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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3740_Библиотеки_им_академика_М_И_Перельмана
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F. C. Wells and N. Moorjani
ab
Fig. 10.3 Operative images demonstrating (a) mobilisation of the superior vena cava and (b) tension placed on the caval snuggers to raise a line
of tension at the superior margin of the right superior pulmonary vein
artery, non-coronary sinus of aorta, and superior vena cava
are at risk due to their proximity to the incision.
Fig. 10.4 Operative image demonstrating mobilisation of
Sondergaard’s interatrial groove and incision into the left atrium
Superior Left Atrial Roof Approach
An incision is made across the right atrial free wall and continued between the superior vena cava and the right atrial
appendage (Fig.10.8a). From there, it is extended across the
interatrial septum and the roof of the left atrium passing
behind the aortic root towards the commissure between the
left coronary cusp and the non-coronary cusp (Fig.10.8b).
Although this incision gives good access to the mitral valve
(Fig.10.8c), the roof is the weakest part of the left atrium and
this tissue can be relatively friable when closing the incision.
In addition, the sino-atrial node artery, left main coronary
Horizontal Trans-Septal Bi-Atrial Approach
A horizontal incision is made between the right superior and
inferior pulmonary veins across the free wall of the right
atrium (Fig.10.9a). The incision is then continued across the
interatrial septum through the fossa ovalis and the left atrial
free wall (Fig.10.9b). Again, although it offers good access
to the mitral and tricuspid valves (Fig.10.9c), it can be difcult to close.
Minimal Access Approaches totheMitral Valve
Following general anaesthesia with a single-lumen endobronchial tube and placement of external debrillation
pads, the patient is positioned supine with slight elevation
(30°) of the right chest, using an inated pressure bag
(Fig.10.10).
The right femoral artery and vein are exposed through a
3cm groin crease incision and cannulated using a Seldinger
technique, supported by 5/0 polypropylene purse strings
(Fig. 10.11). The arterial cannula sits in the common iliac
artery, whilst the venous 3-stage cannula positioned in the
inferior vena cava, right atrium, and superior vena cava,
under TOE guidance.
Additional venous drainage can be obtained with a second venous cannula inserted percutaneously through the
right internal jugular vein, especially in patients requiring
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10 Surgical Access totheMitral Valve
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Fig. 10.5 Operative images demonstrating the self-retaining mitral valve retractor blades in situ from the (a) superior aspect of the operating table
and (b) right side of the operating table
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of the 30° camera and in the sixth intercostal space in the
anterior axillary line for insertion of the pump sucker.
Following initiation of cardiopulmonary bypass, an inverted
C-shaped incision is made in the pericardium anterior to the
right phrenic nerve and access to the heart is facilitated by
pericardial and diaphragmatic retraction sutures, as required.
An additional 3mm stab incision is placed in the right second or third intercostal space in the anterior axillary line,
through which a Chitwood aortic cross-clamp is inserted.
Following aortic cross-clamping, antegrade cardioplegia is
delivered through a long 35cm cardioplegia cannula, inserted
into the right lateral aspect of the ascending aorta (Fig.10.12).
Alternatively, an endoballoon can be used to occlude the
ascending aorta, with an internal channel to deliver antegrade cardioplegia, which is passed via the femoral artery. In
Fig. 10.6 Operative image demonstrating surgical view of the mitral
valve following insertion of self-retaining retractor blades and annuloplasty sutures
such instances, right radial artery monitoring is used to be
certain that balloon migration and innominate artery obstruction have not occurred. Retrograde cardioplegia can also be
delivered through a percutaneous trans-jugular catheter
concomitant tricuspid valve surgery or with an increased
body surface area. Vacuum-assisted cardiopulmonary bypass
is used with mild hypothermia (32–34°C).
There are a number of minimally invasive incisions
described in the literature ranging from a right thoracotomy
of vary sizes giving direct access to the mitral valve to a
periareolar incision using a completely endoscopic technique. One example is performing a 5–7cm right anterolateral thoracotomy in the fourth intercostal space in the
submammary fold followed by insertion of a soft tissue
retractor. A 10-mm thoracoport is then placed in the right
placed in the coronary sinus under TOE guidance. Carbon
dioxide is administered at 4 L/min via the camera port
throughout the procedure.
