Inflammation of the nasal and bronchial mucosa characterizing rhinitis and asthma are probably manifestations of the same disease. Multiple functional observations, pathogenic and clinical support that assertion. It is noteworthy that most asthma patients, who underwent a nasal endoscopic polypectomy, improve your asthma after surgery. This improvement would be related to the administration of oral steroids that these patients usually receive after surgery, or the disappearance of nasal discomfort caused by nasal polyps to improve ventilation. But this does not explain why this improvement, in some cases lasting for months after the operation, and without receiving oral steroids. It is speculated that severe nasal inflammation due to nasal polyps stimulate the bone marrow to produce more eosinophils, an increased supply of blood eosinophils, and consequently, a major bronchial eosinophilic inflammation, aggravating asthma. However, it is noteworthy that studies have evaluated the clinical impact in asthma after endoscopic nasal polypectomy, are scarce or performed on a small number of cases, the results are inconsistent and do not allow categorically whether or not such positive association. And more importantly, none of them included measurements of airway inflammation and hypothesized relationship between bronchial eosinophilic inflammation and nasal polyposis, aclarar.La remains finding that provides nasal endoscopic polypectomy objective improvement of severe asthma it could be a future therapeutic option to consider in patients with asthma and rhinosinusal polyposis.

Sinonasal polyposis (SP) is a chronic inflammatory disease of the lining of the nasal passages and sinuses, with a prevalence of approximately 2-3% of the general population. The prevalence of asthma in patients diagnosed with SP is much greater than that of the general population and can reach half of the cases and indicate a more severe phenotype and worse control in asthmatic patients without SP. It is possible that the pathophysiologic mechanisms underlying the development of SP and concomitant asthma are the same and both processes can be considered the same disease.

Recommendations of major clinical practice guidelines for the treatment of SP include administration of intranasal topical steroids at high doses, and in subjects who do not respond to this treatment or are more severe, administering a course of systemic steroids orally for 10-14 days or surgical intervention including polypectomy and removal of the diseased mucosa endoscopically, known as functional endoscopic sinus surgery (FESS).

In this context, it is noteworthy that most asthma patients, who underwent functional endoscopic sinus surgery for bilateral polyposis (FESS-BP) stated it dramatically improved their asthma after surgery. This improvement could be related to the effect of oral steroids these patients often receive after surgery, or the disappearance of nasal discomfort caused by nasal polyps as ventilation improves after the intervention. However, these reasons do not sufficiently explain the fact that this improvement, in some cases extends for months after surgery, when patients are no longer receiving oral steroids.

It has been speculated that severe nasal inflammation which involves the presence of nasal polyps would constantly stimulate the bone marrow, causing on the one hand increased production of eosinophils and the other an increase in adhesiveness, and thus, an important eosinophilic bronchial inflammation. This is in line with a usual clinical observation according to which patients with asthma and sinonasal polyposis, often suffer more severe asthma; and severe sinus inflammation is one of the aggravating factors recognized in severe uncontrolled asthma.

However, studies that have assessed the clinical impact in asthma after FESS-BP, are only a few or have been performed on a small number of cases. Consequently, the results are inconsistent and do not allow to categorically establish whether this positive association exists or not. Most importantly, however, none of them included measurements of bronchial inflammation in the study variables, so that the hypothesis of the possible relationship between eosinophilic bronchial inflammation and nasal polyposis remains without having been tested.

Moreover, the finding that the FESS-BP provides an objective improvement of asthma, could be a future therapeutic option to consider in patients with severe asthma and sinonasal polyposis.

Inclusion Criteria:

• Patients of both sexes aged ≥ 18 and younger than 70 years diagnosed with persistent asthma (according to GEMA4.0 criteria) (18) and grade II and III bilateral sinonasal polyposis of Lildholdlt (9,19), which, as indicated in routine clinical practice established by an otolaryngologist, will undergo FESS.

Exclusion Criteria:

• Intermittent asthma;
• exacerbation of asthma that required treatment with parenteral steroids one month prior to visit 1;
• concomitance of other chronic respiratory diseases (bronchiectasis, fibrosis, etc.);
• other disabling severe comorbidities in the opinion of the investigators;
• previous noninflammatory sinonasal pathology;
• corticosteroid-dependent patients or managed with other immunomodulatory treatments.
• Patients with a history of previous nasal surgery.

Patients with persistent asthma and grade II and III bilateral sinonasal polyposisand, by voluntary decision of the otolaryngologist and the patient, who will offer alternatives treatment to the candidate patient, following the recommendations of clinical practice guidelines.

If the patient is indicated in routine clinical practice FESS-BP, will be offer to enter to the study.

If the patient is NOT indicated in routine clinical practice FESS-BP or reject intervention, will be also offer to enter to the study.