Chronic rhinosinusitis with nasal polyps (CRSwNP) is a persistent inflammatory disorder of the sinonasal mucosa characterized by nasal obstruction, nasal discharge, impaired smell, facial pressure, and the presence of nasal polyps. Epidemiological data indicate that approximately one-third of patients with chronic rhinosinusitis have the nasal polyp phenotype, although reported prevalence varies between populations and diagnostic methods [1].

CRSwNP is a heterogeneous disease with several inflammatory patterns. In many patients, particularly those with more severe disease, type 2 inflammation predominates and is associated with eosinophilic infiltration and increased activity of cytokines such as interleukin-4, interleukin-5, and interleukin-13 [2]. This inflammatory background is clinically relevant because persistent inflammation can continue after treatment and contributes to the recurrent nature of the disease.

The impact of CRSwNP extends beyond local sinonasal symptoms. Patients may experience substantial impairment in daily activities, sleep, work productivity, and overall quality of life. The SNOT-22 is among the most frequently used patient-reported outcome measures in CRSwNP, with reported baseline scores in surgical populations ranging from 25 to 73, reflecting considerable variation in symptom burden [3].

Initial management generally includes topical corticosteroids and saline irrigation, with systemic treatment used in selected patients. ESS is considered when symptoms and objective disease persist despite appropriate medical therapy. The purpose of surgery is to remove obstructive disease, improve sinus drainage, and facilitate delivery of postoperative topical medication; it does not directly eliminate the underlying inflammatory tendency [4]. ESS is an effective component of treatment for patients who remain inadequately controlled with medical therapy [5].

Assessment of outcomes after ESS requires both objective disease measures and patient-reported assessment. The SNOT-22 has demonstrated high internal consistency and test-retest reliability, with a reported minimal important difference of approximately nine points, making it useful for evaluating clinically meaningful changes after treatment [6]. Computed tomography provides an objective assessment of sinus involvement, and the Lund-Mackay system is commonly used to quantify radiological disease severity. However, radiological findings do not always correspond closely with symptom-based disease assessment, emphasizing the value of combining objective and subjective measures [7].

Despite appropriate surgery and postoperative treatment, recurrent nasal polyposis remains a major challenge in long-term management. Recurrence is influenced by several factors, including inflammatory phenotype, asthma, eosinophilic disease, previous surgery, and the extent of sinonasal involvement. A recent systematic review identified multiple clinical and inflammatory characteristics associated with recurrence, while also highlighting variability between studies in the strength of individual predictors [8]. Identifying patients at greater risk may help clinicians tailor postoperative surveillance and long-term treatment.

The present study therefore aimed to determine the frequency and timing of nasal polyp recurrence during 24 months following ESS in patients with CRSwNP and to evaluate the relationship of selected clinical and radiological factors with recurrence. Changes in SNOT-22 scores during follow-up were also assessed to determine the longer-term effect of ESS on patient-reported symptoms and quality of life.

Study Design A Prospective Cohort Study was conducted to assess postoperative recurrence and changes in quality of life among patients with chronic rhinosinusitis with nasal polyps (CRSwNP) following endoscopic sinus surgery (ESS). Study Location The study was conducted at ENT department of Pakistan Institute of Medical Sciences, Islamabad. Study Duration The study was carried out from July 2022 to June 2025. Each patient was followed for 24 months after surgery. Study Population Patients with confirmed CRSwNP who underwent ESS for persistent disease despite medical treatment were considered for inclusion. Sample Size and Sampling A total of 116 patients who met the eligibility criteria and completed 24 months of follow-up were included. Patients were selected using consecutive convenient sampling technique. Inclusion Criteria Patients with CRSwNP who underwent ESS and completed the scheduled 24-month follow-up were included. Exclusion Criteria Patients with incomplete follow-up or insufficient clinical records were excluded. Data Collection Baseline information included age, sex, smoking, allergic rhinitis, asthma, aspirin/NSAID sensitivity, previous ESS, peripheral eosinophilia, Lund-Mackay score, and severity of nasal polyposis. Relevant clinical and endoscopic findings were recorded during follow-up. SNOT-22 Assessment Disease-specific quality of life was assessed using the validated 22-item Sinonasal Outcome Test (SNOT-22) [6]. Scores were recorded before surgery and at 3, 6, 12, 18, and 24 months after ESS. Higher scores indicated greater symptom burden. Surgical Procedure and Follow-up ESS was performed according to the extent of sinonasal disease. Patients were reviewed at 3, 6, 12, 18, and 24 months postoperatively. Clinical and nasal endoscopic assessments were performed during follow-up. Recurrence was recorded when nasal polyposis reappeared according to the study's predefined clinical/endoscopic criteria. Outcome Measures The primary outcome was recurrence of nasal polyposis within 24 months. Secondary outcomes included changes in SNOT-22 scores and the association of asthma, peripheral eosinophilia, previous ESS, severe polyposis, and high Lund-Mackay score with recurrence. Statistical Analysis Data were analysed using IBM SPSS Statistics version 27. Continuous variables were presented as mean ± standard deviation and categorical variables as frequencies and percentages. Relative risk (RR) with 95% confidence intervals (CI) was used to assess associations between selected factors and recurrence. A p value <0.05 was considered statistically significant. Results were presented in tables, graphs, and a forest plot. Ethical Considerations Ethical approval was obtained from hospital’s ethics committee (approval no. F-202234/134/ENT). Patient confidentiality was maintained, and informed consent was obtained according to institutional requirements.

