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is identified and typically divided, enhancing exposure and
allowing more space for the graft as it courses from the axilla
to the subcutaneous space. The axillary artery medial to the
pectoralis minor is then isolated because the proximal anastomosis is optimally placed as close to the chest as possible to
minimize the risk of kinking or graft avulsion during rotational
shoulder movement. Avoiding more lateral dissection further
reduces the risk of injuring the medial and lateral cords of the
brachial plexus as they emerge anteriorly to form the median
nerve. A tunnel is created between the axillary and femoral arteries in the subcutaneous space, tracking deep to the pectoralis
major muscle and inferiorly along the midaxillary line before
coursing medial to the anterior superior iliac spine; this latter
orientation is important to avoid kinking of the conduit in the
sitting position. Long, rigid tunneling devices with a removable
central obturator are specifically designed for this step and have
helped lower the incidence of graft infection by obviating the
need for counterincisions.
The CFAs are then dissected through standard bilateral short
groin incisions, and a second subcutaneous tunnel is fashioned
between them in an extrafascial suprapubic plane. A Dacron or
polytetrafluoroethylene (PTFE) graft, typically 8 mm in diameter, is then drawn through the tunnel. Although there is no
convincing evidence that one graft material is superior to
the other, several reports support the common practice of
using an externally reinforced graft.
60,61
Newer grafts are available that are prefigured in an axillobifemoral configuration,
thereby reducing from four to three the number of anastomoses needed. As in aortobifemoral bypass grafting, unrestricted
outflow should be ensured by carrying the hood of the femoral
grafts down over the profunda orifice and performing an endarterectomy or profundaplasty when necessary. If a prefigured
graft is unavailable, the origin of the cross-femoral graft can be
tailored to the body habitus of the patient. In most cases, the
graft is taken off the distal hood of the descending axillofemoral graft. In particularly obese individuals, however, it may be
preferable to move the takeoff more proximally to prevent kinking at the level of the inguinal ligament. Orienting the takeoff of
the crossover graft at an acute angle to give an S-shaped final
configuration has been associated with higher patency rates in
some studies.
62
Many of the complications following axillofemoral grafting are
directly related to the graft and potentially avoidable. Disruption of
the proximal anastomosis, or axillary pullout syndrome, can be minimized by proper orientation of the proximal hood and ensuring
that the descending limb of the graft is free from undue tension.
63
Kinking and subsequent thrombosis of the graft can be reduced by
strict attention to tunnel position and use of a reinforced conduit.
Given the minimal physiological insult, most patients undergoing
axillofemoral grafting are ambulatory and able to tolerate a regular
diet on the first postoperative day.
Reported long-term patency rates of axillofemoral grafts have
varied significantly, ranging from as low as 29% to as high as
60,64–66
85%.
Favorable results were reported by Passman et al.,67 who
achieved 5-year patency rates of 74% and a long-term limb salvage
rate of 89%, and who are vocal advocates of a wider use for this
approach. In general, axillobifemoral grafting should be reserved
for high-risk patients with significant tissue loss and in danger of
limb loss, and not be used for treating claudication.
FEMOROFEMORAL BYPASS
Femorofemoral bypass grafts are ideally suited to patients with preserved flow in both the aorta and one iliac branch, but occlusion
or severe stenosis of the contralateral iliac not amenable to percutaneous treatment (
Figs. 21-6 and 21-7A-B). Although possible to
perform under local anesthesia in high-risk patients, it is best carried out under regional or general anesthesia. On occasion, it has
been performed in an intensive care unit setting in the particular
instance of a leg rendered acutely ischemic by placement of
FIGURE 216 Oblique-view digital subtraction angiogram indicating
a long-segment total occlusion of left external iliac artery (EIA). Extra-
anatomical left-to-right femorofemoral or iliofemoral bypass grafting would
be appropriate options for this anatomical disease distribution (see also
Fig. 21-7).
an intraaortic balloon pump. Technical details are identical to
those of the crossover component of the axillobifemoral grafting
discussed earlier. The suprapubic tunnel is created in a gentle C
curve just superficial to the deep fascia, and can in most instances
be completed by blunt finger dissection approaching from both
groin incisions. Although some surgeons advocate placement of
the tunnel beneath the rectus sheath, this is a minority view. Again,
if warranted by the presence of significant concomitant femoral
disease, an endarterectomy or profundaplasty is indicated prior to
completion of the proximal or distal anastomosis.
Graft failure due to progression of inflow disease following
femorofemoral grafting is less problematic than one might predict. Some investigators have argued that the increased flow
through the donor iliac artery following restoration of bilateral
outflow, in essence shifting the aortic bifurcation to a more distal
point, serves to impede further development of atherosclerotic
disease. Animal studies correlating blood flow and shear stress
with intimal hyperplasia lend support to this explanation.68 Maini
and Mannick reported a 5-year cumulative patency rate of 80%.
This is similar to other reports in the literature
favorably with the 85% rate seen with conventional aortobifemoral bypass grafting.
