Treatment of Ruptured and Nonruptured Aneurysms Using a Semisolid Iodinated Embolic Agent

Abstract

Saccular aneurysms (SAs) are focal outpouchings from the lateral wall of an artery. Depending on their morphology and location, minimally invasive treatment options include coil embolization, flow diverter stents, stent‐assisted coiling, and liquid embolics. Many drawbacks are associated with these treatment options including recanalization, delayed healing, rebleeding, malpositioning of the embolic or stent, stent stenosis, and even rupture of the SA. To overcome these drawbacks, a nanoclay‐based shear‐thinning hydrogel (STH) is developed for the endovascular treatment of SAs. Extensive in vitro testing is performed to optimize STH performance, visualization, injectability, and endothelialization in cell culture. Femoral artery saccular aneurysm models in rats and in pigs are created to test stability, efficacy, immune response, endothelialization, and biocompatibility of STH in both ruptured and unruptured SA. Fluoroscopy and computed tomography imaging consistently confirmed SA occlusion without recanalization, migration, or nontarget embolization; STH is also shown to outperform coil embolization of porcine aneurysms. In pigs with catastrophic bleeding due to SA rupture, STH is able to achieve instant hemostasis rescuing the pigs in long‐term survival experiments. STH is a promising semisolid iodinated embolic agent that can change the standard of medical practice and potentially save lives.

Treatment of Ruptured Wide‐Necked Aneurysms using a Microcatheter Injectable Biomaterial

“…Both the control and the FD groups showed increased infiltration of inflammatory cells as evidenced by MPO immunostaining within the thrombus; this is a normal inflammatory response to thrombosis (Figure 5b). [44] In contrast, the FD+GEA group on day 3 revealed GEA uniformly filling the aneurysm sac; thus, excluding the aneurysm from the circulation (Figure 5a,b). At day 14, partial remodeling with biodegradation of the GEA was seen with increased cellular infiltration, predominantly inflammatory cells, as evidenced by high MPO immunostaining.…”

“…[44] Angiographic Imaging in Rats: To assess embolization efficacy, subgroups of rats had femoral artery angiography through the aorta bifurcation prior to necropsy at 7 or 28 days after surgery as previously described. [44] In brief, anesthetized rats were placed supine on an X-raycompatible table. A midline incision was made in the neck to expose and isolate the left common carotid artery.…”

“…Laser Speckle Contrasts Analysis Imaging: LASCA (PeriScan PIM 3, Perimed) imaging was performed during the surgical procedure to serially assess hind limb perfusion at baseline before surgery and at 1, 3, 7, 14, 21, and 28 days after embolization as previously described. [44] Angiographic Imaging in Rats: To assess embolization efficacy, subgroups of rats had femoral artery angiography through the aorta bifurcation prior to necropsy at 7 or 28 days after surgery as previously described. [44] In brief, anesthetized rats were placed supine on an X-raycompatible table.…”

Shape Self-Adaptive Liquid Embolic Agent for Ultrafast and Durable Vascular Embolization

“…Vascular embolization is a minimally invasive intervention surgery that could selectively deliver embolic agents into the artery to occlude diseased blood vessels. , Owing to its merits of negligible trauma, few complications, and low reoperation incidence as well as rapid recovery, − embolization provides a safe endovascular therapy that has been widely applied for treating various diseases in clinics, such as vascular bleeding, unresectable hepatocellular tumors, and aneurysms. − Notably, the clinical benefit of embolization therapy was greatly determined by embolic agents. An ideal embolic agent should satisfy the requirements of favorable biocompatibility, stable and complete occlusion in the blood vessels, and appropriate but not uncontrollable swelling ability to match the size of targeted vessels without causing overdosed vascular distension.…”

Solvent Exchange Induced In Situ Formed Hydrogel as Liquid Embolic Agents

“…[8] Moreover, Stewart et al and co-workers reported an in situ gelling liquid embolic agent based on the polyelectrolytes complex coacervate containing salmine-inositol hexaphosphate, which can transfer from an injectable fluid into a nonflowing solid material by changing ionic concentration. [9a] On the other hand, Oklu et al developed a series of injectable and self-healable shear-thinning hydrogels by simply mixing charged nanoclay with silk, [10] extracellular matrix, [11] lyophilized platelet-rich plasma, [12] and gelatin, [13] respectively. These shear-thinning hydrogels can effectively embolize the porcine renal artery, internal iliac artery, and femoral aneurysm.…”