Long Term Sinusitis Outcomes of Endoscopic Skull Base Surgery: Comparison of Minimally Invasive Pituitary Surgery versus Expanded Endoscopic Surgery for Malignancy

Objectives: Our purpose was to investigate prevalence of chronic rhinosinusitis in patients after endoscopic skull base surgery and compare outcomes in patients after minimally invasive pituitary surgery (MIPS) versus resection for malignant tumors.

Study Design: A retrospective cohort study of 111 patients after endoscopic skull base surgery.

Methods: Radiographic imaging obtained at least 3 months after surgery, symptoms, and endoscopic findings were used to determine the presence of chronic rhinosinusitis. Time to presentation, location of sinusitis, impact of radiation therapy, and disease management were evaluated.

Results: One hundred eleven patients underwent endoscopic skull base surgical resection at our institution from 8/2008 – 9/2012. 46 patients had this for treatment of skull base malignancy and 65 patients for treatment of benign pituitary pathology. 85 patients (55 MIPS, 30 malignancy) met our inclusion criteria with late (>3 months) post-operative imaging as part of their clinical care. The malignancy cohort had significantly greater prevalence of sinusitis on repeat imaging with 26 patients vs 12 in MIPS cohort (60% vs 21.8%, one tailed t-test p < 0.005). While average Lund-Mackay score did not differ between both groups (avg 6.3, range 2–12), MIPS patients more commonly demonstrated sinusitis in the ethmoid sinuses and ostiomeatal complex, while frontal and maxillary sinuses were more often involved in patients with malignancy. Clinical sinusitis manifested earlier in the MIPS cohort as compared with malignancy cohort (average 15.8 months. vs 23.3 months). Six MIPS patients (9.2%) reported recurrent symptoms of sinusitis with one pursuing endoscopic sinus surgery for treatment; while 8 patients (17.4%) were symptomatic in malignancy group and 3 had endoscopic sinus surgery.

Conclusions: This study demonstrates that endoscopic skull base surgery for presents a risk factor for chronic rhinosinusitis, the risk is significantly greater for patients undergoing expanded skull base surgery as compared with MIPS. Development of signs and symptoms occur over a large time frame and present earlier after MIPS than after a large resection. Despite increased prevalence in both populations as compared with general population, most patients were managed with medical therapy and irritations.