33
70–72
and compares
With its high patency rates and low associated morbidity,
cross-femoral grafting is an excellent option in patients with
favorable anatomy. Given the risk of late graft failure from progression of inflow disease and the potential need to reintervene on
previously dissected femoral beds should a later aortobifemoral graft be needed, however, it has traditionally been advised to
proceed directly to aortobifemoral grafting in good-risk patients
with any evidence of atherosclerotic disease in the aorta or
patent iliac vessels. In the current era, aortic or iliac angioplasty
and/or stenting in combination with cross-femoral grafting is a
viable alternative in this setting, particularly for those patients at
increased operative risk.
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ABC
FIGURE 217 Patent common or external iliac artery (EIA) may be used as donor vessel for (A) iliofemoral, (B) ilioiliac, or (C) iliobifemoral bypass
grafts depicted. Lesions depicted in A and B would also be appropriate for femorofemoral grafts, whereas lesion in C would be appropriate for aortobifemoral or
axillobifemoral grafting.
ILIOFEMORAL BYPASS
Iliofemoral grafting is another alternative to aortobifemoral
grafting for a selected group of patients with hemodynamically significant disease limited to the EIA (see
Fig. 21-6). Currently, most
patients with this anatomical pattern of disease would typically
undergo an attempt at percutaneous recanalization of a tightly
stenotic or long-segment external iliac occlusion. Indeed, as the
success rates with such efforts increase, the number of iliofemoral bypass grafts performed has continued to fall. However, if the
percutaneous approach is unsuccessful, an iliofemoral bypass
remains an excellent surgical option because it can be performed
with minimal morbidity and cardiopulmonary insult and avoids
the long, descending limb necessitated by an axillofemoral graft
(see
Fig. 21-7). Because the grafts are situated within the pelvis, they
are also better protected from kinking, infection, and thrombosis
than either axillofemoral or femorofemoral grafts. Less disturbance
of inguinal lymph nodes and lymphatic channels typically occurs
with the more limited dissection necessary.
Either the ipsilateral common iliac or proximal EIA can serve
as the donor site, and if need be, a bifurcated graft can be used
and taken to both femoral vessels. Alternatively, bilateral iliofemoral grafts or an ilioiliac graft can be fashioned as appropriate. Iliac
exposure can be achieved through an oblique suprainguinal “transplant” incision and development of the retroperitoneal plane, which
affords excellent proximal exposure even in the obese patient. Care
must be taken in isolating the donor vessel and tunneling the graft
to avoid injury to the ureter coursing over the iliac bifurcation. If a
crossover graft is used, it can be tunneled retroperitoneally in the
iliac fossa or across the properitoneum deep to the rectus sheath.
In early experience with iliac origin grafts reported by Couch
et al., there were no operative deaths and a 77% 4-year patency
rate.73 Nearly half of these patients were operated on for limb salvage in the face of critical ischemia. In patients undergoing revascularization with bilateral iliofemoral grafts, the 4-year patency
rates were 92%, whereas an 85% patency rate was seen if both the
superficial and deep femoral vessels were patent.
series of iliofemoral bypass grafting have indicated similar patency
71,74
rates.
73
Other reported
THORACIC AORTA–TO–FEMORAL ARTERY BYPASS
As early as 1961, Blaisdell et al. reported on a novel extra- anatomical
bypass from the descending thoracic aorta to the femoral artery,
followed by a femorofemoral bypass.
75
Although carried out in
the setting of sepsis after a ruptured aneurysm repair and not for
occlusive disease, it provided a new alternative when the infrarenal
aorta was inaccessible or inappropriate as a donor vessel. The
procedure is performed through a thoracotomy incision, typically entering the chest through the eighth or ninth interspace.
A muscle-sparing technique in which the latissimus dorsi muscle
is not divided aids in postoperative pain management. The distal
descending thoracic aorta is circumferentially dissected enough
to allow for clamp control, with care taken to avoid injury to the
adjacently positioned esophagus. A tunnel is fashioned by separating the diaphragm from the posterior chest wall over a distance of
two finger breadths. In 1994, Criado and Keagy76 reviewed the literature and summarized 193 reconstructions taken off the descending thoracic aorta. Not unexpectedly, the majority were performed
for thrombosis or infection of a previously placed aortic graft,
although some primary procedures undertaken in the setting of
a “hostile” abdomen were included. Cumulative 5-year primary
and secondary patency rates of 73% and 83%, respectively, were
obtained, and the operative mortality rate was 6%.
76
LAPAROSCOPIC REVASCULARIZATION
There is an increasing interest in applying laparoscopic techniques to the treatment of aortic occlusive disease, reflected in a
small but growing body of literature of individual case series.
Some surgeons have favored a more limited approach using
hand-assisted techniques and smaller incisions,
ers have championed the use of complete laparoscopic or robotassisted revascularization.
