Hematoma in the Retzius space: A life-threatening complication after laparoscopic rectal cancer surgery

• This case represents the first documented instance of Retzius hiatus hemorrhage directly attributed to pelvic peritoneal suspension using a purse-string needle during laparoscopic rectal cancer surgery. • The case underscores how the Retzius space's large volume and loose connective tissue allow significant, clinically occult hemorrhage, delaying recognition until life-threatening hemorrhagic shock develops. • Successful management hinges on meticulous perioperative technique (precise puncture, vertical needle passage) and immediate surgical re-exploration upon detecting a Retzius space hematoma to prevent catastrophic outcomes.