Outcomes of Functional Endoscopic Sinus Surgery in Chronic Rhinosinusitis: A Systematic Review and Meta-Analysis

Chronic rhinosinusitis (CRS) is a prevalent health problem that affects many people around the world and can require surgical intervention if conservative therapy fails. Functional endoscopic sinus surgery (FESS) is a minimally invasive surgical procedure commonly used to manage CRS. The success of FESS depends on various factors, and larger studies are necessary to determine its efficacy in managing CRS in this population. This systematic review and meta-analysis of the available literature aims to provide a comprehensive assessment of the effectiveness of FESS in the Middle East. We followed the standards outlined by PRISMA and the Cochrane Handbook for systematic reviews. The primary outcome of interest was the quality of life (QOL), and the secondary outcome was the recurrence of CRS. This systematic review and meta-analysis was conducted, and sensitivity analysis was performed to examine the robustness of the results. Six studies were included. The review found that the QOL significantly improved (p < 0.001). Two studies reported recurrence of CRS after FESS, and data showed that the recurrence of CRS after surgery was 6%. FESS is an effective intervention for CRS, but further research is needed on recurrence rates.


Introduction And Background
Chronic rhinosinusitis (CRS) is a common health problem that affects millions of people around the world, with a prevalence of up to 10% in some populations [1].CRS is characterized by inflammation of the paranasal sinuses and nasal mucosa and is associated with symptoms such as nasal congestion, facial pain, and headache [2].Despite the availability of various medical treatments, some patients with CRS may not respond to conservative therapy and may require surgical intervention.Functional endoscopic sinus surgery (FESS) is a minimally invasive surgical procedure commonly used to manage CRS [3].The procedure aims to restore normal sinus ventilation and drainage by removing inflamed tissue and obstructions within the sinuses, thus improving symptoms and quality of life [4].Although FESS effectively manages CRS, the outcomes of FESS in the Middle East and North Africa (MENA) remain largely undetermined.The Saudi population, for example, has unique demographic and cultural characteristics, and the prevalence of CRS in this population has been reported to be as high as 13.9% [5].
Various factors influence the management of CRS in the Middle East.One of the critical factors is the lack of awareness among the general public about the disease and its management.Studies have shown that a large population in the Middle East lacks knowledge about CRS, which can lead to delays in seeking medical attention and proper treatment [6].The availability and accessibility of healthcare services have also affected the manner of CRS management in the region.As a result, patients in the region often have to endure delayed diagnosis and treatment, which can further worsen the condition of patients with CRS.
Despite the challenges, FESS has delivered reliable results as an effective treatment option for patients with CRS.A primary outcome observed in most experimental trials was the high rate of improvement in symptoms and quality of life (QOL).A study conducted in 2006 on 47 patients who underwent FESS for CRS found that 87.2% of the patients reported a significant improvement in their symptoms after surgery and 72.4% reported an improvement in their QOL [7].Similarly, Bunzen et al. experimented on 58 patients.They reported similar findings, with 86.2% of patients reporting an improvement in their symptoms and 77.6% reporting an improvement in their QOL [8].Alrajhi et al. also reported a significant improvement in CRS symptoms, as observed in 60 CRS patients undergoing FESS.Symptoms such as nasal obstruction, post-nasal drip, and facial pain were reported to improve significantly.The patient's QOL was also reported to show a marked improvement post-surgery [9].These positive outcomes of FESS are common among Middle Eastern CRS patients.Al-Qudah et al. [10] investigated another group of 78 patients and reported that FESS significantly improved the symptoms of CRS.Through self-reported data, the researchers found that patients significantly improved their QOL post-surgery.The study also reported a low complication rate and no significant adverse events [10].
However, it is important to note that the success of FESS depends on various factors, including the severity of the disease, the extent of surgery, and patient factors such as smoking status and adherence to postoperative care.Studies in the Middle East have also reported positive outcomes of FESS in patients with CRS.However, a common limitation in most of these studies remains the lack of appropriate patient selection and unreliable preoperative management.A larger pool of patients is necessary to assess the outcomes of FESS in the Middle Eastern population to determine the efficacy of this procedure in the management of CRS in this demographic.The primary purpose of this review is to evaluate the available evidence on the outcomes of FESS in the treatment of CRS in the Middle East, including its efficacy, safety, and patient satisfaction.The findings of this review can help inform clinical practice and improve the quality of care for CRS patients in the Middle East.