Access to the mitral valve can be obtained through a standard left atriotomy, or right atrial trans-septal approach if
tricuspid valve disease is also present. Specialised surgical
instruments, including a left atrial retractor, are then used to
perform the majority of standard mitral valve surgical techniques. De-airing is performed using aortic root suction and
by distending the left atrium during closure, with TOE
guidance.
fourth intercostal space in the mid-axillary line for insertion
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Fig. 10.7 Vertical transseptal bi-atrial approach to the
mitral valve with (a) an
incision made across the right
atrial free wall through the
right atrial appendage and
down to the left atrial roof;
(b) the incision extended
across the interatrial septum
through the fossa ovalis; and
(c) giving excellent access to
the mitral and tricuspid valves
F. C. Wells and N. Moorjani
a
Antegrade
cardioplegia
Aortic cannula
SVC cannula
with snare
IVC cannula
with snare
Right
atriotomy
incision
b
Fossa ovalis
Tr icuspid valve
Ostium of
coronary sinus
Incision
across
atrial septum
c
Mitral valve
Tr icuspid valve
Cardioplegia
cannula in the
coronary sinus
Right
atrium
a
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a
b
b
c
c
Fig. 10.8 Superior left atrial roof approach to the mitral valve with (a)
an incision made across the right atrial free wall and continued between
the superior vena cava and the right atrial appendage; (b) the incision
extended across the interatrial septum and the roof of the left atrium
passing behind the aortic root; and (c) giving excellent access to the
mitral and tricuspid valves
Fig. 10.9 Horizontal trans-septal bi-atrial approach to the mitral valve
with (a) an incision made between the right superior and inferior pulmonary veins across the right atrium; (b) the incision extended across
the interatrial septum through the fossa ovalis; and (c) giving excellent
access to the mitral and tricuspid valves
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Fig. 10.10 Positioning of the patient prior to minimally access mitral
valve surgery, with the skin incision and positioning of ports marked
onto the anterior and lateral chest wall and the patient placed with the
right chest elevated to 30°, using an inated pressure bag
F. C. Wells and N. Moorjani
Fig. 10.12 Operative setup for minimally invasive mitral valve surgery, following aortic cross-clamping and delivery of antegrade cold
blood cardioplegia
third intercostal space in the anterior axillary line and the
right trocar in the sixth intercostal space in the anterior axillary line, avoiding any internal and external arm conicts.
The 3-D high-resolution endoscope is placed through the
medial portion of the mini-thoracotomy, with the other
instruments passed through the remainder of the incision.
Fig. 10.11 Cannulation of the right femoral artery and vein
Robotic Mitral Valve Surgery
Robotic mitral valve surgery can be performed either as port
access surgery with robot assistance using a 3–4 cm right
submammary incision, or as a robot-performed totally endoscopic procedure using a 15mm ‘working port’, placed in
the right fourth intercostal space in the anterior axillary line.
The robotic camera is placed in the right fourth intercostal
space just lateral to the mid-clavicular line. Otherwise, the
initial setup for robotic surgery is similar to videoscopic
mitral valve surgery with respect to femoral cannulation and
antegrade intra-aortic cardioplegia. Following opening of the
left atrium, the positions of the left and right robotic instrument arms are determined to provide optimal visualisation of
the mitral valve. Commonly, the left trocar is placed in the
Robotic mitral valve surgery requires a number of components, including
• An endoscope, which consists of two parallel cameras,
channelled to each of the operator’s eyes, providing up to
10× magnication in 3D.
• Miniaturised standard surgical instruments, mounted on
long thin shafts, which provide tremor-free movement
through multiple degrees of freedom.
• Bedside unit, with articulating arms that allow the endo-
scope and instruments to be electronically controlled at
the surgeon’s console.
• Surgeon’s console, which comprises of:
– A viewing screen, which provides true 3-D vision with
improved visualisation.
– Two hand controllers, which directly translate the hand
and nger motions of the surgeon to the instruments.
– A series of foot pedals, which allow camera focus,
movement of instrument supports, and electrocautery.
Suggested Reading
Barac YD, Glower DD.Port-access mitral valve surgery-an evolution
of technique. Semin Thorac Cardiovasc Surg. 2020;32(4):829–37.
Chitwood WR Jr. Robotic mitral valve surgery: overview, methodology,
results, and perspective. Ann Cardiothorac Surg. 2016;5(6):544–55.
Glower DD. Surgical approaches to mitral regurgitation. J Am Coll
Cardiol. 2012;60(15):1315–22.
Surgical Correction ofDegenerative
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Mitral Valve Disease
FrancisC.Wells
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Degenerative mitral valve disease is a common cardiac
lesion. Presentation is most commonly in late middle and old
age. As the name suggests, it is a result of the wear and tear
generated through decades of high-pressure stress on valve
leaets malformed to carry the load. This will become clear
when the anatomy of the valve is considered.
