Infrainguinal Occlusive Disease Differential Diagnoses

Updated: Nov 13, 2023
  • Author: Christian Ochoa, MD; Chief Editor: Vincent Lopez Rowe, MD, FACS  more...
  • Print

Diagnostic Considerations


Although ischemic findings in the face of absent pulses clearly pinpoint arterial insufficiency as the culprit, intermittent claudication, even when associated with absent pulses, is not always due to arterial insufficiency.

If symptoms are not always reproducible (ie, if the patient sometimes has "good days" when ambulation is not limited by claudication) or if the symptoms are associated with low back pain or radiculopathy, the clinician should consider the possibility of pseudoclaudication, which occurs as a result of spinal stenosis or cauda equina syndrome.

In that case, the pulse deficit may be an incidental finding of asymptomatic atherosclerosis. Noninvasive vascular laboratory testing (see Laboratory Studies), lumbosacral imaging, and neurologic evaluation all may contribute to distinguishing between these possibilities.

Two rather unusual conditions, venous claudication due to extensive iliofemoral venous thrombosis and chronic compartment syndrome due to calf muscle hypertrophy in athletes, result in a bursting type of pain in the calf with ambulation, which subsides slowly with elevation. In each case, the etiology is impaired venous outflow.


Patchy areas of ischemia involving the feet, especially in the presence of palpable pedal pulses, suggest the possibility of atheroembolism of plaque fragments from ulcerated, though nonocclusive, proximal atherosclerotic plaques or from thrombus lining the wall of an infrarenal aortic aneurysm (see Abdominal Aortic Aneurysm). [25]

Thromboangiitis obliterans (Buerger disease)

Severe ischemia of the toes with absent pedal pulses but normal proximal pulses in a man aged 35-50 years who smokes cigarettes may be the result of thromboangiitis obliterans (Buerger disease). [26]  Ischemia of the fingers may also be present. The digits are cool, moist, mottled, and sometimes have tender shallow ulcers. Migratory superficial phlebitis may occur.

Collagen vascular disease must be excluded. [27]  Angiography reveals pathognomonic findings of "corkscrew" arteries. Treatment is discontinuance of smoking and good local wound care. Because of the poor quality of the distal arteries, vascular surgery is rarely possible.

Complex regional pain syndromes

Complex regional pain syndromes (CRPSs; eg, posttraumatic pain syndromes, causalgia, mimocausalgia, Sudeck atrophy, reflex sympathetic dystrophy) have been classified by the World Health Organization (WHO) into the following two variants:

  • CRPS II (ie, causalgia), which is associated with a demonstrable nerve injury
  • CRPS I (ie, mimocausalgia, reflex sympathetic dystrophy, Sudeck atrophy), which includes the remainder

Causalgia (from Greek kausos ["heat"] and algos ["pain"]) was first described in patients with arterial and nerve injuries sustained during the American Civil War. Both variants of CRPS remain poorly understood and often misdiagnosed.

Although the exact pathophysiology is elusive, the sympathetic nervous system clearly plays a focal role. Therefore, surgical sympathectomy—perfected decades ago by vascular surgeons to manage nonreconstructible arterial disease (a common situation at the time)—was once the mainstay for treatment of the CRPSs.

Although surgical sympathectomy is now mostly notable only for historic purposes, sympathetic blockade is quite effective and is commonly performed for the CRPSs. Consequently, the treatment of CRPSs is currently performed mainly by pain management specialists. Nonetheless, because the vascular surgeon has always been primarily responsible for the diagnosis of extremity symptoms, it is not uncommon for patients with CRPS to report to a vascular surgeon because of extremity pain.

Such pain may occur after extremity trauma but may seem disproportionate to the degree of injury. [28]  Pain may also manifest after delayed revascularization of an acutely ischemic extremity. The diagnosis is often one of exclusion and thus requires a high index of clinical suspicion.

The diagnosis should be considered more strongly if severe superficial burning pain and agonizing hypersensitivity are present and are associated with vasomotor abnormalities such as edema, erythema, and hyperhidrosis. Radiographic studies may demonstrate relative and patchy osteopenia in the involved extremity.

In addition to symptomatic relief, management of CRPSs requires sympathetic blockade. This is best performed during the early (acute) stage, when the clinical course may be reversible. As the disease progresses, the erythema gives way to cyanotic mottling, the acute edema transforms to brawny edema, and the pain becomes unrelenting and disabling. These findings occur at approximately the third month and represent the second (dystrophic) stage. At this point, both plain radiographs and bone scans tend to demonstrate indicative findings.

Over time, disuse leads to atrophy, soft-tissue fibrosis, and joint contractures. Radiographs confirm ankylosis and severe osteoporosis. This signals the third (atrophic) stage. Note that atrophy can also occur because of intentional disuse for anticipated secondary gain. Such patients reportedly do not respond to treatment until litigation has concluded.

Typically, the clinician does not even consider the diagnosis of a CRPS until the second stage. At that point, a dramatic clinical response to sympathetic blockade may confirm the diagnosis. Unfortunately, too much damage may have already occurred for sympathetic ablation to be effective and to break the vicious cycle of pain, sympathetic overactivity, and pain; the progression of the CRPS may be inexorable and irreversible.

One other caveat is that in the face of coexisting arterial disease, the vascular surgeon who may attribute the symptoms to ischemia and thereby may consider bypass should be aware that a surgical incision tends to exacerbate the pain in an extremity afflicted with a CRPS.

For more information, see Complex Regional Pain Syndrome in Emergency Medicine.

Popliteal artery entrapment syndrome

Intermittent claudication occurring in younger persons (from the teens to approximately age 45 y), particularly males, raises the possibility of popliteal artery entrapment syndrome. [29]

In this unusual condition, the artery follows an aberrant course around the gastrocnemius, usually medial to the medial head instead of between the two heads of this muscle. Ambulation causes the muscle to compress the artery and results in transient loss of distal blood flow. Over time, the artery may thrombose or become aneurysmal.

Before complete thrombosis, this condition can sometimes be confirmed clinically by noting loss of the pedal pulse upon active plantarflexion or passive dorsiflexion of the foot. Computed tomography (CT) or magnetic resonance imaging (MRI) can reveal the muscular abnormality, and angiography with stress views can confirm the diagnosis.

Treatment entails sectioning the aberrant muscle fibers. Bypass grafting is needed if the occlusion is chronic. Assessing the contralateral side is important because one third of cases are bilateral.

Cystic adventitial disease of popliteal artery

Intermittent claudication of abrupt onset occurring in a relatively young male also may be the result of cystic adventitial disease of the popliteal artery. [30]

This rare congenital anomaly is the result of ganglionlike cysts, perhaps from an adjacent synovium, compressing the artery. This compression may eventually lead to thrombosis of the artery.

Prior to occlusion, pedal pulses may be found to disappear with flexion of the knee joint. Ultrasonography (US), CT, or MRI may demonstrate the cyst, whereas angiography may demonstrate a characteristic hourglass deformity, which has been termed the scimitar sign.

Cystic adventitial disease of the popliteal artery is treated surgically by removing the cyst. Vascular bypass is required if occlusion has occurred. [31]