Aspiration Thrombectomy Restores Flow in Patients With Peripheral Arterial Occlusion: PRISM Registry

Hollywood, FL—Mechanical aspiration is a safe and effective option for the treatment of peripheral or visceral arterial occlusions either as a frontline therapy or in patients who failed thrombolysis, according to the results of the PRISM registry presented on Monday at the 2016 International Symposium on Endovascular Therapy (ISET).

In a range of patients with thromboembolic occlusions, 88% of those treated with the Indigo percutaneous mechanical thrombectomy system (Penumbra) achieved TIMI 2 or 3 flow immediately after use of the aspiration device alone.

“The system was designed after watching how well stroke therapy worked with vacuum devices,” James Benenati, MD, of the Miami Cardiac and Vascular Institute in Florida, told TCTMD. “We thought if it worked well in stroke, why wouldn’t it work in the periphery if we had larger catheters. We started looking at this with small catheters that were designed for the brain and then eventually these bigger catheters came out, and now with acute clot, we can actually pull back and aspirate significant amounts of clot without have having to use thrombolytics.”

At ISET, Benenati presented data on 83 patients enrolled in PRISM, a retrospective, single-arm, multicenter registry. The aspiration system was used in patients who failed thrombolysis, as first-line therapy in patients with acute limb ischemia, and in patients with occlusions caused by embolization of debris from a preceding intervention. Just over half of patients had occlusions in the popliteal and tibial arteries, and one-third had occlusions either in the superficial femoral, profundis femoris, or common femoral artery. 

At baseline, two-thirds of patients had a TIMI score of zero, and one-third had a TIMI score of 1. Immediately after the use of aspiration thrombectomy, 36.6% of treated patients achieved a TIMI score of 2 and 51.2% achieved a TIMI score of 3. At the completion of all interventions—the use of thrombectomy plus any secondary procedure—96% of patients had a TIMI score of 2 or 3. 

The alternative for patients with thromboembolic arterial occlusions is either surgical bypass or catheter-directed thrombolysis, Benenati told TCTMD. While they perform thrombolytic procedures in their clinical practice, it is a costly and risky procedure. In addition, there are certain patients who can’t undergo thrombolysis because they are at an increased risk of bleeding from anticoagulation. “This provides us with a quick, safe alternative,” he said. “Ultimately, the idea here is that we can save physicians time and also provide cost-savings for the hospital. If we can aspirate, remove the clot and prevent a thrombolytic procedure, or even shorten a thrombolytic procedure, we decrease the time for monitored beds, we save money on the cost of the drug, and we don’t have to use protection devices.”

There were no device-related serious adverse events reported among the treated patients, but procedure-related serious adverse events occurred in 7.2%. In total, serious adverse events were recorded in 10 of the 83 treated patients. Benenati noted that the patients in this population are often very sick and some of these serious adverse events are related to baseline comorbidities.

Session moderator Shaun Samuels, MD, also of Miami Cardiac and Vascular Institute, said he was skeptical of the technology when it was first introduced into their clinical practice. However, it has become his “go-to technology in cases of acute lower-extremity ischemia.” Benenati agreed with the system’s effectiveness, but noted there is a learning curve, one that’s “not terribly steep.”

The mechanical thrombectomy system was approved in 2007 for the revascularization of occluded intracranial vessels in patients with acute ischemic stroke. The Indigo system received FDA clearance for arterial use in 2012 and clearance for venous use in 2015.      

Source: 
Benenati JF. Vacuum-assisted thrombectomy in the peripheral Circulation: PRISM trial interim results. Presented at: International Symposium on Vascular Therapy; February 8, 2016; Hollywood, FL.

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 View ISET 2016 Slides