Reduced recurrence rates can be achieved by using standardized surgical techniques for mesh reinforcement in hernia surgery (1–3). Accordingly, several different types of meshes are used worldwide in hernia surgery. In the US alone, some 800,000 inguinal hernia (4) and 400,000 ventral hernia, including primary and incisional (5), operations are performed annually. In Sweden, 16,000 inguinal and 7,000 ventral hernias are reported on an annual basis in the national registers. In Germany, 275,000 inguinal and 100,000 ventral hernia operations are carried out annually.

In a review (6), the reported incidence of mesh-related infections following hernia repair was between 1 and 8% in different series. The incidence was influenced by the underlying comorbidities, type of mesh, surgical technique, and the strategy used to prevent infections. Risk factors to determine the onset of mesh infection were a prolonged operation time (7, 8), the extent of contamination of the surgical site (9), and early complications of the wound (seroma, hematoma, and infection) (8). In the Cochrane review of laparoscopic versus open surgical techniques for ventral or incisional hernia repairs, the overall infection rate was 13% after open and 3% after laparoscopic mesh repair (10).

Prevention of mesh infections continues to be the best strategy (11). Not all infections necessitate mesh removal. In the Cochrane review, only 3.3% of meshes had to be removed following open and 0.7% following laparoscopic ventral and incisional hernia repairs (10). It was possible to preserve 17 (55%) of meshes through conservative treatment in a case series of 31 infected meshes after incisional hernias repair (7). In a study on in ventral hernia repairs by Liang et al., a total of 30 out of 407 (7.4%) were re-operated due to an infection and the mesh could be saved in 10 out of these 30 (33%) (9). Reoperations were performed evenly spread from operation up to 10 years after the primary operation. In another series, it was possible to preserve 12 out of 13 (92%) were VAC^® was used in addition in 11 patients (12). The rate of mesh removal due to infection following inguinal hernia repairs was reported to be 0.13% (13). The interval between hernia operation and mesh removal could be up to 10 years or longer.

In a review by Darehzereshki et al. including eight retrospective studies, with a total of 1,229 patients comparing different biological to synthetic mesh repair in ventral and incisional hernias. It was demonstrated that biological grafts were associated with significantly fewer wound infections (p < 0.00001) but with no difference in recurrence rate (14).

The aim to look at evidence for situations were a biological mesh would work as a replacement of a removed infected synthetic mesh.

A literature search of the Medline database was performed using the PubMed search engine. The following key words were used: biological mesh, replacement of infected mesh, ventral hernia AND infected mesh, inguinal hernia AND infected mesh, mesh infection AND biological mesh, infected synthetic mesh AND biological mesh. Two thousand five hundred one citations were found. After checking the title and abstracts, 20 publications remained included in this study. Seven of these publications, four case series and three case reports, do report on the replacement of a synthetic by a biological mesh (Table 1).

The treatment options were removal of the infected mesh alone, replacement of the infected with a new synthetic mesh, and replacement of an infected synthetic with a biological mesh.

Mesh procedures are standard practice for surgical repair of both inguinal, ventral and incisional hernias (1–3). As the number of hernias treated worldwide continues to grow, also the number of hernia meshes implanted each year rise inexorably. Mesh infection rate in inguinal hernia surgery is below 1% and is not regarded as a clinical problem. However, surgeons often have to deal with mesh infections after ventral and incisional hernia surgery, which is estimated to be between 1 and 8% (6). The primary treatment modality is conservative. This is successful in eliminating mesh infection in over 50% of cases without mesh removal (7, 10). The most common bacterial agent is Staphylococcus aureus. With increasing proportion of methicillin resistance (MRSA), the treatment options in long-standing wound infections might be problematic to handle (11). There are no recommendations on how long a conservative regime is acceptable. Polypropylene and polyester meshes can be saved in a higher proportion that a laminar mesh-like ePTFE. Extensive ePTFE mesh infections are best managed by mesh explantation (11). Pros and cons must though be weighed against each other according to the scenario presented. If conservative treatment fails, the mesh must be explanted (8, 15).

In mesh infection, biological meshes are increasingly used for replacement as synthetic meshes by some are regarded as contraindicated (5). The publications included in the present review demonstrated that there were three approaches that could be taken depending on the individual patient situation. The first option was to remove the infected mesh without a new implant. This is the most common option after inguinal hernia surgery, since the transversalis fascia is thickened by fibroses after the mesh removal (13). Using this approach, no inguinal hernia recurrence was seen on mean follow-up of 62 months in a case series (13). This does, however, not apply for incisional and ventral hernias. Tolino et al. reported on a recurrence rate of 23% after removal of an infected mesh following incisional hernia operation without reimplantation of a new mesh (8).

The second option was to replace the infected polypropylene mesh with a new polypropylene mesh (15). The short-term results showed a relative uneventful postoperative course after mesh replacement in 27 patients. Six (22%) patients developed a minor wound infection and were treated with dressings and antibiotics, five (19%) patients had wound infections requiring debridement and one required complete mesh removal. On follow-up, there were three hernia recurrences, one with an enterocutaneous fistula. Ninety-five percent of the patients undergoing mesh replacement were considered cured from chronic mesh infection after a mean follow-up of 74 months (15).

The third option was to replace the explanted synthetic mesh with a biological mesh (5, 16–20). Long-term results were successful only if bridging was omitted (5, 16, 17). An unacceptably high recurrence rate was observed following bridging with biological meshes (5, 16, 17). When bridging was avoided, good results were obtained for replacement of an infected synthetic mesh with a biological (5, 16, 17). An algorithm for treatment of ventral/incisional hernia mesh infection is presented in Figure 1.

It can be concluded that a mesh can be saved in more than half of patients suffering from an infection after implantation of a synthetic mesh for an incisional hernia. If mesh explanation is necessitated a replacement seems safe either using a synthetic or a biological mesh if fascia could be closed. Bridging seems to result in a high failure rate using a biological mesh. Further studies are needed to create a better evidence-based platform for specific therapeutic decision-making.

AM: literature search, selection of the literature, review of the literature, and writing of the manuscript. F Ka: literature search, selection of the literature, review of the literature, and revision of the manuscript. F Kö: literature search, selection of the literature, review of the literature, and revision of the manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.