Infected mesh salvaging using negative pressure wound therapy with instillation (NPWTi): a case report

Introduction

Background

Abdominal wall wound dehiscence with mesh exposure is a dangerous adverse event associated with significant morbidity, with an incidence ranging from 0.4% to 1.2% and a mortality rate of up to 25% (1).

Rationale and knowledge gap

To date, there are no standard protocols that define the optimal length of vacuum therapy with instillation, particularly for each specific clinical setting where this treatment can be administered effectively (2). Recent studies have shown contrasting results regarding the reduction of hospital stay length for cases of abdominal wall dehiscence with exposed mesh, treated with negative pressure wound therapy with instillation and dwell time (NPWTi-d) or with traditional vacuum assisted closure-therapy (NPWT) (2,3). The rate of hernial recurrences is slightly higher in the NPWTi group compared to the traditional vacuum-assisted closure group (3). However, small studies on limited sample sizes suggest a reduction in the total expense of treatment with NPWTi, calculated as the number of both hospitalizations and surgeries needed for complete wound closure (2,3).

Objective

In this case report, we present our experience with a patient treated with NPWT and 0.05% sodium hypochlorite instillation. We present this case in accordance with the CARE reporting checklist (available at https://acr.amegroups.com/article/view/10.21037/acr-24-49/rc).

Case presentation

In September 2021, a 54-year-old female patient was admitted to the Surgical Department of Lagosanto’s Hospital (Ferrara, Italy) for an outpatient visit. The patient presented with an abdominal recurrence of post-incisional hernia that began about 2 months prior, was growing, and slightly painful. Her clinical history included being overweight (body mass index 26.8 kg/m²), hypertension, type 2 diabetes, pancreatic body-tail resection, splenectomy, and a laparotomic plastic of laparocele with on-layer mesh performed in 2019.

Computed tomography (CT) scan revealed a median abdominal herniation with a cranio-caudal extension of about 14 cm containing omental and colic content and a hernial gate of about 8 cm [M3-L3-W2 according to the European Hernia Society (EHS) classification]. The patient was admitted for a planned laparoscopic laparoplasty intervention, which was converted into a laparotomy due to intense perivisceral adhesions. A Rives-Stoppa plastic intervention was performed with a 26 cm × 36 cm polypropylene mesh (Bard^®).

The postoperative course was regular, with the patient starting oral intake of fluids on the second postoperative day and complete per os re-alimentation the day after. Early mobilization was performed, and no in-hospital glucose alterations were recorded, even after re-alimentation. Leukocyte levels gradually decreased after a perioperative intravenous empiric antibiotic treatment with clarithromycin for 3 days. She was discharged in good clinical condition on the fourth postoperative day.

After 13 days, during a planned outpatient visit, a small subcutaneous collection of fluid was noted, and a deep culture swab was performed. Despite the absence of temperature, the patient was treated with amoxicillin-clavulanate for 6 days. The subsequent antibiogram performed on two different sets of peripheral blood samples showed sensitivity to the antibiotic therapy performed and isolated Klebsiella pneumoniae.

Three days later, during the second planned outpatient visit, the patient presented with a temperature of 38 ℃, dehiscence of the upper third part of the surgical wound, macerated skin, purulent fluids, and mesh exposure. The patient was re-admitted to the hospital, and an abdominal CT scan revealed a wide collection of purulent fluids on the abdominal prosthesis, without other intra-abdominal complications.

Culture tests were performed and it was noted thatthe white blood count showed neutrophilic leukocytosis (11.83×10³/µL neutrophils out of 17.70×10³/µL) and elevated C-reactive protein (CRP) (31.51 mg/dL). Therefore, we decided to proceed with surgical debridement and the application of negative pressure therapy (KCI Veraflo Cleanse with 0.05% sodium hypochlorite instillation) (Figures 1,2).

Figure 1 Laparotomic wound, first presentation after mesh infection.

Figure 2 Laparotomic wound with exposure of mesh infection.

Initially, an empirical broad-spectrum antibiotic treatment with piperacillin/tazobactam was undertaken for six days. But the culture tests from biological fluid obtained from the first reoperation and wound swab, allowed the isolation of Pseudomonas aeruginosa with intermediate sensitivity to piperacillin/tazobactam, as well as pan-sensitive Klebsiella pneumoniae, Gemella haemolysans (a gram-positive, catalase-negative, facultative anaerobic coccal bacterium, in our case poorly viable), and Actinomyces spp (possible contaminant, for which an antibiogram was not performed). Following a discussion of the case, the antibiotic therapy was switched to meropenem for an additional 8 days in combination with tigecycline.

