Evaluation of the PROPEL® mini sinus implant for the treatment of frontal sinus disease

Influence of Pre-Operative Estimation of Draf III Expected Diameter on Surgical Outcome

Introduction: The DRAF III procedure is indicated for the treatment of benign and selected malignant frontal sinus pathology. Several attempts have been made to find an intra or pre-operative measurement that was predictive of the feasibility of this operation and its success. Among those, the frontal sinus outflow tract anteroposterior diameter (FOAP) appears to be the one with the highest applicability in clinical practice, since it is easy to measure on pre-operative CT scan. The objective of the study is to evaluate whether the minimum and maximum frontal sinus outflow anteroposterior diameters (FOAP min and FOAP max) are associated with the risk of failure and consequently with the need for surgical revision. Secondly, we ought to evaluate whether the angle between the glabella and the nasion on the sagittal plane could influence surgical outcome. Material and Methods: This is a retrospective study on patients who underwent DRAF III for benign pathologies at a tertiary Italian referral center from January 2000 to July 2022. FOAP min and FOAP max were measured on the mid-sagittal sections of a pre-operative CT scan. The glabella-nasion angle (G-N angle) was calculated on the same sagittal section. These measurements were compared between patients who experienced a recurrence and those who did not. If a post-operative CT scan was available, the obtained anteroposterior diameter (OD) of the frontal sinus neo-ostium was also measured on the same section. A correlation analysis was performed between the three pre-operative radiologic parameters and OD. Results: Twenty-nine patients were included in the study. Six patients experienced restenosis requiring surgical revision. The median FOAP max resulted significantly higher in patients who did not experience recurrence (median: 14.8 mm, IQR: 3.84) than in patients who experienced a recurrence (median: 11.9 mm, IQR: 1.14) (p = 0.04). The FOAP max also showed a good positive correlation with OD (p = 0.0001; r = 0.7). The correlation between FOAP min and OD was not statistically significant, nor was a correlation found between FOAP min and recurrence risk. The G-N angle was not significantly different in patients who experienced recurrence and those who did not, nor did it show a correlation with OD. Discussion: The FOAP max might be a valid pre-operative radiologic parameter to guide a surgeon's approach to a DRAF III procedure, as it is easy to measure, shows a good correlation with OD, and seems to influence the risk of recurrence.

Reduction in healthcare resource use through 24 months following sinus surgery with steroid-eluting implants in chronic rhinosinusitis patients with and without nasal polyps: a real-world study

OBJECTIVE

To investigate the impact of steroid-eluting implants after endoscopic sinus surgery (ESS) on health care resource use (HCRU) in chronic rhinosinusitis patients with (CRSwNP) and without (CRSsNP) nasal polyps.

METHODS

This retrospective, observational cohort study using real-world evidence data included adult patients with CRS who underwent ESS in 2015-2019 with at least 24 months of data before and after ESS. Patients who received implants were matched to patients who did not based on a propensity score developed using baseline characteristics and NP status. HCRU was compared between cohorts within each CRSwNP and CRSsNP subgroup using chi-square tests (binary variables).

RESULTS

The implant cohort in the CRSwNP subgroup had fewer all-cause outpatient (90.0% vs. 93.9%, p < .001) and all-cause otolaryngology (64.3% vs. 76.4%, p < .001) visits as well as fewer endoscopy (40.5% vs. 47.4%, p = .005) and debridement (48.8% vs. 55.6%, p = .007) procedures than the non-implant cohort. The implant cohort in the CRSsNP subgroup had fewer all-cause outpatient (88.9% vs. 94.2%, p < .001) and all-cause otolaryngology (53.5% vs. 74.4%, p < .001) visits as well as fewer endoscopy (31.8% vs. 41.7%, p < .001) and debridement (36.7% vs. 53.4%, p <.001) procedures than the non-implant cohort. Revision sinus surgery was reduced in the implant cohort in both subgroups, and reached statistical significance in the CRSwNP subgroup (3.8% vs. 6.0%, p = .039) but not in the CRSsNP subgroup (3.6% vs. 4.2%, p = .539).

