Supraumbilical primary trocar insertion for laparoscopic access: the relationship between points of entry and retroperitoneal vital vasculature by imaging.

Objectives: Advances in laparoscopy have demonstrated that supraumbilical primary ports can be desirable in complex cases with large masses. This study evaluated distances to vital retroperitoneal vasculature that were encountered with 45- and 90-degree angle entry from the umbilicus and 2 commonly described supraumbilical entry points at 3 and 5 cm cephalad from the umbilicus.

Study Design: Retrospective analysis of computed tomography scans of the abdomen and pelvis from 100 randomly selected women who were 18-50 years old with normal anatomy was performed. Three-dimensional models of sagittal sections were generated using IMPAX software. Measurements from the abdominal wall at the umbilicus and 3 and 5 cm cephalad with 45- and 90-degree angles to retroperitoneal structures were performed.

Results: With 90-degree angle entry, the abdominal wall thickness (AWT) was thinnest at the umbilicus; however, the thickness at 3 and 5 cm was similar. AWT increased at all sites with 45-degree angle entry, and the same pattern was observed. AWT and intraperitoneal distance positively correlated with body mass index and supraumbilical entry points. With 90-degree angle entry, the aorta was 1.9 cm (95% confidence interval [CI], 1.4-2.4) and 2.5 cm (95% CI, 2.0-2.9) farther away at 3 and 5 cm cephalad compared with umbilical entry. In one-third of the cases, regardless of port placement, a vascular structure other than the aorta was the most anterior vessel. With 45-degree angle entry at the umbilicus, no vessels were encountered. With 45-degree angle entry at 3 and 5 cm cephalad, the aorta was the most anterior vessel in 1% and 2% of cases, respectively, and was noted to be 1.0 cm (95% CI, 1.0-1.0) and 2.3 cm (95% CI, 1.2-3.3) farther away than with 90-degree angle entry. A vessel other than the aorta was encountered in 4% and 7% of cases at 3 and 5 cm, respectively.

Conclusion: According to theoretic modeling, supraumbilical primary port placement can be implemented safely in laparoscopy. With supraumbilical entry, the distance to retroperitoneal vessels was greater than at the umbilicus. Compared with a 90-degree angle, with a 45-degree angle entry, it was uncommon to encounter vasculature, and all measured distances were greater.