77,80,81
The purported benefits of shorter
79
whereas oth-
77,78
hospital stays, less perioperative pain, and fewer postoperative
complications are balanced against longer operative times and
lack of long-term data to support the durability of this alternative
approach. It remains at present an extremely technically challenging procedure with a significant learning curve. As the technology
advances and improvement is seen with anastomotic devices and
instrumentation, the role of aortofemoral bypass will likely expand
and become more defined. At present, however, it has failed to gain
widespread acceptance and is routinely undertaken in only a limited number of centers.
Infrainguinal Arterial Occlusive Disease
Infrainguinal arterial occlusive disease is the most prevalent
manifes tation of chronic arterial occlusive disease encountered
and treated by the vascular surgeon. Isolated disease of the SFA
typically manifests as calf muscle claudication, whereas patients
with multilevel disease involving the superficial femoral, popliteal,
and tibial arteries generally have rest pain or ischemic tissue loss.
The ischemia ulcerations usually begin as small, dry ulcers of the
toes or heel area and progress to frankly gangrenous changes of
the forefoot or heel, with greater degrees of arterial insufficiency.
Several identifiable patterns of disease are recognized, with smokers typically having disease limited to the SFA and corresponding
symptoms of claudication. Diabetes most often targets the popliteal and tibial vessels, and patients may present with frank tissue
necrosis with no history of claudication.
Infrainguinal reconstruction for treatment of peripheral vascular occlusive disease has been increasingly successful for both
long-term palliation of intermittent claudication and for salvage
of limbs threatened by critical ischemia. There are times when
primary amputation represents the safest and most advisable solution in the face of irreversible ischemia, particularly in cases where
extensive infection or tissue necrosis is present. In addition, certain patient populations may have a combination of risk factors
that may be predictive of a prohibitively poor outcome. This may
include patients of advanced age or those in a dependent living
situation on hemodialysis.82 Otherwise, an attempt at reconstruction is almost always indicated when a limb is threatened by severe
ischemia. Improvements in perioperative management and surgical technique have allowed progressively more distal reconstructions to be successfully completed in an older, sicker, and more
challenging patient population. In general, high rates of relief
for claudication and up to an 80% to 90% limb salvage rate may
be anticipated for patients with critical ischemia at institutions
devoted to peripheral bypass surgery.
A large prospective randomized double-blinded multicenter
trial, the Project of Ex Vivo Graft Engineering via Transfection
III (PREVENT III), was recently conducted to evaluate the efficacy of edifoligide in preventing autogenous vein graft failure
in lower extremity revascularization for critical limb ischemia
83
(CLI).
Although the trial failed to show any significant primary
patency or limb salvage benefit of the studied medication, it did
provide valuable contemporary information regarding infrainguinal bypass outcomes. In the study cohort of 1404 patients from
83 North American sites, the 30-day operative mortality rate was
2.7%. Assisted primary patency, limb salvage, and survival at 1 year
were 77%, 88%, and 84%, respectively.83 A validated risk score
subsequently created to allow stratification of patient risk factors in the setting of limb-threatening ischemia demonstrated that
amputation-free survival was negatively associated with dialysis
dependence, tissue loss, age older than 75, anemia, and coronary
artery disease.
one of the first comprehensive evaluations of patient quality of life
before and after surgical revascularization. Notably, patients undergoing successful surgical revascularization reported a significant
quality-of-life improvement at 1 year compared to baseline levels.
The two major indications for surgical intervention of
infrainguinal arterial occlusive disease are claudication and limbthreatening critical ischemia. Claudication is a relative indication,
given the natural history of the disease; of patients with claudication, only 1% per year will ultimately progress to limb loss.
As such, it remains a subjective assessment on the parts of both
patient and surgeon as to the relative degree of disability a given
level of claudication pain represents.
84
The PREVENT III dataset additionally provided
85
86,87
Role of Percutaneous Transluminal Angioplasty
Of relevance in this regard is the significant shift in the indications for percutaneous intervention for infrainguinal occlusive disease witnessed in recent years. As the associated risks of balloon
angioplasty and stenting have fallen and relative success rates
have risen, the threshold for offering endovascular treatment to
claudicants has decreased considerably. Patients once considered
appropriate only for risk factor modification, exercise therapy, and
medical treatment are now increasingly being offered percutaneous revascularization as a secondary or even primary treatment
option (see Chapter 20). The relative merits of early intervention
as opposed to traditional risk factor modification and exercise
therapy for individuals with claudication remains controversial.88
Some authors have found no improvement in quality-of-life outcomes following percutaneous treatment for claudication over
and above supervised exercise training programs and have also
demonstrated endovascular therapy to be cost-ineffective for this
indication.
ing percutaneous intervention with supervised exercise programs
and optimal medical management, as indicated by improved
quality-of-life indices.
In terms of patients with severe limb ischemia secondary to
infrainguinal occlusive disease, the awaited long-term results of the
Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL)
trial recently became available.
ized controlled trial performed in 27 U.K. centers from 1999-2004.
