And Montgomery does not dispute that ramipril is in fact effective at preventing or treating stroke, which is the entire premise of his patent. The treatment of complete subglottic stenosis (SGS) remains a challenge due to anatomic and technological limitations.A closeup view of the stenosis in a 9yearold boy with spiraling subglottic stenosis. A closeup view of the stenosis in a 9yearold boy with spiraling subglottic stenosis. This spiraling subglottic stenosis is not complete circumferentially. The HLA mismatch was 2A, 2B, and 2DR (i.e. , a complete mismatch). Pulmonary artery anomaly Abnormality in the formation of the pulmonary artery such as stenosis or atresia.