Endoscopic Monitoring of Postoperative Sinonasal Mucosa Wounds Healing

Nasal epithelium lies on the basement membrane, situated on the lamina propria. Pseudostratified columnar (respiratory) epithelium is composed of four major types of cells: ciliated cells, nonciliate cells, goblet cells and basal cells, ensuring mucus production and transport, resorption of surface materials, and formation of new epithelial cells. Lamina propria consists of two layers of seromucous glands, i.e. superficial and deep layers. Just beneath the basement membrane, lymphocytes and plasma cells form a lymphoid layer. Maintenance of normal ventilation/aeration of sinus spaces is necessary for normal functioning of paranasal sinuses. The sinus labyrinth spaces and ostia of various sinus areas can be visualized by use of endoscopic techniques, e.g., in functional endoscopic sinus surgery (FESS). Ventilation and normal sinus function can be maintained by this minimally invasive method. Endoscopic sinus surgery (ESS) is the superior surgical method of treatment for recurrent acute sinusitis, chronic sinusitis, obstructive nasal polyposis, extramucous fungal sinusitis, periorbital abscess, rhinoliquorrhea, antrochoanal polyp, foreign body extraction, mucocele, dacryocystorhinostomy, excision of various tumors of the sinuses, nose, anterior, middle and posterior cranial fossa, epistaxis control, optic nerve decompression, choanal atresia, and orbit decompression. . Functional endoscopic sinus surgery (FESS), a minimally invasive technique, remains the most widely accepted therapy for chronic rhinosinusitis (CRS) and nasal polyposis (NP) after failure of medical treatment. FESS aims to remove inflammatory mucosa and to restore both ventilation and drainage of the sinus cavities. However, healing quality significantly influences the functional outcome. The exact mechanism of mucosal healing after sinus operation remains unclear. Postoperative wound healing is a highly coordinated process that includes coagulation, i.e. clot formation, inflammatory stage, and tissue formation and remodeling. During the process of healing, the extracellular matrix of nasal mucosa may be directly influenced by the growth factor (GF), while the expression of GF receptors may influence the cell phenotype and its adhesion. Endoscopic observation of the nasal and sinus mucosa healing after FESS revealed four clinical stages: stage 1 characterized by the formation of abundant crusts, lasting for 1-10 days; stage 2 characterized by obstructive lymphedema, with pronounced swelling of residual mucosa, lasting for up to 30 days; stage 3 characterized by mesenchymal growth, when pale, edematous mucosa is transformed to red mucosa, lasting for up to 3 months; and stage 4 characterized by cicatrix formation, lasting for 3-6 months.