This seminal work was designed to compare a strategy of open
surgical revascularization first to that of percutaneous angioplasty
first in a population of patients with severe limb ischemia, and
represents the only level-I evidence comparing these treatment
modalities to date. The initial analysis published in 2005
difference in the primary endpoints of overall or amputation-free
survival for open surgery vs. angioplasty, though it did find that
surgery was more costly in the short term. The more recently published longer-term follow-up results also indicated the two study
arms had equivalent amputation-free and overall survival by intention to treat analysis.
2 years (representing 70% of the total cohort), open surgical bypass
conferred improved overall survival and a trend toward improved
amputation-free survival. The trialists concluded that for patients
with available autologous vein and a life expectancy exceeding
2 years, the preferred method of revascularization is open bypass
surgery. They further noted that when percutaneous angioplasty
was employed as the primary intervention, it had a significantly
negative impact on the outcome of future surgical revascularization attempts.
Occlusive disease of the tibial vessels, once thought to be the
exclusive domain of operative bypass, is increasingly being
treated percutaneously. The impact of these trends on the natural history of the disease, and to what extent the expanding reach
of percutaneous therapy will affect subsequent operative management in a given patient, remains to be seen. Certainly, as enthusiasm
for less invasive options has spread to include the infrapopliteal
level, the relative roles of surgical and percutaneous intervention are being further redefined. Newer-generation atherectomy
devices, drug-eluting balloon angioplasty, and flexible stents
designed to withstand the unique torsional forces of the leg
or with drug-eluting capability may significantly improve the
patency and durability rates currently seen.
infrainguinal percutaneous intervention is better defined, however,
surgical revascularization remains the standard for any patient
with critical limb ischemia. For patients with favorable anatomy
and significant operative risk, and for treatment of claudication in
general, percutaneous therapy has assumed a more primary role.
Duplex ultrasonography, MRA, and CTA are increasingly used as
first-line modalities in the assessment of patients with infrainguinal
occlusive disease (see Chapters 12, 13, and 14). Although a growing
body of literature supports use of duplex scanning as a stand-alone
preoperative mapping modality,
89
Others have noted an additive benefit when combin-
90,91
92
The BASIL trial was a random-
93
94
However, for patients who survived beyond
95,96
Until the efficacy of
97
this requires a highly dedicated
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276
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vascular laboratory and, to date, has not gained wide acceptance.
Magnetic resonance angiography and CTA are particularly useful
as noninvasive screening tests to determine patient suitability for
percutaneous therapy. In some instances, operative planning may
be based solely on such noninvasive radiographic information, but
many surgeons are reluctant to undertake surgical reconstruction
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without the confirmation afforded by standard contrast angiogra-
21
phy. This is particularly true if the distal target is at the tibial or
pedal level, where CTA and MRA technology remains more limited.
Operative Management
Infrainguinal bypass can be performed under general anesthesia
or, in the appropriate patient, under regional, spinal, or epidural
anesthesia. The multiple sites of dissection and the harvesting of
saphenous vein or an alternative vein conduit make these procedures particularly suited to a two-team approach. The time saved,
particularly in cases involving potentially more tedious arm vein
or lesser saphenous vein harvesting, has direct benefit in minimizing the total anesthetic load and physiological insult to the patient.
Typically, the site proposed for the distal anastomosis is explored
first to ascertain whether the preoperative imaging was accurate in
predicting the suitability of the target vessel. On occasion, the operation is begun with an on-table angiogram to clarify the anatomy if
preoperative imaging was deferred or ambiguous.
The above-knee popliteal vessel is easily exposed through a
medial thigh incision, with subsequent posterolateral retraction of
the sartorius muscle. The popliteal artery, with its accompanying
vein and nerve, is found just posterior to the femur. The vessel
is palpated to determine the presence of atherosclerotic plaque,
which will guide the extent of dissection and the optimal bypass
target site. The below-knee popliteal artery is also exposed through
a medial incision in the proximal calf (
vein is to be harvested, the incision is made directly over the vein to
minimize creation of devascularized skin flaps. With the exposed
vein carefully protected, the incision is carried through the deep
muscular fascia, and the medial head of the gastrocnemius is
reflected posterolaterally to expose the below-knee popliteal fossa.
The distal popliteal artery is then dissected free from the adjacent
Fig. 21-8). If the saphenous
tibial nerve posteriorly and popliteal vein medially. If the distal
target is the tibioperoneal trunk, the dissection is continued along
the anteromedial surface of the distal popliteal artery after dividing the origin of the soleus muscle from the tibia (
Fig. 21-9). In
instances in which the below-knee popliteal artery has previously
been exposed or where sepsis is involved, a lateral approach with
excision of a segment of proximal fibula is a useful alternative
approach to the below-knee popliteal artery.
