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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3795_Библиотеки_им_академика_М_И_Перельмана-1
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Figure 11. Intra-operative picture showing prolapse of the RCC after valve sparing-reimplantation.
Injecting saline solution with pressure into the aortic root allows closure of the valve and can unveil
cusp prolapse.
Central Leaflet Plication and Triangular Resection
The central plication is the most used technique in our experience to correct cusp
prolapse. Videos of this and other techniques of cusp repair are also available on line . A 5-0
or 6-0 polypropylene suture, depending on the thickness of the cusp tissue, is used for
plication passing the stitch from the aortic to ventricular side of the leaflet and back to the
aorta in order to have a fold of excess tissue on the aortic side of the cusp (Figure 12). If the
excess of tissue is substantial, the plication can be extended onto the body of the leaflet by a
running suture (Figure 13) and eventually a triangular resection of the leaflet can also be
performed.
Figure 12. Intra-operative pictures showing the result of central plication to treat RCC prolapse. The
reference stitch passes through the middle point of both the LCC and NCC. After alignment of the
RCC, the excess of tissue on the RCC becomes evident.
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Figure 13. Intra-operative pictures showing the result of central plication and triangular resection to
treat RCC prolapse. The locked running suture starts from the belly of the cusp, where the fold of the
plication begins, to the free margin. The plication stitch and the running suture stitch are then tied
together.
Free Margin Resuspension
For resuspension of the prolapsing free margin, we use two 7-0 polytetrafluoroethylene
(PTFE) sutures that will shorten the free margin by pulling up the cusp (Figure 14).
Figure 14. Intraoperative picture showing the result of free-margin resuspension to treat prolapse of left
coronary cusp (LCC). Two running sutures of PTFE are passed over and over the free margin from one
commissure to the other. These stitches are then pulled gently to shorten the excessive length of the
LCC free margin.
Each PTFE suture is first secured to the apex of the commissure and then run over the
full length of the free margin to reach the opposite commissure. The length of the free margin
is therefore reduced by gently pulling the PTFE sutures until the free margin reaches the
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reference point. This 2-steps technique allows symmetric and homogenous shortening of the
free margin.
In general, the free margin plication is a more adaptable and versatile technique and is
our preferred approach for prolapse repair. There are, however, a few situations in which
resuspension is particularly useful. This technique is indicated in the setting of a fragile free
margin with multiple small fenestrations. In either case, these cusp repair techniques can
restore leaflet coaptation and provide a durable solution to cusp prolapse.
Cusp Fenestration Repair
Small fenestrations in the area of the commissures in an otherwise normal cusp do not
usually need to be repaired. When the fenestration is large or when it is ruptured with a lack
of continuity in the free margin, then the fenestration must be repaired with patch material.
The decision for the type of patch material is principally at the surgeon’s discretion as no
strong evidence exists on the superiority of one material over another and different types of
patches have been used. We currently use either bovine pericardial patch or autologous
pericardium. Non-treated autologous pericardium is preferred in cases of simpler repairs, like
small fenestration or perforation, while treated autologous or bovine pericardium are
employed in more complex repairs such as commissure reconstruction.
The patch is trimmed in the form of the defect but 2 mm bigger the size, so as to prevent
restriction of cusp surface following the suture. The patch is usually sutured on the aortic
surface of the cusp with a continuous 6-0 polypropylene sutures. One edge of the patch is
used as new free margin in case of ruptured fenestration or is used to reinforce the free
margin when the fenestration is not ruptured. Large fenestrations are frequently present on
both sides of the commissure and one patch fixed to the commissure and distributed between
the two cusps (Figure 15) or two separate patches can be used to treat the lesion. Small
fenestration close to the free margin can be repaired with free margin resuspension by PTFE
as seen above.
Figure 15. Intraoperative picture showing the result of repair of a commissural fenestration at the level
of the LCC/NCC with a single heterologous patch.
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Cusp Perforation
Perforation is defined as tissue defect at the belly of the cusp with preservation of the free
margin and it might represent the only cause of AI. The perforation can be the result of an
endocarditis, resection of a fibroelastoma or iatrogenic. Very small perforation (up to 2-3mm)
can be closed directly with 6-0 polypropylene sutures. Large perforations of one or more
cusps will need a patch repair (Figure 16).
