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178
a
b
Sinutub
G. Soppa et al.
be ejected in a laminar ow pattern, with little
stress on the aortic leaets and aortic wall [2].
Background andIndications
forSurgery
Aortic root replacement is performed for pathology
of the aortic root, including aneurysm, dissection,
connective tissue disease and in some cases, endo-
Fig. 16.1 (a) Laminar ow through the aortic valve dur-
ing systole. (b) Currents formed within the aortic sinus in
diastole, helping to initiate aortic valve closure and assist
with coronary ow [1]
carditis of the aortic valve. Valve- sparing aortic
root replacement (VSRR) is performed for aortic
aneurysm when the aortic valve leaets are normal
and the aortic valve annulus is not dilated. Annular
size greater than 28mm, have a higher rate of late
aortic incompetence due to progressive annular
dilation [3, 4], hence a full root replacement may
be the preferred option depending upon the
patient’s comorbidities. Operations of the aortic
root carry signicant risks and morbidity [5]. Given
the interplay of the aortic root components already
described, the main aim of the Yacoub technique of
VSRR is to restore and maintain the form and functional integrity of the aortic root. We describe in
detail our preferred technique for VSRR for aortic
root aneurysms (Fig.16.3).
Intra-operative Transoesophageal
Echocardiography (TOE)
Measurements
Intra-operative TOE assessment of the aortic valve
for incompetence due to leaet prolapse or annular
dilatation is carefully assessed and the measurements, shown in Fig.16.2a, b, are recorded. These
measurements, taken in the mid- oesophageal aortic
valve long axis view, are the following: (1)
Diameter of the LVOT, just below the leaet attach-
Mid-sinusal level
Anatomic
ventriculo-arterial
junction
Virtual basal ring
a
Fig. 16.2 (a, b) Aortic root measurement at various levels required for planning VSRR procedure. Double-ended arrow
provides height of commissures
ular junction
b
16 Valve Sparing Aortic Root Procedure: Yacoub’s Procedure
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179
ment, (2) Diameter at the level of the leaet attachments, (3) Diameter of the sinuses, (4) Diameter of
the sinotubular junction (STJ), (5) Diameter of the
aneurysm above the STJ and (6) Commissural
height, measured as the distance from imaginary
lines between measurements (2) and (4).
Operative Technique
Cannulation Strategy
Following median sternotomy, cardiopulmonary
bypass (CPB) is established at 35 °C through
central (distal ascending aorta or proximal aortic
a
arch) or peripheral (femoral or axillary) cannulation if concomitant aortic arch surgery is required
or to maximise the excision of the ascending
aorta. Venous return is achieved usually by right
atrial (or bicaval) cannulation depending on the
need for concomitant procedures (Fig. 16.3b).
Myocardial protection is achieved using antegrade cold blood-based cardioplegic solution
with topical cooling of the myocardium. A left
ventricular vent is inserted via the right superior
pulmonary vein (RSPV) (Fig.16.3c). Subsequent
maintenance cardioplegia is instituted via the
coronary ostia. The aortic cross clamp is applied
distally as possible, ensuring the entire width of
the aorta is safely within the clamp. Prior to this,
b
c
Fig. 16.3 Aortic root aneurysm (a) with right atrial to
distal ascending aorta CPB and isolation of aorta from
main pulmonary artery (b). Cross-clamp applied and ante-
d
grade cold blood cardioplegia delivery and insertion of
RSPV vent (c). The aorta is transected well above the ST
junction (d)
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G. Soppa et al.
to facilitate clamping of the entire aorta when the
ascending aorta is dilated, the aorta is dissected
away from the main pulmonary artery using diathermy and a tape is passed around the aorta.
Valve Assessment
The ascending aorta is opened transversely after
administration of cardioplegia. Care is taken to
a
perform the aortotomy well above the STJ and
valve commissures (Fig.16.3d).
The integrity of the aortic valve is inspected to
determine if it can be repaired (Fig.16.4a). This
involves an assessment of the morphology of the
aortic valve and root systematically, i.e. valve leaflets, coronary ostia, aortic annulus and ventriculoaortic junction. The leaets are inspected for
symmetry, fenestrations, cusp fusion or prolapse.
