Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3683_Библиотеки_им_академика_М_И_Перельмана
.pdf
ventricular septal defect (Fig. 21.10B). After patch closure of the defect, the leaflets are resutured to the rim of
leaflet tissue along the annulus with a 6-0 or 7-0 Prolene suture.
Injury to the aortic valve
Care must be taken in the initial incision along the septal and anterior leaflet to remain only on tricuspid valve
tissue. The aortic valve may lie quite close below the valve, and with the aorta decompressed may fall closer to
the tricuspid valve, making it more likely to be subject to injury.
The needle is passed through the tricuspid leaflet approximately 2 mm from the annulus in a horizontal mattress
fashion back into the right ventricle, taking a horizontal mattress bite of the patch before penetrating the leaflet
once again. This maneuver is continued in a clockwise direction until the other arm of the Prolene suture is met,
so that both arms of the suture can be snugly tied to each other (Fig. 21.10C).
FIG. 21.11 Incorporation of excessive leaflet tissue in the suture line producing tricuspid valve insufficiency.
Buttressing the Sutures
The Prolene suture may cut through the thin, tricuspid leaflet tissue. The suture line can be buttressed with
multiple pledgets or a strip of autologous pericardium. With the interrupted suture technique, pledgeted sutures
are used.
Prevention of Tricuspid Insufficiency
Incorporation of excessive leaflet tissue in the suture line results in tricuspid insufficiency (Fig. 21.11). The suture
line along the tricuspid leaflet should not exceed a distance of 2 mm from the tricuspid annulus.
Tricuspid Valve Repair
After securing the patch, the anterior and septal leaflet tissue is carefully teased back over the patch with a nerve
hook or fine forceps. Often, one or two interrupted 6-0 Prolene sutures are used to approximate the anterior and
septal leaflets and/or septal and posterior leaflets to ensure a competent tricuspid valve. The valve may be
tested by injecting saline into the right ventricle.
When the repair is completed, the atriotomy is closed with a continuous suture of 5-0 or 6-0 Prolene.
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
P.267
TRANSVENTRICULAR APPROACH TOVENTRICULAR SEPTAL DEFECT
All septal defects, except those occurring near the left ventricular apex, can be closed through a right
ventriculotomy. When there are associated lesions, such as infundibular
stenosis (as in tetralogy of Fallot), a vertical ventriculotomy may be used. A transverse ventriculotomy has some
theoretical advantages, especially when an aberrant coronary artery crosses the anterior wall of the right
ventricle (Fig. 21.12).
FIG. 21.12 A: Right ventriculotomy along entire length of infundibulum (large dashed line) and vertical
pulmonary arteriotomy from annulus to confluence (small dashed line). B: Transverse right ventriculotomy.
Avoiding the Coronary Arteries
Every precaution should be taken to avoid dividing an aberrant coronary artery (Fig. 21.13). When the left
anterior descending coronary artery originates from the right coronary artery, it courses across the anterior wall
of the right ventricle. Its accidental division results in severe and often fatal myocardial dysfunction. If this
P.268
unfortunate event occurs, the two severed ends of the vessel should be oversewn, and the left internal thoracic
artery harvested and anastomosed to the more distal left anterior descending coronary artery (see Chapter 9).
FIG. 21.13 Division of an aberrant coronary artery by a ventriculotomy.
Infundibular Hypertrophy Obscuring the Location of the Defect
Infundibular hypertrophy may obscure the location of the perimembranous type of defect. The hypertrophied
muscle bands should be incised and/or excised to the extent needed to relieve the outflow tract obstruction. If
visualization of the ventricular septal defect is still not adequate, the defect should be approached transatrially
(see Chapter 23).
Interrupted Suture Technique
The technique for transventricular closure of the perimembranous ventricular septal defect is essentially the
same as that described for the transatrial approach. The edges of the ventriculotomy incision are retracted with
fine pledgeted sutures or vein retractors. The margins of the defect are inspected and interrupted fine pledgeted
braided 4-0 or 5-0 double-armed sutures are started at the 12 o'clock position, along the muscular rim in an
everting manner. Both needles are then passed through a patch of Gore-Tex slightly larger than the defect (Fig.
