Cyanoacrylate glue is used as an embolic agent for several decades [1]. The nearly instantaneous and permanent target-vessel occlusion is a major advantage but can also be challenging. The utilization of cyanoacrylate glue spans across a multitude of embolization indications, encompassing its application in both arteries and veins [1]. Within the venous system, the primary indications include the management of pelvic congestion syndrome and varicoceles through gonadal vein embolization, pre-hepatectomy portal vein embolization, and the treatment of chronic venous insufficiency via embolization of lower limb veins. In arterial contexts, its primary applications are centered around the management of hemorrhage, treatment of arteriovenous malformations, and intervention in tumoral lesions. Tumor embolization with glue addresses several potential objectives, including the alleviation of pain, inhibition of tumor growth, induction of size reduction, and management of acute hemorrhage. It often serves as a preparatory step for surgery by minimizing blood loss and facilitating the resection process [1], [2], [3]. Intra-arterial glue distribution must be accurately controlled during the injection to ensure that the occlusion is confined to the target vessel, preventing reflux into the parent vessel and the occurrence of unintended emboli. Cyanoacrylate glues are radiolucent and solidify rapidly by polymerisation upon contact with body fluids. They are therefore injected in combination with ethiodized oil (Lipiodol® Ultra Fluid, Guerbet, Villepinte, France), which not only provides radiopacity but also slows the polymerisation rate. The glue concentration can be chosen to obtain the polymerisation rate that best suits the treatment goal [4]. A lower glue concentration results in greater distality of glue penetration within the vascular bed [5]. Absolute ethanol (AE) can also be added to the mixture to accelerate polymerisation and change the adhesive properties of the glue [6].

The pressure cooker technique was initially developed for non-adhesive liquid embolic agents containing ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide [7,8]. However, recent studies have demonstrated its potential utility in adhesive glue embolization as well. This technique, by allowing proximal vessel occlusion, decreases the risk of reflux along the microcatheter and enhances distal glue progression within the vascular network. [9]. Regardless of how occlusion is obtained (i.e., with a double-lumen balloon or proximal glue plug with coils), this technique stops blood flow around the microcatheter during glue injection, thereby modulating the polymerisation reaction.

The tissue toxicity of cyanoacrylate glue has been extensively studied [10], [11], [12], [13], [14], [15]. Glue deposition within a vessel triggers an acute inflammatory response in the vessel wall and surrounding tissues. A foreign-body reaction with giant cells and fibrosis is apparent after approximately 30 days. N‑butyl‑2 cyanoacrylate (NBCA), which is the most widely used cyanoacrylate glue, can be combined with metacryloxysulfolane (MS), resulting in metacryloxysulfolane-n‑butyl‑2 cyanoacrylate (MS-NCBA, Glubran®2, GEM) to lessen the cytotoxic and inflammatory effects [16]. Histopathological studies have focused on lesions produced by cyanoacrylate glue injection under free-flow conditions. However, blocked-flow injection is now used in clinical practice in several indications.

The objective of this study was to investigate acute histological arterial vessel-wall changes after embolization with MS-NBCA in several concentrations under both free-flow and blocked-flow conditions, in an in vivo animal model.