Aspirex Could Push Through to New Era in Mechanical Thrombectomy

A study of a mechanical thrombectomy device in the treatment of acute venous occlusions was given a 24-month update today by Michael Lichtenberg, an interventional radiologist and head of the Arnsberg Vascular Clinic (Arnsberg, Germany). Dr Lichtenberg is the principal investigator of a prospective post-market clinical study on the Aspirex Mechanical Aspiration Thrombectomy System (Becton, Dickinson and Company) “We are doing a lot of venous cases and treating a lot of patients with acute deep vein thrombosis (DVT),” he told LINC Today. “I was asked to organize this trial to analyze the safety and efficacy of this catheter to remove thrombus from patients with iliofemoral DVTs.”

The trial represents the first and only for the Aspirex system, evaluating the safety and efficacy of this device. At LINC, Dr Lichtenberg outlined the device components, the nature of the study, the patients included, lesion characteristics and endpoints, and other outcomes data. “We analyzed patients with acute iliofemoral DVTs, but also in some other regions,” he said. 

The prospective trial was conducted at nine centers around Europe and included 81 patients with symptoms of acute thrombosis or occlusion. “After 24 months we can report on 66 of these 81 patients, especially in terms of preventing post-thrombotic syndrome [PTS], and symptoms after DVT treatment,” noted Dr Lichtenberg.

After 24 months, the primary efficacy endpoint was 97.5%. “To remove thrombus and restore blood flow is the very definition of procedural success,” he added. “This shows the efficacy of such a device, and this is super important.”

The results weren’t altogether unexpected, said Dr Lichtenberg, who has provided follow-up data previously. Nevertheless, they were a welcome set of results. “I was very excited to see these results. The Aspirex is a very good device for mechanical thrombectomy because it proves the high-level concept of mechanical thrombectomy in patients with acute venous thrombosis.”

That is important, he went on, because the current guidelines advocate conservative treatment with anticoagulation. “What we’ve learned based on studies is that a lot of patients have a high risk of PTS when on conservative treatment alone,” he said, noting a more than two-fold risk in many cases. “We advocate that patients with extended DVTs go for mechanical thrombectomy.”

The Aspirex device is one of several existing devices on the market that specialize in thrombus removal by mechanical means. “Some devices have data, some devices just claim to be very effective,” commented Dr Lichtenberg. “But claims are not very helpful.”

In other words, every device needs prospective data for safety and efficacy in order to change the prevailing view of the most appropriate treatment for DVT in the guidelines. Indeed, many patients are potential candidates for mechanical thrombectomy, but currently are not being treated. “Can we prevent PTS in these patients if we just remove the thrombus?” asked Dr Lichtenberg.

The CLOUT registry¹ is another study of interest, this time assessing another device (ClotTriever, Inari Medical). “It is a very large prospective registry analyzing efficacy and safety, and there are very good 2-year data,” said Dr Lichtenberg. “That should be another piece of this big puzzle that will help convince people about conservative treatment.”

The DEFIANCE randomized controlled trial² (ClotTriever) also has promise in changing future guidelines, he added. There might be several approaches to clot removal, including pharmacomechanical thrombectomy, but Dr Lichtenberg predicts a fundamental change going forward. “I think there’s a clear shift away from thrombolytic therapy to pure mechanical thrombectomy,” he reasoned. “We are now concentrating more and more on just mechanical thrombectomy at no risk for the patient. Thrombolytic agents—which might be harmful for the patient in terms of bleeding risk or other complications—are unnecessary with modern devices.”

In his closing remarks, Dr Lichtenberg urged colleagues at LINC assess whether their patients might benefit from mechanical thrombectomy. “Check every patient—check if they might be a candidate for thrombectomy to avoid PTS,” he stressed. “If you have any doubts, please reach out to the centers of excellence dealing with this in every country. They can help assess whether a patient might be a candidate for mechanical thrombectomy.”

References

1. Shaikh A, Zybulewski A, Paulisin J, et al. Six-month outcomes of mechanical thrombectomy for treating deep vein thrombosis: analysis from the
500-patient CLOUT Registry. Cardiovasc Intervent Radiol. 2023;46(11):1571–1580.

2. DEFIANCE: RCT of ClotTriever system versus anticoagulation in deep vein thrombosis (DEFIANCE). ClinicalTrials.gov. Available at: https://classic.clinicaltrials.gov/ct2/show/NCT05701917; accessed May 2024.