Cusp plication is performed if there is evidence of
b
c
Fig. 16.4 Aortic valve inspection (a) and sizing of the annulus (b). Excision of root aneurysm and isolation of coronary
buttons (c) and measurement of leaet height (d)
d
16 Valve Sparing Aortic Root Procedure: Yacoub’s Procedure
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181
cusp prolapse. The depth of each sinus is measured. Commissural height is measured
(Fig. 16.4d). The leaet cusps should be normal
and the aortic annulus should not be dilated or the
leaets should not appear stretched with little
coaptation. The position of the coronary ostia,
their proximity to the valve commissures and nadir
of the relevant sinus and annulus, as well as intramural course is noted. If there is a single coronary
ostium, great care must be ensured in mobilising
the coronary button. Differences in the depth of
each sinus must be appreciated in the remodelling
procedure as this impacts on how the prosthetic
graft is tailored. Mild aortic regurgitation is usually caused by separation of the commissures at
the STJ level due to the aortic aneurysm if no leaflet prolapse exists. This can usually be corrected
by re- suspending the commissures.
Preparation oftheAortic Root
If the valve is deemed to be suitable for VSRR,
the annulus is sized using an aortic valve sizer.
The diseased aorta is excised, leaving a 3–5mm
rim of tissue above the aortic annulus and around
the coronary buttons which are partially mobilised (Fig. 16.4c). Care must be taken to ensure
enough remnant aortic sinus to sew the graft. The
extent of coronary button mobilisation is dependent on the aneurysm size and degree of freedom
required to reach the prosthetic graft without
kinking of the coronary artery. If the coronary
artery follows an intramural course, careful dissection to maintain the integrity and position of
the coronary ostium must be maintained without
disturbing the commissures. Haemostasis around
the coronary buttons and RVOT muscle is secured
at this stage with low power cautery.
Customising theGraft
A prosthetic graft 3mm larger than the measured
annular size is selected. This avoids inducing aortic stenosis or cusp prolapse. Teon-buttressed
4/0 polypropylene stay sutures are placed on each
of the commissures and traction applied upwards
until optimum coaptation of the cusps is achieved,
with the Teon pledget being placed on the outside of the commissure. The distance between the
commissures at this position is measured. This is
roughly one-third the circumference of the
required graft. The graft is cut at three points to
match the commissures of the aortic valve and
shaped to match the aortic sinuses of Valsalva in
depth and width (Fig. 16.5a–d). The cut on the
graft usually extends at least nine rings into the
graft or at least one and a half times the height of
the commissures. It can be further trimmed later,
as required. The three commissures are sutured to
the corresponding apices of the cuts on the graft,
using 4/0 polypropylene, with the suture passing
from inside the graft to the outside. Care is taken
to ensure that the orientation is exactly in the
long axis of the graft, with no distortion, ensuring
symmetry (Fig.16.5e). The graft is then lowered
into position and the sutures tied, with the knots
on the outside. The excess graft at the sinuses can
be trimmed at this stage (Fig.16.5f).
After securing the middle of the graft neo-
sinus to the nadir of the remaining sinus, a continuous 4/0 polypropylene is used to suture the
graft to the remaining aortic sinus tissue
(Fig. 16.6a). This step ensures symmetry of the
sinuses and commissures which must be a key
aim of the VSRR remodelling technique. The needle is passed outside the graft on reaching the
commissure and the suture tied to the commissurexing sutures. This suture line needs to be haemostatic and, so, care is taken to ensure that there is
good apposition between the annulus and the
graft, without any irregularities. Needle entry into
the tissues at 90° degrees with minimum torqueing of the needle will aid in reducing needle hole
size and therefore improve haemostasis. This process is repeated for each neo-sinus. Following formation of all neo-sinuses, additional interrupted
sutures are used, if necessary, to close any potential leakage areas as this is inaccessible after the
cross clamp is released (Fig.16.6b). The graft is
lled with saline and competence of the aortic
valve is checked (Fig.16.6c). The left coronary
ostia is then fully mobilised and an opening made
in the graft opposite the coronary button, using
thermal cautery. It is anastomosed to the opening
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G. Soppa et al.
