Left-sided maxillary sinusitis (absence of the air transparency of left maxillar sinus). Image source: Wikipedia, public domain.
Does sinus surgery help asthma symptoms in patients with chronic sinusitis and asthma?
Yes, according to most studies.
The long-term impact of functional endoscopic sinus surgery on asthma was positive: 90% of patients reported feeling better in a small study http://bit.ly/C9xSq
Endoscopic sinus surgery (ESS) had a favorable effect on asthma in patients with symptomatic chronic sinusitis http://bit.ly/bNlEB
Functional endoscopic sinus surgery improved nasal and asthma symptoms in patients with nasal polyposis http://bit.ly/3OXkHV
However, chronic rhinosinusitis in asthmatics showed worse postoperative outcomes than in nonasthmatics http://bit.ly/4s1Xfl
Related:
Sinusitis: A Short Review
Multi-symptom Asthma is Closely Related to Nasal Blockage, Rhinorrhea and Symptoms of Chronic Rhinosinusitis http://goo.gl/sU4AU