Purpose Data on primary (PH) and incisional hernias (IH) are often pooled, even though several studies have illustrated that these are different entities with worse outcomes for IHs. The aim of this study is to validate previous research comparing PHs and IHs and to examine whether hernia width is an important contributor to the differences between these hernia types. Methods A registry-based, prospective cohort study was performed, utilizing the French Hernia Club database. All patients undergoing PH or IH repair between September 8th 2011 and May 22nd 2019 were included. Baseline, hernia and surgical characteristics, and postoperative outcomes were collected. Outcomes were analyzed per width category (≤ 2 cm, 3–4 cm, 5–10 cm and > 10 cm). Results A total of 9159 patients were included, of whom 4965 (54%) had PH and 4194 (46%) had IH. PHs and IHs differed significantly in 12/15 baseline characteristics, 9/10 hernia and surgical characteristics, and all outcomes. Overall, complications and re-interventions were more common in patients with IH. After correcting for width, the differences between PH and IH were no longer significant, except for medical complications, which were more common after IH repair compared to PH. Conclusion After correcting for hernia width, most outcomes do not significantly differ between PH and IH, indicating that not hernia type, but hernia width is an important factor contributing to the differences between PH and IH.

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.

Aim To obtain tension-free closure for giant incisional hernia repair, anterior or posterior component separation (ACS, PCS) is often performed. In extreme patients, ACS and PCS may be combined. The aim of this study was to assess the additional medialization after simultaneous ACS and PCS. Material and Methods Fresh-frozen post mortem human specimens were used. Both sides of the abdominal wall were subjected to retro-rectus dissection (Rives-Stoppa), ACS and PCS, the order in which the component separation techniques (CST) were performed was reversed for the contralateral side. Medialization was measured at three reference points. Results ACS provided most medialization for the anterior rectus sheath, PCS provided most medialization for the posterior rectus sheath. After combined CST 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 PCS after ACS provided 15% to 16%, and additional ACS after PCS provided 32% to 38% of the total medialization after combined CST. For the posterior rectus sheath, additional PCS after ACS provided 50% to 59%, and additional ACS after PCS provided 11% to 17% of the total medialization after combined CST. Retro-rectus dissection alone contributed up to 41% of maximum obtainable medialization. Conclusions ACS provided most medialization of the anterior rectus sheath and PCS provided most medialization of the posterior rectus sheath. Combined CST provides marginal additional medialization, clinical use of this technique should be carefully balanced against additional risks.