Evaluating the Role of Sinus Surgery on the Non-diseased Contralateral Side in Patients With Unilateral Sinus Disease: A Systematic Review.

Functional endoscopy sinus surgery (FESS) is a frequently employed surgical technique to treat patients with sinus diseases. However, limited studies are available that discuss the impact of sinus surgery on the non-diseased contralateral side. The present review was conducted to examine existing literature regarding the role of sinus surgery on the non-diseased contralateral side in patients with unilateral sinus disease (USD). We conducted a comprehensive systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Relevant literature was searched from different electronic databases, including PubMed, Scopus, Cochrane Library, ScienceDirect, and Google Scholar, until February 2025. Studies' screening, selection, quality assessment, grading for certainty of evidence, and data extraction were done by two independent reviewers, and any disagreement was resolved by discussion. Results were integrated into tables and synthesized through a narrative summary. A total of 10 studies (N = 1,233 patients), aged 27.5-64.4 years, with a higher ratio of female participants, were included in the present review. Different pathological conditions were reported in selected studies, including chronic rhinosinusitis (CRS) alone, CRS with nasal polyposis (NP), antrochoanal polyp (ACP), fungus ball, benign tumor, malignant neoplasia, NP alone, acute or chronic unilateral sinusitis, and unilateral allergic fungal rhinosinusitis (AFRS). Most studies observed significant patient improvement, with a high success rate in improving symptoms such as nasal obstruction and postnasal drainage. However, studies also reported disease recurrence on the non-diseased contralateral side. Multiple medical interventions typically involve β-lactam antibiotics, decongestants, mucolytics, and nasal steroids to reduce inflammation and control the recurrence of diseases. Most studies showed a low risk of bias. In addition, no publication bias was observed. No serious concern was found in the reporting of these observational studies and found low risk of bias among the studies. A high level of certainty of evidence was observed. The present findings highlight that unilateral FESS improves one side of sinusitis; however, it gradually affects the non-diseased contralateral side, suggesting the importance of patient counseling and resulting in disease events on the contralateral side. Further, multicentre studies with large sample sizes are needed to validate these findings. Our study explores the potential benefits of operating on the contralateral side in cases of USD to prevent future recurrence on the previously uninvolved side.