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/m2 (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.

An Evaluation of Tension Measurements During Myofascial Release for Hernia Repair

Tension-free repairs have revolutionized the way we repair hernias. To help reduce undue tension when performing ventral hernia repair, multiple different techniques of myofascial releases have been described. The purpose of this project is to evaluate tension measurements for commonly performed myofascial releases in abdominal wall hernia repair. Patients undergoing myofascial release techniques for their ventral hernias were enrolled in a prospective Institutional Review Board-approved protocol to measure abdominal wall tension from June 1, 2011 to August 1, 2019. Abdominal wall tensions were measured using tensiometers before and after myofascial release techniques. Descriptive statistics were performed and data were analyzed. Thirty patients had tension measurements (5 anterior myofascial separation, 25 posterior myofascial separation with transversus abdominis release [TAR]). Average age was 60.1 years (range 29-81), 83% Caucasian, 53% female, and 42% recurrent hernias. The average hernia defect in patients undergoing anterior myofascial release was 117.3 cm2, and the average mesh size was 650 cm2. The reduction in tension after anterior release was 4.7 lbs (2.7 lbs vs 7.4 lbs). The average hernia defect in patients undergoing posterior myofascial release (TAR) was 183 cm2, and the average mesh size was 761.36 cm2. The reduction in tension after bilateral posterior rectus sheath incision was 2.55 lbs (5.01 lbs vs 7.56 lbs) with 0.66 lbs further reduction in tension after TAR (4.35 lbs vs 5.01). In this evaluation, abdominal wall tension measurements are shown to be a feasible adjunct during open hernia repair. Preliminary data show tension reductions associated with the different myofascial release techniques and, with further study, may be a useful intraoperative adjunct for decision making in hernia repair.