Transcript Document

AORTO-ILIAC DISEASE
BASIC SCIENCE
March 8th, 2006
References include Sabiston, 17t ed. 2010-17, Rush Review of Surgery, 3rd ed. 452-66
1.
A 64-year-old non-smoker complains of severe lower extremity pain with walking
beyond two blocks. With rest, the pain resolves. Regarding claudication, which of
the following is true?
a. The pain suffered is reproducible and is caused by muscle ischemia
b. It is associated with a relatively high limb loss rate
c. Annual risk of mortality is approximately 5%
d. A conservative regimen of exercise and risk factor modification does not
effectively stabilize or reverse symptoms in the majority of
patients.
e. Approximately 70% of patients with claudication come to operation within 5
years because disease progression.
1.
A 64-year-old non-smoker complains of severe lower extremity pain with walking
beyond two blocks. With rest, the pain resolves. Regarding claudication, which of
the following is true?
a. The pain suffered is reproducible and is caused by muscle ischemia
b. It is associated with a relatively high limb loss rate
c. Annual risk of mortality is approximately 5%
d. A conservative regimen of exercise and risk factor modification does not
effectively stabilize or reverse symptoms in the majority of
patients.
e. Approximately 70% of patients with claudication come to operation within 5
years because disease progression.
1. (A,C) Arterial claudication causes reproducible muscle ischemic pain
from inadequate oxygen delivery. While mortality, usually from
cardiovascular causes, approaches a yearly risk of 5%, the annual
risk of limb loss in those with claudication is only 1%. Over half of
all patients stabilize or improve with conservative management. 2030% of patients with claudication will require an operation within 5
years due to disease progression.
2. After two years of disease progression, the patient in the above example begins to
develop foot pain during the night that is so severe, it wakes him from sleep. He has
recently begun to dangle the leg off the end of the bed, as this seems to alleviate some
of the pain. In this patient, which of the following is true?
a. Rest pain is an indication for surgical revascularization
b. Pedal ulcers are likely to heal quickly due to the robust granulation tissue
that forms in those with ischemic rest pain
c. These days, prior to surgical intervention, most patients are routinely sent
for medical optimization despite no observed improvement in
perioperative morbidity and mortality
d. A percutaneous intervention at the level of the common iliac artery is
less likely to last 5 years than one at the common femoral artery
e. PTA is ideal for opening up long segments of stenosis
2. After two years of disease progression, the patient in the above example begins to
develop foot pain during the night that is so severe, it wakes him from sleep. He has
recently begun to dangle the leg off the end of the bed, as this seems to alleviate some
of the pain. In this patient, which of the following is true?
a. Rest pain usually indicates a need for surgical revascularization
b. Pedal ulcers are likely to heal quickly due to the robust granulation tissue
that forms in those with ischemic rest pain
c. Prior to surgical intervention, most patients are routinely sent
for medical optimization despite no observed improvement in
perioperative morbidity and mortality
d. A percutaneous intervention at the level of the common iliac artery is
more likely to last 5 years than one at the common femoral artery
e. PTA is ideal for opening up long segments of stenosis
Rest pain is an imbalance where oxygen supply does not meet metabolic requirements.
This is a harbinger for tissue loss, and indicates a need for revascularization. The
diminished tissue perfusion impairs normal healing mechanisms. Medical optimization,
especially the initiation of beta-bocker therapy is critical in decreasing perioperative
morbidity and mortality. Aortoiliac occlusive disease has been increasingly addressed
with angioplasty and stents. Studies have shown that results are more favorable for
common iliac (80% patency) than common femoral (50%). The percutaneous treatment
of long lesions have poorer outcomes compared to isolayed short lesions.
Complete occlusion of the distal aorta and/or bilateral common iliac arteries requires
aortofemoral bypass. Which of the following is true regarding the operation?
a. The groins are exposed and the femoral vessels are dissected BEFORE the
abdomen is entered.
b. A midline intraperitoneal incision, or a retroperitoneal flank incision can be
made for exposure.
c. Following the proximal aortic anastamosis, subcutaneous tunnels
are developed above the inguinal ligament to pass through the distal limbs of
the prosthetic graft.
d. Tissues are closed over the prosthetic graft.
e. 10-year patency rates approach 80%
Complete occlusion of the distal aorta and/or bilateral common iliac arteries requires
aortofemoral bypass. Which of the following is true regarding the operation?
a. The groins are exposed and the femoral vessels are dissected BEFORE the
abdomen is entered.
