Small Intestine Submucosa (SIS) Implants in Experimental IPOM Rep Alexander H. Petter-Puchner, M.D, * ,2 Rene H. Fortelny, M.D,† ,1,2 Nadja Walder, M.D, * Salvador Morales- Conde, M.D,‡ Simone Gruber-Blum, M.D, * Wolfgang O ¨ hlinger, M.D, * and Heinz Redl, Ph.D * *Ludwig Boltzmann Institute for Experimental and Clinical Traumatology and Cluster for Tissue Regeneration, Vienna, Austria; †II Department of Surgery, Wilhelminenspital der Stadt Wien, Vienna, Austria; and ‡Advanced Laparoscopic Unit, University Hospital Virgen del RocA ˜ o, Sevilla, Spain Submitted for publication October 30, 2008 Background. Synthetic meshes can cause adverse effects (e.g., adhesions, mesh infection) in intraperito- neal onlay mesh repair (IPOM). Although data for its biocompatibility as well as degradation behavior is still scarce, small intestine submucosa (SIS) implants have been suggested as a favorable alternative for IPOM repair. The aim of the study was to assess safety and efficacy of SIS used as allo- or xenograft in an ex- perimental model of IPOM repair, with the purpose of creating a critical awareness for specific aspects of the biomesh concept among researchers and surgeons alike. Main outcome parameters were adhesion forma- tion, tissue integration, shrinkage, and dislocation. Materials and Methods. Open IPOM repair was per- formed in 16 Sprague Dawley rats and two minipigs. SIS implants were 2 3 2cm in rats (one per animal) and 6 3 8cm in pigs (four per animal). All implants were fixed with six nonresorbable sutures. Observa- tion period was 17 and 28 d (n [ 8) in rats and 28 d in pigs. Outcome parameters were assessed macroscopi- cally, and histologic samples (H and E staining) were obtained. Results. Upon autopsy, SIS appeared to be only mod- erately integrated. Dislocation of five SIS implants in the rats and of two SIS implants in the pigs were observed although all sutures were still in place. No seroma forma- tion or infection was detected macroscopically, but sub- stantial shrinkage and adhesion formation at the margins of implants and suture sites were frequently ob- served. Histology confirmed the macroscopic finding of limited integration and substantial shrinkage. The path- omorphology was similar in both species. Conclusions. Small intestine submucosa implants are susceptible to shrinkage, dislocation, and adhesion formation in experimental IPOM repair in rats and pigs. These findings are in accordance with literature and warrant further investigations of SIS implants in hernia repair. Ó 2010 Elsevier Inc. All rights reserved. Key Words: porcine small intestine submucosa; experimental IPOM; shrinkage; adhesions. INTRODUCTION Intraperitoneal onlay mesh repair (IPOM) has be- come a standard procedure for the repair of incisional hernias [1, 2]. Although this technique has obvious technical advantages,including tension-free repair and laparoscopic detection of occult, multiple hernias, it can be associated with some adverse effects such as adhesion formation, mesh infection or shrinkage. The synthetic IPOM meshes most commonly used are made of polymers, often layered with absorbable anti- adhesive barriers [3–5]. Along with refined mesh tech- nologies, the atraumatic fixation of meshes, for example with fibrin sealant (FS) contribute to reducing compli- cations in IPOM [6]. Recent literature suggests the potential benefits of bi- omeshes. Biomeshes can be divided into two main cate- gories. First, products derived from animalsources, e.g., porcine small intestine submucosa (SIS; Surgisis, Cook, Bloomington, IN), porcine cross linked collagen (PCL; PermaCol, Covidien, Aldershot, UK) and bovine pericard (TuM; Tutomesh, Tutogen, Neunkirchen, Ger- many) [7–11]. Implants processed from decellularized human cadaveric skin (AD; Alloderm, KCI, Branch- burg, NJ) form a second category of human allografts 1 To whom correspondence and reprint requests should be addressed at Department ofVisceral Surgery, Wilhelminenspital, Vienna, Austria, Montleartstrasse 37, A-1171-Vienna. E-mail: rene. fortelny@wienkav.at. 2 These two authors contributed equally to this study. 0022-4804/$36.00 Ó 2010 Elsevier Inc. All rights reserved. 264 Journal of Surgical Research 161, 264–271 (2010) doi:10.1016/j.jss.2009.04.007