Frontal Sinus Patency After Sinus Surgery Using Triamcinolone-Impregnated Plant-Based Sinus Spacers

INTRODUCTION

Functional endoscopic sinus surgery (FESS) is performed to restore the sinus’s normal function in patients with chronic rhinosinusitis (CRS) who have failed appropriate medical management. A critical factor in achieving the success of this intervention is sinus ostia patency. To this end, intranasal steroid administration in the early post-operative period is the mainstay of treatment for preventing post-operative scarring, edema, polyps, and crusting.

The frontal sinus is particularly predisposed to impaired drainage post-operatively due to its complex and variable anatomy, narrow drainage pathway dimensions, and tendency for circumferential scarring. Although surgical management has significantly advanced, preservation of frontal recess patency post-operatively remains a challenge due to the often-narrow confines of the frontal recess and ostium.

At our institution, plant-based polysaccharide frontal sinus spacers (NexPak X, Hemostasis LLC, St. Paul, Minn.) are inserted into the frontal recesses bilaterally and soaked in 40 mg of triamcinolone intra-operatively, after a FESS. This paper aims to describe our technique for preserving frontal sinus ostium patency.

Methods

We conducted a retrospective review of all patients who underwent FESS for CRS at the Royal Victoria Hospital operated on by a single surgeon between January 2018 and April 2022. Patients without at least one endoscopic report following their first post-operative visit were excluded. The study was reviewed and approved by the McGill University Health Centre Research Ethics Board. We performed data analysis using Stata Statistical Software version 17.0. Categorical variables were expressed as the total number and percentage, whereas continuous variables with normal distribution were presented as mean ± standard deviation (SD). For non-parametric variables, their median and interquartile range were used after confirming their distribution with the Shapiro–Wilk normality test. In instances of small sample sizes (n < 3), the range was reported instead of the interquartile range. The univariate analysis was conducted using Chi-square and Mann–Whitney tests. A p-value < 0.05 was considered statistically significant.

Surgical Technique

Preparation of the Spacer: The NexPak spacer is cut into two mirror-image pieces, resulting in a shape that resembles a whistle. Its shape includes a narrow tail section, approximately 3-5 mm wide and 3 cm long, and a broader tip section, measuring approximately 1 cm in both width and length. To avoid the spacer expanding and losing its structural integrity once it comes in contact with blood during the insertion process, the narrow end is covered in antibiotic ointment, creating a thin hydrophobic barrier and facilitating its proper positioning within the frontal recess. The narrow tail of the spacer is then inserted into the frontal recess, leaving the broader tip in the middle meatus, just below the axilla of the middle turbinate. This larger end holds the middle turbinate remnant medially, preventing lateralization, and facilitates retrieval at the first post-operative visit.

Steroid Use: Using a 22-gauge needle and syringe, 1 mL (40 mg) of triamcinolone is then injected into each spacer, causing it to enlarge and securing the spacer in place. The entire spacer is then allowed to imbibe triamcinolone from the bottom up by slowly wetting the larger end that is kept devoid of ointment.

Patients are advised to use saline sprays or rinses six to eight times per day in the first week or two; no topical or oral corticosteroid medications are used during this period, aside from what has been injected into the spacer. Patients are also advised that on rare occasions, the spacer can be dislodged in the post-operative period and may fall out with rinsing; there is no need to take any action; just follow up as planned. If mucosal inflammation is judged to be severe by the surgeon at the first post-operative visit, a course of prednisone consisting of 30 mg tapering over three weeks can then be offered.

Spacer Removal: This spacer is maintained in place until the first post-operative visit, typically at two weeks, after which it is manually removed in clinic. It is removed by debridement, mainly with a Fraser suction, although a curved suction may also be used. Occasionally, there is a thin superficial crust that benefits from removal with a grasping instrument such as a fine Blakesley or large alligator forceps.

Endoscopic Evaluation: Frontal sinus patency was categorized as patent (> 5 mm) (Data S1), narrow (< 5 mm with clear visualization of the frontal sinus) (Data S2), or stenosed (complete occlusion with no visualization of the frontal sinus) (Data S3), based on documentation of nasal video endoscopy. Patency was assessed at post-operative visits by the senior author.

Results

A total of 74 patients met the inclusion criteria. The study period overlapped with the SARS-CoV-2 pandemic and, as such, many post-operative visits occurred virtually. In the instance of any symptoms, the patients were scheduled for an in-office visit for endoscopic evaluation. Any virtual visits were discarded, and only in-office visits were included. Endoscopic visits were unavailable at 12 months for eight patients; however, all eight had a documented endoscopy at their five-month follow-up.

Frontal Sinus Ostium Patency

The one-year patency rates were 95.45% (63/66) for the left and 96.97% (64/66) for the right frontal sinuses at the final follow-up. Within a small subset of patients (n = 3), stenosed frontal sinuses were identified on endoscopy, encompassing bilateral stenosis in two patients and unilateral stenosis of the left side in one patient. One patient developed narrowing at two weeks and then complete stenosis at nine months. The other two patients developed complete stenosis at 12 months. Surgical intervention for the two patients with bilateral stenosis was scheduled at nine and 12 months, respectively, whereas the third patient with unilateral left-sided stenosis did not require surgical intervention because of mild post-operative symptoms. A third symptomatic patient underwent surgical re-intervention at 11 months for frontoethmoidal recess obstruction evident on imaging despite apparent endoscopic patency. All patients with symptoms inconsistent with findings on endoscopy were sent for CT imaging, and no other such cases were identified.

Surgical re-intervention consisted of revision frontal sinusotomy in one case and frontal drill-out in two cases. Among the patients with stenosis requiring surgical intervention, one had no pre-operative polyps, the second had a polyp grade of 3, and the third had no documented pre-operative polyp grading. Furthermore, their pre-operative Lund–Mackay scores were, respectively, 11 (1 for frontal sinus) and 10 (2 for frontal sinus); the third was undocumented. The mean age of this cohort was 58 years old; all three were female with concomitant asthma, and they were all non-smokers. One patient had Sjögren’s syndrome with severe asthma and seronegative rheumatoid arthritis, leading to excessive scarring post-operatively. Another patient had two previous sinus surgeries and developed severe osteoneogenesis post-operatively. A statistically significant association was found between frontal patency and autoimmune diseases, such as Sjögren’s, psoriatic arthritis, and ankylosing spondylitis, as well as between frontal stenosis and CRS without nasal polyps. Given the small sample size and the contradiction to existing literature, however, these findings are likely due to random variation rather than a true association.

Additionally, partial stenosis or narrowing of the frontal sinus ostium was identified in four additional patients: one with right-sided narrowing observed at two weeks, two with bilateral narrowing at five months, and one with bilateral narrowing at two weeks, which was judged not to be clinically significant at the subsequent two visits.

Conclusion

Inserting a plant-based polysaccharide spacer impregnated with triamcinolone into the frontal recesses and keeping it in place for two weeks is an easy-to-use method for reducing the rate of frontal sinus ostium stenosis and surgical revision in patients with CRS who have undergone FESS.