21.14). Slight traction on this stitch improves exposure and facilitates the placement of the next stitch (Fig.
21.15).
Suturing is continued in this manner in a counterclockwise direction along the superior rim (that overlies the
aortic valve) until the central fibrous junction of the septum, aortic root, and tricuspid annulus is reached. The
needle of the next stitch is passed through the tricuspid tissue close to the annulus, the muscular rim of the
defect,
and the patch. The other arm of the needle is now passed through the tricuspid tissue and the patch. This is a
true transitional stitch.
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
FIG. 21.14 Technique for closure of a ventricular septal defect by interrupted sutures.
Suturing is then continued from the starting point in a clockwise direction, moving outward to a distance of 3 to 5
mm from the rim of the defect to avoid the underlying conduction tissue. Where the tricuspid annulus becomes
part of the inferior rim of the defect, the needle of the next suture is passed through the tricuspid leaflet, the
muscular septum 3 to 5 mm from the rim of the defect, and the patch. The other arm of the needle is now passed
through the tricuspid valve and the patch. The remaining sutures are passed from the right atrium through the
tricuspid leaflet approximately 2 mm from the annulus before they are passed through the patch. When all the
sutures are satisfactorily placed, the patch is lowered into position and the sutures are snugly tied (Fig. 21.16). It
may be preferable to place all the sutures first, tagging each one separately, and then bring each suture through
the patch held by the assistant.
FIG. 21.15 Exposure is improved by gentle traction on the previously placed stitch.
FIG. 21.16 Completion of patch closure of ventricular septal defect using the interrupted suture technique.
Alternatively, a continuous 5-0 Prolene suture can be used, sewing the patch to the ventricular side of the septal
leaflet 1 to 2 mm from the annulus in the region of the tricuspid valve. When the septal defect has been
satisfactorily repaired, the ventriculotomy is closed with two layers of continuous 5-0 Prolene suture (Fig. 21.17).
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
P.269
FIG. 21.17 Closure of ventriculotomy.
Injury to the Aortic Valve
The aortic valve leaflets are immediately below the superior margin of the defect and can be punctured during
suturing if deep needle bites are taken in this area. Suturing in this area should therefore incorporate the crista
marginalis, which holds sutures well.
Prevention of Heart Block
The bundle of His pierces the central fibrous body and the tricuspid annulus before crossing into the ventricular
septum and following a course along the inferior margin of the defect toward the left ventricular side of the
septum. Suturing along this course can be somewhat hazardous and may culminate in heart block. When using
the interrupted suture technique, the safest approach is to place sutures 3 to 5 mm from the inferior rim of the
defect.
Transitional Sutures
The junction where the tricuspid annulus forms the margin of the defect is also most vulnerable to a residual
septal defect. Again, a transitional stitch incorporating the tricuspid leaflet, the muscular septum well away from
the rim of the defect, and the patch (in that order) ensures a more secure closure.
SUBARTERIAL VENTRICULAR SEPTAL DEFECT
These defects may be associated with the development of aortic insufficiency. Even if small, these defects
should probably be closed to prevent progression of aortic insufficiency and aortic valve leaflet damage.
Technique for Closure
A right ventriculotomy may be used; however, the transpulmonary approach is preferred. If there is significant
aortic insufficiency, the aortic valve should be repaired before the ventricular septal defect is closed.
Standard cannulation is performed with a single venous cannula. Cardiopulmonary bypass is commenced, and
moderate systemic cooling is begun. The aorta is cross-clamped, and cold blood potassium cardioplegic solution
is infused directly into the aortic root.
