It is estimated that 350,000-500,000 ventral hernia repair surgeries are performed each year in the United States. Over the past 60 years, the soft tissue repair market has grown to include over 50 types of hernia repair materials. Surgeons typically implant these materials in the orientation that provides maximum overlap of the mesh over the defect, with little regard for mechanical properties of the mesh material. The majority of research on the mechanical properties of abdominal tissue and hernia repair materials has been limited by the lack of a physiologically relevant loading environment. The current goal of this project within our lab is to develop a device to apply and measure a representative coughing force applied to a porcine abdominal wall. In addition to loading the tissue, we seek to track three-dimensional abdominal deformation during each loading-unloading cycle.

Surrogate Abdomen

This device is used to change pressures under a large piece of abdominal tissue.

Mesh Mechanics

Many mesh types were tested to fully characterize and compare the mechanical properties.

Tissue Ingrowth

This study evaluated how mesh density, pore size, and pore shape affected the ingrowth of tissue into implanted meshes.

Surrogate Abdomen Testing

Images below are of preliminary testing of a porcine abdominal wall with corresponding 3D-strain tracked mesh of normal abdominal pressure and maximum abdominal pressure.

In vivo abdominal wall deformation

The purpose of this study was to (1) evaluate the efficacy of utilizing a fluoroscopic system to reconstruct static 3D spaces from a set of 2D images using a single rotating C-arm fluoroscope, (2) validate the system’s ability to accurately track a grid arrangement of beads, and (3) develop a protocol to compute 3D strain measurements of implanted hernia meshes at different abdominal presses and time points.

Collaborators

Dr. Jeffrey Blatnik – Minimally Invasive Surgery, Washington University

Publications

9. Lake SP, Stoikes NFN, Badhwar A, Deeken CR: Contamination of hybrid hernia meshes compared to bioresorbable PhasixTM Mesh in a rabbit subcutaneous implant inoculation model. Annals of Medicine in Surgery, 46:12-16, 2019[PubMed]

8. Kahan LG, Brunt ML, Lake SP, Tan WH, McAllister J, Yu J, Thompson Jr. DM, Blatnik JA: Evaluating mechanical integration at the mesh-tissue interface in ventral hernia repair. Surgical Endoscopy, 32(2):820-830, 2018. [PubMed]

7. Deeken CR, Lake SP: Mechanical properties of the abdominal wall and biomaterials utilized for hernia repair. Journal of Mechanical Behavior of Biomedical Materials, 74:411-427, 2017. [PubMed]

6. Kahan LG, Guertler C, Blatnik JA, Lake SP: Validation of single c-arm fluoroscopic technique for measuring in vivo abdominal wall deformation. Journal of Biomechanical Engineering, 139(8):084502, 2017. [PubMed]

5. Est S, Roen M, Chi T, Simien A, Castile RM, Thompson Jr. DM, Blatnik J, Deeken CR, Lake SP: Multi-directional mechanical analysis of synthetic scaffolds for hernia repair. Journal of Mechanical Behavior of Biomedical Materials, 71:43-53, 2017. [PubMed]

4. Cooney GM, Lake SP, Thompson Jr. DM, Castile RM, Winter DC, Simms CK: The suture pullout characteristics of human and porcine line alba. Journal of Mechanical Behavior of Biomedical Materials, 68:103-114, 2017. [PubMed]

3. Cooney GM, Lake SP, Thompson Jr. DM, Castile RM, Winter DC, Simms CK: Uniaxial and biaxial tensile stress-stretch response of human linea alba. Journal of Mechanical Behavior of Biomedical Materials, 63:134-140, 2016. [PubMed]

2. Lake SP, Ray S, Zihni A, Thompson Jr. DM, Gluckstein J, Deeken CR: Pore size and pore shape – but not mesh density – alter the mechanical strength of tissue ingrowth into synthetic mesh materials in a porcine model of ventral hernia repair. Journal of the Mechanical Behavior of Biomedical Materials, 42:186-197, 2015. [PubMed]

1. Deeken CR, Thompson Jr. DM, Castile RM, Lake SP: Biaxial analysis of synthetic scaffolds for hernia repair demonstrates variability in mechanical anisotropy, non-linearity and hysteresis. Journal of the Mechanical Behavior of Biomedical Materials, 38C:6-16, 2014. [PubMed]