The left atrioventricular valve, referred to as the Mitral
valve (the sixteenth century anatomist, Andreas Vesalius
would seem to be the rst person to ascribe the name Mitral
to the valve, opining that it appeared to him to be similar to
an inverted bishop’s Mitre), is a complex structure. It has a
dual function. First, to render unidirectional ow through the
left side of the heart and second to support the geometry of
the left ventricular cavity through the cardiac cycle. In the
case of a failing valve, stenotic or regurgitant, simple excision will result in altered ventricular systolic and diastolic
function. Dr. Walter Lillehei rst reported this phenomenon
in a seminal paper in 1964 [1]. Complete excision of the
valve leaets and their supporting cords resulted in early
ventricular failure in spite of a well-functioning replacement
valve. Therefore, a key component of either valve reconstruction or replacement is the retention or reconstruction of
the sub-valve connections. Mitral valve reconstruction
retains the normal force distribution on the leaets and the
support of the ventricle. The insertion of a synthetic valve
with cordal and papillary muscle retention will alter the
alignment in relation to the ventricular wall but this seems
not to visibly alter ventricular performance. However, retrospective data would seem to indicate that valve replacement
even with sub-valve preservation results in earlier and worse
mortality than in mitral valve repair, particularly in the
elderly [2].
F. C. Wells (*)
Royal Papworth Hospital, Cambridge University Group of
Hospitals, Cambridge, UK
e-mail: francis.wells@nhs.net
Table 11.1 Carpentier functional classication of mitral valve lesions
Type 1: Orice dilatation or leaet perforation
Type 2: Excessive leaet motion: elongated and/or ruptured cords
and papillary muscles
Type 3: Restrictive leaet motion: rheumatic/calcic valve with xed
leaets, fused and shortened cords and papillary muscles or
functional distortion of LV wall in ischaemic or cardiomyopathic
disease sates
This observation and the imperfect solution of prosthetic
valve replacement have led to a signicant move towards
valve reconstruction. Although the earliest attempts to
manage mitral regurgitation included various techniques
for valve retention, it really was the seminal work of
Professor Alain Carpentier that brought mitral valve repair
into the main stream and the gold standard treatment. His
methodical approach based upon a structural classication
of lesions gave a foundation for decision-making enabling
surgeons to discern the most appropriate surgical solution
for individual lesion sets [3]. Table 11.1 shows the
Carpentier classication.
Type 1 Lesions
Orice dilatation results from traction on the atrioventricular
junction by a dilating left ventricle (LV) or left atrium (LA).
Primary causes of LV stretch are various forms of cardiomyopathy. Secondary causes are volume overload as in aortic
valve regurgitation or mitral regurgitation. Ischaemic brosis
in the ventricular wall can also lead to ventricular dilatation.
Infero-basal ischaemia will often lead to brosis in the wall
at the origin of the papillary muscles causing their distortion
and hence leaet distraction. These secondary causes can be
corrected by a number of different approaches which are
dealt with in another chapter.
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
F. C. Wells (ed.), Atlas of Cardiac Surgery, Springer Surgery Atlas Series, https://doi.org/10.1007/978-3-031-43195-1_11
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F. C. Wells
Type 2 Lesions
Type 2 lesions comprise the degenerative group. The mitral
valve can be thought of as the lynch pin (a structure, person
or thing vital to normal function) within of the left ventricle.
As was mentioned in the opening to this chapter, the continuous loop of leaets, cords, papillary muscle, and ventricular
wall returning to the origin of the leaets at the base of the
ventricle at the atrioventricular junction form a support for
the ventricular chamber of profound importance. At the end
of systole, the valve leaets are bearing very high closing
pressures which must be distributed evenly across the valve
leaet surfaces. Any interference with this force distribution
will cause excess stress loading on the relatively unsupported
part of the valve. This is caused by malformations of the
components of the valve. Abnormal distribution of papillary
muscles from their normal horseshoe shape will alter load
sharing and result in uneven load spread.
Also, deep clefts to the annulus in the mural leaet interrupt load sharing and again will cause excess loading per
surface area. It is almost the rule that either side of a mural
leaet prolapse will be deep clefts with often abnormal papillary muscle support; the P2 segment being the most common (Fig.11.1).
The mitral leaets are arbitrarily divided into three parts
(Fig.11.2).
The competent mitral valve depends upon an even area of
coaptation of leaet commissures of approximately 0.8cm
in height (Fig.11.3). Restoration of uniform coaptation of
leaets is the bed-rock of mitral valve reconstruction/repair.
Uniform use of the lexicon in mitral valve disease is
important for consistent reporting and discussion.
