Mechanical and Histological Characteristics of Phasix™ ST Mesh in a Porcine Model of Hernia Repair

Abstract

Purpose

The objective of this study was to determine mechanical and histological properties of Phasix™ ST Mesh in various defect sizes and characterize the tissue replacing Phasix™ ST Mesh in a porcine model of ventral hernia repair.

Methods

Simulated hernia defects were surgically created in the midline of twenty-four (n = 24) Yucatan pigs. Treatment groups included 8 cm defect sutured closed (buttress) and unclosed 4 cm and 8 cm defect groups. Phasix™ ST Mesh (15 cm diameter circle) was implanted laparoscopically and fixated circumferentially with SorbaFix™ Absorbable Fixation System fasteners. The repair sites underwent mechanical, molecular weight, and histological evaluation at 48 and 72 weeks postimplantation.

Results

Mechanical testing of Phasix™ ST Mesh-repaired sites revealed similar strengths at both time points for all three repair types, p > 0.05 in all cases (48 weeks: 142.4 ± 6.0 N, 142.3 ± 16.5 N, and 168.8 ± 38.5 N; 72 weeks: 110.0 ± 18.3 N, 138.6 ± 42.2 N, and 160.6 ± 42.0 N for 4 cm defect, 8 cm defect, and 8 cm buttress, respectively. mean ± SEM) No significant differences were observed over time except at 72 weeks postimplantation when the 4 cm defect group exhibited significantly lower strength than the T₀ strength of Phasix™ ST Mesh (204.6 ± 5.0 N, p < 0.05). The molecular weight of Phasix™ ST Mesh decreased over time, regardless of repair type. Histological analysis showed comparable mature collagen/fibrovascular tissue around and within the Phasix™ ST Mesh interstices, including the segment of mesh overlying the defect.

Conclusion

Phasix™ ST Mesh-repaired sites exhibited similar mechanical strengths and histological properties across all defect sizes in this porcine model.

KEYWORDS:

• Absorbable
• biologically-derived
• hernia repair
• mesh
• Phasix™ ST mesh
• poly-4-hydroxybutyrate

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Correction

Disclosure of interest

Dr. Deeken is the owner of Covalent Bio LLC, which received consulting fees from BD for this project, as well as other, unrelated projects. Mrs. Gagne and Dr. Badhwar are employees of BD.

Author contributions

Study conception and design: Gagne, Badhwar. Acquisition of data: Deeken, Gagne, Badhwar. Analysis and interpretation of data: Deeken, Badhwar. Drafting of manuscript: Deeken, Badhwar. Critical revision: Deeken, Gagne, Badhwar. Final approval of the version submitted for publication: Deeken, Gagne, Badhwar.

Mesh contribution to overall repair site ball burst strength was obtained using the measured molecular weight data and the Martin et al. in vitro data to predict mesh contribution [10].