Rare artery embolism leaves man paralyzed after leg procedure, doctors report

The report, authored by Jing Wang, Jing Li, Xuemin Zhang, Xiaoming Zhang, and Tao Zhang, documents an exceptionally rare complication. Lower extremity paralysis after peripheral endovascular therapy is usually blamed on ischemia–reperfusion injury, distal embolization of atherosclerotic material, or acute in situ thrombosis. Paralysis caused specifically by embolism of the internal iliac artery trunk is so uncommon that the authors warn it may be overlooked entirely when postoperative neurological deficits are initially attributed to spinal or cerebral causes, a diagnostic detour that can cost precious hours of limb and nerve viability.

Three years before this admission, the man had undergone balloon angioplasty and stent implantation in the left iliac and popliteal arteries. He returned with a month of bilateral intermittent claudication that had progressed to a right toe ulcer. Preoperative computed tomographic angiography revealed a formidable burden of disease: occlusion of the left external iliac and popliteal artery stents, occlusion of both femoral and popliteal arteries and the proximal left profunda femoris artery, and focal severe stenosis or occlusion of both anterior tibial arteries, both peroneal arteries, and the right posterior tibial artery. After multidisciplinary consultation, the team planned bilateral lower extremity endovascular recanalization.

Working through a retrograde right femoral puncture, the operators crossed the occluded left external iliac segment, aspirated intraluminal thrombus and hyperplastic intima with an 8F Rotarex mechanical thrombectomy catheter, and treated residual stenosis with 6-mm and 7-mm balloons. The team then switched to the left femoral artery to treat the contralateral right femoropopliteal artery, completing thrombus aspiration, femoropopliteal and infrapopliteal balloon angioplasty, and placement of a thrombolysis catheter, through which 250,000 IU of urokinase was administered as a bolus. One hour after the procedure ended, the patient suddenly developed the profound left leg weakness and sensory loss that set off the diagnostic alarm.

What followed was a rapid exclusion cascade. Emergency abdominal and pelvic non-contrast CT, lumbar spine MRI, brain CT and MRI, and lower extremity CTA ruled out nerve compression from a retroperitoneal or psoas muscle hematoma, stroke, and intraspinal disease, but showed new occlusion of the internal iliac artery. Thrombolytic infusion was stopped immediately, and glucocorticoid therapy was given during the workup. Nine hours after the original procedure, the team performed emergency thrombus aspiration through a left brachial approach, removing organized thrombus with a 6F, 135-cm catheter and then dilating the vessel with a 2.5 mm × 80 mm balloon. Patency of the left internal iliac artery was substantially restored, with a total ischemia time of approximately 10 hours.

The authors attribute the paralysis primarily to worsening lower extremity ischemia caused by the loss of collateral perfusion from the internal iliac artery rather than to isolated lumbosacral plexopathy, reasoning that the lumbosacral plexus is also supplied by lumbar segmental arteries, so occlusion of the internal iliac artery alone rarely causes plexopathy. They acknowledge, however, that the subsequent hybrid procedure is a potential confounding factor, so the final neurological recovery cannot be attributed solely to internal iliac revascularization.

Recovery stalled at that point. Pain in the left limb worsened, analgesics provided poor relief, and muscle strength plateaued. Because the common femoral artery was severely calcified and completely occluded, the team judged that endovascular therapy alone was unlikely to succeed and performed hybrid surgery as an emergency bailout: left femoral endarterectomy with autologous great saphenous vein patch angioplasty, followed by through-and-through access via retrograde puncture of the left popliteal artery stent and distal recanalization of the peroneal and posterior tibial arteries with 2-mm and 3-mm balloons. Postoperative swelling and blistering developed, but a measured delta pressure of 40 mm Hg ruled out acute compartment syndrome. After one month of rehabilitation, muscle strength remained grade III, tactile, pinprick, and position sensation were diminished, and the patient required assistance with standing, ambulation, and activities of daily living.

After Rotarex thrombectomy of the occluded left external iliac and femoropopliteal arteries through a right common femoral approach, the left femoral artery was used to recanalize the contralateral limb, and fragmented thrombus or hyperplastic intima may have been displaced during subsequent catheter and guidewire manipulation across the iliac bifurcation. Multicenter data on Rotarex treatment of in-stent occlusion report a distal embolization rate of 5.5 percent. The retrieval of large organized thrombus fragments during the emergency brachial-approach aspiration supports embolization of procedural debris rather than de novo in situ thrombosis, although the authors concede that without histopathological examination or compositional analysis, organized thrombus could not be distinguished from atherosclerotic debris or a mixture of both, making the embolization attribution speculative.

In patients with external iliac artery occlusion and severe multivessel disease of the superficial femoral, popliteal, anterior tibial, posterior tibial, and peroneal arteries, distal perfusion may depend heavily on collateral flow from the internal iliac artery, so embolization of its trunk can abruptly interrupt supply to the lumbosacral plexus through the iliolumbar and lateral sacral arteries while simultaneously worsening distal limb ischemia. The authors additionally flag persistent sciatic artery, a rare congenital anomaly with a reported prevalence of 0.04 to 0.06 percent that directly connects the internal iliac artery to the popliteal artery, as a differential diagnosis, though preoperative CTA ruled out that variant in this patient.

In patients with severe bilateral LEAOD and in-stent reocclusion, staged bilateral recanalization should be considered when mechanical thrombectomy is planned; when bilateral lesions are treated concomitantly, prophylactic use of an embolic protection device may be considered, though none was used here because the complication was not anticipated. Preoperative CTA should specifically assess the internal iliac ostium, the extent of internal iliac collateral perfusion, and congenital variants. And if sudden postoperative paralysis occurs, clinicians should not rely solely on neurological explanations: urgent spinal and whole-limb vascular imaging is required, with prompt revascularization when arterial occlusion is suspected. The case has limitations, including a short follow-up period, no perfusion imaging or electrophysiological testing to substantiate the causal link, and the absence of longer-term data; at a three-month telephone follow-up the patient reported no further neurological improvement.

Subject of Research: A case report of ischemic paralysis caused by internal iliac artery embolism after endovascular recanalization for lower extremity arteriosclerosis obliterans.

Article Title: Ischemic paralysis caused by internal iliac artery embolism after endovascular recanalization for lower extremity arteriosclerosis obliterans: a case report

Article References: Wang, J., Li, J., Zhang, X., Zhang, X., & Zhang, T. (2026). Ischemic paralysis caused by internal iliac artery embolism after endovascular recanalization for lower extremity arteriosclerosis obliterans: a case report. CVIR Endovascular, 9(1), Article 131. https://doi.org/10.1186/s42155-026-00783-8

Image Credits: AI Generated

DOI: 10.1186/s42155-026-00783-8

Keywords: internal iliac artery embolism, lower extremity arteriosclerosis obliterans, endovascular recanalization, ischemic paralysis, lumbosacral plexopathy, mechanical thrombectomy, Rotarex, balloon angioplasty, collateral perfusion, in-stent reocclusion, case report, peripheral vascular intervention