The main pulmonary artery is opened transversely just above the commissures. A small vein retractor is then
placed through the pulmonary valve to expose the ventricular septal defect. To further assess the degree of the
aortic valve prolapse and insufficiency, blood cardioplegic solution is administered into the aortic root. All the
aortic cusps may be visualized through the septal defect if it is at least moderate in size. In fact, one of the aortic
P.270
valve leaflets may be prolapsing through and partially closing the defect. An autologous pericardial patch fixed
with glutaraldehyde or patch of gortex is cut slightly larger than the defect and attached to the right ventricular
aspect of the defect using 6-0 or 5-0 Prolene continuous suture. Superiorly, the patch must be secured to
annulus of the pulmonic valve. In this area, the needle is brought through the patch and then passed through the
base of the valve leaflet. The needle is then placed back through the leaflet and again through the patch. This
weaving suture line is continued until the edge of the defect is seen apart from the pulmonary annulus. If the
leaflet tissue is friable, the pulmonary artery side of the suture line can be reinforced with a thin strip of
pericardium. When the suture line is completed, the sutures are tied snugly (Fig. 21.18).
FIG. 21.18 Closure of a subarterial ventricular septal defect through the pulmonary artery.
The pulmonary arteriotomy is then closed with a running 5-0 or 6-0 Prolene suture. The aortic cross-clamp is
removed after filling the heart, and deairing is carried out through the cardioplegic site. Transesophageal echo
evaluation should confirm a competent aortic valve and complete closure of the ventricular septal defect.
Injury to the Aortic Valve
Because there is often a close association between the aortic and pulmonary valve annulus with this anomaly,
care must be taken in placing the sutures along the superior aspect of the ventricular septal defect. A too deeply
placed needle may incorporate the aortic leaflet tissue and result in significant aortic insufficiency. In addition, if
one of the
aortic leaflets is prolapsing through the defect, care must be taken to not incorporate or injure the leaflet during
closure of the defect.
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Injury to the Pulmonary Valve
The superior rim of the septal defect is adjacent to the pulmonary annulus. Closure of the defect entails placing
sutures from within the pulmonary artery at the annulus. The leaflets of the pulmonary valve can be traumatized
or perforated in the process. Use of a pericardial strip on the pulmonic side to buttress the suture line may be
required.
MUSCULAR VENTRICULAR SEPTAL DEFECTS
Muscular ventricular septal defects have completely muscular margins and may occur anywhere in the muscular
septum. In selected cases, the first approach to such defects may be pulmonary artery banding. Depending on
their location, muscular defects can be approached through the right atrium and/or a right ventriculotomy. In the
past, a limited left ventriculotomy near the apex was used to close muscular defects in the more distal portion of
the septum. However, because of significant operative mortality and morbidity secondary to left ventricular
dysfunction, this approach is rarely used. Many muscular ventricular septal defects can be located and closed
through a right atriotomy using a small right-angled clamp or coronary artery probe passed through the foramen
ovale into the left ventricle to demonstrate the defect, or by excluding the apex of the right ventricle in the region
of the defect with a large patch. Apical muscular ventricular septal defects can be closed in the cardiac
catheterization laboratory using transcatheter closure devices. Recently, intraoperative closure of muscular
ventricular septal defects with a device (under echocardiographic guidance) has been found to be especially
advantageous in patients too small to undergo transcatheter techniques who have defects difficult to approach
through standard incisions. As newer devices become available, the management of patients with multiple
muscular ventricular septal defects may evolve toward primary repair using hybrid surgical-catheter techniques
and away from preliminary pulmonary artery banding.
22
Atrioventricular Septal Defect
This anatomic complex has been referred to as an atrioventricular canal. The septal defect includes the inferior
segment of the atrial septum and the superior segment or the inflow portion of the interventricular septum. The
atrioventricular valves are developed in an abnormal, but varied manner.
In all but the mildest forms, there is a common atrioventricular valve, which is made up of six leaflets of variable
size and shape attached to normally or abnormally located papillary muscles by chordae tendineae. This
common atrioventricular valve can be subdivided into mitral and tricuspid components or segments, each with
three leaflets. The leaflets constituting the tricuspid valve are designated right superior, right inferior, and right
lateral, and those comprising the mitral valve are designated left superior, left inferior, and left lateral (Fig. 22.1).