a
b
dc
fe
Fig. 16.5 Steps of fashioning the prosthetic graft (a–d) and xing the commissures (e, f)
in the graft, using continuous 5/0 polypropylene
(Fig.16.6d). This is repeated for the right coronary ostia. We do not use strips or rings of Teon
to ensure further haemostasis of the coronary
anastomosis. We believe this can complicate the
procedure and its need is obviated by accurate
suturing. Furthermore, if future surgery is needed,
Teon can cause severe adhesions and thus mak-
16 Valve Sparing Aortic Root Procedure: Yacoub’s Procedure
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183
Fig. 16.6 Steps of completing the proximal suture line and re-implantation of the coronary buttons
184
G. Soppa et al.
a
Fig. 16.7 Completion of a ‘closed’ distal anastomosis (a) and nal result (b)
b
ing redo surgery complex. The graft is then
trimmed to the required length distally and anastomosed to the distal ascending aorta, using continuous 4/0 polypropylene (Fig. 16.7a). If the
remaining ascending aorta is larger than the graft,
but does not require replacement, then the graft
can be trimmed and cut more obliquely to match
the size of the remaining aorta. The cross clamp is
then released after a thorough, TOE-guided, deairing procedure. The competence of the aortic
valve is assessed on TOE with a suitable afterload and coaptation length of the aortic valve leaflets noted (ideally 7–9mm). When possible, ow
in both coronary arteries is conrmed on colourDoppler imaging. Following conrmation of satisfactory valvular function, CPB is discontinued
and haemostasis secured (Fig.16.7b).
Remodelling vs. Reimplantation
Both methods of VSRR have been widely debated
over the years. There has been a suggestion that
the remodelling technique, as originally
described, does not stabilise the aortic annulus
and therefore, the annulus may dilate over time
and result in aortic regurgitation, particularly in
patients with Marfan Syndrome.
A number of modications of both the remod-
elling technique and reimplantation technique
have been described. In 2006, Lansac and colleagues described the addition of a subvalvar
prosthetic annuloplasty ring to the remodelling
technique and reported a lower reoperation rate
for patients with annuloplasty ring as opposed to
those undergoing the standard technique (13 vs.
4.2%) [6].
In addition, Schäfers and colleagues have
emphasized that measurement of valve cusp
effective height and correction of valve cusp prolapse, result in good mid and long-term outcomes.
In their series, 173 of 274 patients with signicant
pre-operative aortic regurgitation underwent
valve cusp repair. Freedom from aortic regurgitation of grade 2 or more was 91% and 87% at 10
years for bicuspid and tricuspid aortic valves
respectively. Freedom from reoperation was 96%
at 5 and 10 years, and freedom from valve replace-
16 Valve Sparing Aortic Root Procedure: Yacoub’s Procedure
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185
ment was 98% at 5 and 10 years [7]. David’s
reimplantation series demonstrated slightly
improved freedom from moderate to severe aortic
regurgitation of 98.3% and 92.9% at 5 years and
10 years respectively. Overall freedom from reoperation was 94.8%, with 296 of 374 patients
undergoing reimplantation and the rest undergoing remodelling [8]. However, remodelling of the
aortic root was associated with non-signicant
higher risk of reoperation (hazard ratio=3.37; CI:
0.88–12.82; P=0.07) [8].
A criticism of the originally described reim-
plantation technique was the non-physiological
reconstruction of the aortic root and what impact
implanting the aortic valve within a straight tube
graft had on the native valve cusp leaets.