b. A midline intraperitoneal incision, or a retroperitoneal flank incision can be
made for exposure.
c. Following the proximal aortic anastamosis, subcutaneous tunnels
are developed above the inguinal ligament to pass through the distal limbs of
the prosthetic graft.
d. Tissues are closed over the prosthetic graft.
e. 10-year patency rates approach 80%
Completing the femoral exposure limits the time that the abdomen
is open. While either standard or retroperitoneal approach is
acceptable, the tunnelling of the left limb is made more difficult by the
retroperitoneal approach. The tunnels are passed in deep
retroperitoneal tunnels beneath the inguinal ligament. Tissue are
closed over the synthetic graft, either tretroperitoneal soft tissue or
omentum. 5-year patency is 70-88%. At ten years it decreases to
66%-78%.
4. A 78-year old female has a large pelvic tumor that is applying compression on the
descending aorta. The patient complains of ischemic symptoms as aortic inflow is
insufficient. In performing an extra-anatomic bypass, which of the following is true?
a. The procedure aims to limit morbidity by avoiding the peritoneal cavity
b. The first anastamosis performed is the fem/fem bypass, then the ax/fem.
c. The conduit of choice is Dacron (Polyester)
d. If the upper extremity disease burdens are equal, one should always choose
the right axillary artery as it has a lower chance of developing subclavian
occlusive disease.
e. It is a reliable surgery with a 5-year patency rate of 70% established in the
literature.
4. A 78-year old female has a large pelvic tumor that is applying compression on the
descending aorta. The patient complains of ischemic symptoms as aortic inflow is
Insufficient. In performing an extra-anatomic bypass, which of the following is true?
a. The procedure aims to limit morbidity by avoiding the peritoneal
cavity
b. The first anastamosis performed is the fem/fem bypass, then the ax/fem.
c. The conduit of choice is Dacron (Polyester)
d. If the upper extremity disease burdens are equal, one should always
choose the right axillary artery as it has a lower chance of
developing
subclavian occlusive disease.
e. It is a reliable surgery with a 5-year patency rate of 70% established in the
literature.
Originally used after complications from prior aortoiliac surgeries, it is now used in
patients inwhom an intraperitoneal operation would be too morbid. PTFE is the
conduit of choice, and the anastamosis should be performed at the axilla first, then to
the ipsilateral femoral vessel, followed by a fem/fem bypass coming off the hood of
the PTFE graft. In choosing the axillary artery, the goal is to choose the one with
less disease. If they have equal disease, choose the right axillary artery as it
has a lower chance of developing subclavian occlusive disease. Extra-anatomic
bypass has variable success rates reported, with patency at five years listed at
anywahere from 17%-70%.
5.
Following balloon angioplasty of a single iliac lesion, a 68-year-old-man’s symptom
of buttocks claudication with exertion resolve. With regard to aortoiliac disease, which
of the following are true?
a. Impotence is common as there is decreased blood through the internal
iliacs and the arteries of the external genetalia with a higher lesion
b. claudication is to be expected, but tissue loss would be rare
c. Over 50% of patients will have lower extremity hair loss and brittle toe
nails as a manifestation of chronic ischemia
d. Concomitant cardiac disease is a frequently encountered comorbidity in
this patient population.
e. Balloon angioplasty is successful in alleviating isolated iliac lesions
5.
Following balloon angioplasty of a bilateral high iliac lesions, a 68-year-old-man’s
symptoms of buttocks claudication with exertion resolve. With regard to his aortoiliac
disease, which of the following are true?
a. Impotence is common as there is decreased blood through the external
iliacs and the arteries of the external genetalia with a higher lesion
b. claudication is to be expected, but tissue loss would be rare
c. Over 50% of patients will have lower extremity hair loss and brittle toe
nails as a manifestation of chronic ischemia
d. Concomitant cardiac disease is a frequently encountered comorbidity in
this patient population.
e. Balloon angioplasty is successful in alleviating isolated iliac lesions and
improving inflow for subsequent distal revascularization surgery
As described, Leriche’s syndrome, has a component of intermittent thigh claudication
and impotence from hypogastric artery occlusion with decreased flow through the
pudendal artery and the corpora cavernosum. Distal pulses are usually diminished or
absent, but trophic changes are absent due to collaterals. Tissue loss implies distal
disease, except in the case of shower emboli from the occlusive iliac plaque causing
a “blue toe” syndrome. This population is prone to cardiac disease and 10% of
patients with AOD will have associated aortic aneurysms. Angioplasty works to
alleviate isolated lesions and in concert with distal surgery to improve inflow prior
to surgical revascularization.
