A 9-year-old boy has been suffering from multiple bronchiectasis since he was 3 years old. Exacerbations occur frequently (34 times a year), after conservative therapy there are short remission periods. The disease progresses, the child is physically underdeveloped, presents with pale skin, acrocyanosis, deformed nail plates in the shape of "clock-face" Bronchography reveals saccular bronchiectases in the lower lobe of the right lung. What further treatment tactics should be chosen?