CONCLUSIONS

Overall, patients receiving implants had lower HCRU for 24 months after sinus surgery independent of nasal polyp status, and revision surgery was reduced in CRSwNP patients. These findings provide additional evidence that long-term reductions in HCRU may be achieved with steroid-eluting implant use during sinus surgery.What is known on this topicPatients with chronic rhinosinusitis with nasal polyps (CRSwNP) have a disproportionately higher burden of disease and consume greater healthcare resources than chronic rhinosinusitis patients without nasal polyps (CRSsNP).CRSwNP patients represent approximately 30% of CRS patients who undergo surgery, but their clinical course is disproportionally complicated by disease recurrence and revision surgery.Steroid-eluting sinus implants have been shown in clinical trials to improve short-term postoperative outcomes after endoscopic sinus surgery (ESS) in CRS patients in general.A recent real-world evidence study reported that steroid-eluting sinus implants following ESS were associated with a reduction in HCRU in CRS patients followed for 18 months, but the impact of implants on HCRU in CRSwNP and CRSsNP patients separately remains unknown. What this study addsIn this observational study, reduced HCRU was observed in CRSwNP and CRSsNP patients who receive steroid-eluting sinus implants.Use of implants in CRSwNP and CRSsNP patients was associated with a significant reduction in healthcare visits (all-cause outpatient, all-cause otolaryngology), and sinus procedures (endoscopy, debridement).Revision surgery was significantly reduced in the implant cohort of CRSwNP patients and trended lower in the implant cohort of CRSsNP patients.Use of implants had no significant impact on all-cause ER/urgent care visits or sinus-related imaging.

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.

Short-term postoperative efficacy of steroid-eluting stents for eosinophilic chronic rhinosinusitis with nasal polyps: a randomized clinical trial

BACKGROUND

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is a refractory clinical phenotype with high symptom burden and relapse rate. Steroid-eluting stents are safe and effective for reducing polyp size, symptom burden, and the need for revision sinus surgery. This study aimed to evaluate the efficacy and safety of steroid-eluting stent implantation on the surgical outcomes of patients with ECRSwNP.

METHODS

This prospective, multicenter, randomized, intrapatient-controlled trial recruited patients aged 18 to 65 years with ECRSwNP requiring surgery. Ninety-eight patients were enrolled and randomly implanted with absorbable steroid-eluting stents containing mometasone furoate in one sinus at the end of surgery. All patients received standard postoperative care and follow-up. The primary outcome was the Lund-Kennedy endoscopic score within 12 weeks post-surgery. Secondary outcomes included nasal symptoms scores, nasal resistance, acoustic rhinometry, nasal nitric oxide levels, 3-dimensional volumetric computed tomography scores, and eosinophil counts in the ethmoid mucosa.

RESULTS

Ninety-five patients completed the trial. At postoperative weeks 4, 8, and 12, the Lund-Kennedy scores were significantly lower on the treatment side than on the control side (all p<0.01). Compared with the treatment side, the control side exhibited higher tissue eosinophilia at week 4 and higher volumetric, nasal obstruction, and total nasal symptom scores at postoperative week 8 (p = 0.011, p = 0.011, p<0.01, and p = 0.001, respectively). No adrenal cortical suppression or serious side effects were observed.

CONCLUSION

Steroid-eluting stents reduce postoperative sinus mucosal edema and eosinophilic inflammation, with persistent effects after stent disintegration, and are a good supplementary post-surgical treatment in patients with ECRSwNP. This article is protected by copyright. All rights reserved.

Smart design of patient centric long-acting products: from preclinical to marketed pipeline trends and opportunities

INTRODUCTION

We see a development in the field of long-acting products to serve patients with chronic diseases by providing benefits in adherence, efficacy and safety of the treatment. This review investigates features of long-acting products on the market/pipeline to understand which drug substance (DS) and drug product (DP) characteristics likely enable a successful patient-centric, low-dosing frequency product.

AREAS COVERED

This review evaluates marketed/pipeline long-acting products with greater than one week release of small molecules and peptides by oral and injectable route of administration (RoA), with particular focus on patient centricity, adherence impact, health outcomes, market trends, and the match of DS/DP technologies which lead to market success.

