Multiple bioabsorbable corticosteroid-eluting stent placement with associated skull base injury

Biomechanical characteristics of self-expanding sinus stents during crimping and deployment_A comparison between different biomaterials

Self-expanding sinus stents are often used in functional endoscopic sinus surgery to treat inflamed sinuses. The PROPEL self-expanding sinus stent offers mechanical support to the sinus cavity to prevent restenosis. The stent is made of a bioabsorbable material (PLGA) that disappears after wound healing. However, complications such as foreign body sensation and severe stent migration/expulsion have been reported after implantation. Little is known about the contact characteristics of self-expanding sinus stents from when the stent is crimped into the insertion device through to deployment into the sinus cavity. This current study developed a test platform to analyze the biomechanical behavior of the stent during this process. Three common bioabsorbable materials, PLGA, PCL and Mg alloy, were evaluated to understand how the choice of material affects the biomechanical characteristics of self-expanding sinus stents. The results showed that the material can have a considerable influence on the contact characteristics during crimping and deployment. When crimped, the PLGA and Mg alloy stents showed much higher plastic strain and contact stress than the PCL stent. When deployed, the PCL stent had the largest contact area (4.3 mm²) and the lowest contact pressure (0.1 MPa) on the inner surface of the sinus canal. The results indicate that PCL could be a suitable choice for self-expanding sinus stents. This current study provides a method for observing the biomechanical characteristics of sinus stents during stent crimping and deployment.

Management of the middle turbinate during and after sinus surgery

PURPOSE OF REVIEW

Treatment of the middle turbinate (MT) during and after endoscopic sinus surgery (ESS) has been controversial. Historically, there has been concern that resection of the MT may result in smell loss and frontal sinus stenosis. However, these concerns must be balanced by knowledge that a residual diseased MT may result in surgical failure. This review discusses the current evidence on treatment of the MT during and after ESS.

RECENT FINDINGS

Several review articles have shown the safety of performing MT resection. Studies have not shown increase rates of frontal sinus stenosis, olfactory loss, or empty nose syndrome. However, the benefit of MT resection is highly debated. There have also been many recent advances and technological developments to assist in management of the postoperative MT.

SUMMARY

The literature supports the safety of performing MT resection, however, the benefit of resection over preservation is controversial. New technologies and techniques exist that may aid in preventing postoperative MT lateralization.

Complications Associated with PROPEL Mometasone Furoate Bioabsorbable Drug-eluting Sinus Stents From 2012 to 2020

BACKGROUND

Till date, there have been no studies that have analyzed a database to examine postmarket adverse events associated with PROPEL mometasone furoate bioabsorbable drug-eluting sinus stents.

OBJECTIVE

To determine the postmarket complications associated with PROPEL mometasone furoate bioabsorbable drug-eluting sinus stents.

METHODS

The US Food and Drug Administration's Manufacturer and User Facility Device Experience database was searched for adverse events associated with PROPEL bioabsorbable drug-eluting sinus stents between January 1, 2012 and December 31, 2020. Data were extracted and analyzed from medical device reports (MDRs) that involved sinus stents.

RESULTS

After 47 MDRs were identified, 25 reports involving PROPEL bioabsorbable drug-eluting sinus stents were reviewed, from which 40 adverse events were recorded. Of these, there were 32 adverse events to patients and 8 device malfunctions. The most common adverse events to patients included infection (21.8%), oropharyngeal obstruction (15.6%), and headache/pain (12.5%). The most common device malfunction reported was migration and expulsion of the stent (87.5%).

CONCLUSIONS

PROPEL sinus stents have been shown to be effective in preventing sinus outflow obstruction after functional endoscopic sinus surgery. Both adverse events to patients and device malfunctions are reported infrequently. A more comprehensive understanding of rare postmarket complications seen with PROPEL sinus stents may further aid informed decision-making regarding their usage.

A thermoresponsive hydrogel system for long-acting corticosteroid delivery into the paranasal sinuses

Delivering localized treatment to the paranasal sinuses for diseases such as chronic rhinosinusitis (CRS) is particularly challenging because of the small natural openings leading from the sinuses that can be further obstructed by presence of inflammation. As such, oral steroids, topical nasal sprays or irrigation, and surgery can be utilized to treat persistent sinonasal inflammation, but there exists a need for post-operative options for long-term steroid delivery to prevent disease recurrence. In the present study, a Thermogel, Extended-release Microsphere-based-delivery to the Paranasal Sinuses (TEMPS) is developed with the corticosteroid mometasone furoate. Specifically, the bioactive steroid is released for 4 weeks from poly(lactic-co-glycolic acid) (PLGA) microspheres embedded in a poly(N-isopropylacrylamide) (p-NIPAAm)-based hydrogel. The temperature-responsive system undergoes a reversible sol-gel transition at 34-35 °C such that it can be applied as a liquid at ambient temperature, conforming to the sinonasal epithelium as it gels. In a rabbit model of CRS, TEMPS was maintained in rabbit sinuses and effectively reduced sinonasal inflammation as characterized by micro-computed tomography and histopathology analysis. Ultimately, the combination of controlled release microspheres with a thermoresponsive hydrogel provides flexibility for encapsulating therapeutics in a reversible and conforming system for localized delivery to the sinuses.