It is of clinical and anatomic significance that in normal hearts, the anterior mitral leaflet contributes to one-third,
and the posterior leaflet contributes to two-thirds of the annulus of the mitral valve. In an atrioventricular septal
defect, this ratio is reversed; the posterior (left lateral) leaflet contributes to one-third and the bileaflet anterior
cusp (the left superior and inferior leaflets together) contributes to two-thirds of the mitral valve annulus (Fig.
22.2).
From the clinical point of view, however, there are partial, intermediate, and complete forms of atrioventricular
septal defects. In the partial form, there exists an ostium primum type of interatrial septal defect. Here the
atrioventricular valves are attached to the crest of the interventricular septum, and there is usually no
interventricular communication below the valves. The anterior leaflet of the mitral valve, which has a cleft of
varying degree, is considered to form part of a trileaflet mitral valve (Fig. 22.1B). In most patients, the mitral valve
is competent.
The intermediate form is similar to the partial form of atrioventricular septal defect. The main distinguishing
feature is the incomplete attachment of the atrioventricular valves to the ventricular septum. This results in
usually multiple small interventricular communications. Varying degrees of underdevelopment of the leaflet
tissues may also be present.
The complete form of atrioventricular septal defect, as its name implies, is a defect in both the lower atrial and
upper ventricular septum. The configuration and details of the attachment of the atrioventricular leaflets to the
ventricular septum are quite variable.
Rastelli reviewed atrioventricular canal specimens obtained at autopsy at the Mayo Clinic and proposed a
classification of atrioventricular septal defects that essentially focuses on the shape, size, location, and details of
the attachments of the left superior leaflet. In type A, which is commonly seen, the left superior leaflet is over the
left ventricle and its chordal attachment is to the crest of the ventricular septal defect (Fig. 22.3A).
In type B, which is rare, the chordal attachment of the left superior leaflet is to an abnormally located papillary
muscle on the right ventricular aspect of the interventricular septum (Fig. 22.3B). In type C, which is seen quite
often, the left superior leaflet is large and bridges the ventricular septal defect and right ventricle. Its chordal
attachments are variable (Fig. 22.3C). It is a matter of the degree of overriding of the left superior leaflet on the
ventricular septum that determines the type of defect.
Unbalanced Atrioventricular Septal Defect
Approximately 10% of patients have unbalanced atrioventricular septal defects. If the common atrioventricular
valve is located more over the right ventricle, the left ventricle and other left-sided structures may be
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
P.272
underdeveloped. When the common atrioventricular valve sits predominately over the left ventricle, a hypoplastic
right ventricle with or without pulmonary outflow tract obstruction is usual.
OSTIUM PRIMUM ATRIAL SEPTAL DEFECT
The ostium primum type of atrial septal defect is part of the atrioventricular septal defect complex, sometimes
referred to as a partial form of the atrioventricular canal. Clinically, a large ostium primum that is usually
nonrestrictive is seen, but there is also always a cleft in the anterior leaflet of the mitral valve (Fig. 22.4). The
mitral valve in these cases should be considered a trileaflet structure, and this should be kept in mind whenever
a repair is attempted.
FIG. 22.1 Mitral-tricuspid valve relationship. A: In the normal heart, the mitral and tricuspid valve annuli are not in
direct contact with each other. They are connected only by the fibrous skeleton of the heart as it encircles the
aortic annulus. B: Partial atrioventricular septal defect (ostium primum atrial septal defect). The mitral and
tricuspid valve annuli are fused, but there is no interventricular communication between the left and right sides of
the heart. C: Complete atrioventricular septal defect. AL, anterior leaflet; PL, posterior leaflet; SL, septal leaflet;
LS, left superior; RS, right superior; RL, right lateral; RI, right inferior; LI, left inferior; LL, left lateral.
Соседние файлы в папке Библиотека им академика М.И. Перельмана