Rare and rarer: percutaneous transcatheter mitral commissurotomy using over-the-wire technique in a patient with mucopolysaccharidosis-a case report.

Background: Percutaneous transcatheter mitral commissurotomy (PTMC) by the Inoue technique is the traditional technique to relieve rheumatic mitral stenosis. Mucopolysaccharidoses, a group of rare lysosomal storage disorders, result in skeletal and vertebral anomalies and cardiac valvular abnormalities. The coexistence of both pathologies is rare, and mitral stenosis in such a scenario may pose significant technical challenges. Case summary: We present the case of a short statured 15-year-old girl with mucopolysaccharidosis Type VI with severe mitral stenosis and moderate aortic stenosis. Echocardiography revealed features suggestive of rheumatic involvement rather than due to the syndrome. Due to high surgical risk and unique anatomical characteristics, percutaneous approach was more amenable than surgery. The patient underwent successful PTMC using an unconventional over-the-wire technique instead of the traditional Inoue technique. Discussion: This case highlights the importance of a case-based approach in unique anatomic and high-risk situations for better outcomes, which may need out-of-the-box thinking.