6. A 50-year-old diabetic individual who has smoked 1 PPD for the last 30 years
presents with a non-healing ulcer on his lateral malleolus. His surgeon performs an
arteriogram on the affected side, and tells the patient surgical revascularization for limb
salvage is required. With regard to femoropopliteal bypass, which of the following are
true?
a. Patency for prosthetic grafts and autologous conduits are nearly equal
b. Patency rates are higher when bypass is performed before the onset distal tissue
loss
c. Continued cigarette smoking adversely affects graft patency
d. Patency rates are unaffected by whether the vein is reversed or left in situ
e. Diabetes adversely affects graft patency
6. A 50-year-old diabetic individual who has smoked 1 PPD for the last 30 years
presents with a non-healing ulcer on his lateral malleolus. His surgeon performs an
arteriogram on the affected side, and tells the patient surgical revascularization for limb
salvage is required. With regard to femoropopliteal bypass, which of the following are
true?
a. Patency for prosthetic grafts and autologous conduits are nearly equal
b. Patency rates are higher when bypass is performed before the onset
distal tissue loss
c. Continued cigarette smoking adversely affects graft patency
d. Patency rates are unaffected by whether the vein is reversed or left in situ
e. Diabetes adversely affects graft patency
The gold standard for arterial reconstruction below the inguinal ligament, and
especially below the knee, is the reversed saphenous vein graft, though recent literature
suggests that in-situ can achieve equal results. Both can achieve 5-year patency rates
of 75%-80%. Earlier bypass translates to higher patency rates because the intervention
is performed at an earlier point in the disease progression. Other things that will
decrease patency are continued cigarette smoking, small vein size, poor distal runoff, or
the use of synthetic material below the knee. It is important to note that limb salvage
exceeds graft patency, and in many cases (up to 50%) when the healing is complete,
limb salvage is maintained despite subsequent loss of graft patency.
7. A patient who underwent an aorto-fem bypass has suffered a LATE
graft limb occlusion. Which of the following, constitutes an acceptable
treatment option?
a. Non-operative therapy
b. Thrombolytic therapy
c. Redo aorto-fem
d. fem-fem bypass
e. Graft limb thrombectomy
7.
A patient who underwent an aorto-fem bypass has suffered a LATE graft limb
occlusion. Which of the following, constitutes an acceptable treatment option?
a. Non-operative therapy
b. Thrombolytic therapy
c. Redo aorto-fem
d. fem-fem bypass
e. Graft limb thrombectomy
The cause of late occlusion of a graft limb in most cases is progression of
atherosclerosis. Except in cases of profound limb ischemia necessitating emergent
operative intervention, aortography should be attempted. Inactive patients without
limb-threatening ischemia or those with comorbidities might best be treated with a
non-operative approach. Between an actual operative intervention and nothing is
thrombolytic therapy. It is only of value in acute thrombosis and has a severe sideeffect profile. Since any graft thrombosis with a degree of limb-threatening ischemia
need an operative intervention, the use is limited. In patients with a unilateral occlusion
of a short duration, with no proximal aortic pathology, surgical graft embolectomy has
shown a success rate of 90%. The benefit is that the intervention need only be through
a high groin incision under local or regional anesthesia. An excellent solution in these
cases, especially if the occlusion is more chronic, is a fem-fem bypass, to bring the
blood flowing through the other limb of the graft back to the occluded side. It is
technically easier, faster, and safer than a redo aortic procedure. For those with an
aneurysmal or degenerated graft, a redo aortic graft placement may be necessary. In
a case where the graft is occluded, but not degenerating, and the abdomen is felt to be
too hostile, an extra-anatomic bypass is always an option.
8.
Following placement of an aortoiliac bypass graft, the patients develops a
lingering infection and a fluid collection around the graft. What facts about
aortic graft infection are true?
a. Infected prosthetic aortic grafts occur more commonly with aorti-iliac bypass
than with aorto-femoral bypass
b. S. aureus is the most commonly isolatd pathogen from the grafts
c. Ultrasonography is the preferred diagnosis modality for graft infections
d. Most prosthetic aortic graft infections are diagnosed 1 year after
implantation
e. Graft excision, secure aortic stump closure, and extra-anatomix reconstruction
are required for all infected prosthetic aortic grafts.
