Some risk factors for refractory chronic sinusitis: an immunohistochemical and electron microscopic study.

The goal of the present work was to investigate possible risk factors for the poor response of some cases of chronic sinusitis to endoscopic sinus surgery in spite of the precision of the surgical technique. Eleven adult patients who were scheduled for revision endoscopic sinus surgery underwent a complete allergy workup. At the time of surgery, a tiny biopsy was taken from the maxillary sinus mucosa close to the middle turbinate.