Original sentence: Only the first 2 cm of the superior part is mobile (not covered by peritoneum) the distal 3cm of the first part along with the rest of the duodenum is retroperitoneal (immobile)
Edited sentence: Only the first 2 cm of the superior part is mobile (not covered by peritoneum) - the distal 3cm of the first part along with the rest of the duodenum is retroperitoneal (immobile)