Cholesterol embolization can occur spontaneously or as a result of an endovascular procedure. The incidence of cholesterol embolization during a lower extremity revascularization procedure is unknown and is felt to be under reported. In patients undergoing cardiac catheterization procedures, the incidence of clinically significant cholesterol embolization is around 2%.
During an endovascular procedure, atherosclerotic plaque is disrupted and cholesterol crystals can break off and embolize causing occlusion of the arterioles in the foot. This results in an intense inflammatory reaction with arteriolar occlusion and tissue ischemia. In most instances the degree of injury is limited and at most areas of tissue loss occur. In some instances, minor amputations may also occur. Rarely, the extent of embolization can be severe and limb threatening. There are no proven treatments to improve the outcome of patients.
The patient below is a 52 year old male with Type 1 diabetes and critical limb ischemia who underwent revascularization for a non healing ulcer of the 1st toe.
The patient had severe occlusive disease involving all 3 tibial arteries. Pre-revascularization pedal artery ultrasound showed a long segment occlusion of the posterior tibial artery.
The lateral plantar artery was also occluded.
The medial plantar artery was patent with a severe monophasic low velocity waveform.
The anterior tibial artery had multiple severe stenoses and a short occlusion (not shown). The dorsalis pedis artery was patent and was the best target in the foot.
The patient underwent orbital atherectomy and angioplasty of the anterior tibial artery without difficulty (images not shown). Angiogram of the foot at the end of the procedure shows the medial tarsal artery to be widely patent with a connection to the medial plantar artery.
5 days post procedure, at regular follow up, the patient had skin changes in the medial plantar artery angiosome (supplied by the medial tarsal artery) consistent with cholesterol embolization. Presumable, the embolic material traveled into the medial plantar angiosome through its connections with the medial tarsal artery, a branch of the dorsalis pedis artery.
Two weeks after revascularization, the skin in the area of embolization has sloughed off. Eventually there was complete skin healing without any amputation.
Cholesterol embolization is an infrequent sequelae after lower extremity revascularization.
Peripheral arterial disease (PAD) and its more severe variant critical limb ischemia (CLI) can be notoriously difficult to diagnose.