Editing Aortoiliac occlusive disease

== Pathophysiology ==

* AIOD typically begins at aortic terminus and COA origins and slowly progresses proximally and distally
* Claudication symptoms can often be managed easily non-operatively for years due to good collaterals (lumbar and hypogastric arteries connecting to circumflex iliac, hypogastric, femoral, PFA recipients), and rarely leads to CLTI
* 40% have concomitant SFA disease and 35% have orifical PFA disease
* Generally doesn't progress proximally to level of visceral arteries
* 'Small aortic syndrome' or 'hypoplastic aortic syndrome' 
** Typically found in young women smoke
** Focal stenosis posteriorly at or proximal to the aortic bifurcation
** Durability of endovascular intervention or endarterectomy is often poor, especially if they keep smoking
* Leriche syndrome
** Impotence
** Claudication
** Lower extremity pallor and atrophy of leg muscles
** Absent femoral pulses
* Pelvic ischaemia
** Hip and buttock claudication, erectile discomfort, cauda equina syndrome

== Evaluation ==

* Risk factors
** Old age
** Smokers
** HTN
** Hyperlipidaemia
** Diabetes
* Symptoms
** Hip/thigh/buttock claudication, along with absent femoral pulses
** Leriche syndrome
** Tissue loss
** Rest pain
* Exam
** >20mm Hg drop between brachial and proximal thigh pressure represents significant aortoiliac stenosis

== Imaging ==

* Segmental Doppler pressures
* Duplex USS is hard because of overlying bowel gas patterns
* CTA is best first imaging option, probably
* Criteria for iliac stenosis:
**

{| class="wikitable"
|Stenosis
|PSV
|-
|>50%
|>200cm/s; PSV ratio >2.5
|-
|>75%
|PSV 400cm/s; PSV ratio >5; EDV >40cm/s
|}

** CFA velocity <45cm/s with an associated monophasic waveform pattern are nearly 90% accurate in identifying a proximal iliac artery lesion

== Treatment ==

=== Indications for intervention ===

* Disabling intermittent claudication that significantly affects a patient's daily lifestyle despite optimal medical therapy
* Ischaemic rest pain
* Tissue loss

=== Medical interventions: ===

* Smoking cessation
* Weight loss
* Antiplatelets
* Treat:
** HTN
** Hyperlipidaemia
** Diabetes
* Trial of organised exercise program

=== Endovascular vs open: ===

* Type A and B: endovascular offered first
* Type D: open revasculararisation, unless precluded by comorbidity
* Type C: probably also endovascular first now


=== Surgical revascularisation ===

* Aortobifemoral bypass grafting is now the preferred open approach for patients with advanced disease but acceptable operative risk
** Dacron graft tunneled directly on top of existing vessels down to CFA
**
* Femorofemoral bypass
** Dependent on a nice patent contralateral inflow vessel
** Graft is tunneled across superfiscial to the pubis from one side to the other
* Axillobifemoral bypass
** Used in ill, older patients with infrarenal aortic or iliac occlusive disease resulting in critical limb ischaemia
* Results are excellent, with 10 year AFB graft patency of 85%. Younger patients do worse, unknown why. Extra-anatomic graft results are slightly worse but still acceptable.

=== Endovascular ===

=== Pre-op optimisation ===

* Evaluate cardiac, pulmonary, renal, cerebrovascular and haematologic disease
* Assume CAD
* In CKD, delay until after contrast load has been excreted from angiogram
* Periop beta blockade and continuation of aspirin


[[Category:Vascular]]