Although exposure of the proximal posterior and peroneal vessels can be gained by extending the tibioperoneal trunk dissection distally, more distal exposure of these vessels is best gained
through targeted medial incisions. The posterior tibial artery is
found more medially on the reflected soleus muscle, whereas
the peroneal artery is deeper and more lateral. The posterior tibial artery at the level of the ankle is a relatively easier target given
the proximity of the vessel to the skin surface. The initial incision
is made just posterior to the medial malleolus, and the artery is
exposed by division of the overlying retinaculum. Further distal
dissection allows access to the bifurcation and medial and lateral
plantar branches.
from the anterolateral aspect of the calf (see
98
The anterior tibial artery is typically approached
Fig. 21-9) and is found
deep within the anterior compartment with the adjacent deep peroneal nerve and anterior tibial veins. The dorsalis pedis artery is easily exposed through an axial incision on the dorsum of the foot just
lateral to the extensor hallucis longus tendon (see
Fig. 21-9).
Following exposure of the distal anastomotic target vessel, the
site of the proximal anastomosis is dissected. For patients with SFA
disease, this will most commonly be at the level of the common
femoral artery. The artery is mobilized as already described, from
the level of the inguinal ligament to its terminal bifurcation. The
distal extent of this dissection is dictated by the presence of concomitant femoral plaque. Lymphatic tissue overlying the femoral
vessels is best ligated and divided to prevent postoperative development of lymph fistulas or lymphoceles. If an extensive endarterectomy or profundaplasty is required, the proximal profunda
femoral artery is dissected along its proximal length accordingly.
If all or part of the SFA is spared of signifi cant atherosclerotic
involvement, the proximal anastomosis can be moved distally as
dictated by the particular anatomical pattern of disease, and a
Popliteus muscle
A
Popliteal artery
Popliteal vein
B
Gastrocnemius muscle
saphenous
vein
C
FIGURE 218 Exposure of popliteal artery below knee. Medial incision is made (A) directly overlying course of great saphenous vein (B). After posterior
reflection of the gastrocnemius muscle the tibial nerve, popliteal vein, and popliteal artery are encountered in the deep posterior compartment.
Femoral
artery
Saphenous
vein
Saphenous vein
Popliteal space
Tibial peroneal
Posterior tibial artery
FIGURE 219 Placement of incisions for femoropopliteal and
femorotibial bypass and for greater saphenous vein harvest. These
should avoid the incision lines for a below-knee amputation.
trunk
Anterior
tibial artery
Peroneal
artery
Dorsalis
pedis artery
so-called distal origin graft can be fashioned99 (Fig. 21-10). This situ-
ation is particularly applicable to the diabetic population, where
infrapopliteal disease is the rule, and sparing of the superficial
femoral and popliteal arteries is not uncommon. It is also used in
situations where conduit is sparse and a moderately diseased proximal vessel is accepted as an inflow source for a more distal origin
bypass graft in the interests of performing a fully autologous vein
graft rather than using prosthetic material. An increasingly popular approach when only limited conduit is available is to combine,
either concurrently in the operating room or as a staged preoperative procedure, catheter-based treatment of the superficial femoral
or popliteal artery inflow with more distal bypass.
99
AUTOGENOUS VEIN BYPASS
In general, infrainguinal bypass surgery is best performed with
autogenous vein conduit, preferably the ipsilateral greater saphenous vein if available.
100
This is particularly true for grafts extending below the knee, where prosthetic conduits of Dacron or PTFE
have significantly poorer patency rates. The first report of a femoropopliteal bypass graft using autogenous greater saphenous vein
in a reversed orientation was by Kunlin in 1951.
5
Given the orientation of the vein valves, the vein is reversed such that the distal
end of the vein is sewn to the proximal inflow artery, and the larger
proximal end of the vein is sewn to the distal outflow artery. The
vein is harvested through a long incision overlying the course of
the vein or by more tedious but less invasive sequential skip incisions with intervening cutaneous skin bridges (see
Fig. 21-9). All
side branches are ligated, and after harvest, the vein is cannulated
and gently dilated with a solution containing heparin and papaverine to assess its suitability. Veins with chronic fibrosis or that fail
to dilate to a diameter of 3 mm or greater will likely have poor longterm function.
For prosthetic grafts, a tunnel is usually fashioned through the
subsartorial plane between the groin incision and the aboveknee popliteal space in the interests of protecting the graft
from subsequent infection. For vein conduits, it remains the surgeon's preference as to whether the graft is tunneled deeply or
in a superficial location in the subcutaneous space. The more
superficial configuration greatly facilitates ongoing clinical examination and ultrasonographic surveillance as well as later surgical revision, but it carries a risk of graft exposure should there be
wound-healing problems. Occlusion from trauma to grafts placed
superficially has been of theoretical but not practical concern.
The order of anastomoses is surgeon dependent, with strong
feelings expressed in each camp. Before occluding the target
vessel, the patient is systemically anticoagulated with 5000 to
10,000 units of heparin. The artery is then clamped proximally
and distally and incised, the vein spatulated, and a beveled anastomosis is carried out. Typically, a 5-0 monofilament suture of
Prolene is used for the femoral anastomosis, a 6-0 suture is used
at the popliteal level, and a very fine 7-0 suture is used at the tibial
or pedal level. If the target tibial vessel is deep within the calf and
visibility is challenging, a technique of “parachuting” the heel of
the distal anastomosis is often employed. After completing the
first anastomosis, the graft is carefully marked to ensure against
mechanical twisting or kinking of the graft during the tunneling
process. One of the benefits of performing the proximal anastomosis first is that following release of the clamps, adequacy of
flow through the graft can be assessed.
