Antibiotic Mesh
By Lisa K Jennings, PhD
Co-founder / Chief Scientific Officer, Ariste Medical
With more than 400,000 procedures performed annually, ventral hernia repair is among the most common surgeries in the United States (1), but often results in high rates of infection which can lead to excess morbidity and healthcare expenses (2). An innovative, patented, drug-embedded polymer for implantable and non-implantable devices plans to improve these outcomes, by preserving device integrity and consequently mitigating numerous complications. Developed by pre-commercial stage medical device company Ariste Medical, this polypropylene mesh for open ventral hernia repair carries the proven antibiotics minocycline and rifampin to prevent mesh contamination by bacterial pathogens associated with surgical site infections, such as MRSA and E. coli (3,4). The FDA 510(k) clearance represents more than a decade of dedicated research and development, during which Ariste has been awarded multiple patents positioning it as a flexible technology capable of delivering novel drug-device combination products to address complications associated with implantable surgical devices, including infection, inflammation, or clotting.
Causes of Hernia Repair Infection
The most reported healthcare-associated infection in the United States is surgical site infection (SSI) (5). Infection often occurs when bacteria from the skin are allowed to enter the wound cavity made during the operation, and bacteria can attach themselves to the mesh itself, colonizing in the pores of the material used for these procedures. The majority of infections require treatment, and some require surgeons to remove the implanted mesh and re-implant a replacement product. Despite improvements in infection control practices, SSIs remain a significant cause of morbidity and mortality and result in increased hospital stay and excess healthcare costs. Infection of the wound triggers the body’s immune response, causing inflammation and tissue damage, as well as slowing the healing process. Thus, infection of surgical mesh can have costly consequences and severe impact on a patient’s life due to the need of multiple surgeries, longer hospital stays, and expensive long-term antibiotics. Patients’ work and home lives are also significantly impacted.
Higher rates of SSI occur most often after open versus laparoscopic hernia repair (6). Reported infection rates are affected by anatomic site, surgical approach, and other risk factors such as bowel obstruction or necrosis, patient follow-up period, and surveillance methods.
The Infection rate among all patients undergoing open ventral hernia repair has been reported to range from 1% – 10%; however, incidence of infection has been reported up to 30% (7). The wide infection range depends upon the type of mesh, the technique, the anatomic site, infection reduction strategy, and the patient population (7). Patient-related risk factors or co-morbidities include obesity, chronic obstructive pulmonary disease, diabetes mellites, and hypertension. It was for these patients that the Ariste antibiotic-embedded mesh was developed, to provide an extra layer of protection against a common and potentially debilitating infection.
Advantage of Embedded Antibiotics
It is not always easy for a systemic antibiotic to reach sufficient concentrations in the tissue where the mesh has been implanted. With the Ariste antibiotic-embedded mesh, the antibiotic coating is a frontline defense for reducing the bacterial contamination of the mesh during open hernia repair and preventing bacteria colonization after the wound has been closed. Additionally, localized antibiotics may result in fewer side effects and permit a compliance-independent dosage of the medication. It is also possible to achieve considerably higher active ingredient concentrations focused in the place where infection is initiated – the wound created by open ventral hernia repair. Importantly, the Ariste antibiotic-embedded mesh does not adversely impact the desirous properties of the mesh such as porosity, tensile strength, or mesh weight. The mesh performs as the surgeon would expect for any synthetic product.
Durability of Synthetic Mesh vs. Alternatives
Why would a surgeon choose this mesh over alternatives, such as biologics or fully absorbable products? The Ariste mesh provides the ideal combination of the long-term durability of synthetic mesh with the protection of historically proven antibiotics. Surgeons no longer must compromise on durability to seek a lower risk of infection. This is what occurred when surgeons moved towards use of biologics and absorbable mesh, neither of which provide durable support for the weakened hernia repair.
Interestingly, recent data have shed more light on the use of biological mesh for single-stage repair of hernias in contaminated or clean-contaminated fields. Initially thought to be the better option and more resistant to bacterial infection, we now know that biologics offer no advantage in infection prevention. New studies have demonstrated that synthetic mesh offers better performance in contaminated fields and clean-contaminated fields where bacterial colonization has already occurred. In a recent clinical trial of 253 patients randomized to polypropylene mesh vs biologic mesh for ventral hernia repair, it was demonstrated that the polypropylene mesh had significantly lower recurrence, a similar safety profile, and significant cost savings compared with the biological mesh (8, 9).
Fully absorbable mesh may offer advantages in reducing the risk of infection, but they fail to provide the durable structural support achievable with synthetic mesh. With the Ariste mesh, the combination of a synthetic mesh providing adequate, long-term mechanical support with an effective broad-spectrum antibiotic coating that mitigates bacterial colonization may be the ideal, cost-effective treatment for patients at risk of infection.