The patient also underwent surgical reviews with the removal of necrotic tissue and systematic repositioning of vacuum-assisted closure therapy, performed (on days 1, 4, and 25 post-admission), while the surgical mesh remained in situ. The vacuum device was programmed for negative pressure therapy with instillation every 6 hours of 100 cc of 0.05% sodium hypochlorite and continuous aspiration at −125 mmHg.

During the 20 days of therapy and hospitalization, we observed a slow and gradual normalization of the inflammatory markers was observed, together, together with a progressive improvement in the condition (Figures 3,4). The patient was discharged on the 20^th post-operative day, with a plan for traditional wound care with three visits per week until February 2022. After nine months (May 2022), a photographic report of the wound was made (Figure 5).

Figure 3 Treatment with negative pressure wound therapy with instillation.

Figure 4 Laparotomic wound during negative pressure wound therapy with instillation therapy. Surgical debridement of residual fibrine tissue.

Figure 5 Last wound medication (about 9 months later).

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

Wound dehiscence is an infrequent but severe complication (1–2%) following the restoration of the abdominal wall with synthetic materials, with significant morbidity and mortality (as high as 38% in some reports) (2). Such complications are relevant in terms of costs and often require multidisciplinary involvement, extended hospital stays or prolonged home care, expensive materials, and operative surgeries with or without replacement of the exposed mesh. NPWT has been a recognized and widely applied adjunct in the management of complex wounds since 1997 (4). Since its introduction, various abbreviations for NPWT have emerged in the literature, but according to Kim et al., NPWT remains the preferred acronym (5).

Negative pressure therapy (vacuum-assisted closure), due to its mechanical macro- and micro-tensile effects on tissues, stimulates both the formation of granulation tissue and angiogenesis. In a retrospective study by Scandinavian researchers on 48 patients with exposed mesh after abdominal hernia surgery (treated with NPWT), the entire mesh was salvaged in 44 patients (92.2%), while four meshes were partly excised. NPWT contributed to wound healing in 88% of all cases, with a median healing time of 110 days (range, 3–649 days) (6).

An important evolution of NPWT, first introduced in 2004, involves the instillation of a topical solution followed by a dwell time and its later removal via negative pressure cycles (NPWTi) (7). Before 2008, antibiotic solutions were commonly used in NPWTi, but a recent study has almost completely replaced these with antiseptics (5).

A PubMed literature search for articles about NPWTi-d and abdominal mesh found only four articles in English (2,3,8,9). Although there are several reports on the successful management of infected wounds with NPWTi, the treated wounds appear very heterogeneous, with no consensus on which types of wounds would benefit most from this treatment (7).

For this reason, in 2019, an international consensus guideline on the general framework of NPWTi use was developed by a panel of experts, updating the earlier guideline from 2013. Previous experiences indicated that NPWTi devices could enhance the benefits of traditional NPWT, especially in infected sites with prosthetic material like abdominal meshes. However, in 2019, no consensus was reached on the need for NPWTi in wounds with exposed synthetic mesh over an intact abdominal wall (73% consensus reached, compared to the minimum required of 80%) (10).

Based on this expert consensus statement, normal saline solution is usually the preferred solution for NPWTi, though the use of sodium hypochlorite, as chosen for our patient, is also generally accepted for its (still unconfirmed) antimicrobial effect at low concentrations (e.g., 0.0025%). According to current recommendations, we performed the dwell time for 20 minutes with a negative pressure time of about 6 hours at a pressure of −125 mmHg (5).

However, it is important to remember that the evidence from the 2019 panel is limited to expert opinions, and current literature lacks randomized placebo-controlled trials concerning this aspect of surgical laparocele treatments.

After reviewing the articles on this topic, we found a case report by Japanese researchers who treated a patient with NPWTi in a manner similar to ours. This patient had an infected mesh after abdominal wall surgery but, unlike our case, had a lower spread of infection and no CRP elevation or fever; in that case the mesh was salvaged by negative-pressure wound therapy too (9).

Conclusions

Based on our experience and the limited literature available on this topic, NPWTi seems to be a safe and effective treatment option for abdominal wall wound dehiscence with mesh exposure. It may represent a valid therapeutic choice, especially for patients with a high risk of surgery-related morbidity and mortality.

As previously stated, given the scarcity of literature dedicated to this topic, further evidence from larger patient samples is necessary to better understand whether NPWTi is a reliable adjunctive therapy for wounds with exposed mesh over intact abdominal walls.

Acknowledgments

None.

Footnote

Reporting Checklist: The author has completed the CARE reporting checklist. Available at https://acr.amegroups.com/article/view/10.21037/acr-24-49/rc

Peer Review File: Available at https://acr.amegroups.com/article/view/10.21037/acr-24-49/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://acr.amegroups.com/article/view/10.21037/acr-24-49/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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