Vol.:(0123456789) 1 3 Hernia https://doi.org/10.1007/s10029-018-1808-y ORIGINAL ARTICLE Sublay repair results in superior mesh incorporation and histological fbrogenesis in comparison to onlay and primary suture in an experimental rat model F. Ponce Leon 1,5,6  · J. E. F. Manso 2  · V. L. Abud 4  · W. Nogueira 3  · P. C. Silva 2  · R. Martinez 2 Received: 20 April 2018 / Accepted: 18 August 2018 © Springer-Verlag France SAS, part of Springer Nature 2018 Abstract Purpose To compare adhesion scores, repair strength and histological fndings among sublay, onlay and primary repair incisional hernioplasty techniques. Surgical repairs were employed directly on healthy animals, without previous hernia induction, to avoid confounding factors related to hernia development. Methods Forty Wistar rats were divided into four groups, control, simulation, onlay and sublay. After 42 days, adhesion intensity, tensile strength of the abdominal wall and anatomopathological histological substrate were compared. Results SL group presented greater adhesion scores (p < 0.0001), higher tensiometric (p < 0.0001), and was characterized by more histiocytes, mononuclear cells, macrovacuolar granulomas and type I collagen on histological analysis. Pearson correlation between adhesions and tensiometry, and between tensiometry and neocollagenization showed a strong positive association (r = 0.8905 and 0.6757, respectively in SL group, p < 0.05). Conclusion Mesh positioning in sublay compartment was followed by increased adhesion development and provides a stronger mesh–tissue attachment, in addition, resulted in a diferent histological profle of the infammation/repair sub- strate. The intensity of these fndings was directly correlated, suggesting they could be the result of a common biological phenomenon. Our fndings indicate that mesh placement following the retromuscular technique generates a superior repair response, and give clues to a better understanding of the superiority of sublay repair in achieving lower recurrence rates. Characterization of the cellular and molecular elements responsible for the superiority of this technique is in our view an essential prerequisite aiming for improvements in the therapeutic options for the treatment of this disease. Keywords Incisional hernia · Sublay · Adhesions · Tensiometry · Collagen Introduction An incisional hernia (IH) occurs when there is a partial or total discontinuity of a previously incised and sutured fascia, allowing the protrusion of contents through the defect on the aponeurosis [1]. Despite the high prevalence of this disease, results of the available therapeutic options are still very poor, and recurrence rates following surgical repairs are higher than 15% even in high-quality specialized centers [2–4]. The mechanism of IH development is multifactorial. Associated risk factors include obesity, old age, malnutri- tion, inefcient metabolism, due to inadequate digestion and/ or assimilation of nutrients, pregnancy, dialysis and previous infections. Irrespective of the cause, a common pathophysi- ology implicated in hernia development involves defective repair response, resulting in a poor wound healing substrate and insufcient collagen deposition [5]. * F. Ponce Leon 1 Interdisciplinar Surgical Science Post-Graduate Course, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil 2 Department of Surgery, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil 3 Department of Pathology, Hospital da Força Aérea do Galeão (HFAG), Rio de Janeiro, RJ, Brazil 4 Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil 5 Departamento de Pós Graduação em Ciências Cirúrgicas da Universidade Federal do Rio de Janeiro (UFRJ), Carlos Chagas Filho avenue, Centro de Ciências da Saúde-UFRJ, block K, 2nd foor, Ilha do Fundão, Rio de Janeiro, RJ 21941590, Brazil 6 Rio de Janeiro, Brazil