Outcomes after endoscopic sinus surgery for unilateral versus bilateral chronic rhinosinusitis with nasal polyposis

Background: Endoscopic sinus surgery (ESS) is a safe and reliable procedure for the treatment of chronic rhinosinusitis (CRS) and nasal polyposis (NP). Although most cases of CRS with NP occur bilaterally, we occasionally encounter patients with unilateral sinus disease with NP. Because no study has been conducted on the surgical outcomes between unilateral and bilateral CRS with NP after ESS, we evaluated subjective and objective outcomes between patients with unilateral and bilateral CRS with NP. Methods: A total of 181 patients diagnosed with CRS with NP were enrolled. Twenty-three patients had unilateral CRS with NP and 158 patients had bilateral disease. The extent of NP, Lund-Mackay score, and involved sinuses were evaluated with nasal endoscopy and preoperative computed tomography (CT). Objective and subjective surgical outcomes were assessed 6 months after ESS, using endoscopic findings, the Sino-Nasal Outcome Test 20 (SNOT-20), and visual analog scales. Results: The extent of NP and Lund-Mackay score did not differ significantly between the two groups. The SNOT-20 and six main symptom scores included in the questionnaire were significantly improved 6 months postoperatively in both groups, with no significant difference between the groups. However, the unilateral group showed significantly better objective outcomes than the bilateral group. Conclusion: Unilateral CRS with NP showed more favorable objective surgical outcomes than bilateral disease. We suggest that the developmental mechanisms of the two disease entities may be different and that bilateral CRS with NP may be more intimately associated with a patient's innate tendency to develop NP.