The use of synthetic mesh in an infected field is generally considered a relative contraindication. We know, however, that there is low‐level evidence that synthetic mesh can be placed in an infected field without a mesh infection. Also, many have shared their experience regarding successfully placing synthetic mesh in contaminated fields or potentially contaminated fields. Important points to help decision making are
- the types of infected fields based on bacterial species, load, and extent of infection
- the surgical techniques used to maximize the possibility of good outcome after implantation of synthetic mesh in an infected field
- the types of mesh characteristics which should be considered if synthetic mesh is to be used in an infected field
Prior to the introduction of biologic meshes in the late 1990’s/early 2000’s, synthetic meshes (both absorbable and non‐absorbable) were the only available products for closing fascial defects that could not be closed primarily or covered with skin closure alone. The typical patient is a patient with an open abdomen with or without skin deficit. Modern literature currently dissuades surgeons from considering synthetic mesh for fascial defect closure. The rate of acute mesh infection is high, at least 60‐80%. If healing and granulation does occur through the mesh, the rate of chronic mesh infection is equally high. Chronic mesh infection manifests itself as a non‐healing wound, frequent cycles of wound dehiscences followed by spontaneous closure, sinus tracts that cycle between purulent drainage and spontaneous closure, chronic pain, infected seromas that temporarily resolve with drainage and antibiotics, and so on. Today, the general consensus is that the likelihood that a mesh infection will heal is very low, thus multiple rounds of antibiotics, drainage, and even local debridement of mesh will fail, and thus total excision of the mesh is indicated.
Types of infected fields based on bacterial species, load, and extent of infection
Older literature supports the use of synthetic mesh. That said, since we have a much wider array of mesh products and bacterial flora today than we did two decades ago, it is important to appreciate that certain mesh types and bacterial infections are more likely to cause unrelenting mesh infection and therefore should be strong contraindications to mesh implantation in an infected field. MRSA (methicillin resistant Staphylococcus aureus) infection is widely considered a strong contraindication to synthetic mesh implantation. The ability to resist mesh infection in the face of MRSA is very low, and most failures noted in the literature are attributed to the presence of MRSA. In fact, some have advocated that a history of MRSA infection also be a relative contraindication to synthetic mesh implantation. The bacterial load is obviously directly related to the success of mesh implantation
in the infected field.
Surgical techniques used to maximize the possibility of good outcome after implantation of synthetic mesh in an infected field
Surgical debridement must be wide, leaving only grossly uninfected tissue without necrosis or drainage. After wide surgical debridement, in a well‐nourished patient, implantation of synthetic mesh can be considered. In many cases, this may imply a multiple stage procedure, such that the patient’s infected abdominal wall, for example, is widely debrided and left open. Intravenous antibiotic therapy is initiated, and once there are signs of healing and granulation, which implies a lower bacterial load, then implantation of synthetic mesh can be considered. Single‐stage debridement of infected or necrotic tissue followed by mesh implantation is strongly discouraged in most patients. Similarly, mesh implantation in an actively infected site without source control, such as an enteric fistula, is contraindicated.
Types of mesh characteristics which should be considered if synthetic mesh is to be used in an infected field
Familiarity with different types of mesh, and thus tailoring mesh choice to the needs of the patient, is key to improve outcome. In general, the preferred synthetic mesh for infection resistance is monofilament, lightweight (less than 40gm/m2), macroporous (greater than 4mm wide). Absorbable mesh has not been shown to have significant advantages over non‐absorbable mesh, as it tends toward a higher rate of fistula formation. Polypropylene mesh is the most commonly used mesh when placed in a contaminated or infected field. Newer generation mesh are available that are macroporous and thus granulation tissue will grow within its interstices at a rapid rate, as long as infectious source control has been performed. Most studies regarding failure of synthetic mesh in infected fields were performed using microporous and/or heavyweight mesh; thus it is possible that the newer
generation mesh will have improved outcome if placed in infected fields. Expanded polytetrafluoroethylene (ePTFE) is generally regarded as a contraindication for use in contaminated or infected field, although there are case series of salvaging ePTFE after infection. There is no reported experience using the newer generation macroporous monofilamentous PTFE. Polyester is a multifilamentous mesh that is lightweight. Data is conflicting regarding its use in infected fields. Stoppa had used polyester mesh in his patients and he was able to salvage any mesh infections. Data
from the 1980’s and 1990’s are generally against the use of polyester‐based mesh in infected fields and have correlated it with a significantly higher rate of infection when placed in clean fields. Modern data is conflicting, with many reports suggesting that polyester can be safely placed in a potentially contaminated field. In general, polyester use is discouraged in contaminated or infected fields.The choice of anatomical placement of the mesh may have significant impact on outcome. In general, if there is a high bacterial load, such as an infected abdominal wall that requires wide debridement, then the mesh should not be covered by skin closure. Wet to dry dressings or negative pressure dressings may reduce the bacterial load at the mesh and encourage granulation and integration of the tissue with the mesh. The quicker the integration of the mesh into the tissues, the less likely the mesh will be chronically infected. However, if the mesh is not well integrated initially, then bacterial slime may accumulate at the level of the synthetic
mesh fibers, making it resistant to antibiotic or local wound therapy. If the overall bacterial load is low, and the skin and fascia can be closed, then the mesh is best served if abutted against well‐vascularized tissue, such as the rectus muscle. Thus, the retrorectus position of the mesh has been shown to have a protective effect on the mesh, with reports of significantly lower than expected mesh infections. This is the preferred technique over intraperitoneal or onlay placement of the mesh. The mesh must be placed flat, without overlap of layers, and without wrinkling of buckling. Bacteria will be trapped and infections cannot be salvaged if the mesh is folded over, wrinkled, or where there are stacks of knots of non‐absorbable sutures used to sew the mesh in place.
