There is a critical need to develop a new device to noninvasively treat mesh infections without removing the mesh. In the absence of such a device, the treatment of mesh infections will remain highly invasive and costly. This study's objective is to optimize cavitation-based histotripsy to treat surgical mesh infections. Histotrips generates/excites a cloud of micron sized bubbles in the tissue which mechanically shred the targeted cells. The physics of microbubble collapse promotes lysis of bacteria attached to the implant enhancing the destruction of the bacteria biofilm causing the infection.
Specific Aim #1 : Verify biofilm destruction on a mesh target. Our preliminary studies treated biofilms on planar surfaces. The working hypothesis is that the ultrasound will be equally effective at treating biofilms on the mesh structure. This hypothesis will be tested by in vitro and in vivo experiments where infected meshes will be treated with ultrasound induced cavitation under varying exposure conditions.
Specific Aim #2 : Evaluate the impact of the therapy on mesh functionality. With infection, the fibrous tissue disintegrates at the site of infection and the mesh loosens. Further loosening in the short term might also occur in the vicinity of the mesh from the histotripsy exposure. However, if the extent of damage is small (i.e., less than a few millimeters), then we hypothesize the tissue will heal around the mesh as is expected during normal implantation following the treatment. This hypothesis will be tested using a rabbit peritoneal mesh infection model. This project is significant because once developed thousands of patients each year would have an alternative to invasive surgery for treating mesh infections. The proposed research is innovative because it will potentially provide a noninvasive treatment option where there are no other alternatives currently.

Public Health Relevance

The proposed research is relevant to public health because it is expected to lead to a treatment of infections on surgical meshes following hernia repair. Such a tool would provide a noninvasive treatment option that does not currently exist reducing the number of surgeries and complications associated with hernia repair.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21EB020722-02
Application #
9272396
Study Section
Biomedical Imaging Technology B Study Section (BMIT-B)
Program Officer
King, Randy Lee
Project Start
2016-05-11
Project End
2018-02-28
Budget Start
2017-03-01
Budget End
2018-02-28
Support Year
2
Fiscal Year
2017
Total Cost
$225,724
Indirect Cost
$58,891
Name
Iowa State University
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
005309844
City
Ames
State
IA
Country
United States
Zip Code
50011
Bigelow, Timothy A; Thomas, Clayton L; Wu, Huaiqing et al. (2017) Histotripsy Treatment of S. Aureus Biofilms on Surgical Mesh Samples Under Varying Pulse Durations. IEEE Trans Ultrason Ferroelectr Freq Control 64:1420-1428