Biomechanical Features of Reinforced Esophageal Hiatus Repair in a Porcine Model Natalia Amigo, PhD, a Cecilia Zubieta, MD, b Juan Martin Riganti, MD, b Mauricio Ramirez, MD, b Pedro Renda, MD, b Romina Lovera, MD, b Ariel Pascaner, PhD, a Carlos Vigliano, MD, PhD, a,b Damia ´ n Craiem, PhD, a D. Adam Young, PhD, c Thomas W. Gilbert, PhD, c,d and Alejandro Nieponice, MD, PhD a,b,e, * a Instituto de Medicina Traslacional, Trasplante y Bioingenierı´a (IMeTTyB), Universidad Favaloro-CONICET, Buenos Aires, Argentina b Esophageal Unit, Hospital Universitario Fundacio ´n Favaloro, Buenos Aires, Argentina c ACell, Inc, Columbia, Maryland d Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania e McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pensilvania article info Article history: Received 31 May 2019 Received in revised form 24 July 2019 Accepted 29 August 2019 Available online xxx Keywords: Hiatal hernia Extracellular matrix Hiatoplasty Biologic scaffold Surgical mesh abstract Recurrence rates in the laparoscopic repair of the hiatal hernia range from 12% to 59%. Limitation of reinforcement has been principally the risk of adverse events caused by syn- thetic materials. Biologic and resorbable synthetic materials are valid alternatives. This study compares the host response to all these materials after hiatal hernia repair. A total of 20 Landrace pigs, underwent laparoscopic primary hiatal hernia repair and reinforced with a polypropylene mesh (PROLENE: polypropylene [PP]), an absorbable synthetic scaffold (GOR- EBIO-A: polyglycolic acid [PGA]), a urinary bladder matrix scaffold, (Gentrix: urinary bladder matrix [UBM]), or without reinforcement, control group (C). Animals were survived for 3 months. Endpoints included gross morphology, biomechanical testing, and histology. Pigs in PP and PGA groups showed fibrosis at the repair site, with robust adhesions. In UBM and C groups, only mild adhesions were found. Load at failure (gr) and stiffness (gr/mm) of PP were higher than C group (PP:2103  548.3 versus C:951.1  372.7, P ¼ 0.02; PP:643.3  301 versus C:152.6  142.7, P ¼ 0.01). PGA and UBM values for both parameters were in between PP and C samples. However, stiffness in UBM was tended to be lower than PP group, and approached a significant difference (643.3  301 versus 243  122.1, P ¼ 0.0536). In UBM group, the histology resembled native tissue. By contrast, PP and PGA groups showed mononuclear infiltrates, fibroencapsulation, necrosis, remnants of mesh, and disorganized tissue that was validated with a histologic score. In this setting, UBM scaffolds showed the most appropriate features for hiatal hernia repair, recovering the tissue properties that can help reduce the possibility of early failure and prevent complications associated with the implanted material. ª 2019 Elsevier Inc. All rights reserved. * Corresponding author. Esophageal Unit, Hospital Universitario Fundacio ´ n Favaloro, Av Belgrano, 1752, Buenos Aires, Argentina. Tel./fax: 541143781200x1748. E-mail address: anieponi@ffavaloro.org (A. Nieponice). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.JournalofSurgicalResearch.com journal of surgical research  february 2020 (246) 62 e72 0022-4804/$ e see front matter ª 2019 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jss.2019.08.026