Fig. 11.1 (a, b) Abnormal papillary muscles and associated cords in patients with severe mitral regurgitation
Fig. 11.2 Segmentation of the mitral valve leaets for the
purpose of lesion description
A
1
A
3
A
2
P
1
P
2
P
3
a-b. : coaptation height
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Fig. 11.3 The length of
opposing leaets is referred to
as the coaptation height
shown here from (a) to (b)
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a.
b.
a
b
Denitions
Leaet prolapse: Abnormal displacement of the leaet
beyond the plane of the valve.
Flail leaet: Wild and/or erratic movement of the leaet
with ruptured cord(s).
Billowing valve: Leaet body has a soft upward curve
beyond the plane of the annulus.
Barlow’s valve: A valve that is signicantly larger than
the normal with orice area of up to 40% greater. Leaets
have multiple scallops and are thickened with often multiple
areas of prolapse.
Myxomatous valve (often associated with a Barlow’s
valve): Thickened leaets billowing or prolapsing beyond
the plane of the annulus.
Whilst mural leaet prolapse is the most frequent lesion
(>60%), aortic and bileaet prolapse are also seen frequently
in signicant mitral practices. Of those, central mural leaet
prolapse is the most common. Prolapse of this segment is
commonly associated with ruptured tendinous cords. This
will result in a ail leaet everting into the atrial cavity
(Fig.11.4).
Commissural prolapse is the term used (inaccurately by
strict denition) to describe the prolapse of anterior–superior
or infero-lateral ends of the aortic and mural leaets. The
correct use of the term commissure is the location at which
two objects meet; in the context of heart valves, in this case
the mitral valve, it describes the meeting of the two leaets
throughout their length, not, as is commonly thought, as the
two ends of the leaets, however the former use of ‘commissure’ has irreversibly entered the lexicon.
Aortic and bileaet prolapse are commonly found in
Barlow’s disease. This condition is accompanied by a valve
orice up to 40% greater than normal with signicant excess
leaet tissue. There are, commonly, multiple deep clefts in
the mural leaet and also in the aortic leaet (Fig.11.5).
There are several combinations of lesions of the mitral
apparatus that are often found together. Each valve demands
individual analysis on preoperative echocardiogram but particularly at operation. The phenomenon of echo ‘drop-out’
may camouage secondary and tertiary lesions. This is when
a larger lesion overshadows a lesser one, thereby interrupting
the echo return from the secondary lesion. As mentioned earlier, the restoration of full and even coaptation is the goal of
repair. Therefore, it is important to remedy all lesions found.
Leaet coaptation is eroded by ventricular and/or atrial
dilatation resultant upon the dilating effect of increasing volume overload. As coaptation height reduces the base of the
left ventricle begins to move outwards further pulling on the
atrioventricular junction. If bileaet prolapse progresses, it
can give rise to the appearance of the mural leaet arising
from the wall of the atrium and not the usual junctional anatomy. Recently, this has received the term mitral annular dysjunction or M.A.D.Once full coaptation is restored normal
motion of the atrioventricular junction is restored with downward descent of both leaets into the ventricular chamber at
the end of systole.
The modern mitral surgeon has many tools in the surgical
toolbox. The most frequently used are listed here and will be
discussed and illustrated in the following text.
1. Leaet resection
(a) Quadrangular resection
(b) Quadrangular resection plus sliding annuloplasty
(c) Triangular resection
(d) Leaet height reduction
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a
Fig. 11.4 (a, b) Ruptured cord with ail segment
Ruptured cord
b
2. Cordal replacement
3. Commissural plication
4. Aleri edge-to-edge technique
5. Annular decalcication
6. Leaet transfer
Fig. 11.5 Barlow’s valve revealing multiple deep clefts, excess leaet
tissue, and prolapsing leaets. Note the variation in height of the leaet
segments
The choice of surgical procedure depends both upon the
lesion and surgeon preference. For example, the prolapsing/
ail mural leaet may be managed with leaet resection,
cordal replacement, or by edge-to-edge sutures.
Valve Exposure
Minimal access procedures will be discussed elsewhere. My
preferred access is via a mid-line sternotomy with bi-caval
cannulation. The heart is arrested with intermittent antegrade
cold blood cardioplegia (Fig.11.6). An incision is made posterior to the interatrial groove. It is extended superiorly
underneath the superior vena cava, and inferiorly underneath
the inferior vena cava until the atrial wall turns upon itself
superiorly (Fig.11.7).
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a
b
c
Fig. 11.6 (a–c) Mid-line sternotomy with bi-caval cannulation, antegrade cardioplegia, and external cold
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