A total of 116 patients with chronic rhinosinusitis with nasal polyps underwent endoscopic sinus surgery and completed the 24-month follow-up. During the study period, 35 patients (30.17%) developed recurrent nasal polyposis, while 81 patients (69.83%) remained recurrence-free.

The characteristics of the patients included in the study are shown in table 1 below.

Table 1: Baseline characteristics of patients

At 6 months, recurrence was observed in 3 patients (2.59%). The cumulative recurrence increased to 10 patients (8.62%) at 12 months, 22 patients (18.97%) at 18 months, and 35 patients (30.17%) at 24 months as shown in figure 1 below.

Figure 1: Cumulative and individual recurrence after Endoscopic Sinus Surgery

Among the evaluated clinical factors, asthma, peripheral eosinophilia, previous ESS, and severe polyposis were significantly associated with recurrence. Recurrence occurred in 56.0% of patients with asthma compared with 23.1% without asthma (p<0.001). Similarly, recurrence was observed in 60.0% of patients with peripheral eosinophilia compared with 19.8% without eosinophilia (p<0.001).

Patients with a history of previous ESS had a recurrence rate of 50.0%, compared with 26.0% among those without previous surgery (p=0.02). Severe polyposis was also significantly associated with recurrence, occurring in 51.3% of affected patients compared with 19.5% of those without severe polyposis (p<0.001). High Lund-Mackay score was not significantly associated with recurrence as high score was 40% and 23.9% in cases with and without recurrence respectively (p>0.05). These associations are detailed in table 2 below.

Table 2: Factors associated with recurrence

SNOT-22 scores improved substantially after treatment, declining from 51.2 at baseline to 23.0 at 3 months and reaching the lowest mean score of 21.4 at 6 months. Thereafter, scores gradually increased to 29.1 at 24 months but remained considerably lower than baseline, suggesting sustained improvement in sinonasal symptoms and quality of life over the follow-up period as shown in figure 2.

Figure 2: Mean SNOT-22 scores during follow-up

Overall, 35 of 116 patients (30.17%) developed recurrent nasal polyposis within 24 months following ESS, while 81 patients (69.83%) remained recurrence-free. Asthma, peripheral eosinophilia, previous ESS, and severe polyposis were associated with a higher risk of recurrence. Patients with recurrence also required additional postoperative treatment more frequently and had poorer symptom scores at 24 months.

The forest plot displays the relative risk (RR) for each clinical factor associated with recurrence, together with the corresponding 95% confidence interval (CI). The vertical reference line represents an RR of 1.0. Peripheral eosinophilia showed the strongest association with the outcome (RR 3.00, 95% CI 1.77–5.08), followed by severe polyposis (RR 2.60, 95% CI 1.49–4.55), asthma (RR 2.38, 95% CI 1.42–3.99), and previous ESS (RR 1.88, 95% CI 1.07–3.27). All four factors were significantly associated with increased risk. A high Lund-Mackay score was not significantly associated with the outcome (RR 1.63, 95% CI 0.93–2.83) as shown in figure 3 below.