Figure 16. Intraoperative picture showing a large perforation, due to infective endocarditis, of the RCC.
A heterologous pericardial patch has been trimmed to close the defect. The patch has a diameter 1mm
larger than the defect in order to avoid cusp tension following the suture.
AORTIC VALVE REPAIR IN BICUSPID AV
Bicuspid aortic valve (BAV) is the most common congenital cardiac anomaly in the adult
population and is also associated with a peculiar aortopathy. For the purpose of valve repair,
it is noteworthy that BAV is almost constantly associated with dilatation of the VAJ, which
should be therefore addressed during BAV repair.
Anatomical Considerations
Bicuspid aortic valves may be divided into 2 general types . Type 0 BAVs have 2 very
symmetric aortic sinuses, 2 commissures facing at 180°, and a symmetric base of
implantation of the 2 cusps. This configuration is nonetheless present in a minority of cases
(±7%). The mechanism of aortic regurgitation in this setting is usually related to cusp
prolapse or dilatation of the aortic root.
Type 1 BAVs, which are significantly more common, present 2 cusps fused together
along a median raphe (Figure 17).
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Figure 17. Intra-operative picture illustrating a Type-I BAV with incomplete fusion of the LCC and
RCC, a small raphe and a pseudo-commissure.
In most of the cases the fusion involves the LC and RC cusps, and much less frequently
the other possible combinations. The conjoined cusp is usually larger than the non-conjoined
cusp (usually the non-coronary cusp) resulting therefore in a more or less asymmetric valve
apparatus. The conjoined cusp accounts for a proportion of valve circumference that varies
between 180° and 240°. Depending on the degree of cusp fusion, the raphe can be more or
less developed and can forms a ‘‘pseudo-commissure’’ on the aortic wall which is
nonetheless lower than the true commissures. Commissural orientation is defined as the angle
limited by the lines passing through the 2 commissure and the central axis of the valve. The
angle is measured on the non-conjoined cusp (Figure 18). We have extensively described the
relation between commissure orientation in type 1 BAVs, length of fusion and height of the
commissure . We have also proposed a new surgical-oriented classification22 grouping type 1
BAVs in 1) very symmetric BAVs with a 160-180° commissural orientation resembling type
0 valves, 2) quite asymmetric BAVs with 140-160° orientation, 3) very asymmetric BAVs
and tricuspid-like with a commissure orientation angle <140°. The second group of BAVs is
also the most numerous. Techniques for BAV repair can differ importantly between these 3
groups. Respect or improvement of the 180° symmetry seems to be advisable and associated
with better valve durability. Further, we’ll see that restoring BAV symmetry during repair can
in most of the cases allow to avoid use of patch that is associated to worse outcomes.
Two mechanisms of AI are commonly observed in type 1 valves. One is prolapse of the
conjoined cusp (“prolapsing” Type 1) wherein the raphe is generally thin and pliable and the
conjoined cusp well-developed with a near to normal geometric height (Figure 19).
The other is restriction of the conjoined cusp (“restrictive” Type 1) wherein, despite the
larger base of insertion of the conjoined cusp, the raphe is thickened and rigid and the cusp is
therefore restrictive with a smaller surface and small geometric height (Figure 20). Generally,
prolapsing Type 1 BAVs tend to have a commissural orientation in the 160°-180° range while
restrictive type 1 BAVs tend to be more asymmetric (commissural orientation of 120-160°).
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Figure 18. A. Intraoperative picture of a symmetric type-I BAV with LCC/RCC almost complete
fusion, a small raphe and commissural orientation of almost 180°. B. Intraoperative picture of an
asymmetric type-I BAV with LCC/RCC quite incomplete fusion, a well-developed raphe and
commissural orientation of 140°.
Figure 19. Intra-operative picture illustrating a symmetric type I bicuspid aortic valve with RCC/LCC
fusion and prolapse of the conjoined cusp. The free margin of the conjoined cusp (black arrow) is
indeed lower than the free margin of the non-conjoined cusp.
