aortic root
• our results
Mechanisms of AR
in many cases is a combination of:
Root pathology
Asc. Aortic aneurysm (STJ)
Root aneurysm:
STJ
Annular dilataion
Cusp pathology
Cusp Prolapse
Calcific degeneration
Commissural pathologies
I. Patients with root enlargement have
dilated aortic anulus :25-30mm
Courtesy A. Hamdan
Freedom from reoperation after repair in patients with preoperative
AVD of >28 mm depending on the use of root replacement.
Significant failure in patients with a > 28 mm Annulus whether they
have a SCA or “Remodeling” Root.
Aicher D et al. Circulation 2011;123:178-185
Effect of annulus diameter

Six geometries with different annulus diameters

Calculated by expanding or shrinking the AA of normal case (24mm)

The other dimensions were not changed
20mm
C-C section
22mm
24mm
26mm
28mm
30mm
Influence of the geometry on coaptation
5
4
average
hc [mm]
3
2
hC
1
0
15
16
17
18
geometric height [mm]
19
3,5
3
2,5
average 2
hC [mm] 1,5
1
0,5
0
20
22
24
26
AA diameter [mm]
28
30
Dilated Annulus, What are the
surgical options?
Sub-Commissural Annuloplasty
BAV repair (SCA): fails in the short term
p = 0.0003
5 years
34 ± 12%
94 ± 5%
86 ± 10%
J. Bavaria et al: STS 2013
JTCVS 2011
13
Circular Annuloplasty
Expansible Band
Lansac 2006
PTFE annuloplasty
Kazui, Svensson, Schäfers
2007
II. The Effective Height Concept
Coaptation vs. effective height


The effective height correlates well with valve coaptation
The cusps in all the cases with hE<9mm prolapsed during
diastole
hE
hc [mm]
5
4,5
4
3,5
3
2,5
2
1,5
1
0,5
0
dAA
7
9
11
hE [mm]
cusp area
13
III. BAV NFC angles (120-180 degrees)
160º
4 BAV geometries with different
NFC angle
• Four common BAV geometries were generated, include one raphe and
different NFC angles from 120° to 180°
180°
160°
140°
120°
Method
s
120°
160°
140°
180°
Effective Orifice Area (EOA) at Peak
Systole
θNFC
180°
160°
140°
120°
EOA [cm²]
2.11
2.38
2.44
2.84
•
Increased NFC angle followed by decreased effective orifice area and
centered opening
Echo Results
Taken from 12 non-pathologic BAV patients
NFC Angle
180°
150°
120°
Number of Patients
3
2
7
EOA
2.5 [cm²]
3.35 [cm²]
3.65 [cm²]
Velocity
1.83 [m/s]
1.55 [m/s]
1.41 [m/s]
Pressure Grad.
14 [mmHg]
10 [mmHg]
8.4 [mmHg]
Echo Video
Max
Opening
EOA- Model Vs. Echo
Conclusions
• The same opening pattern:
Decreased NFC angle followed by increased effective orifice area and eccentric
opening
FSI results: Jet Flow Velocity and direction
180°
160°
140°
120°
Flow Velocity - Peak Systole
Results
 Jet flow velocity of the four geometries during peak systole (time of 0.115 sec):
180°
160°
140°
120°
140°
 The structural and the jet flow
velocity simulations for the 140°
model, during systole
Stress Distribution – Diastole
Diastole (Time 0.34 [Sec])
θNFC
180°
160°
140°
120°
Flow Shear Stress - Peak
Systole
(LV side view, time=0.115)
NFC
Fuse
d
cusp
180°
160°
140°
120°
FSI models
Both FSI and Dry
Dry models
Conclusions
Summary: Models Performance
Scores
Jet Flow Direction
Flow Shear Stress
EOA
Stress Diastole
120°
140°
160°
180°
+
+
+++
++
++
++
++
++
++
+++
++
+++
+++
+++
+
++
7
8
10
9
• Tradeoff Between the jet flow direction to the effective orifice area
• The minimal stresses distribution were found in the 160° model
• The inadequate performance of the 120° model can explain the early failure of
BAVs with NFC angle<160°
Freedom from reoperation BAV repair
depending on the orientation of the 2 normal
commissures
Aicher D et al. Circulation 2011;123:178-185
Root Replacement
RE-Implantation (David)
Valsalva Graft
Graft Sizing- depending on GH
• 2/3 of Average GHmm X 2 +4 mm
• Example :
2/3 of 18mm=12mm X 2= 24mm+4=28mm graft
Re-implantation BAV
Patients: 2004-2014
227 patients
AVSS
81(36%)
Root
97 (43%)
STJ
49 (21%)
Isolated Cusp
18 18%
(22%)
CuspUAV/BAV
intervention
43 47%
(44%)
CuspUAV/BAV
intervention
41%
UAV/BAV
Surgical Procedure
• 13 cases (6%) were Redo surgery
• 50 patients (22%) underwent concomitant
procedure
• 39 patients (17%) hemi/arch replacement
Early Results
• 1 patient died, (0.4% of in hospital
mortality)
• Major Complications:
– CVA 2 (0.9%)
– Acute Kidney Injury 8 (3.5%)
– Pacemaker 5(2.2%)
Late Results
• Mean FU time was 75±37 months
• Clinical FU was completed to 100%
• Echo follow up was completed to 97%
Late Survival
• There were 15 cases (6.6%) of late death
• Overall survival rate for 5 years was
94.4%
Late Clinical Outcomes
• At FU, 208 (91.6%) patients were NYHA
class l or ll.
• Re-operation: 16 pts (7%)
• Freedom from re-operation or severe AI in
5-years of follow-up was 87.6%
Freedom from AI or Re-operation
(in Patients who Underwent Replacement of Aorta)
Pericardial Patch for Partial
Cusp Replacement
Pericardial Patch Augmentation
Patients with Cusp Repair
Predictors for Failure
Freedom from reoperation after repair
depending on the use of a pericardial patch
Other materials(Cor-matrix, Gortex membrane, Cardiocell)
Aicher D et al. Circulation 2011;123:178-185
Summary
• Low operative risk, morbidity and mortality rates
• Good early and late functional state
• However, significant recurrence if cusp repair is
needed, especially if pericardial patch is used
• Failure is due to calcification and degeneration of the
patch
• An alternative for pericardial patch is needed
Thank you