Trial to Test Gel-Coated Coils for Treating Aneurysms

Bernard Bendok (Northwestern University)

A clinical trial at Northwestern University and other sites will test a new gel-coated coil as a treatment to repair ruptured brain aneurysms. The post-market study will test the gel-coated coil against standard bare platinum coils to see which is better at preventing future rupturing or leaking.

An aneurysm is a balloon-like bulge in an artery caused by the force of blood pushing against the weakened or injured artery walls. When an aneurysm ruptures, dangerous bleeding inside the body occurs. If the rupture occurs in the brain, called a cerebral aneurysm, stroke can result.

“In many cases, brain aneurysms remain silent until there’s a major problem,” says  Bernard Bendok, a neurosurgeon at Northwestern Memorial Hospital and professor of neurological surgery and radiology at Northwestern’s medical school (pictured right), who is the principal investigator of the study. “Most are not found until they rupture or are found incidentally on brain images taken to assess another condition. The number one sign to look for is a sudden and extremely severe headache. If this occurs, one should seek immediate medical attention.”

If caught early enough, cerebral aneurysms can be treated with surgery or coils that fill the damaged artery and block the blood flow. Inserting the coil requires minimally invasive surgery using a catheter to insert the coil and X-ray guidance to put the coil in place. While less invasive than surgery, coils have not been considered as reliable a treatment for aneurysms since the coil does not completely fill up the damaged artery and blood still sometimes gets through.

This trial — called Hydrogel Endovascular Aneurysm Treatment Trial or HEAT — will test a new type of coil, made by Microvention of Tustin, California, that has a outer-layer coating of hydrogel polymer. Microvention says that once inserted in the damaged artery, the gel-coated coil expands to provide extra filling of the vascular space, a process that takes about 20 minutes.

“Coils are not always able to fill the aneurysm completely, which leaves dead space in the aneurysm. This space has been associated with a higher rate of aneurysm recurrence,” says Bendok. “The new coils are made with platinum and a hydrogel that expands over time to eliminate the space between the coils, potentially limiting the need for future treatment.”

The trial is expected to enroll 600 patients, some 20 of which at Northwestern Memorial Hospital in Chicago. HEAT is an international randomized study that seeks to determine how the gel packed coils measure up to the standard option in preventing future aneurysm recurrence. Patients may be eligible for the trial if they are between the ages of 18 and 75 years with aneurysms 3 to 14 mm in size, and amenable to coiling. An estimated 30 sites around the world are expected to join the trial.

Read more:

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• Start Up to Develop Nanotech Therapy for Artery Disease

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