Figure 20. Intra-operative picture illustrating a symmetric type I bicuspid aortic valve with incomplete
fusion of the RCC and LCC and a restrictive raphe causing aortic regurgitation.
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Surgical Techniques for BAV Repair
Various surgical techniques can be employed to repair regurgitant BAV. A thorough
analysis of the valve should find out any abnormality that needs to be addressed during the
repair. Valve assessment should go through cusp anatomy, quantity and quality of cusp tissue,
commissure orientation, dilatation of VAJ and/or aorta, and quality of aortic wall tissue.
Surgical strategies should include: cusp repair, annuloplasty and root management.
Cusp Repair in BAV
In type 0 valves, the degree of prolapse should be assessed as usual by comparing the
prolapsing cusp with the non-prolapsing cusp. Whenever both cusps are prolapsing, the
objective of repair is to restore the height of coaptation at the mid-height of the Valsalva
sinuses which usually corresponds to an effective height of 10mm. This can be achieved by a
central plication of the prolapsing cusp. Thickened, fibrotic areas of the cusp (typically the
central aspect of the free margin) can be thinned gently with a blade to ease the plication and
make the coaptation surface more pliable and regular.
In type 1 valves, cusp repair consists essentially in the management of the fused cusp,
and particularly the raphe. In prolapsing BAVs, raphe repair consists generally in closing first
the unfused portion close to the free margin, then the effective height is sorted out and the
residual prolapse is corrected by central plication (Figure 21).
Figure 21. Intra-operative picture illustrating central plication of the conjoined cusp to treat cusp
prolapse in BAV.
In restrictive Type 1, the fibrosis of the raphe is removed with a blade or scissors sparing
as much as possible the leaflet tissue. After raphe resection, the quantity of remaining cusp
tissue must be assessed. If the quantity of tissue is adequate and the edges of the leaflet can be
repaired directly with a running or interrupted 6-0 polypropylene suture. In case of lack of
adequate tissue an autologous or heterologous pericardial patch should be used to fill the
defect. In the past these were the most challenging cases and were associated with the worst
outcome due to patch degeneration over time. Nowadays, we the implementation of a
reductive annuloplasty of the VAJ, particularly in the anterior muscular area towards the
RVOT, which corresponds to the conjoined cusp in the common RC-LC configuration,
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allows to reapproximate the edges of the leaflet and to correct the gap without using the patch
or with very small ones. In general, if the valve has a commissure orientation >140° (2nd
BAV group), a triangular patch may be needed to fill the defect but the valve configuration
will be kept bicuspid. If the commissural orientation is even tighter (close to 120°) and the
valve very asymmetric, it is convenient to create a new commissure using one patch (the
“butterfly technique”) and transform the valve into a tricuspid valve (Figure 22).
Figure 22. Intra-operative picture illustrating a type I restrictive BAV with a commissural orientation of
120°. After resection of the raphe, commissural orientation is respected and a neo-commissure is
created with a single patch (butterfly technique).
The new commissure should arrive to the height of the sino-tubular junction. Once the
valve is repaired, again the geometric height is measured a central plication is eventually
employed if it is still too low.
When root replacement is indicated and patch repair is also needed, we advise to perform
the repair before root replacement because it is much easier to work on the valve inside the
native root (or eventually once the sinuses are resected) than inside the vascular graft.
Nonetheless cusp plication and direct closure of the raphe are generally performed once the
valve is reimplanted into the graft because the reimplantation technique itself impacts the
height of coaptation. However, we also advise to put the stitches for the proximal suture line
before patch or any cusp repair is performed because there is an easier access to the VAJ.
Annuloplasty and Aorta Management
In the absence of BAV regurgitation, aneurysm of the ascending aorta will be treated by
classical supracoronary ascending aorta replacement.
Aortic root aneurism without regurgitation is treated with valve sparing root replacement
with the reimplantation technique. The technique of reimplantation in BAV is roughly the
same than in TAV. The external root dissection is performed deeply to reach the level of the
basal ring all along the circumference of the valve. It is noteworthy that at the level of the
anterior commissure (in the usual situation of a LC/RC fusion) the stitches for the proximal
suture should be few millimeters higher than the basal ring in order to avoid injuring the
membranous septum and the conduction bundle. In the rare case of a right-non (RC-NC)
leaflet fusion, the nadir of the conjoined cusp is precisely et the level of the membranous
septum. To avoid injury to the conduction bundle and the risk of a complete AV block, the
annuloplasty stitches can be omitted at this level. The Valsalva graft sizing is based on the
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height of the posterior commissure (LC-NC commissure). The proximal suture line stitches
are passed through the proximal end of the graft respecting the curve for the membranous
septum (Figure 23).
