Morphometric evaluation of the linea alba in fresh corpses

Purpose

Diastasis recti abdominis is an increase in the distance between the medial borders of the two rectus muscles. It is most often triggered after intra-abdominal pressure increases, such as postpartum or in obesity. Most publications are based on radiological studies or are done in certain subgroups, without unanimous reference values of the distance between the rectus abdominis or standardization.

Methods

Forty-one cadavers were studied. Exclusion criteria: signs of abdominal trauma, major burns, presence of scar from previous abdominal surgery, clinical signs of abdominal hernia, and identification of hernia during cadaver dissection. Linea alba (LA) length, width, and thickness were measured with a flexible tape measure and digital caliper. Anatomical landmarks were established, and subdivisions were described based on them to compare the cadavers.

Results

Sex and age had little effect on LA width, thickness, or length. Obesity (compared to normal weight) was the only variable that promoted an increase in the LA width (p < 0.01). The supraumbilical length varied with the total height of the evaluated cadavers (p < 0.01), but the infraumbilical length did not (p = 0.11).

Conclusion

The general statistical results of this study, regarding the evaluation of LA measurements in cadavers, showed that ethnicity, sex, and age have little effect on the width, thickness, or length of the LA. LA width differed significantly with abdominal circumference.

Prevalence and risk factors for diastasis recti abdominis: a review and proposal of a new anatomical variation

PURPOSE

Diastasis recti abdominis (DRA) or rectus diastasis is an acquired condition in which the rectus muscles are separated by an abnormal distance along their length, but with no fascia defect. To data there is no consensus about risk factors for DRA. The aim of this article is to critically review the literature about prevalence and risk factor of DRA.

METHOD

A total of 13 papers were identified.

RESULTS

The real prevalence of DRA is unknown because the prevalence rate varies with measurement method, measurement site and judgment criteria, but it is certainly an extremely frequent condition. Numbers of parity, BMI, diabetes are the most plausible risk factors. We identified a new anatomical variation in cadaveric dissection and in abdominal CT image evaluation: along the semilunar line the internal oblique aponeurosis could join the rectus sheath with only a posterior layer, so without a double layer (anterior and posterior) as usually described. We conducted a retrospective review of abdominal CT images and the presence of the posterior insertion only could be considered as a risk factor for DRA.

CONCLUSION

Further studies with large sample size, including nulliparous, primiparous, pluriparous and men too, are necessary for identify the real prevalence.