During a Nissen fundoplication, after establishing pneumoperitoneum, what is the next step?

In a Nissen fundoplication, once pneumoperitoneum is established, the next critical step involves mobilizing and dividing the stomach from the omentum. This step is vital because it allows for better access to the esophagus and the structures surrounding the stomach, which is essential for properly performing the fundoplication procedure. Mobilization of the stomach facilitates the necessary manipulation and positioning required to wrap the upper part of the fundus around the esophagus effectively.

The other options represent steps that occur later in the surgical process or are specific techniques that may not follow immediately after establishing pneumoperitoneum. The dissection of the phrenoesophageal membrane is an important step but follows after the stomach has been mobilized. Wrapping the fundus around the esophagus is the primary outcome of the procedure and occurs after confirmation of adequate mobilization and preparation of the surrounding structures. Additionally, the saline drop test is typically performed to assess the integrity of the closure rather than being a step immediately following pneumoperitoneum.