EXPERT OPINION

Emerging trends are expected to change the field of long-acting products in the upcoming years by increasing capability in engineered molecules (low solubility, long half-life, high potency, etc.), directly developing DP as long-acting oral/injectable, increasing the proportion of products for local drug delivery, and a direction towards more subcutaneous, self-administered products. Among long-acting injectable products, nanosuspensions show a superiority in dose per administration and dosing interval, overwhelming the field of infectious diseases with the recently marketed products.

Real-world evidence analysis of the impact of steroid-eluting implants on healthcare resource use among chronic rhinosinusitis patients undergoing sinus surgery

OBJECTIVE

To compare healthcare resource use (HCRU) in patients undergoing sinus surgery with or without steroid-eluting sinus implants.

METHODS

A retrospective, observational cohort study using real-world evidence data (OM1, Inc, Boston, MA, USA) was conducted on adult patients with chronic rhinosinusitis (CRS) with or without nasal polyps who underwent endoscopic sinus surgery between 2014 and 2019 and had at least 18 months of data both before and after surgery. Patients receiving implants ("implant cohort") were matched to patients who did not receive implants ("non-implant cohort") based on a propensity score developed using baseline characteristics. Chi-square for binary variables and analysis of variance tests for continuous variables were applied to compare HCRU measures.

RESULTS

Comparison of the implant (N = 1983) and non-implant (N = 1983) cohorts during the 18-month follow-up period demonstrated significantly lower HCRU in those receiving implants, including all-cause outpatient visits (94.3% vs. 96.6%, p < .001), all-cause otolaryngologist visits (47.3% vs. 59.6%, p < .001) and all cause ER/urgent care visits (9.2% vs. 11.8%, p = .007), as well as sinus-related endoscopies (39.1% vs. 43.8%, p = .003). Although not statistically significant, fewer patients in the implant cohort had undergone repeat surgeries (4.6% vs. 5.3%, p = .273).

CONCLUSION

Patients with steroid-eluting sinus implants had lower HCRU over a post-operative period of 18 months. These findings support the contention that reductions in HCRU may be achieved using steroid-eluting implants during sinus surgery.What is known on this topicChronic rhinosinusitis (CRS) causes severe symptoms that lead to poor quality of life.Endoscopic sinus surgery (ESS) is 76-98% effective in improving CRS patients' symptoms.Surgical outcomes can be compromised in the immediate post-operative period by scarring, adhesion formation, and early polyp recurrence.Oral and topical corticosteroid therapy has become integral to the maintenance of successful surgical outcomes, the management of post-operative scarring and edema, and the prevention of nasal polyp recurrence.Steroid-eluting sinus implants have been shown in clinical trials to improve postoperative outcomes after ESS by delivering localized, sustained release of corticosteroids directly onto inflamed sinus tissue.What this study addsThis observational study is one of the first to use real-world evidence to assess the effect of steroid-eluting sinus implants on healthcare resource use (HCRU) in patients with chronic rhinosinusitis who underwent sinus surgery with or without implants.Use of implants significantly reduced HCRU, including all-cause outpatient visits (94.3% vs 96.6%, p < .001), all-cause otolaryngologist visits (47.3% vs 59.6%, p < .001), and all-cause ER/urgent care visits (9.2% vs 11.8%, p = .007), as well as sinus endoscopy (39.1% vs 43.8%, p = .003).Use of implants had no significant effect on sinus procedures such as debridement and polypectomy, as well as sinus-related imaging such as CT, MRI, and x-ray.

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.

Preventive Measures of Middle Turbinate Lateralization After Endoscopic Sinus Surgery: An Updated Review

Introduction: The middle turbinate (MT) is the most important anatomical structure inside the nasal cavity and a landmark in the identification of skull base, ethmoid cells, and lamina papyracea. Postoperatively, lateralizationof the MT can cause synechia and obstruction of the middle meatus and the maxillary, ethmoid, or frontal sinuses.

Objective: To review the current literature about the outcome of different techniques used intraoperatively to prevent lateralization of MT after functional endoscopic sinus surgery (FESS).