Figure 3: Forest Plot of risk factors associated with the outcome

In this cohort of 116 patients with CRSwNP, 35 (30.17%) developed recurrent nasal polyposis within 24 months after ESS. Recurrence increased progressively from 2.59% at 6 months to 30.17% at 24 months. Asthma, peripheral eosinophilia, previous ESS, and severe polyposis were significantly associated with recurrence, whereas a high Lund-Mackay score showed a non-significant trend. Despite recurrence, SNOT-22 scores improved substantially, from 51.2 at baseline to 21.4 at 6 months and remained lower at 24 months (29.1). The 24-month recurrence rate in our study is comparable with the range reported in previous studies. Vlaminck et al. observed recurrence in 62% of 133 patients during a minimum 10-year follow-up, highlighting the progressive nature of CRSwNP [9]. In contrast, Hoseini et al. reported only 8% recurrence requiring further surgery after 2 years in 100 patients with massive nasal polyposis [10]. DeConde et al. reported endoscopic recurrence rates of 35%, 38%, and 40% at 6, 12, and 18 months, respectively, in a prospective multicenter cohort [11]. Previous ESS was also associated with recurrence in our cohort (RR 1.92, 95% CI 1.10–3.34). DeConde et al. reported a similar association between previous surgery and recurrence, with an odds ratio of 2.6 (95% CI 1.5–4.6) [11]. Similarly, a meta-analysis of 45 studies involving 34,220 patients found higher revision rates among patients with previous polypectomy (26.0%) compared with the overall revision rate of 18.6% [12]. This suggests that previous surgery may identify patients with a more persistent or treatment-resistant disease course. Differences in recurrence definitions, disease severity, postoperative treatment, and follow-up duration may explain the variation between studies. The association with asthma was consistent with previous evidence. Our patients with asthma had more than twice the risk of recurrence (RR 2.43, 95% CI 1.46–4.05). Gill et al., in a cohort of 33,090 patients, reported revision rates of 21.5% in patients with asthma compared with 10.8% in those without asthma [13]. Sella et al. similarly identified asthma as a major predictor of recurrence, reporting a hazard ratio of 3.27 in patients with CRSwNP [14]. These findings support asthma as an important marker of a more persistent disease phenotype. Peripheral eosinophilia showed the strongest association in our study (RR 3.04, 95% CI 1.81–5.09). Wang et al. found that blood eosinophil levels combined with asthma history could predict recurrence, with proposed eosinophil thresholds of 3.7% in patients with asthma and 6.9% in those without asthma [15]. This supports the potential usefulness of peripheral eosinophilia as an accessible marker for postoperative risk assessment. Severe polyposis was associated with increased recurrence in our study (RR 2.63, 95% CI 1.52–4.55). Bai et al. demonstrated that preoperative clinical and inflammatory characteristics could help predict postoperative polyp recurrence, supporting the relevance of baseline disease phenotype in long-term outcomes [16]. A high Lund-Mackay score showed an increased but non-significant risk of recurrence in our cohort (RR 1.67, 95% CI 0.97–2.89; p=0.07). Aguiar et al. found higher Lund-Mackay scores among patients requiring revision surgery, suggesting that radiological disease extent may have prognostic value [17]. The absence of statistical significance in our study may reflect differences in outcome definition, sample size, or patient characteristics. The improvement in SNOT-22 demonstrates substantial symptomatic benefit following ESS. The mean score decreased by 29.8 points from baseline to 6 months and remained 22.1 points below baseline at 24 months. Le et al., in a meta-analysis of 15 studies including 3,048 patients with CRSwNP, reported a pooled improvement in SNOT-22 following surgery, supporting the sustained patient-reported benefit of ESS [18]. The subsequent modest increase in scores in our cohort may reflect the chronic and recurrent nature of CRSwNP rather than complete loss of surgical benefit. Overall, our findings indicate that ESS provides meaningful improvement in quality of life but does not eliminate the risk of recurrent CRSwNP. Asthma, peripheral eosinophilia, previous ESS, and severe polyposis were important recurrence-associated factors, while the role of radiological severity appeared less consistent. These findings support continued postoperative medical treatment and long-term surveillance, particularly in patients with recognized clinical or inflammatory risk factors.

Endoscopic sinus surgery resulted in substantial improvement in sinonasal symptoms and quality of life in patients with chronic rhinosinusitis with nasal polyps. However, 30.17% of patients developed recurrence within 24 months. Asthma, peripheral eosinophilia, previous ESS, and severe polyposis were significantly associated with recurrence, with peripheral eosinophilia showing the strongest association. Although SNOT-22 scores increased slightly after the initial postoperative improvement, they remained considerably lower than baseline at 24 months. These findings highlight the importance of identifying high-risk patients and ensuring appropriate postoperative treatment and long-term follow-up to maintain disease control and reduce the impact of recurrence.