Adnan Siddiqui, MD, PhD

Results from a clinical trial by senior author Adnan Siddiqui, MD, PhD, show that in many cases of large vessel occlusion, the use of a stent retriever may not always be necessary.

Trial Shows Aspiration is Valid Therapy in Stroke Thrombectomy

Published February 13, 2018

Findings published in JAMA Neurology show that in stroke patients with large vessel occlusion (LVO), the removal of the clot occurs as efficiently after aspiration-based clot removal alone as it does after aspiration-based clot removal performed with a stent retriever.

“Our findings were certainly not surprising for us, but they may surprise some in the larger community where not using a stent retriever has been considered heresy.”
Adnan Siddiqui, MD, PhD
Vice chair and professor of neurosurgery

Adnan Siddiqui, MD, PhD, vice chair and professor of neurosurgery, is senior author on the paper, which was published Jan. 2. Elad I. Levy, MD — who is the L. Nelson Hopkins III, MD, Professor and Chair of the Department of Neurosurgery — is a co-author.

Findings May Surprise Neurosurgical Community

Results from the clinical trial show that in many cases of LVO, among the most severe types of stroke, the use of a stent retriever may not always be necessary.

“Our study has found that these two strategies — stent retrieval of the clot versus aspiration of the clot as an initial step — are equivalent in terms of their ability to efficiently achieve recanalization, the restoration of blood flow, and they produce equally successful clinical outcomes,” says Siddiqui, who is also chief medical officer of the Jacobs Institute.

The findings also demonstrate that safety measures and good clinical outcomes produced by both methods, including the incidence of serious, device-related adverse events, were comparable.

“Our findings were certainly not surprising for us, but they may surprise some in the larger community where not using a stent retriever has been considered heresy,” Siddiqui notes. “We now have level-one evidence showing that both of these strategies are equally effective.”

Study is 1st Randomized Trial to Compare Strategies

Inspired by SUNY Distinguished Professor of Neurosurgery L. Nelson Hopkins, MD, who founded the Jacobs Institute and formerly chaired the department, Siddiqui and Levy have pioneered numerous advances that have changed the standard of care for stroke patients around the world.

They led the SWIFT PRIME clinical trial, which found in 2015 that when used together with conventional clot-busting drugs, wire mesh stent devices produced much better clinical outcomes than the drugs alone.

“Stent retriever devices, which capture the clot in a wire mesh, were used in the majority of cases in the seven major trials in 2015 — including SWIFT PRIME — that demonstrated unequivocally that mechanical removal of a clot is superior to medical therapy for acute ischemic stroke caused by large vessel occlusion,” Siddiqui explains.

“However, high volume centers such as ours had started to employ large bore aspiration catheters for clot removal as a first pass technique prior to using stent retrievers. This is the first randomized trial in the U.S. comparing these two strategies with a novel stent retriever to test if these two strategies are comparable to each other.”

Levy, Siddiqui Have Used Aspiration Alone Since 2012

The national study was conducted at 25 sites, including Kaleida Health’s Gates Vascular Institute, where Siddiqui and Levy lead the internationally renowned stroke program. The study enrolled 198 patients of both genders after screening more than 8,000 patients.

At Kaleida, Siddiqui and Levy have seen the benefits of using aspiration alone in their own patients, where they have been using the technique since 2012.

Instead of mechanically removing the clot by catching it in the wire mesh cage of the stent retriever, aspiration involves threading a catheter into the brain that then attempts to remove the clot through suction alone.

The technique is considered less risky than stent retrievers because the clot typically does not need to be traversed and the catheters are positioned in parts of the blood vessel that are still open and therefore visible.

Siddiqui says the use of aspiration first also has an additional economic advantage.

Co-Authors from 12 Other States and Germany

In addition to Levy and Siddiqui, who also see patients at UBMD Neurosurgery, the paper has co-authors from institutions across the United States and in Germany:

  • Emory University School of Medicine in Atlanta
  • Swedish Medical Center in Englewood, Colorado
  • JFK Medical Center in Edison, New Jersey
  • Mercy Health — St. Vincent Medical Center in Toledo, Ohio
  • Rush University Medical Center in Chicago
  • Medical University of South Carolina in Charleston, South Carolina
  • Novant Health Forsyth Medical Center in Winston-Salem, North Carolina
  • Physicians Regional Medical Group in Naples, Florida
  • Froedtert Hospital in Milwaukee, Wisconsin
  • Universitätsklinikum Erlangen in Erlangen, Germany
  • Texas Stroke Institute in Plano, Texas
  • University of Iowa in Iowa City, Iowa
  • Massachusetts General Hospital in Boston
  • Lenox Hill Hospital in New York City