C.  Serial duplex scanning to detect recurrent stenosis before symptoms occur. D.  No follow-up.

The patient had post angioplasty ABPI in the left leg of 0.97. His symptoms completely resolved. He was therefore not referred for supervised exercise. Eleven years later he returned complaining of the return of his left leg claudication and a recent onset of erectile dysfunction. In that time period he had re-commenced smoking, but less than he had done previously. He had also undergone a coronary artery bypass graft for unstable angina. Two years following the bypass his angina had recurred. He continued to hunt but by now walking was difficult due to occasional angina attacks, breathlessness up hills and more recently pain in the left thigh and calf. On examination his left femoral pulse was weak, the distal pulses were absent in the left leg and a soft bruit was heard over the right ­femoral artery.

Question 8

What is the likely aetiology of this man’s erectile dysfunction?

A.  Advancing age.

B.  Side effect of his cardiac medication.

C.  Arterial insufficiency.

D.  Endocrine failure.

In view of the history of peripheral arterial disease with an internal iliac artery stenosis arterial insufficiency was considered the most likely cause for impotence; this is the most commoncauseofimpotenceinthisagegroup.Anotherangiogramwasrequested,theangiogram shows that the left internal iliac artery has re-stenosed and the external iliac artery has progressed to an occlusion. The common femoral artery reforms from collaterals and the distal run-off (neither shown) was preserved.

Question 9

Into which of the following The TransAtlantic Inter-Society Consensus (TASC) categories would you put the new occlusion of the external iliac artery?

A.  TASC A

B.  TASC B

C.  TASC C

D.  TASC D

E.  TASC E

The patient insisted on being relieved from his symptoms “no matter what the risks”. Discussion with his cardiologist revealed that the most recent coronary angiogram showed

morbidity and mortality.2 The prescription of nicotine replacement therapy is of benefit in patients who find it difficult to quit.3 The benefit of exercise for relieving the symptoms of intermittent claudication has long been recognised.4 The type and frequency of exercise to yield maximum benefit has been examined in a systematic review and Cochrane Collaboration Overview; advice alone is of little benefit but supervised exercise programmes (achieving maximal walking distance for at least 30 min three times a week) can achieve a 150% increase in walking distance or 6-min increase in walking time.5,6 A systematic review failed to show any association between beta-blockers and worsening claudication.7 If the beta blocker is stopped another antihypertensive agent, such as a calcium channel blocker or ACE inhibitor, should be substituted for control of hypertension, as treating hypertension reduces the stroke risk by 38%, cardiovascular risk by 14% and peripheral vascular events by 14%.8 A systematic review by the Anti-platelet Trialists Collaboration has proven the benefit of 75–1,500 mg aspirin daily in achieving a 25% reduction in the risk of death, stroke or myocardial infarction.9 A post-hoc subgroup analysis of patients with peripheral vascular disease in the CAPRIE trial showed additional benefit for clopidogrel.10 The additional benefit is small (196 patients on clopidogrel to prevent one death) and not justified except for the 20% of patients who are aspirin intolerant. There is no evidence of benefit from warfarin.11 It is also important to start the patient on statin therapy as this intervention has been shown to achieve an equivalent reduction in morbidity and mortality to aspirin.12,13 [Q1: A, C, D and (E)]

The patient returns having modified his risk factors and is no better. His claudication is affecting his quality of life. The options for management are persistence with unsupervised exercise, a supervised exercise programme, drug therapy or intervention (angioplasty or bypass). Cilostazol is the only drug shown to be effective at relieving the symptoms of intermittent claudication in a small randomised trial.14,15 However, it is expensive and the effect is shortlived. Intervention can only be considered once the anatomy of the underlying stenosis is known. As the presenting symptom is intermittent claudication and the patient has a weak left femoral pulse with normal right leg pulses we suspect a single level left iliac stenosis. It was decided to image the lesion. [Q2: C, (B)]

The optimal imaging of aortoiliac lesions is dependent on the facilities available. It is preferabletofirstobtainnon-invasiveimagestoallowtheapproachtoalesiontobeplanned, ensure the appropriate equipment is available and obtain the appropriate patient consent. Duplex scanning has become a useful tool for non invasive evaluation of aortoiliac occlusive disease.16 However, duplex in the aortoiliac segment is highly dependent on patient’s body habitus and experience of the operator. A helical multi-detector row (32 or 64 detectors) CT scanner can provide highquality cross-sectional images of the aorta, iliac arteries and even arteries down to the feet. CT scans have the advantage to the surgeon of familiarity and show calcified vessel walls. The disadvantages of CTA are the risk of contrastinducednephropathy,patientexposuretoionisingradiationandthetimeittakestoreformat the images.17,18 Contrast-enhanced magnetic resonance angiography (MRA) can also image the aortoiliac segment, Fig. 17.4. It is the investigation of choice in patients at risk of con- trast-induced renal impairment. In a comparison of CTA and MRA in imaging the aorta and iliac segments, sensitivity and specificity for the detection of lesions were equivalent. CTA took longer to reformat and report; a greater proportion of patients expressed a preference for CTA.19 MRA is contraindicated in patients with pacemakers and ferromagnetic intracranial aneurysm clips. Intra-arterial digital subtraction angiography now has a limited

