The median umbilical ligament is the fibrous remnant of the urachus, the embryonic canal connecting the fetal bladder to the allantois. In adults it runs from the apex of the bladder to the umbilicus in the midline, covered by the median umbilical fold of the peritoneum. It is distinct from the paired medial umbilical ligaments (umbilical artery remnants) which lie on either side.
A vestigial structure with no function in adults; serves as the midline landmark between the two medial umbilical ligaments on the anterior abdominal wall peritoneum in laparoscopy.
The median umbilical fold and its ligament are the central landmark for orientation in laparoscopy, flanked by the medial umbilical folds. Urachal remnants from incomplete obliteration of the urachus produce urachal cysts, sinuses, diverticula, or patent urachus depending on the location and extent of persistence. Urachal carcinoma arises from urachal remnant epithelium, presenting as a midline infra-umbilical abdominal mass with haematuria. Laparoscopic excision of the urachal remnant with a bladder cuff is standard treatment.
An incompletely obliterated segment of the urachus forms a midline cystic mass between the umbilicus and the bladder dome that may become infected, producing suprapubic pain and a palpable midline mass visible on CT, requiring complete excision of the cyst and associated urachal remnant.
A rare adenocarcinoma arising from urachal remnant epithelium presents as a midline anterior abdominal wall mass with mucus in the urine, treated by en bloc excision of the mass with bladder partial cystectomy and umbilical resection given its predilection for contiguous spread.
