ABSTRACT
Linea Alba Closure Anatomy The linea alba is formed by blending of the fascia of the internal and external sheaths on the ventral midline of the abdomen (Figure 31-1). The linea alba is thicker and has greater breaking strength near the umbilicus than in the more cranial parts of the abdomen.15.17 Fibers of the linea alba run perpendicular to the direction of suture tension and this feature appears to provide for strong closure of the ventral midline incision.14,15 With a paramedian approach, only the external fascia of the rectus sheath is closed (Figure 31-1). This fascia composes the abdominal tunic and the aponeurosis of the external abdominal oblique, which has fibers interwoven with those of the aponeurosis of the internal abdominal oblique (Figure 31-1). There is no advantage to including the internal sheath (aponeurosis of the transverse abdominal muscle) because its fibers run along the line of suture tension and, therefore, are easily torn. Also, in the dog, inclusion of this layer in closure of paramedian incisions did not provide greater strength of closure than suturing only the external sheath.18
