The MicroFlow Spacer: A Drug-Eluting Stent for the Ethmoid Sinus

Abstract

To evaluate the short-term outcomes and safety of a newly introduced drug-eluting ethmoid stent. Prospective study of 23 patients with a total of 40 implanted ethmoid sinuses. Two tertiary care medical facility. Twenty-three patients with medically refractory chronic rhinosinusitis were treated with patient-appropriate endoscopic sinus surgery, with the modification of treating the ethmoid sinuses with an ethmoid stent infused with triamcinolone, instead of conventional endoscopic ethmoidectomy. Patients were then followed up over 6 months. Outcomes were assessed by interval changes in 20-item Sino-Nasal Outcome Test (SNOT-20) and Lund-MacKay CT scores. Safety was determined by adverse events. Overall, the pre-op SNOT-20 mean score was 2.18, versus post-op score of 1.02, an improvement of 1.16 that was both statistically (P \ 0.001) and clinically significant. Ethmoid-specific and side-specific Lund-MacKay mean scores both also showed statistically significant improvements. Pre-op ethmoid-specific LundMacKay mean score was 1.93, versus post-op score of 1.10, an improvement of 0.83 (P \ 0.001). Pre-op side-specific Lund-MacKay mean score was 5.75, compared with post-op score of 2.95, an improvement of 2.80 (P \ 0.001). There were no significant intra-op or post-op complications encountered. This triamcinolone-infused ethmoid stent appears safe and effective in treating chronic ethmoid sinus disease within the defined follow-up period. The ability to deliver medication directly to diseased mucosa holds wideranging potential.

Retained Drug-eluting Stents and Recalcitrant Chronic Rhinosinusitis: A Case Report

“…No complications were encountered and it was recommended that insertion of the Stratus Spacer into the ethmoid sinuses should be used with C-arm fluoroscopy for novice users. 11 …”

Drug-Eluting Nasal Implants: Formulation, Characterization, Clinical Applications and Challenges

“…They are intended to fill the ethmoid sinus cavity, which would otherwise be filled with blood and mucous [ 63 ]. Examples of clinically approved middle meatal implants include Propel™ implant [ 72 ], Relieva Stratus™ MicroFlow spacer [ 73 ] and the Sinu-Foam™ spacer [ 74 , 75 ].…”

“…This device is temporary requiring manual removal after 30 days and a new device may be implanted if needed [ 83 ]. This device also is not suitable for patients with extensive polyps [ 73 ]. Finally, certain adverse events have been reported for the device [ 81 ] and orbital violation following its placement has been reported [ 84 ].…”

Topical Drug Delivery for Chronic Rhinosinusitis

“…The device is approved for saline, however, in an attempt to deliver corticosteroid, physicians have placed triamcinolone into the device reservoir. Investigations have revealed that the device eludes 0.3 ml of triamcinolone acetate 40 mg/ml over 2 to 4 weeks 91 . Approved by the FDA in 2011, the Propel sinus implant (Intersect ENT, Palo Alto, California) is a newer bioabsorbable implant that self-expands in the sinus cavity and releases 370 µg of mometasone furotate over 4 weeks 92 .…”