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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3643_Библиотеки_им_академика_М_И_Перельмана.pdf
266
grade fl ow and for purging any atheromatous debris. An
oblique anastomotic embouchement is created to facilitate
reimplantation into the CCA. Preparation of the VA usually takes place while clamping the CCA; thus, tolerance
to clamping is evaluated. Clamping of the CCA is generally well tolerated. Adventitia is peeled off at the site of
anastomosis (previously marked), and an anastomotic orifi ce is created with the aid of a vascular punch of 4–4.5 mm.
The VA is anastomosed in such a way as to resemble a
natural branch of the CCA (the resultant angle of about
60° is facing upward). Note that the anastomotic site lies
on the posterior and lateral side of the CCA. The vascular
clamps will facilitate the temporary rotation of the CCA,
until completion of the anastomosis. Just before closing
the anastomosis, the VA is declamped fi rst and reclamped
after a few seconds. The CCA is temporarily declamped
distal and proximal. The anastomosis is closed. The CCA
is declamped proximally, while distally it still remains
clamped. A fine needle is inserted into the CCA just
under the distal clamp for additional de-airing. The distal
CCA clamp is removed while still keeping the needle for
1–2 min in site. The last to be declamped is the VA. It is
important to check thoroughly the anastomosis and the
VA stump.
With more lengthy plaques on the VA, the opening of
the bony canal is indicated to obtain an additional segment
of the VA (Fig.
12.2 ). The transverse process of C 6 can be
easily torn with the aid of a rongeur but with the precaution of not leaving in place any bony spicule. Particular
attention is needed to protect the nervous trunk of C 6 .
Numerous venous tributaries will easily bleed and require
a good hemostasis. If more extensive lesions involve the
V2 segment of the VA, we advocate performing a revascularization of the V3 segment and not to open more cranially the bony canal: this latter procedure is more time
consuming, while the anastomosis will be more diffi cult to
perform above the level of C 6 .
Reimplantation of the VA into the SCA As stated before,
this technique is seldom used in our center, due to the quality
of the SCA wall (as compared with that of the CCA). In
cases with more suitable SCA wall and when the distance
between the CCA and the VA appears greater than usual, the
reimplantation of the VA into the SCA can be performed
(Fig.
12.3 ).
CCA-to-VA Bypass In cases when the VA cannot be mobi-
lized enough or there is no suffi cient length for a safe reimplantation into the CCA, a bypass can be performed between
the two arteries, using autologous vein or a vascular prosthesis (generally, a PTFE graft). The distal anastomosis on the
VA is performed fi rst with the same precautions to avoid
rotation of the vessels. In complex procedures with aorta-tocarotid bifurcation bypass, the VA can be safely reimplanted
into the graft (the neo-CCA). The V1 segment can be also
endarterectomized and prepared for bypass or reimplantation
(Fig. 12.4 ).
Indirect VA revascularization is achievable with SCA or
BCT revascularization (see Chap. 14 ).
Revascularization of the V3 segment of the VA
(Fig. 12.5 ) must be considered in many more instances as
revealed by the elegant studies of Berguer and Kieffer [
3 ,
4 ]. Various techniques are available [ 5 ]: bypass to the V3
(usually from the carotid bifurcation), transposition of the
ECA, transposition of the occipital artery, and transposition
of the V3 into the ICA. In our experience, patients required
concomitant carotid surgery, and the VA was bypassed
from the carotid bifurcation using autologous vein. We
describe below the technique we apply. The carotid bifurcation and the V3 segment of the VA are approached
through a single cervical incision starting anterolateral at
the level of the thyroid cartilage and extending posterior
over the SCM and under the mastoid process at about 1 cm
(as described in Chap. 4 ). After partially dividing the SCM
and the prevertebral musculature, the distance between the
carotid bifurcation and the V3 appears reduced. The loop
between C 1 and C 2 will allow exposure of about 2 cm of the
VA. When the entire V2 segment is diseased, only a distal
bulldog clamp on the VA will suffi ce. The distal anastomosis on V3 is performed fi rst. The proximal end of the graft
is anastomosed on the carotid bifurcation. If lesions are
present at this level, the CEA is also indicated, and the
proximal end of the graft will serve as patch for the carotid
bifurcation too.
