Mometasone implant for chronic rhinosinusitis

Abstract

The Propel mometasone-eluting stent (Intersect ENT, Palo Alto, CA) is the first Food and Drug Administration-approved device for delivering steroid medication into the ethmoid cavity following surgery. The implant is composed of a biodegradable polymer in a lattice pattern that expands in a spring-like fashion to conform to the walls of a dissected ethmoid cavity and contains a total of 370 μg of mometasone furoate designed for gradual release over 30 days. The purpose of this article is to review the mode of action and the evidence supporting the efficacy of this novel technology. Three recently published clinical trials have demonstrated that the mometasone-eluting stent produced statistically significant reductions in inflammation, polyp formation, and postoperative adhesions. In addition, the implant has been found to significantly reduce the need for postoperative administration of oral steroids and to decrease the frequency of postoperative lysis of adhesions. Minimal adverse effects were reported in these trials and included infection, crusting, and granulation tissue formation. Although the placement of steroid-impregnated packing, stents, sponges, and gels has previously been used in the postoperative sinus cavities, the Propel mometasone-eluting stent introduces a new mechanism for localized and controlled delivery of topical therapy directly to the nasal mucosa for chronic rhinosinusitis.

Benefit of Preoperative Oral Steroids during Sinus Surgery when Utilizing Concentrated Topical Epinephrine

“…These have been demonstrated to have good efficacy with few side effects [17,18,19]. In addition, the recent introduction of implantable steroid-eluting polymer matrices have also demonstrated clinical efficacy [3,20]. …”

In-Office Use of a Steroid-Eluting Implant for Maintenance of Frontal Ostial Patency after Revision Sinus Surgery

“… 11 Only two device-related adverse events have been reported thus far, an exacerbation of sinus pressure secondary to crusting and granulation tissue leading to implant removal. 13 Although rare, hypersensitivity reactions to stent components have been previously reported. However, these were primarily in association with retained nonabsorbable stents containing metal struts.…”

Stent Hypersensitivity and Infection in Sinus Cavities

“…1 The stent polymer matrix is impregnated with mometasone furoate, which is a glucocorticosteroid and constitutes the prodrug of the free-form mometasone. As a scaffold, the stent maintains medialization of the middle turbinate and prevents the development of scarring between the middle turbinate and the lateral nasal wall.…”

“… 14 Therefore, hypersensitivity to implanted stent components, although rare, is an existing possibility and should be always brought to mind when symptoms perpetuate after stent insertion and despite application of appropriate medical therapy. Bioabsorbable, allergy-free, poly lactic acid self-expanding stents and nickel-free stainless steel stent materials 15 in combination with balloon dilatation 1 may provide an interesting and minimally invasive future development. These stents would control underlying inflammation and/or hypersensitivity in chronic rhinosinusitis that occurs in conjunction with sinus ostial dilatation.…”

“…Bare metal stents, drug-eluting stents, self-expanding stents, and biodegradable self-expanding stents are used for treatment of arterial stenoses, aortic aneurysms, and in sinus surgery because they can maintain sinus patency. 1 Areas of stent implantation beyond coronary, cerebral arteries and carotids include 2 otorhinolaryngological diseases, gastric outlet obstructions, pancreatobiliary tract obstructions, for prevention of postendoscopic retrograde cholangiopancreatography pancreatitis, oesophageal leaks, stenotic complications after tracheal resection, intestinal stenoses, postoperative intraabdominal, and pelvic fluid collections. They have been also used experimentally for the treatment of retinal detachment.…”