A window is also called a transthoracic pericardiostomy, a surgical procedure done for large and/or recurrent pericardial effusion in which a 4-cm flap of pericardium is removed from the heart so that pericardial fluid can drain into the chest cavity. The pericardial flap can be used for biopsy (if there is concern for infectious or malignant pericardial effusion). When a pericardial window is performed, there may initially be a large-bore drain as well. However, the point of the window is to allow fluid to continuously drain into the chest cavity until the tissue fibroses and scars and the window “closes.” Only 5-10% of patients who get a window will have reaccumulation of the effusion, as demonstrated in this study.
The least invasive technique for relieving pericardial effusion is pericardiocentesis; the most invasive is pericardiectomy. A pericardial window is somewhere in-between. (There is also something called balloon pericardiotomy which is analogous to balloon valvuloplasty.) Risks include arrhythmia, infection, clot, and very rarely, cardiac perforation.
When pericardiocentesis is performed, there may be a decision to place a pericardial drain (a small-bore catheter) to allow extra fluid to be removed. The drain is usually removed when output decreases to 25-50 cc over 24 hours. Unfortunately, up to 60% of patients who receive pericardiocentesis may have reaccumulation of the effusion.