Fig. 17.4 Magnetic resonance angiogram (MRA)

of another patient demonstrating occlusion of the right external iliac artery

Fig. 17.5 TASC II classification of aorto-iliac lesions

diagnostic role in the aortoiliac segment. Angiography is invasive and is only performed if artefacts from previous implants (i.e. stainless steel stents) degrade threedimensional imaging, if direct pressure measurements across a stenosis are required or, as in this patient, as the first stage of an invasive procedure following non-invasive imaging. [Q3: D]

The left internal iliac origin and mid-third external iliac artery lesions are TransAtlantic Inter-Society Consensus (TASC) type A lesions, Fig. 17.5.20 [Q4: A]

TheTASCconsensusonthemanagementoftypeAaortoiliaclesions(Recommendation 32) was for endovascular intervention, Table 17.1. Surgical options, endarterectomy or bypass, are reserved for longer stenoses (5–10 cm) or occlusions.20 The reported primary technical success of angioplasty of type A lesions is 98–99% with 60–80% patency at 5 years.21 The 5-year patency of open procedures is slightly better, 90% for aorto-bifemoral bypass, but the patient is exposed to the risks of death (2–3 %), erectile dysfunction and graft infection.22 It is a matter of personal preference whether a left or right percutaneous approachisusedfortheangioplastyasthelesionismid-waybetweentheaorticbifurcation and inguinal ligament. The internal iliac artery may be easier to approach from the contralateral side. [Q5: D or E]

In this case a contra-lateral approach was employed. The size of balloon used for angioplasty depends on the size of the native vessel. 2 and 4 mm balloons are used in the crural arteries, below the knee, and a 15 mm balloon is likely to rupture even a common iliac artery. In this patient a 7 mm balloon was used. [Q6: C]

The optimal management of patients following angioplasty has not been evaluated in randomised control trials. The risks to the artery are thrombosis, myointimal hyperplasia and disease progression. All patients should already be on an antiplatelet agent. Patients are formally heparinised during the procedure and for this short stenosis this is probably adequate. There is no evidence that postprocedure low-molecular-weight heparin, or for that matter any pharmacological agent (e.g. ticlopidine), is of benefit. Routine graft surveillance has been shown to improve the secondary patency of infra-inguinal vein bypass

Table 17.1  TASC II recommendations for management of aorto-iliac lesions

AAA abdominal aortic aneurysm, CFA common femoral artery, CIA common iliac artery, EIA external iliac artery, IIA internal iliac artery (hypogastric artery)

aModified from 31

grafts.23 Surveillance has not been evaluated following iliac angioplasty. The MIMIC Trial has shown that the benefit of angioplasty plus supervised exercise are additive for patients who have stopped smoking with iliac artery occlusive disease and mild to moderate intermittent claudication.24 As myointimal hyperplasia and disease progression both occur, it appears prudent, if not mandatory, to follow up patients. This can be done using clinical examination, arterial duplex or ankle brachial pressure index (ABPI) measurement. Clinical follow-up is cost-effective and in addition is a good way of enforcing a tight control­ of risk factors. [Q7: B]

Erectile dysfunction in this setting is probably due to arterial insufficiency resulting from progression of bilateral iliac occlusive disease. The association of erectile dysfunction with aortoiliac occlusive disease was first described in 1814 by Robert Graham.25 However, it was Rene Leriche in 1940 who operated on a 29-year-old truck driver “who for two years had been suffering from claudicatio intermittens with severe cramps in the leg musculature already after a few hundred meters of walking, and cramp pains also at night. The last weeks before the operation he complained of not being able to complete an intercourse, as both erection and ejaculation was disturbed”.26 [Q8: C]

This patient has suffered disease progression in the intervening years. He has developed a very tight stenosis of the left internal iliac artery, a stenosis or the right internal iliac artery origin, and complete occlusion of the left external iliac. The left external iliac artery occlusion is classified as a TASC type C lesion.20 [Q9: C]

The consensus in 1990, when the TASC guidelines were drawn up, was that definitive recommendations on how to treat such lesions must await more convincing evidence. This situation has not changed. The risks of open aortoiliac bypass surgery and endarterectomy havealreadybeendiscussed.RemoteiliacendarterectomyusingMollringstrippersavoids an abdominal approach and pelvic dissection, has good published technical success rates (88–92%), and 3-year patency just below that of open endarterectomy (60%).27,28 A potential development for the future is laparoscopic aortoiliac surgery.29 In this patient a femo- ral-femoral cross-over graft is not advisable because contralateral lesions may impair the graft inflow and because this procedure would not address the internal iliac stenoses. Had the cardiac antecedents not been present, direct bilateral surgical antegrade revascularization of the lower limbs and one or both internal iliac arteries would have been an excellent solution. However, in the context of unreconstructable coronary artery disease and poor left ventricular function, such a solution is too invasive and carries too great a risk of cardiacdeath.Ontheotherhand,surgicalabstention,althoughnotwithoutjustification,seems exaggerated because quality of life is often as important as its length among middle-aged and aged patients. [Q10: D]

Stenting is generally reserved for the primary treatment of occlusions to reduce the risk of distal embolisation. Stents are also used in management of lesions with a high risk of primary failure; eccentric calcified plaque, residual stenosis greater than 50% or greater than 10 mmHg pressure gradient or if there is local dissection.30 Stenting adds considerably to the cost of the procedure. In this patient, stents were placed into both the external and internal iliac arteries, because of the occlusion and a residual stenosis after angioplasty respectively. [Q11: B, C and possibly E]