Which procedure involves removal of a clot from the pericardial space?

The correct choice is based on the specific procedure being described, which focuses on the removal of a clot from the pericardial space. A pericardiotomy is a surgical approach to the pericardium, the fibrous sac surrounding the heart, and is typically done to gain access to remove fluid, including clots that may have accumulated in the pericardial space. This procedure allows for the evacuation of materials that could be causing cardiac complications, such as constrictive pericarditis or cardiac tamponade, where pressure from fluid buildup affects heart function.

In contrast, pericardiectomy involves the surgical removal of the pericardium itself rather than merely accessing it to remove clots. Cardiomyoplasty refers to the surgical technique that involves using muscle tissue to support heart function, which is unrelated to clots in the pericardial space. Atrioseptoplasty involves creating or repairing an atrial septal defect, which has no connection to the pericardium or clot removal.

Thus, pericardiotomy is the most appropriate choice, aligning with the described scenario of accessing the pericardial space to remove a clot.