Figure 23. Diagram illustrating that during VSRR in BAVs, the vascular graft is evenly divided in order
to respect, or restore, valve symmetry; the stitches for the proximal suture line (red dotted line) should
be few millimeters higher at the level of the anterior commissure (purple line) (corresponding to the
RCC/NCC commissure) in order to avoid the membranous septum and the conduction tissue. The
height of the posterior commissure (corresponding to the LCC/NCC commissure) gives the size of the
graft; the diameter of the graft is equal to the height of the neo-sinus (green line).
In absence of regurgitation the valve is reimplanted respecting the native commissure
orientation. The commissures must be implanted as high as possible inside the graft, ideally at
the level of the neo-STJ. In type 1 BAV, the pseudo-commissure (raphe) is reimplanted in the
graft at grossly the same height as it was in the native root. Then, the distal suture line is
performed. Once the valve is reimplanted, valve coaptation is assessed by measuring the
effective height. Importantly, even if the valve was not leaking, the reduction of the STJ and
root size can induce a prolapse of both cusps. Again, we aim to obtain an effective height of
9-10mm and central free margin plication is added as needed. Importantly effective height
must be measured first at the non-conjoined cusp and adjusted accordingly. Then the effective
height is measured on the non-conjoined cusp and corrected to have both free margins at the
same height.
In case of BAV with significant regurgitation and without root aneurysm (>50mm), the
management of the annuloplasty and aorta will be different in order to obtain a durable
normal valve function. As most of these patients will present with dilated VAJ, annuloplasty
must be performed at the time of surgery whenever the VAJ is greater than 26mm.
Circumferential prosthetic annuloplasty is more stable over time than non-circumferential
techniques like the Cabrol technique, also known as sub-commissural annuloplasty (SCA).
We have shown that the SCA reduces indeed the inter-commissural triangle width and
enhances coaptation. However, SCA does not really reaches the level of the VAJ and it loses
its effect over time with a high risk of recurrent regurgitation. During the last decade, we have
therefore limited the use of SCA in favor of circumferential annuloplasty. Currently, we use
two techniques of annuloplasty, one is the valve sparing root replacement with the
reimplantation technique and the other is the external ring annuloplasty.
The circumferential ring annuloplasty will be used only in case of BAV regurgitation
with strictly normal root dimension (<40mm). The technique consists in fixing an external
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flexible prosthetic band around the VAJ, whether a strip of Dacron graft or the Simplicity®
band (Medtronic Inc.). In these cases, we still need to reach the level of the VAJ therefore
deep external root dissection is performed. However, the ease and depth of external root
dissection is somewhat limited and a bit more difficult compared to the same dissection
during the reimplantation technique because the coronary ostia and the sinuses are not
removed. Moreover, below each coronary artery, a tunnel is created with right-angle forceps
in order to pass the band below the vessel. The surrounding tissue around the coronaries must
be left intact to decrease the risk of injury. Once the dissection is completed, 9-10 pledged
stitches are placed along the basal ring. Most care must be taken to avoid injury to the
coronary arteries. A band of 10mm is usually used and the stitches are distributed
homogenously along its length. Finally, one of the stitches is passed through each extremity
of the band in order to close the circumference. The annuloplasty stitches are tied with a 23 or
25 Hegar dilator inserted through the VAJ in order to correctly reduce its size (Figure 24).
Figure 24. Intra-operative picture showing external annuloplasty with a band. A Hegar dilator is
inserted through the valve to avoid excessive annular reduction.
Figure 25. Intra-operative picture showing a BAV reimplanted into a vascular graft during VSRR with
a commissure orientation of 180°. The selective circumferential annuloplasty and commissure
reimplantation allow restoring valve symmetry.
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