Ligamentum paracolicum dextrum--a new ligament?

During routine laparoscopy, the authors identified an unknown ligament that stretched between the middle segment of the ascending colon and the adjacent lateral abdominal wall. This report discusses the incidence and histology and suggested name for this ligament.

Over a 5-year period, 362 hernias were repaired laparoscopically in children aged from 4 days to 14 years (median 1.7 years; 87 girls and 242 boys). None of the children had undergone previous surgery nor had had concomitant diseases or associated malformations. The ligament was searched for in every child. In addition, 22 adult cadavers were dissected searching for the ligament. Biopsies were taken from the ligament and from adjacent abdominal wall in other cadavers as controls.

During laparoscopy, a ligament of variable size was identified in 152 of the children (43%). This ligament arose at the lateral aspect of the middle ascending colon, occupied half of the circumference, and inserted at the lateral abdominal wall; there was no recognizable relation to any defined structure at the abdominal wall itself. Similar ligaments were also identified during the cadaveric dissections in 14 (64%) of 22 adult cadavers, in which the variable thickness and broadness were also noted. Histological examination of samples taken from the cadavers showed a loosely structured subepithelial layer of connective tissue of variable width, which transitioned gradually into the subperitoneal fat tissue.

This ligament easily evades the attention of surgeons in open surgery, yet becomes evident during laparoscopy. In the semilateral or lateral position, most frequently chosen for transabdominal laparoscopic access to the kidney, the ligament stretches and keeps the colon on top of the kidney. The ligament's clinical and anatomic significance is unknown. Its existence has become more evident with recent use of laparoscopy.