Schäfers and colleagues reported their in vitro
comparison of valve cusp motion in a remodelling and reimplantation techniques using porcine
models. They identied that valve cusp opening
in the reimplantation technique was signicantly
faster with frequent systolic contact of the valve
leaets with the aortic wall than the remodelling
technique, which was seen to demonstrate
smoother valve mobility given the presence of
neo-sinuses of Valsalva [9]. This may be
explained by the reduced physiological distensibility of the aortic root after reimplantation. It has
been noted invivo and there is suggestion that the
valve opening pattern demonstrated in the remodelling technique may impact durability of the
valve. Yacoub and colleagues have demonstrated
that the remodelling technique also maintains
and preserves normal geometry as well as
dynamic function of the root [10]. A modication
of the original reimplantation technique was to
utilise a graft with ‘in-built’ neo-sinuses and this
was described by De Paulis and colleagues in
2000. Long term results from this group have
demonstrated freedom from moderate to severe
aortic regurgitation of 94% at 5 years and 87% at
10 and 13 years, with 6 patients requiring reoperation (1 for endocarditis and 5 for severe aortic
regurgitation) [11].
Given the lack of a specic recommendation
of which technique to use, a recent systematic
review and meta-analysis aimed to provide consensus on which technique should be used [12].
This study looked at 4777 patients between 1988
and 2012. The mean age was 51 and 71% were
male with 46% of patients having severe aortic
regurgitation (varying between 6.4 and 100% in
the included papers). Mean follow up time was
4.4 years. Analysis revealed that there was no difference in terms of survival or reoperation rates
based on the operative technique employed
(reimplantation or remodelling, or modication
of these). The presence of severe pre-operative
aortic regurgitation was the only factor associated with increased risk of reoperation. The
authors conclude that to improve the results of
valve sparing root replacement, maintaining aortic valve cusp effective height and using techniques to reduce the size of a dilated aortic
annulus will help to restore valve coaptation and
maintain function.
In light of the results of this review the choice
of valve sparing procedure should be based on
the technical expertise of team as well as the preoperative characteristics of the patient, i.e. if
annular reduction is required prior to restore and
maintain valve function or if the patient is suitable to have valve preserving surgery.
Key Pearls and Pitfalls
1. Consider VSRR using remodelling technique
where annulus is not dilated and there is no
signicant aortic regurgitation
2. Careful inspection of aortic valve leaets and
address any leaet prolapse prior to root repair
3. Ensure maintenance of symmetry of the root
during repair
4. Avoid excessive mobilisation of the coronary
buttons during dissection
Comprehension Questions
1. Above what aortic annular dimension has
been shown to increase risk of reoperation fol-
lowing VSRR? Answer=C
(a) 24mm
(b) 26mm
(c) 28mm
(d) 30mm
186
G. Soppa et al.
2. A vascular graft of what size should be
selected when performing remodelling
VSRR? Answer=D
(a) Annulus diameter+5mm
(b) Annulus diameter+1mm
(c) Annulus diameter
(d) Annulus diameter+3mm
3. When suturing the scallops of the vascular
graft to the remaining sinus tissue, where
should suturing start? Answer=C
(a) From the commissure towards the nadir
of the sinus
(b) Midway between the top of the commis-
sure and the nadir of the sinus
(c) From the nadir of the sinus
(d) Suturing can begin from any point in the
sinus
4. Cusp motion has been shown to be same in
both the originally described reimplantation
technique versus the remodelling technique
(T/F) Answer=False
References
1. Charitos EI, Sievers H-H. Anatomy of the aortic
root: implications for valve-sparing surgery. Ann
Cardiothorac Surg. 2013;2(1):53–536.
2. Moscarelli M, De Paulis R.The golden perfection of
the aortic valve. Int J Cardiol. 2016;205:165–6.
3. Erasmi AW, Sievers HH, Bechtel JFM, Hanke T,
Stierle U, Misfeld M.Remodeling or reimplantation
for valve-sparing aortic root surgery? Ann Thorac
Surg. 2007;83:S752–6.
4. Patel ND, Weiss ES, Alejo DE, Nwakanma LU,
Williams JA, Dietz HC, etal. Aortic root operations
for Marfan syndrome: a comparison of the Bentall
and valve-sparing procedures. Ann Thorac Surg.
2008;85:2003–10.
5. Stamou SC, Williams ML, Gunn TM, Hagberg RC,
Lobdell KW, Kouchoukos NT.Aortic root surgery in
the United States: a report from the society of thoracic surgeons database. J Thorac Cardiovasc Surg.
