Ball Valve Effect

The free flow of a gas or fluid in one direction coupled with the partial or complete obstruction to flow in the opposite direction, which is classically seen where a mass is tethered to a wall or lumen by a stalk
Cardiology The intermittent flow of blood in one direction which is blocked in the opposite, a finding classically associated with atrial myxoma
Respiratory medicine A partial endobronchial obstruction which allows facile entry but not egress of air, resulting in a build-up of pressure in the terminal airways and potential rupture of alveoli; air percolates into soft tissues, causing interstitial emphysema
Complications Extreme BVE leaks may cause tension pneumothorax with increased positive pressure in the hemithorax, shifted mediastinum and compromised circulation
Urology The partial obstruction of urinary output when a mass—e.g., a leimyoma—is present at the trigone and blocks outflow at the internal urethral orifice