Background: Biomaterials have become popular for incisional hernia repair given their relative safety and reduced perioperative complications. Though mesh materials have decreased recurrence rates, they also still carry high risks of infection and recurrence. Biological based alternatives that more closely resemble “native” abdominal wall biomechanical phenotype may improve surgical outcomes if seeded with autologous fibroblasts.
Purpose: Using an acellular myofascial (AMyo) scaffold, we studied whether AMyo impregnated with autologous fibroblasts (AMyo+Fib) improves abdominal wall phenotype relative to other prosthetic materials after incisional hernia repair and recovery.
Methods: 40 male Sprague-Dawley rats were randomly assigned to one of 5 surgical groups: 1) Sham, 2) Mesh, 3) ADerm, 4) AMyo, 5) AMyo+Fibroblasts. All groups received an abdominal wall skin flap; the 4 experimental groups received an additional 5cm incision through the linea alba which was left open. Skin flaps in all groups were then repaired. Fibroblasts were seeded into scaffolds for the AMyo+Fib group using a syringe and incubated for 7 days before implantation. On POD 28, after incisional hernia maturation, the experimental groups were repaired in the underlay technique. On accumulated POD 56, each rat was evaluated.
Results:
| Table 1. Summary of repaired incisional hernia data collected at POD 56. | ||||||
| Dependent variable | Incisional Hernia Surgical Repair Group | Significance | ||||
| Sham | Mesh | ADerm | AMyo | AMyo+Fib | ||
| Number of rats | 8 | 8 | 8 | 8 | 8 | |
| Adhesion Scale 0-5 with 0 being none. | 0±0 Rank=4.5 | 3.62±0.92 Rank=29.06* | 3.62±1.30 Rank=28.94* | 1.38±0.74 Rank=16.0*,† | 1.20±0.45 Rank=15.0 †,** | Kruskal-Wallis; * vs Sham, † vs Mesh & ADerm, ** vs Mesh & Allo, ** vs AMyo+Fib |
| Infection- yes | 0% | 12.5% | 37.5% $ | 12.5% | 0% | Binomial test, $ |
| CT scan confirmed Recurrence | 0% | 0% | 12.5% $ | 0% | 0% | Binomial test, $ |
| Appearance of ulcers | 0% | 12% | 0% | 50% $ | 40% | Binomial test, $ |
| Fistula - yes | 0% | 12% $ | 0% | 0% | 0% | Binomial test, $ |
| Max Load, N | 16.7±4.7 | 18.1±4.5* | 16.4±3.9 | 11.5±5.0*, † | 13.5±5.0 | * vs Sham; † vs Mesh. Power=.95 |
| Max Elongation, mm | 27.4±6.4 | 36.4±10.5 | 27.5±5.4 | 29.2±13.0 | 31.1±9.4 | NS, Power=0.67 |
| Elongation % | 68.5±16.1 | 89.9±26.3 | 68.0±12.7 | 72.9±32.5 | 77.9±23.7 | NS, Power=0.63 |
| Compliance, mm/N | 0.91±0.54 | 0.96±0.40 | 0.69±0.22 | 1.2±0.51** | 1.2±0.66** | ** vs ADerm; Power=0.74 |
| Stiffness, | 1.4.±0.64 | 1.24±0.60 | 1.65±0.77 | 0.98±0.44** | 0.99±0.38** | ** vs ADerm Power=0.78 |
| Energy at break, mJ | 249.5±113.4 | 343.4±0.42 | 1.88.5±68.3 | 175.5±129.7† | 206.0.5±100.9† | † vs Mesh. Power=0.94 |
| Break location | Muscle100%
| Muscle 25% Interface 75% | Muscle 44% Interface 56% | Muscle 15% Interface 85% | Muscle 90% Interface 10% |
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| Angiogenesis | Control | No | Yes | Yes | Yes |
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| Cell integration | Control | No | Yes | Yes | Unknown |
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The AMyo+Fib group ranked second after Sham on adhesions, had no infections, no fistulas, and no hernia recurrence. Addition of the fibroblasts to AMyo beneficially increased load, energy at break, and maintained the favorable compliance found in AMyo scaffold repaired abdominal wall.
Conclusions: AMyo+Fib more closely resembles “native” abdominal wall biomechanical properties thus improving our surgical outcomes by decreasing recurrence and select perioperative complications. AMyo impregnated with autologous fibroblasts (AMyo+Fib) improves abdominal wall phenotype relative to other prosthetic materials after incisional hernia repair and recovery.