Mini- or less-open sublay (E/MILOS) operation vs open sublay and laparoscopic IPOM repair for the treatment of incisional hernias: a registry-based propensity score matched analysis of the 5-year results

Background: Open sublay and laparoscopic IPOM repair have specific disadvantages and risks. In recent years, this evidence led to a paradigm shift and induced the development of new minimally invasive techniques of sublay mesh repair. Methods: Pioneering this trend, we developed the endoscopically assisted mini- or less-open sublay (MILOS) concept. The operation is performed trans-hernially via a small incision with light-holding laparoscopic instruments either under direct, or endoscopic visualization. After dissection of an extra-peritoneal space of at least 8 cm, port placement and CO₂ insufflation, each MILOS operation can be continued endoscopically (EMILOS repair). All E/MILOS operations were prospectively documented in the Herniamed Registry with 1- and 5-year questionnaire follow-ups. Propensity score matching of incisional hernia operations comparing the results of the E/MILOS operation with the laparoscopic intraperitoneal onlay mesh operation (IPOM) and open sublay repair from all other institutions participating in the Herniamed Registry was performed. The results with perioperative complications and 1-year follow-up have been published previously. Results: This paper reports on the 5-year results. The 5-year follow-up rate was 87.5% (538 of 615 patients with E/MILOS incisional hernia operations). Comparing E/MILOS repair with laparoscopic IPOM and open sublay operation, propensity score matching analysis was possible with 448 and 520 pairs of operations, respectively. Compared with laparoscopic IPOM incisional hernia operation, the E/MILOS repair is associated with significantly fewer general complications (P = 0.004), recurrences (P < 0.001), less pain on exertion (P < 0.001), and less chronic pain requiring treatment (P = 0.016) and tends to result in fewer postoperative complications (P = 0.052), and less pain at rest (P = 0.053). Matched pair analysis with open sublay repair revealed significantly fewer general complications (P < 0.001), postoperative complications (P < 0.001), recurrences (P = 0.002), less pain at rest (P = 0.004), less pain on exertion (P < 0.001), and less chronic pain requiring treatment (P = 0.014). A limitation of this analysis is a relative low 5-year follow-up rate for laparoscopic IPOM and open sublay. Conclusions: The E/MILOS technique allows minimally invasive trans-hernial repair of incisional hernias using large standard meshes with low morbidity and good long-term results. The technique combines the advantages of sub-lay repair and a mini- or less-invasive approach. Trial registration: ClinicalTrials.gov Identifier NCT03133000.