Occasionally, such extensive calcification of the target vessel
is encountered that the risk of a significant injury from clamping, even with the minimally traumatic clamps in use today, is
prohibitively high. In such cases, proximal inflow and distal artery
backbleeding can be controlled by occlusion balloons placed
intraluminally. For distal anastomoses at the knee or more distal
level, another alternative technique is use of a proximally placed
sterile pneumatic tourniquet. This is particularly advantageous
when sewing to diminutive distal tibial or pedal targets, where the
impact of a crush injury or plaque dislodgment on graft function
could be considerable. Removing the need for clamps by using
the tourniquet has two more advantages. First, it improves operative visibility. Second, and more importantly, given that less longitudinal and circumferential dissection are needed, the degrees of
vessel spasm and venous bleeding that frequently accompany vessel exposure at this level are kept to a minimum.
Flow through the graft and outflow arteries is assessed with
continuous-wave Doppler ultrasound following completion of
the bypass. Ideally, a contrast angiogram is also performed after
directly cannulating the proximal graft (
Fig. 21-11). This allows for
immediate repair of any technical defects—for example, intraluminal thrombus, twisting or kinking of the graft, or retained valve
cusps, that are identified
duplex ultrasonography is a sensitive screen for hemodynamically
significant abnormalities within the graft.
101
(Fig. 21-12). Intraoperative completion
102,103
Current reports of the 5-year results of reversed saphenous vein
graft using modern techniques have been excellent, with primary
and secondary patency rates of 75% and 80%, respectively, and
limb salvage rates of 90%.
IN SITU
GRAFTING
104,105
There has been ongoing enthusiasm in some circles for in situ
vein bypass grafting, whereby except for its proximal and distal
extent, the greater saphenous vein is left undisturbed in its native
bed. This technique was first described in 1962
popularized by Leather and Karmody in the late 1970s.
106
but was later
107
Recent
reports of in situ saphenous vein grafting have indicated 5-year
graft patency rates approaching 80% and limb salvage rates of
84% to 90%.
105,108–110
The approach minimizes trauma to the vein during excision
and handling, and in theory enhances preservation of the vasa
vasorum and endothelium. It further lowers the considerable
risk of wound healing complications seen with traditional vein
harvesting and facilitates creation of more technically precise
anastomoses because the proximal and distal vein diameters are
more closely matched to those of the inflow and outflow target
vessels (Fig. 21-13). Extent of proximal vein mobilization is dic-
tated by location of the saphenofemoral junction relative to the
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A B C
D E
FIGURE 2110 A-E, Arteriogram indicating preservation of superficial femoral artery (SFA) and popliteal arteries with mid-calf occlusions of all three infrageniculate
vessels. This anatomical pattern of disease is amenable to “distal origin” vein grafting from below-knee popliteal or proximal posterior tibial artery to dorsalis pedis
artery.
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A
B
C
FIGURE 2111 Intraoperative completion
arteriograms of distal anastomoses to aboveknee popliteal (A), below-knee popliteal (B), distal
posterior tibial (C), and dorsalis pedis (D) arteries.
proposed site of the proximal anastomosis. It may at times be necessary to perform an endarterectomy of the SFA if the length of proximal vein is insufficient. Lysis of the valve cusps is obligatory given
the nonreversed configuration, and is facilitated by newer less traumatic valvulotomes that function safely through the blinded seg-
D
ments of undissected graft. Critics of this technique argue that the
advantages listed have not translated into improved graft function
or patency. They further argue that the time required and dissection involved in finding and ligating substantial side branches—
which can develop into physiologically important arteriovenous
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FIGURE 2112 Intraoperative completion arteriogram of in situ
femoropopliteal vein graft indicating retained valve, visualized as a
filling defect in graft, and persistent arteriovenous fistula (AVF).
fistulae (AVF) that “steal” distal flow—obviates the stated benefits
of this approach. Newer techniques using angioscopy and endoluminal coiling
concerns.
Angioscopic-assisted valve lysis has been employed for more
than a decade but has not gained widespread favor. Although
there is a significant learning curve with this technology, and operative times—at least initially—are significantly prolonged, advocates
cite fewer wound complications, shorter hospital stays, and
decreased recuperative periods as potential benefits. Proponents
of routine angioscopy for direct visualization of valve lysis stress its
particular utility in demonstrating such unsuspected endoluminal
venous pathology as phlebitic strictures, webs, and fibrotic valve
cusps.
arm vein is used, when endoluminal pathology is more frequently
encountered and is presumably partly responsible for suboptimal
results.
