In-vivo evaluation of a reinforced ovine biologic: a comparative study to available hernia mesh repair materials.

PURPOSE: Two innovative reinforced biologic materials were studied in a non-human primate hernia repair model. The test articles, which combine layers of ovine decellularized extracellular matrix with minimal amounts of synthetic polymer, were evaluated for their biologic performance as measured by inflammatory response, healing kinetics, integration, and remodeling into functional host tissue. For comparison, seven clinically used biologic and synthetic meshes were also studied. METHODS: Animals were implanted with test articles in surgically created full-thickness midline abdominal wall defects, and evaluated macroscopically and histologically at 4, 12, and 24 weeks. RESULTS: Macroscopically, biologics resorbed and remodeled into naturally appearing tissue; the reinforced biologics appeared similar, but remodeled earlier and were less prone to stretch. Synthetics developed a layer of reactive tissue above and separate from the contracted mesh structure. At early time points, the collagen networks of biologics and reinforced biologics were infiltrated by host cells primarily as a peripheral layer on the biologics. As early as 12 weeks, the collagen networks associated with the reinforced biologics remodeled into organized host collagen. By 24 weeks, both reinforced biologics and biologics had low levels of inflammation. In contrast, a foreign body response persisted at 24 weeks with the synthetics, which had developed less organized collagen, separate in space from the actual mesh. CONCLUSIONS: The current study shows a favorable response to reinforced biologics, which were associated with an initial inflammatory response, resolving by later time points, followed by active remodeling, and the formation of new morphologically functional collagen.

Abdominal ultrasonography of the normal St. Kitts vervet monkey (Chlorocebus sabaeus).

BACKGROUND: Normal ultrasonography of non-reproductive abdominal and male reproductive anatomy in the vervet monkey were prospectively assessed. This has not been previously reported. METHODS: Ten non-sexually active male and 10 non-gravid female clinically healthy vervet monkeys between 5 and 12 years of age and weighing between 3.13 and 6.85 kg were evaluated with ultrasound. Individuals were randomly divided by gender groups into one of two immobilization protocols and scanned at 18.0 MHz. RESULTS: High-quality images of the liver, gallbladder, kidneys, urinary bladder, spleen, adrenal glands, gastrointestinal tract, and testes were acquired. The prostate was never visualized. Abdominal lymph nodes other than an ileocolic, the pancreas, and the female reproductive tract were not evaluated. Gastric and duodenal motility were significantly different between immobilization protocols (P<0.05). CONCLUSIONS: Abdominal sonographic anatomy was successfully characterized and normal size parameters for non-reproductive abdominal viscera and the testes were established.