Teaching Case

Acute embolic popliteal artery occlusion

The patient presented with acute ischemia of his right leg. Acute pain occurred two days earlier but the patient did not see his doctor just at the day of admission. He was known to suffer from absolute arrythmia. No preexisting claudication was reported. Physical examination reveiled a pale and cold left lower limb; femoral pulse was palpable but popliteal and both foot pulses were absent. Clinical diagnosis of peripheral embolization was made and the patient was presented for angiography and potential percutaneous treatment. Angiography via an antegrade femoral puncture of the left side showed complete fresh occlusion of the popliteal artery, no distal arteries besides very tiny collaterals were visible (Fig. 1).

After introduction of an 8 F sheath with a removable hub (TASC 800, Cook Inc.) over a stainless steal guidewire , a Terumo guidewire was carefully probed into the occlusion to identify any stenotic obstacle. After doing so the circumference of the thrombus is faintly visible (Fig. 2 a) . After a couple of attempts to remove the clot by aspiration embolectomy using an 8 F open end aspiration catheter, only minor portions of the thrombus could be removed. In order to speed up the intervention an 8 F mechanical thrombodestruction catheter ( Clot buster, Bard Inc.) was advanced into the occlusion . After a single pass of the clot buster, major parts of the artery were cleared (Fig. 2 b). The remaining clot within the popliteal artery were then successfully destroyed by advancing the system into the distal popliteal artery (Fig. 2 c). It was, however, avoided, to lead the system selectively into the lower thigh arteries whose proximal portions were also filled by clots (Fig. 2 c). These clots were subsequently thrombectomized by each a single aspiration using the 8 F aspiration catheter. To guide the catheter into the artery, a coated guidewire was carefully advanced into each artery passing the embolus. After aspiration both the popliteal artery and the lower thigh arteries were cleared (Fig. 3 a and b); no downward embolization besides a tiny embolus in a very small interosseal artery was detected. Patient was put on long-term heparinization as a bridge to warfarin therapy. Mechanical thrombectomy using aspiration thrombectomy, hydrodynamic thrombectomy or clot destruction using the clot buster system are feasible techniques especially in embolic or segmental thrombotic femoral artery occlusion. Especially in fresh clots, the success rate is reliable. As aspiration thrombectomy is the method of choice in short thrombi, long segment thrombosis is more difficult to treat. Mechanical devices help to shorten the intervention time considerably and avoid thrombolysis. The major risk of mechanical thrombectomy is, however, downward embolization into the pedal arteries which can worsen the situation. To avoid this complication, a pressure cuff may be placed around the lower thigh inflated up to systolic pressure compressing the lower limb arteries. This trick is recommendable if the trifurcation is free from thrombus. If the proximal lower limb arteries are also involved, it is helpful to guide the clot buster only into the distal popliteal artery but to leave the trifurcation alone. The very last thrombosed segment is then aspirated by catheters. If embolization occurs in spite, suction embolectomy using 4 F coated large lumen catheters (Terumo Glidecath) can be performed even down from the pedal arteries or thrombolysis has to be added. The end point of each treatment should be at least one or two lower limb arteries open down to the foot