8.
Following placement of an aortoiliac bypass graft, the patients develops a
lingering infection and a fluid collection around the graft. What facts about
aortic graft infection are true?
a. Infected prosthetic aortic grafts occur more commonly with aorti-iliac bypass
than with aorto-femoral bypass
b. S. aureus is the most commonly isolatd pathogen from the grafts
c. Ultrasonography is the preferred diagnosis modality for graft infections
d. Most prosthetic aortic graft infections are diagnosed 1 year after
implantation
e. Graft excision, secure aortic stump closure, and extra-anatomix reconstruction
are required for all infected prosthetic aortic grafts.
Incidence of graft infection is 1% following aorto-iliac bypass, 1.5% - 2% following
aorto-femoral bypass. Mortality from an infected graft has been reported as high as
50%. Most common pathogen is S. epidermidis. The most sensitive imaging tool for
diagnosis is CT. Most cases are diagnosed beyond 1 year after surgery. While most
are excised en masse with extra-anatomic bypass. Those that present late, with lowvirulence, can be excised segmentally with replacement in stages. Regardless of the
method of graft removal, all patients are placed on long-term/life-long antibiotics.
9. St. Luke’s vasculopath arrives to the E.R. with a necrotic forefoot that will require
a transmetatarsal amputation. Unfortunately, her fem-pop bypass from 2002 has been
down for an unknown period of time. To facilitate healing a redo bypass will be
attempted. As her native saphenous vein has already been used in that leg, which of
the following could be used as an alternative?
a. Contralateral greater saphenous vein
b. Umbilical vein allograft
c. Cephalic and basilic arm vein autografts
d. Lesser saphenous vein graft
e. PTFE
9. A St. Luke’s vasculopath arrives to the E.R. with a necrotic forefoot that will require
a transmetatarsal amputation. Unfortunately, her fem-pop bypass from 2002 has been
down for an unknown period of time. To facilitate healing a redo bypass will be
attempted. As her native saphenous vein has already been used in that leg, which of
the following could be used as an alternative?
a. Contralateral greater saphenous vein
b. Umbilical vein allograft
c. Cephalic and basilic arm vein autografts
d. Lesser saphenous vein graft
e. PTFE
PTFE have similar patency rates at 36 months for fem-AK pop
reconstructions. Arm veins can be effective, though they are short
(requiring an extra anastamosis in joing two segments) and may be
thrombosed due to chronic hospital cannulation. Umbilical vein
allograft can be used, though of late it has becoming far less employed,
as it is prone to late aneurysm formation and eventual thrombosis.
Lesser saphenous vein grafts can be short and thin, but are effective
for reconstruction. Composite grafts are always an option if length is
an issue. In many cases t he goal is just to heal the wound, resulting in
long-term limb salvage, not necessarily long-term graft patency.
10. A patient with a known friable aortic plaque presents with a acute onset of a cold
left foot. Regarding the operative management of lower extremity arterial embolism,
which are true?
a. Embolectomy can be performed in most cases with balloon “Fogarty” catheters.
b. Aortoiliac emboli should be removed through an abdominal approach.
c. Brisk back-bleeding is a reliable indicator of successful complete distal
embolectomy.
d. Wide fasciotomy should be avoided in heparinized patients because of the risk
of hemorrhage.
10. A patient with a known friable aortic plaque presents with a acute onset of a cold
left foot. Regarding the operative management of lower extremity arterial embolism,
which are true?
a. Embolectomy can be performed in most cases with balloon “Fogarty”
catheters.
b. Aortoiliac emboli should be removed through an abdominal approach.
c. Brisk back-bleeding is a reliable indicator of successful complete distal
embolectomy.
d. Wide fasciotomy should be avoided in heparinized patients because of the risk
of hemorrhage.
Thromboembolectomy should be performed with balloon catheters through an easily
accessible artery proximal to the embolic site. In this case, since the source was
aortic, even though the symptoms are currently unilateral, bilateral femoral cutdowns
should be performed to clear both arterial trees. Back-bleeding is NOT indicative of
successful embolectomy, merely the presence of a patent arterial side-branch proximal
to the thrombus that has formed at the embolic site. The gold standard to assess
completeness of the embolectomy is return of pulses and an intraoperative
arteriography. Limb ischemia of 4-6 hours requires a low threshold for a
concomitant fasciotomy. It should be performed regardless of the heparinized status
of the patient.