Synthetic mesh is not manufactured for placement in infected fields. The off‐label use of this product has been performed for decades, mostly out
of necessity to cover large defects in multiply morbid patients. With this experience, we have gathered some insight into what patient populations may be appropriate risk candidates for implantation of synthetic mesh, what mesh products to use, and the best techniques to use in order to result in the least morbidity for the patient. Mesh infection, both chronic and acute, has reached high proportions in some of our tertiary referral practices. Some who do see the severe effects these can have on the patient’s quality of life tend to shy away from using synthetic mesh an an environment that can potentially lead to mesh infection. There has been a reemergence though of reports of safe usage of lightweight mesh in selected situations.
1. Trunzo JA. Ponsky JL. Jin J. Williams CP. Rosen MJ (2009) A novel approach for salvaging infected prosthetic mesh after ventral hernia repair. Hernia 13(5):545‐9.
2. Voyles CR, Richardson JD, Bland KI, Tobin GR, Flint LM, Polk HC (1981) Emergency abdominal wall reconstruction with polypropylene mesh. Ann Surg
3. Mc Neeley SG jr, Hendrix SL, Bennett SM, Singh A, Ransom SB, Kmak DC, Morley GW (1998) Synthetic graft placement in the treatment of fascial dehiscence with necrosis and infection. Am J Obstet Gynaecol 179:1430–1435.
4. Kendrick JH, Casali RE, Lang NP, Read RC (1982) The complicated septic abdominal wound. Arch Surg 117:464–468.
5. Gilsdorf RB, Shea MM (1975). Repair of massive septic abdominal wall defects with Marlex mesh. Am J Surg 130:634–638.
6. Jones JW, Jurkovich GJ (1989) Polypropylene mesh closure of infected abdominal wounds. Am Surg 55:73–76.
7. Nagy KK, Fildes JJ, Mahr C, Roberts RR, Frosner SM, Joseph KT, Barrett J (1996) Experience with three prosthetic materials in temporary abdominal wall closure. Am Surg 62: 331–335.
8. van’t Riet M, de Vos van Steenwijk PJ, Bonjer HJ, Steyerberg EW, Jeekel J (2007) Mesh repair for postoperative wound dehiscence in the presence of infection: is absorbable mesh safer than non‐absorbable mesh? Hernia 11(5):409‐13.
9. Carbonell AM, Matthews BD, Dreau D, et al. The susceptibility of prosthetic biomaterials to infection (2005) Surg Endosc 19:430–435.
10. Bleichrodt RP, Simmermacher RKJ, Lei B van der, Schakenraad JM(1993) Expanded polytetrafluoroethylene patch versus polypropylene mesh for the repair of contaminated defects of the abdominal wall. Surg Gynecol Obstet 176:18–24.
11. Brown GL, Richardson JD, Malangoni MA, et al. (1985) Comparison of prosthetic material for abdominal wall reconstruction in the presence of contamination and infection. Ann Surg 201:705–711.
12. B. Lauren Paton, Yuri W. Novitsky, Marc Zerey, Ronald F. Sing, Kent W. Kercher, Todd Heniford (2007) Management of Infections of Polytetrafluoroethyleneased Mesh. Surg Inf 8(3): 337‐342.