NONREVERSED SAPHENOUS VEIN GRAFTS
Recognizing the many practical advantages inherent to the in situ
technique, Belkin et al. and others have modified the approach
to infrainguinal bypass grafting with venous conduit to incorporate several of the same principles.
vein is tapered to any significant extent, it is used in a nonreversed
fashion. By optimizing the size matching between the artery and
vein at both the proximal and distal anastomosis sites as discussed
earlier, one can often use smaller veins than would be suitable
for reversed vein grafting. The nonreversed configuration also
allows preservation of the saphenous vein hood, which extends
the available conduit length and is especially beneficial when the
femoral artery is thick walled and diseased.
The vein is harvested and dilated in a similar fashion to reversed
vein grafts, and the cusps of the proximal valve of the greater
saphenous vein are excised under direct vision with fine Potts
scissors. There are currently two main types of valvulotomes available. The modified Mills valvulotome is a short, metal, hockey
stick–shaped cutter that can be introduced through the distal end of the vein or through the side branches. After the proximal anastomosis is performed, and with the perfused conduit on
gentle stretch, the valves are carefully lysed in a sequential fashion by pulling the valvulotome inferiorly. An alternative recently
designed self-centering valvulotome allows lysis of all valves in
a single pass and is believed by some to be less traumatic. Once
111
of larger side branches may help minimize these
112
This adjunct may be particularly useful in cases in which
113
114
In particular, if the harvested
acceptable pulsatile flow is ensured, the distal anastomosis is performed in the standard fashion.
It is important to note that similar patency rates have consistently
been demonstrated regardless of which technique is applied,
109,110
so surgeon preference and comfort level are acceptable reasons
for choosing one method over another.
ALTERNATIVE VEIN SOURCES
The ipsilateral greater saphenous vein (GSV) remains the conduit of choice for infrainguinal arterial reconstructions. However,
the ipsilateral GSV may be unusable or absent in as many as 20%
to 40% of patients requiring surgical revascularization.
115,116
In
patients without adequate ipsilateral GSV, alternative vein sources
include the contralateral GSV, the small saphenous vein, and the
cephalic and basilic arm veins. Some groups advocate preserving
the contralateral GSV and preferentially utilize upper-extremity
veins as the most appealing ectopic autologous conduit,
117
but
the majority of vascular surgeons, the present authors included,
favor the use of contralateral GSV in this setting, citing quite favorable patency and morbidity profiles.
115
Regardless of the strategy
employed, the quality of the vein conduit chosen is of paramount
importance. Preoperative duplex ultrasound surveillance can be
used to reliably assess the presence of available venous conduit,
as well as the relative quality with regard to wall thickness, compressibility, and diameter. The ultimate viability of the vein,
however, is determined intraoperatively following cannulation
and gentle dilation with heparinized saline.
118
In situations in which an adequate single length of vein necessary
to achieve inline pulsatile flow to the ischemic limb is unavailable,
composite grafts whereby shorter usable vein lengths are spliced
together in an end-to-end fashion can be used. Graft patency and
limb salvage rates of such composite grafts are reduced compared
to results with single-segment saphenous vein but have historically
been better than those of prosthetic grafts (see Reoperative Bypass
Surgery).
118
Cryopreserved cadaver vein allografts (CVG) remain
a conduit of last resort, reserved for highly selective cases given
their extremely poor patency rates in comparison to other conduit
choices.
119
PROSTHETIC BYPASS
As stated, it is recommended that infrainguinal bypass surgery
be performed with saphenous vein or an autologous substitute
whenever feasible, given the clearly demonstrated enhanced
patency rates.
100,120
Despite the ample published data supporting
this strategy, some institutions and surgeons more frequently rely
on prosthetic grafts. When the distal target is the above-knee popliteal artery and the tibial outflow is relatively well preserved, this is
an acceptable approach; patency rates in this situation approach
those of vein grafts.
121
A variety of surgical adjunctive procedures,
from patching the distal anastomotic target vessel, to creation of
a distal AVF, to use of various autogenous vein cuffs interposed
between the distal prosthetic and the target artery have all been
attempted as a means of improving patency rates of grafts extending below the knee.
122
More recently, flared grafts designed to minimize turbulence and shear stress between the prosthetic and
native vessel have gained some popularity. Polyester (Dacron)
and PTFE grafts are the two main types of prosthetics available,
and as in other anatomical positions, available data show generally equal results with either choice. The entire procedure is carried out through two small proximal and distal incisions between
which the graft is tunneled anatomically. The selection of a 6- or
8-mm graft is dictated by the size of the native vessels.
REOPERATIVE BYPASS SURGERY
As the patient population treated by vascular surgeons has increased
in age, and more and more challenging cases are accepted for
primary treatment, there has been a corresponding increase in the
incidence of reoperative bypass surgery performed for infrainguinal
AB
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REConsTRuCTivE suRgERy foR PERiPHERAl ARTERy DisEAsE
a
c
b
CD
FIGURE 2113 In situ method of infrainguinal reconstruction. Saphenous vein is left undisturbed in its native bed, except at proximal and distal anastomotic
sites—in this case, common femoral artery (CFA) and tibioperoneal trunk, respectively (A). Saphenofemoral junction is transected in groin, venotomy in femoral
vein is oversewn, and proximal end of saphenous vein is spatulated in preparation for anastomosis (B). After first venous valve is excised under direct vision, graft is
anastomosed end-to-side to femoral artery (C). Flow is then restored through vein graft, and valvulotome passed from distal end to lyse residual valves (D) before
distal anastomosis is performed (E).