H. Muresian
267
Fig. 12.1 Reimplantation of the VA
into the CCA. Panel ( a ) supraclavicular
approach to the CCA and VA at origin
(V0–V1). The VA is exposed between
the CCA and the IJV (the latter is
retracted anteriorly). The CCA is
mobilized. Note the close relationship
between the VA and the CCA. ASM
anterior scalene muscle, Ph phrenic
nerve, BP brachial plexus. Panel ( b ) the
CCA is positioned underneath the IJV,
and the VA is also gently mobilized in
order to choose the proper point of
reimplantation into the CCA. The
arteries are additionally inspected and
palpated for any lesions or parietal
modifi cations that would otherwise
contraindicate reimplantation. Panel ( c )
reimplantation completed. Note the
smooth angle of the reimplanted VA,
resembling a natural collateral of the
CCA. At right: angiographic aspect of
the reimplanted VA
CCA
VA
BP
ASM
IJV
Ph
IJV
VA
BP
ASM
Ph
a
b
Image Gallery
12 Vertebral Artery Revascularization
268
CCA
VA
IJV
BP
ASM
Ph
ICA
ECA
VA
CCA
c
Fig. 12.1 (continued)
H. Muresian
269
CCA
VA
C6
IJV
OH
CCA
VA
a
b
Fig. 12.2 Opening of the bony
canal at C6. Panel ( a ) whenever
the length of the VA is insuffi cient or when the V1 segment
presents extensive atherosclerotic
lesions, a partial exposure in the
bony canal of the VA is
mandatory. Note the extralength
obtained within the bony canal.
The trunk of C6 cervical nerve
must be protected. Panel ( b )
intraoperative aspect of the
reimplanted VA. Note that even
in this case, a smooth curve of
the VA is obtained
12 Vertebral Artery Revascularization
270
Fig. 12.3 VA reimplantation into the SCA. Rarely
performed, the reimplantation into the SCA
depends more on the quality of the SCA wall.
Panel ( a ) surgical approach through a supraclavicu-
lar incision. If necessary, some of the collaterals of
the SCA must be divided in order to mobilize the
artery. BP brachial plexus, Ph phrenic nerve, IJV
internal jugular vein. Panel ( b ) the anastomosis in
an L-T fashion, usually performed with a
continuous 8-0 Prolene suture. Panel ( c ) reimplan-
tation into the SCA, completed. Note that in these
cases, the anterior scalene muscle is divided, for a
better exposure. The phrenic nerve is identifi ed and
protected
IJV
VA
SCA
BP
IJV
CCA
VA
Ph
BP
SCA
a
b
H. Muresian
271
IJV
CCA
VA Ph
SCA
BP
c
Fig. 12.3 (continued)
12 Vertebral Artery Revascularization
272
Fig. 12.4 CCA-to-VA bypass. Whenever the direct reimplantation is
not possible, a bypass between the CCA and the VA is possible, using
prosthetic or autologous venous grafts. Panel ( a ) CCA-to-VA bypass
with a 6 mm PTFE graft. A CEA and patching was concomitantly performed. Panel ( b ) angiographic aspect of the same case, showing the
severe stenosis at the level of the left carotid bifurcation and the
extended lesion at the origin of the VA, the latter requiring endarterectomy of the VA almost to the level of C6. Consequently, the bony canal
was opened and extralength was thus obtained. Panel ( c ) the excised
plaques, from the VA and from the carotid bifurcation, as seen from the
outside and after being sliced. Note the composition of the plaques and
the degree of stenosis in both arteries
CCA
VA
IJV
ICA
ECA
CCA
ICA
ECA
VA
SCA
a
b
H. Muresian
273
VA
CCA
ICA
VA
CCA
ICA
c
Fig. 12.4 (continued)
12 Vertebral Artery Revascularization
274
Fig. 12.5 Revascularization of the V3 segment of the VA. Panel ( a )
concomitant surgical exposure of the carotid bifurcation and of the V3
segment of the VA. Note the good landmark offered by the C2 nervous
trunk. Panel ( b ) a close-up of the reciprocal relationship between the C2
nerve and the V3 segment. Panel ( c ) bypass completed, with a saphe-
nous graft ( G ). The graft can be tunneled in either pre-jugular or retro-
jugular position. A CEA and patching of the carotid bifurcation was
also performed in this patient. The angiographic control shows the
result obtained
CCA
XI
C2
VA
ICA
XI
V3
C2
a
b
H. Muresian
275
G
CCA
ICA
V3
G
ICA
c
Fig. 12.5 (continued)
12 Vertebral Artery Revascularization