Materials and methods: This retrospective narrative literature review provides a summary of current and past research publications about different techniques used intraoperatively to prevent MT lateralization after FESS.

Results: Many methods have been described to prevent the lateralization of MT and synechiae formation. These methods include controlled synechiae, suture lateralization, metal clips, partial resection of MT, middle meatus implants, and steroid-eluting implants and stents.

Conclusion: The ideal FESS should include preservation of the MT, reducing its lateralization, and preventing synechia formation.Different techniques have been discovered in an attempt to prevent this complication.

Meta-analysis of global and high throughput public gene array data for robust vascular gene expression discovery in chronic rhinosinusitis: Implications in controlled release

BACKGROUND

Chronic inflammation is known to cause alterations in vascular homeostasis that directly affects blood vessel morphogenesis, angiogenesis, and tissue permeability. These phenomena have been investigated and exploited for targeted drug delivery applications in the context of cancers and other disease processes. Vascular pathophysiology and its associated genes and signaling pathways, however, have not been systematically investigated in patients with chronic rhinosinusitis (CRS). Understanding the interplay between key vascular signaling pathways and top biomarkers associated with CRS may facilitate the development of new targeted delivery strategies and treatment paradigms. Herein, we report findings from a gene meta-analysis to identify key vascular pathways and top genes involved in CRS.

METHODS

Proprietary software (Illumina BaseSpace Correlation Engine) and open-access data sets were used to perform a gene meta-analysis to systematically determine significant differences between key vascular biomarkers and vascular signaling pathways expressed in sinonasal tissue biopsies of controls and patients with CRS.

RESULTS

Thirteen studies were initially identified, and then reduced to five after applying exclusion principle algorithms. Genes associated with vasculature development and blood vessel morphogenesis signaling pathways were identified to be overexpressed among the top 15 signaling pathways. Out of many significantly upregulated genes, the levels of pro angiogenic genes such as early growth response (EGR3), platelet endothelial cell adhesion molecule (PECAM1) and L-selectin (SELL) were particularly significant in patients with CRS compared to controls.

DISCUSSION

Key vascular biomarkers and signaling pathways were significantly overexpressed in patients with CRS compared to controls, suggesting a contribution of vascular dysfunction in CRS pathophysiology. Vascular dysregulation and permeability may afford opportunities to develop drug delivery systems to improve efficacy and reduce toxicity of CRS treatment.

Local drug delivery systems for inflammatory diseases: Status quo, challenges, and opportunities

Inflammation that is not resolved in due course becomes a chronic disease. The treatment of chronic inflammatory diseases involves a long-term use of anti-inflammatory drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, often accompanied by dose-dependent side effects. Local drug delivery systems have been widely explored to reduce their off-target side effects and the medication frequency, with several products making to the market or in development over the years. However, numerous challenges remain, and drug delivery technology is underutilized in some applications. This review showcases local drug delivery systems in different inflammatory diseases, including the targets well-known to drug delivery scientists (e.g., joints, eyes, and teeth) and other applications with untapped opportunities (e.g., sinus, bladder, and colon). In each section, we start with a brief description of the disease and commonly used therapy, introduce local drug delivery systems currently on the market or in the development stage, focusing on polymeric systems, and discuss the remaining challenges and opportunities in future product development.

Comparison of Bioabsorbable Steroid-Eluting Sinus Stents Versus Nasopore After Endoscopic Sinus Surgery: A Multicenter, Randomized, Controlled, Single-Blinded Clinical Trial

OBJECTIVES

The aim of this study was to compare the efficacy of bioabsorbable steroid-eluting sinus stents versus absorbable Nasopore packs after endoscopic sinus surgery (ESS) for the treatment of chronic rhinosinusitis (CRS).

METHODS

One hundred eighty-one patients with CRS who underwent ESS were randomly assigned to receive a steroid-eluting sinus stent in one ethmoid sinus cavity, whereas the contralateral control side received a Nasopore pack. Endoscopic evaluations were performed 14, 30, and 90 days after the ESS. Postoperative intervention, polyp formation, adhesions, and middle turbinate (MT) position were assessed as efficacy outcomes.