E
arterial occlusive disease. Such reoperative procedures are particularly challenging, both because of the scarring present at the
inflow and outflow target sites and because there is typically a lack
of ipsilateral greater saphenous vein. Whenever possible, the first
problem is addressed by choosing anastomotic sites just above or
below the previous touchdown points, thereby avoiding dissection
through often densely scarred tissue planes. When ipsilateral greater
saphenous vein is absent due to prior infrainguinal or coronary
artery bypass surgery or prior saphenous vein stripping, there are a
number of alternative conduit sites available, as already mentioned.
Chew et al. studied the consequence of using the contralateral
greater saphenous vein in these situations and found it to be the
optimal conduit. Despite the presumably high incidence of contralateral lower extremity as well as coronary occlusive disease
in this population, short- and long-term impacts were found to be
minimal.
115
Use of arm veins, in general, can be extremely technically challenging and for that reason has not been universally adopted.
Often the arm veins distal to the antecubital crease are scarred and
of small caliber, but their more proximal counterparts are often of
excellent size and quality. Dissection of the basilic vein can be
particularly tedious because it has multiple side branches and
lies adjacent to several important nerves. Because arm veins are
often relatively short, a venovenostomy is often required to create
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or foot often can be safely managed conservatively. However,
larger gangrenous lesions of the toe, forefoot, or heel usually
require débridement of all necrotic tissue at completion of the
revascularization procedure. If the ischemia is particularly severe
or infection is present, toe or transmetatarsal amputation may be
necessary to achieve a margin of healthy tissue. This is particularly important in patients with diabetes or end-stage renal disease,
in whom persistent infection or necrosis can result in limb loss
despite the presence of a well-revascularized extremity. Wounds
are usually left open and treated with saline wet-to-dry dressings or
newer vacuum sponge dressings. Serial débridements on the ward
or in the operating room are often necessary for larger wounds,
which can then be surgically closed after an interval healing
A
period or allowed to slowly close via secondary intention.
Unless otherwise contraindicated, all patients are maintained
indefinitely on an antiplatelet regimen with either aspirin or clopidogrel following surgical bypass. As stated earlier, in cases in
which a graft is at increased risk of failure, such as in the redo
setting or when compromised outflow or a marginal conduit
was accepted, the antiplatelet agent may be supplemented with
Coumadin.
124
Aggressive risk factor modification in the form of
smoking cessation, lipid reduction, exercise, blood pressure management, and diabetic blood sugar control is of further paramount
importance in minimizing the risk of disease progression or recur-
125
rence.
More immediately, aggressive rehabilitation maximizes
the chances of and shortens the time to a return to full function
after extensive reconstructive surgery.
B
C
FIGURE 2114 Creation of a composite graft by venovenostomy.
A widely spatulated venovenostomy is optimal (A). The posterior wall (B) and
anterior wall (C) are aligned with separate strands of suture to avoid a “purse
string” effect on the suture line.
composite grafts long enough to complete the arterial reconstruc-
Fig. 21-14). This is performed with generous spatulation of
tion (
each vein hood to create a widely patent vein-to-vein anastomosis.
Given their thin-walled nature, arm vein grafts are also quite prone
to twisting and kinking, and special care must be taken during the
tunneling process to avoid these problems. The more proximal arm
veins can be relatively large, and it is often advantageous to use
one or more of the segments in a nonreversed fashion to better
match the graft to the inflow vessel size.
Not surprisingly, the results of reoperative infrainguinal bypass
surgery do not match those of primary reconstruction. With autogenous vein, 5-year patency rates of 60% and limb salvage rates
of 70% to 80% have been reported.
postoperatively in patients with compromised outflow or in whom
the conduit was of marginal quality and has been associated with
improved long-term patency.
115,123
Coumadin is often used
124
Graft Failure and Surveillance
Postoperative graft failures are typically classified according to
the time interval from surgery as early, intermediate, or late. Graft
thrombosis occurring within 30 days, so-called early graft failures, are generally believed to be due to technical or judgment
errors by the surgeon. Included in this list would be such technical errors as twists, kinks, incompletely lysed valves, or anastomotic
defects, as well as judgment errors in using a poor-quality vein or
targeting an outflow vessel with inadequate runoff to support the
graft. Intermediate graft failures include those between 30 days and
2 years and are generally attributed to the proliferation of intimal
hyperplasia at the anastomoses or prior valve sites within the graft
(
Fig. 21-15). Randomized trials are currently underway to determine
Post-Reconstruction Management
Many patients undergoing surgical reconstruction for arterial
insuffi ciency will require one or more adjunctive operative
procedures of their foot. Small uninfected ulcerations of the toe
FIGURE 2115 Arteriogram demonstrating severe stenosis of distal
graft from intimal hyperplasia, likely at prior valve site.
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