Study Design
This systematic review and meta-analysis was conducted in accordance with the standards of systematic reviews outlined by the Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA).It used the PRISMA extension published in the Cochrane Handbook for systematic reviews and interventions [11].

Literature Search
An extensive literature search was performed from relevant electronic databases, such as PubMed, Cochrane Library, and Scopus.A combination of Medical Subject Headings (MeSH) and keywords related to FESS and CRS were used.Examples of primary keywords used to construct the basic search string were "functional endoscopic sinus surgery" OR "FESS", "chronic rhinosinusitis" OR "CRS," "Middle East" OR "MENA".The names of the Middle Eastern countries were also included in the search.

Inclusion and Exclusion Criteria
Two independent investigators participating in the systematic review and meta-analysis reviewed the identified studies.The inclusion criteria focused on studies that evaluated the outcomes of FESS in the treatment of CRS and studies that reported quantitative data on outcomes such as symptom improvement, QOL, or recurrence rates.All selected studies should be experimental studies that were conducted in the MENA region and published in English.Middle Eastern studies published in other languages, but were translatable into English, were included.
Studies concerning patients with acute sinusitis or other sino-nasal disorders were excluded.Similarly, other surgical techniques, besides FESS, were grounds for exclusion.Priority was given to RCTs for inclusion, as well as cohort studies (CH) and method cohort (MCH), and other study designs were excluded.

Quality Assessment
The quality of the studies included in this meta-analysis was assessed using the Newcastle-Ottawa scale (NOS) for non-randomized studies.The NOS assesses the quality of non-randomized studies based on a selection of participants, comparability of groups, and outcome assessment.Studies will be considered of high quality if they have a low risk of bias or a high score on the NOS.

Data Extraction
Before extracting the data, the included studies were evaluated for risk of bias according to the methodological standards outlined in the Cochrane Handbook of Systematic Reviews of Interventions [11].A standardized Excel sheet was prepared and refined with the purpose of extracting data that would be relevant for this systematic review and meta-analysis.The investigators involved in selecting the studies also extracted relevant information for this review.Data extracted included study identification (such as author and year of publication), study characteristics (such as study design, sample size, and follow-up period), patient characteristics (such as age, sex, and comorbidities), details of the FESS intervention (such as technique and intraoperative complications), and outcome measures (such as efficacy, safety, and patient satisfaction).

Data Analysis
A meta-analysis was performed using a random-effects model to pool the results of eligible studies.Heterogeneity was assessed using the I2 statistic.A level of heterogeneity ≤ 25% was tolerable to ensure that the included studies were homogeneous.The significance of the test shall be determined by the p-value, with the point of statistical significance being ≤ 0.05.Sensitivity analyses were performed using a fixedeffects model analysis.Data were analyzed and plotted on Review Manager software (RevMan 5.4; Cochrane Collaboration, London, UK).

Study Selection
The initial literature search in the databases revealed 144 qualitative studies for inclusion in the systematic review and meta-analysis.Twenty-one studies from these studies were duplicates, which were eliminated, leaving 123 studies for further eligibility assessment.The title and abstract assessment of the remaining studies eliminated 101 articles.A full-text assessment of the 22 remaining studies resulted in the elimination of 16 articles.The remaining six studies were extracted for data (Table 1).The PRISMA flow diagram below (Figure 1) was then developed to illustrate the study selection process.

Quality Assessment
For the six non-RCTs included in this investigation, the NOS appraisal system was used to perform a quality assessment of the involved studies (Table 2) [18].The scores for each item are then summed to give an overall score for the study.The maximum score on the NOS is 9, with higher scores indicating better study quality.

Statistical Analysis
QOL: The QOL outcome was evaluated by five studies.The mean difference in QOL was 23.58 (10.70, 36.46) at a 95% confidence interval.The overall effect of z = 3.59 (p < 0.001) was statistically significant in the change in QOL outcome among patients with CRS undergoing FESS.The level of heterogeneity was high (I2 = 99.59%,p < 0.001).The results of this meta-analysis are reported in Figure 2. Recurring CRS: Only two of the six included studies reported on the recurrence of CRS after FESS.The analyzed studies were found to have high heterogeneity (I2 = 99.47%,p = 0.00).There was an overall recurrence rate of 6% (95% CI = 2.07, 9.91).The results of this analysis are represented in Figure 3.