RESULTS

The stents were successfully deployed in all 181 sinuses. Thirty days after the ESS, the stents significantly reduced the need for surgical intervention compared to the Nasopore (P < .0001). The percentage of cases with polyp formation was significantly lower on the stent sides compared with the Nasopore sides (P < .0001) at 14, 30, and 90 days after ESS. The percentage of severe adhesion was significantly lower on the stents sides than on the Nasopore sides at postoperative day 90 (P = .0003), whereas they were not significantly lower at postoperative days 14 and 30. There were no significant differences between the stent sides and the Nasopore sides regarding the frequency of MT lateralization at all end points. No device-related adverse events occurred.

CONCLUSIONS

Our study demonstrated significant improvement in the early postoperative outcomes by reducing the need for postoperative surgical intervention and polyp formation using steroid-eluting stents when compared with absorbable Nasopore packs. The steroid-eluting sinus stents and the Nasopore packs were each effective in preserving the ethmoid sinus patency and in preventing MT lateralization. A further prospective cohort study with long-term postoperative outcomes is warranted.

Novel Application of Steroid Eluting Stent in Petrous Apex Cholesterol Granuloma

Objective  This study describes the safety and efficacy of mometasone furoate eluting stents in the management of petrous apex cholesterol granuloma approached through an endonasal endoscopic route and assesses the restenosis rate. Methods  Consecutive patients undergoing endoscopic endonasal marsupialization of a petrous apex cholesterol granuloma at a tertiary referral center who had a mometasone furoate eluting stent placed intraoperatively were reviewed in a retrospective fashion. Postoperative endoscopy was used to determine success of surgery and stenting. Results  Five patients were included in the study, three were primary cases and two patients had revision surgeries performed. The steroid eluting stent was placed successfully and safely in all patients with no dural or vascular injuries. The average follow-up duration was 10.6 months. There was no restenosis in three patients and one patient had an immediate restenosis that was debrided in clinic (revision case). This was patent at the 16 months follow-up. One patient also developed stenosis, 4 months after surgery due to sphenoid sinusitis. Conclusion  Mometasone furoate eluting stents are safe and effective in the primary management of petrous apex cholesterol granuloma. Further studies are needed to assess their efficacy in revision cases and for long term results.

Biocompatibility and Pharmacokinetics of Fluticasone-Eluting Sinus Implant in a Rabbit Model

Background

A novel, bioabsorbable, fibrinogen-based implant has been developed as a mucosal dressing after endoscopic sinus surgery (ESS). This implant can be formulated with fluticasone propionate (TP) for local elution of corticosteroid to reduce postoperative inflammation and promote mucosal healing.

Objective

This study investigated the biocompatibility and pharmacokinetics of the implant in a rabbit model.

Methods

Implants with and without TP were placed on both intact and demucosalized maxillary sinuses of 33 New Zealand White rabbits. Sinuses with either intact or denuded bone without implants acted as controls. Histopathologic assessments were carried out at 5, 15, and 28 days. Concentrations of TP in the maxillary sinus mucosa, nasal cavity mucosa, and plasma were measured for up to 44 days.

Results

Implants placed on intact mucosa or denuded bone were grossly integrated within 15 days. Minimal foreign body reaction was seen with negligible differences for inflammation, fibrosis, or bone remodeling among controls, sinuses with the implant, or sinuses with the implant plus TP, at all time points. All samples also showed complete or near-complete percentage reepithelialization at 28 days, although the denuded bone controls demonstrated greater percentage reepithelialization at 5 days compared with denuded bone with the implant or implant plus TP (p <0.0001). The maxillary sinus mucosa demonstrated levels of TP of >140 ng/g up to 44 days. Plasma concentrations of TP were generally very low and were undetectable after day 7.

Conclusions

The implant and the implant plus TP seemed to be biocompatible in rabbits. The implant plus TP effectively eluted steroid locally over at least 44 days, with negligible plasma concentrations. Further studies are warranted regarding potential therapeutic applications in patients undergoing ESS for chronic rhinosinusitis.