Fighting the High Cost of Infection
In a study by Reynolds, et al (10), median direct costs for hernia repairs performed without mesh were $5,432 whereas median direct costs for those using synthetic or biologic mesh were $7590 and $16,970, respectively.
Despite improvement in infection control practices, SSIs remain a significant cause of morbidity and mortality and result in increased hospital stay and excess healthcare costs. Zimlichman, et al, reviewed healthcare associated infections from 1986-2013 with the calculated costs inflated to 2012 US dollars. SSI represented ~34% of the major infections and cost on a per-case basis was $20,785 (11). Mesh infection hospital charges and follow-up costs for one year may be 2.8-fold higher or more compared to patients with no infection.
Financial penalties for patient readmission are considerable and include surgical procedures. In a study of patients undergoing surgery at one of 346 continuously enrolled US hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) between January 1, 2012, and December 31, 2012, the unplanned readmission rate for the 498,875 documented operations was 5.7%. The most common reason for unplanned readmission was SSI (19.5% of all readmissions), with ventral hernia repair representing 26.5% of these incidences.
In summary, reducing the risk of infection will help improve patient outcomes and will translate to reduced costs associated with treatment of infections and with unplanned hospital readmissions. The Ariste antibiotic-embedded mesh is positioned to address several identified needs of surgeons performing open repair of ventral hernia: durable structural support; reduced risk of infection; and reduced cost associated with infection mitigation and unplanned readmission.
Editor’s Note: Lisa K Jennings, PhD is a co-founder of Ariste Medical, a Member of its Board of Managers, and serves as its Chief Scientific Officer. Dr. Jennings was Director of the Vascular Biology Center of Excellence as a tenured Professor at The University of Tennessee Health Science Center (UTHSC) until transiting fully to the private R&D sector. Fully licensing the early technology developed at UTHSC into Ariste Medical, the scientific and engineering team over the last decade has focused on the generation of their drug-device products, the first being an antibiotic embedded polypropylene mesh geared toward reducing complications associated with open hernia repair. In March 2022, Ariste was granted regulatory clearance by the FDA. Dr. Jennings has more than 250 publications in peer-reviewed journals and continues to serve as a leader in the hemostasis and thrombosis field.
References
- https://www.medicalnewstoday.com/articles/319753, 2017.
- Hennessy, S.A., Hranjec, T., Hallowell, P.T., and Schirmer, B.D. Surgical Site Infections Following Ventral Hernia Repair: Does Operative Approach Matter? SAGES, 2015.
- Mangram A.J., Horan T.C., Pearson M.L., Silver L.C., and Jarvis W.R. Guideline for prevention of surgical site infection. Am. J. Infect. Cont. 27:97–134, 1999.
- Timothi F.J. The Staphylococcus aureus “superbug” J. Clin.Invest.1141693–96, 2004.
- Olsen, M.A., Nickel, K.B., Wallace, A.E., Mines, D., Fraser, V.J., and Warren, D.K. Stratification of surgical site infection by operative factors and comparison of infection rates after hernia repair. Infect Control Hosp Epidemiol. 36(3): 329–335, 2015.
- Kaafarani H.M., Kaufman, D., Reda, D., and Itani, K.M.F. Predictors of surgical site infection in laparoscopic and open ventral incisional herniorrhaphy. J. Surg. Res. 163(2);229-34, 2010.
- Brown R.H., Subramanian, A., Hwang, C.S., Chang, S., and Awad, S.S. Comparison of infectious complications with synthetic mesh in ventral hernia repair. Am J. Surg.205: 182-187, 2013.
- Rosen, M.J., Krpata, D.M., Petro, C.C., Carbonell, A., Warren, J., Poulose, B.K., Costanzo, A. Tu, C., Blatnik,J., Prabhu, A.S. Biologic vs synthetic mesh for single-stage repair of contaminated ventral hernias.JAMA Surg. 157(4):293-301, 2022.
- Stolarski, A.E. and Itani, K.M.F. Nailing the coffin on biological mesh in contaminated ventral hernias. JAMA Surg. 157 (4); 302, 2022.
- Reynolds, D., Davenport, D.L., Korosec, R.L., and Roth, J.S. Financial implications of ventral hernia repair: a hospital cost analysis. J. Gastrointest. Surg. 17 (1):159-66, 2013.
- Zimlichman, E., Henderson, H., Tamir, O., Franz, C., Song, P., Yamin, C.K., Keohane, C., Denham, C.R., and Bates, D.W. Health care-associated infections: a meta-analysis of costs and financial impact on the US health care system. JAMA Intern Med. 173(22):2039-462013, 2013.