Abdominal wall dimensions and umbilical position vary widely with BMI and should be taken into account when choosing port locations

Many surgeons rely on the umbilicus when determining the location of ports for laparoscopic procedures and falsely assume that it is located in the vertical midline. The purpose of this study was to assess the degree of variation in umbilical position and abdominal dimensions in the general population. Torso length, abdominal girth, weight, and height were recorded for 259 patients over a 9-month period. Body mass index (BMI) was calculated and used to classify patients into four groups: underweight, normal, overweight, and obese. Average umbilical position for all BMI groups was below the true vertical midpoint and dropped further caudally as BMI increased. In addition, average abdominal dimensions increased with increasing BMI. There was no statistical difference between males and females in each BMI group regarding umbilical position or abdominal dimensions. There is a clear relationship between increasing BMI and a drop in umbilical position as well as an increase in abdominal dimensions. We recommend determining umbilical position and abdominal dimensions prior to placing ports and shifting port positions toward target quadrants.