Medialization after combined anterior and posterior component separation in giant incisional hernia surgery, an anatomical study

Background: To obtain tension-free closure for giant incisional hernia repair, anterior or posterior component separation is often performed. In patients with an extreme diameter hernia, anterior component separation and posterior component separation may be combined. The aim of this study was to assess the additional medialization after simultaneous anterior component separation and posterior component separation. Methods: Fresh-frozen post mortem human specimens were used. Both sides of the abdominal wall were subjected to retro-rectus dissection (Rives-Stoppa), anterior component separation and posterior component separation, the order in which the component separation techniques were performed was reversed for the contralateral side. Medialization was measured at 3 reference points. Results: Anterior component separation provided most medialization for the anterior rectus sheath, posterior component separation provided most medialization for the posterior rectus sheath. After combined component separation techniques total median medialization ranged between 5.8 and 9.2 cm for the anterior rectus sheath, and between 10.1 and 14.2 cm for the posterior rectus sheath (depending on the level on the abdomen). For the anterior rectus sheath, additional posterior component separation after anterior component separation provided 15% to 16%, and additional anterior component separation after posterior component separation provided 32% to 38% of the total medialization after combined component separation techniques. For the posterior rectus sheath, additional posterior component separation after anterior component separation provided 50% to 59%, and additional anterior component separation after posterior component separation provided 11% to 17% of the total medialization after combined component separation techniques. Retro-rectus dissection alone contributed up to 41% of maximum obtainable medialization. Conclusion: Anterior component separation provided most medialization of the anterior rectus sheath and posterior component separation provided most medialization of the posterior rectus sheath. Combined component separation techniques provide marginal additional medialization, clinical use of this technique should be carefully balanced against additional risks.