Methods and devices described herein facilitate improved treatment of body organs. More specifically, devices and methods described herein are for minimally invasive surgery permit improved diaphragmatic access to a body cavity to perform a surgical procedure, for example ablation and/or coagulation of cardiac tissue during minimally invasive surgical access to the heart. The diaphragmatic access described provides direct visualization of anatomic structures within the thoracic cavity such as the posterior left atrium, the posterior side of pulmonary veins, or any other such anatomic structure.