THE ABDOMINAL LINEA ALBA - AN ANATOMO-RADIOLOGIC AND BIOMECHANICAL STUDY

Traditionally, the Linea alba represents the principal route of approa ch in abdominal surgery and in consequence it is the commonest site of incisional hernia The aim of this study was to review its morphology and to study its mechanical parameters of resistance, deformation and elasticity in order to compare these with the prosthetic materials mos t often used in the treatment of incisional hernia. Forty fresh cadave rs were dissected and tests with a dynamometer and ''bursting strength tester'' were performed on samples taken from the linea alba at three leveels: supra-umbilical, subumbilical and umbilical. Forty abdomino- pelvic scans were analysed. The morphologic results allowed definition of diastasis of the rectus mm. in terms of subject age: below 45 year s of age diastasis was considered as a separation of the two rectus mm , exceeding 10 mm above the umbilicus, 27 mm at the umbilical ring and 9 mm below the umbilicus; above 45 years of age the corresponding val ues were 15 mm, 27 mm and 14 mm respectively. In the biomechanical stu dy the subumbilical region exhibited a coefficient of elasticity great er than that of the supra-umbilical portion, but no significant differ ence in resistance was found between the different parts studied. The biomechanical results are compared with the corresponding data for pro sthetic materials.