2014;149(1):116–22.
6. Lansac E, Di Centa I, Bonnet N, Leprince P, Rama A,
Acar C, et al. Aortic prosthetic ring annuloplasty: a
useful adjunct to a standardized aortic valve-sparing
procedure? Eur J Cardiothorac Surg. 2006;29:537–44.
7. Aicher D, Langer F, Lausberg H, Bierbach B,
Schäfers HJ.Aortic root remodeling: ten-year experience with 274 patients. J Thorac Cardiovasc Surg.
2007;134:909–15.
8. David TE. Current readings: aortic valve- sparing
operations. Semin Thorac Cardiovasc Surg.
2014;26(3):231–8.
9. Fries R, Graeter T, Aicher D, Reul H, Schmitz C,
Böhm M, et al. In vitro comparison of aortic valve
movement after valve-preserving aortic replacement.
J Thorac Cardiovasc Surg. 2006;132(1):32–7.
10. Yacoub MH, Aguib H, Gamrah MA, Shehata N,
Nagy M, Donia M, et al. Aortic root dynamism,
geometry, and function after the remodeling operation: clinical relevance. J Thorac Cardiovasc Surg.
2018;156(3):951–962.e2.
11. De Paulis R, Chirichilli I, Scaffa R, Weltert L, Maselli
D, Salica A, et al. Long-term results of the valve
reimplantation technique using a graft with sinuses. J
Thorac Cardiovasc Surg. 2016;151(1):112–9.
12. Arabkhani B, Mookhoek A, Di Centa I, Lansac
E, Bekkers JA, De Lind Van Wijngaarden R, et al.
Reported outcome after valve-sparing aortic root
replacement for aortic root aneurysm: a systematic review and meta-analysis. Ann Thorac Surg.
2015;100(3):1126–31.
Valve-Sparing Aortic Root Surgery
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by theReimplantation Technique
MaralOuzounian, MalakElbatarny,
andTironeDavid
17
Abbreviations
AD Aortic dissection
AI Aortic insufciency
AS Aortic stenosis
AV Aortic valve
AVS Aortic valve sparing
BAV Bicuspid aortic valve
Bio-CVG Bioprosthetic composite valve
grafting
CI Condence interval
CVG Composite valve grafting
HR Hazard ratio
HTAD Hereditary thoracic aortic disorders
IRR Incident rate ratio
M. Ouzounian (*) · M. Elbatarny · T. David
Division of Cardiovascular Surgery, Peter Munk
Cardiac Centre, University Health Network,
Toronto, ON, Canada
University of Toronto, Toronto, ON, Canada
e-mail: Maral.Ouzounian@uhn.ca;
m.elbatarny@mail.utoronto.ca; tirone.david@uhn.ca
LV Left ventricle
LVOT Left ventricular outow tract
M-CVG Mechanical composite valve grafting
OR Odds ratio
RCT Randomized control trial
STJ Sinotubular junction
TAAD Thoracic aortic aneurysmal disease
TAV Tricuspid aortic valve
TEE Transesophageal echocardiography
TTE Transthoracic echocardiography
Learning Objectives
1. Provide an overview of the rationale for AVS
with the reimplantation technique with review
of current evidence.
2. Describe patient selection and dene ideal
patient candidates for reimplantation in the
context of underlying pathology.
3. Describe the step-by-step operative technique
including intraoperative assessment to assess
candidacy and quality of repair.
4. Highlight principles of perioperative management to facilitate success of reimplantation AVS.
5. Discuss outcomes of AVS by the reimplantation technique including:
(a) Comparison with CVG procedures
(b) Outcomes in special populations: BAV,
Marfan Syndrome, Dissection
(c) Recent insights from hemodynamic ow
studies of post-AVS patients
© Springer Nature Switzerland AG 2022
P. P. Punjabi, P. G. Kyriazis (eds.), Essentials of Operative Cardiac Surgery,
https://doi.org/10.1007/978-3-031-14557-5_17
187
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