Physiologic tension of the abdominal wall.

Background: Tension-free abdominal closure is a primary tenet of laparotomy. But this concept neglects the baseline tension of the abdominal wall. Ideally, abdominal closure should be tailored to restore native physiologic tension. We sought to quantify the tension needed to re-establish the linea alba in patients undergoing exploratory laparotomy.

Methods: Patients without ventral hernias undergoing laparotomy at a single institution were enrolled from December 2021 to September 2022. Patients who had undergone prior laparotomy were included. Exclusion criteria included prior incisional hernia repair, presence of an ostomy, large-volume ascites, and large intra-abdominal tumors. After laparotomy, a sterilizable tensiometer measured the quantitative tension needed to bring the fascial edge to the midline. Outcomes included the force needed to bring the fascial edge to the midline and the association of BMI, incision length, and prior lateral incisions on abdominal wall tension.

Results: This study included 86 patients, for a total of 172 measurements (right and left for each patient). Median patient BMI was 26.4 kg/m (IQR 22.9;31.5), and median incision length was 17.0 cm (IQR 14;20). Mean tension needed to bring the myofascial edge to the midline was 0.97 lbs. (SD 1.03). Mixed-effect multivariable regression modeling found that increasing BMI and greater incision length were associated with higher abdominal wall tension (coefficient 0.04, 95% CI [0.01,0.07]; p = 0.004, coefficient 0.04, 95% CI [0.01,0.07]; p = 0.006, respectively).

Conclusion: In patients undergoing laparotomy, the tension needed to re-establish the linea alba is approximately 1.94 lbs. A quantitative understanding of baseline abdominal wall tension may help surgeons tailor abdominal closure in complex scenarios, including ventral hernia repairs and open or burst abdomens.