Discussion
Six studies were included in this systematic review and meta-analysis, with 335 patients observed.All 335 patients were diagnosed with some form of sino-nasal disease, CRS being the common point of interest.Our aim was to determine the outcome of FESS as an intervention for CRS.The review observed the change in QOL as tested by the Sino-nasal outcome test (SNOT-22) questionnaire and the CRS recurrence rate after surgery.
Only three studies reported the recurrence of CRS [12][13][14] [23].FESS has a positive impact on sleep outcomes.Therefore, patients with CRS often complain of excessive sleepiness and fatigue during the day.Since CRS affects the local area and the body as a whole, and FESS reduces the burden of the disease by improving systemic cytokine levels, it is reasonable to assume that FESS would also lead to improved sleep outcomes [15].These symptom improvements inform the overall QOL of the patients under treatment.As a result, more than 80% of patients with co-existing sinusitis and asthma also showed a moderate-to-great improvement in symptoms [23].Improving QOL can be reinforced by increased postoperative care, such as topical steroids.Although QOL can improve with or without irrigation with budesonide, there is a statistically significant improvement in efficacy and safety.

Conclusions
This systematic review and meta-analysis of six studies aimed to determine the outcome of FESS as an effective intervention for the management of CRS in the Middle Eastern population.The review found that a significant majority of patients undergoing FESS reported substantial improvement in their symptoms and an improved overall QOL.This is evident from the reduction in SNOT-22 scores postoperatively, indicating better health outcomes.However, it is crucial to note the variability in recurrence rates of CRS post-FESS, which highlights the need for careful patient selection and management, including considerations of preoperative comorbidities.Nevertheless, there is a need for larger-scale studies and standardized preoperative and postoperative management protocols to further validate these findings and optimize patient outcomes.

FIGURE 1 :
FIGURE 1: PRISMA flow diagram to illustrate the study selection process.

FIGURE 2 :
FIGURE 2: A forest plot of the meta-analysis on the QOL of CRS patients after FESS.

FIGURE 3 :
FIGURE 3: A forest plot of the meta-analysis on the recurrence of CRS after FESS.

TABLE 2 : Results of the quality assessment of the six non-randomized studies according to the NOS.
[17]e data collected indicate an overall CRS recurrence rate of 47/150 (31.33%) after an average follow-up period of nine months.With a p-value of p = 0.11, there was no statistical significance in the recurrence of CRS after FESS.Before Alghonaim et al., multiple studies in the Middle East found that CRS symptoms recur at a high rate after FESS[12].Telmesani[19]and Marglani et al.[20]reported 54.4% recurrence in the eastern province of Saudi Arabia and 55% in Makkah.Following this study, Al Sharhan et al. reported many recurring CRS symptoms in 35/68 (51.47%) patients[13].A year after FESS, in patients diagnosed with CRS with nasal polyps (CRSwNP), the presence of nasal polyps contributed to recurrence.Smith et al. estimated the occurrence of such an event to be 20%.The study also notes a 2.1 likelihood of improvement for patients undergoing surgery[21].Five studies included in this systematic review and meta-analysis used SNOT-22 primarily to assess QOL.Al Sharhan et al. went into depth to explain the underlying elements that led to FESS being a physician's choice of intervention[13].Other investigations take a more direct approach.For instance, Qadeer et al. demonstrated a gradual improvement in the mean score of QOL over a one-year follow-up period.The QOL score is reduced from 52.31 to 13.69, 11.26, 12.5, and 12.81 in postoperative 1st, 3rd, 6th, and 12th months, respectively[14].A similar trajectory has been replicated in other studies outside the Middle East, such as Jayakrishna et al., who reported a mean change of 33.04 with p < 0.001, indicating a high significance[22].Preoperative factors such as smoking, allergies, and asthma were predictors of a poor QOL score after FESS.A study conducted in India opined that smoking, alcoholism, and snuff use predict the outcome of symptom recurrence and QOL[23].Primarily, with FESS, the disease-specific QOL can be significantly improved.Three separate studies demonstrate this finding in Egypt by Behiry et al.[15], Iran by Aghdas et al.[16], and Morocco by Laababsi et al.[17].A significant improvement has been observed in the QOL scores between preoperative and postoperative observations[17].Similarly, a mean score of QOL of 59.38 ± 5.84 was observed before the operation and improved to 24.01 ± 10.48 after surgery.This reduction has been significant across the board, regardless of location.Statistical results indicate a level of significant improvement of p < 0.001.Symptom pattern improvement and QOL are two highly interrelated outcomes in surgery patients.After four quarterly post-surgery observations, Sujatha et al. found positive treatment responses to FESS with a mean change of 75 SNOT score