Lindsey G Kahan1, Spencer P Lake2,3,4, Jared M McAllister1, Wen Hui Tan1, Jennifer Yu1, Dominic Thompson1, L Michael Brunt1, Jeffrey A Blatnik5. 1. Department of Surgery, Washington University in St. Louis School of Medicine, 660 South Euclid Ave, Campus Box 8109, St. Louis, MO, 63110, USA. 2. Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, USA. 3. Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA. 4. Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA. 5. Department of Surgery, Washington University in St. Louis School of Medicine, 660 South Euclid Ave, Campus Box 8109, St. Louis, MO, 63110, USA. jblatnik@wustl.edu.
Abstract
BACKGROUND: Hernia meshes exhibit variability in mechanical properties, and their mechanical match to tissue has not been comprehensively studied. We used an innovative imaging model of in vivo strain tracking and ex vivo mechanical analysis to assess effects of mesh properties on repaired abdominal walls in a porcine model. We hypothesized that meshes with dissimilar mechanical properties compared to native tissue would alter abdominal wall mechanics more than better-matched meshes. METHODS: Seven mini-pigs underwent ventral hernia creation and subsequent open repair with one of two heavyweight polypropylene meshes. Following mesh implantation with attached radio-opaque beads, fluoroscopic images were taken at insufflation pressures from 5 to 30 mmHg on postoperative days 0, 7, and 28. At 28 days, animals were euthanized and ex vivo mechanical testing performed on full-thickness samples across repaired abdominal walls. Testing was conducted on 13 mini-pig controls, and on meshes separately. Stiffness and anisotropy (the ratio of stiffness in the transverse versus craniocaudal directions) were assessed. RESULTS: 3D reconstructions of repaired abdominal walls showed stretch patterns. As pressure increased, both meshes expanded, with no differences between groups. Over time, meshes contracted 17.65% (Mesh A) and 0.12% (Mesh B; p = 0.06). Mesh mechanics showed that Mesh A deviated from anisotropic native tissue more than Mesh B. Compared to native tissue, Mesh A was stiffer both transversely and craniocaudally. Explanted repaired abdominal walls of both treatment groups were stiffer than native tissue. Repaired tissue became less anisotropic over time, as mesh properties prevailed over native abdominal wall properties. CONCLUSIONS: This technique assessed 3D stretch at the mesh level in vivo in a porcine model. While the abdominal wall expanded, mesh-ingrown areas contracted, potentially indicating stresses at mesh edges. Ex vivo mechanics demonstrate that repaired tissue adopts mesh properties, suggesting that a better-matched mesh could reduce changes to abdominal wall mechanics.
BACKGROUND:Hernia meshes exhibit variability in mechanical properties, and their mechanical match to tissue has not been comprehensively studied. We used an innovative imaging model of in vivo strain tracking and ex vivo mechanical analysis to assess effects of mesh properties on repaired abdominal walls in a porcine model. We hypothesized that meshes with dissimilar mechanical properties compared to native tissue would alter abdominal wall mechanics more than better-matched meshes. METHODS: Seven mini-pigs underwent ventral hernia creation and subsequent open repair with one of two heavyweight polypropylene meshes. Following mesh implantation with attached radio-opaque beads, fluoroscopic images were taken at insufflation pressures from 5 to 30 mmHg on postoperative days 0, 7, and 28. At 28 days, animals were euthanized and ex vivo mechanical testing performed on full-thickness samples across repaired abdominal walls. Testing was conducted on 13 mini-pig controls, and on meshes separately. Stiffness and anisotropy (the ratio of stiffness in the transverse versus craniocaudal directions) were assessed. RESULTS: 3D reconstructions of repaired abdominal walls showed stretch patterns. As pressure increased, both meshes expanded, with no differences between groups. Over time, meshes contracted 17.65% (Mesh A) and 0.12% (Mesh B; p = 0.06). Mesh mechanics showed that Mesh A deviated from anisotropic native tissue more than Mesh B. Compared to native tissue, Mesh A was stiffer both transversely and craniocaudally. Explanted repaired abdominal walls of both treatment groups were stiffer than native tissue. Repaired tissue became less anisotropic over time, as mesh properties prevailed over native abdominal wall properties. CONCLUSIONS: This technique assessed 3D stretch at the mesh level in vivo in a porcine model. While the abdominal wall expanded, mesh-ingrown areas contracted, potentially indicating stresses at mesh edges. Ex vivo mechanics demonstrate that repaired tissue adopts mesh properties, suggesting that a better-matched mesh could reduce changes to abdominal wall mechanics.
Authors: L Melman; E D Jenkins; N A Hamilton; L C Bender; M D Brodt; C R Deeken; S C Greco; M M Frisella; B D Matthews Journal: Hernia Date: 2011-01-30 Impact factor: 4.739
Authors: Eric D Jenkins; Lora Melman; Corey R Deeken; Suellen C Greco; Margaret M Frisella; Brent D Matthews Journal: J Am Coll Surg Date: 2011-03 Impact factor: 6.113
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Authors: Barbora East; Martin Plencner; Martin Kralovic; Michala Rampichova; Vera Sovkova; Karolina Vocetkova; Martin Otahal; Zbynek Tonar; Yaroslav Kolinko; Evzen Amler; Jiri Hoch Journal: Int J Nanomedicine Date: 2018-05-28