Gentamicin for prevention of intraoperative mesh contamination: demonstration of high bactericide effect (in vitro) and low systemic bioavailability (in vivo).

INTRODUCTION: Mesh infection is a severe complication after incisional hernia repair and occurs in 1-3 % of all open mesh implantations. For this reason, topical antimicrobial agent applied directly to the mesh is often used procedure. So far, however, this procedure lacks a scientific basis. MATERIALS AND METHODS: Two different meshes (Parietex™, Covidien; Ultrapro™, Ethicon Johnson & Johnson) were incubated with increasing amounts of three different Staphylococcus aureus strains (ATCC 25923; Mu50; ST239) with or without gentamicin and growth ability were determined in vitro. To further address the question of the systemic impact of topic gentamicin, serum levels were analyzed 6 and 24 h after implantation of gentamicin-impregnated multifilament meshes in 19 patients. RESULTS: None of the gentamicin-impregnated meshes showed any bacterial growth in vitro. This effect was independent of the mesh type for all the tested S. aureus strains. In the clinical setting, serum gentamicin levels 6 h after implantation of the gentamicin-impregnated meshes were below the through-level (range 0.4-2.9 mg/l, mean 1.2 ± 0.7 mg/l). After 24 h the gentamicin serum levels in all patients had declined 90-65 % of the 6 h values. CONCLUSION: Local application of gentamicin to meshes can completely prevent the growth of even gentamicin-resistant S. aureus strains in vitro. The systemic relevance of gentamicin in the clinical controls showed to be very low, without reaching therapeutic concentrations.

Early repair of open abdomen with a tailored two-component mesh and conditioning vacuum packing: a safe alternative to the planned giant ventral hernia.

PURPOSE: Once open abdomen therapy has succeeded, the problem of closing the abdominal wall must be addressed. We present a new four-stage procedure involving the application of a two-component mesh and vacuum conditioning for abdominal wall closure of even large defects. The aim is to prevent the development of a giant ventral hernia and the eventual need for the repair of the abdominal wall. METHODS: Nineteen of 62 patients treated by open abdomen over a two-year period could not receive primary abdominal wall closure. To achieve closure in these patients, we applied the following four-stage procedure: stage 1: abdominal damage control and conditioning of the abdominal wall; stage 2: attachment of a tailored two-component mesh of polyglycolic acid (PGA) and large pore polypropylene (PP) in intraperitoneal position (IPOM) plus placement of a vacuum bandage; stage 3: vacuum therapy for 3-4 weeks to allow granulation of the mesh and optimization of dermatotraction; stage 4: final skin suture. During stage 3, eligible patients were weaned from respirator and mobilized. RESULTS: The abdominal wall gap in the 19 patients ranged in size from 240 cm(2) to more than 900 cm(2). An average of 3.44 vacuum dressing changes over 19 days were required to achieve 60-100 % granulation of the surface area, so final skin suture could be made. Already in stage 3, 14 patients (73.68 %) could be weaned from respirator an average of 6.78 days after placement of the two-component mesh; 6 patients (31.57 %) could be mobilized on the edge of the bed and/or to a bedside chair after an average of 13 days. No mesh-related hematomas, seromas, or intestinal fistulas were observed. CONCLUSION: The four-stage procedure presented here is a viable option for achieving abdominal wall closure in patients treated with open abdomen, enabling us to avoid the development of planned giant ventral hernias. It has few complications and has the special advantage of allowing mobilization of the patients before final skin closure. Long-term course in a large number of patients must still confirm this result.

[Management of mesh-related infections]. / Therapie der Netz(-Implantat)-Infektion.

Infections of an implanted hernia mesh are a major challenge. The incidence of mesh infections after incisional hernia repair is about 1% for endoscopic techniques and can be more than 15% in open techniques. Intraoperative mesh contamination is considered to be the primary cause. All woven or knitted hernia meshes have recesses where bacteria may adhere and establish colonies. The bacterial spectrum for mesh infection includes skin pathogens, such as Staphylococcus aureus (including MRSA), Streptococcus spp., as well as E. coli, Enterococcus and Mycobacteria. The therapy approach needs to be tailored to the morphological findings and the treatment for uncomplicated phlegmon is broad spectrum antibiotic therapy. If there is encapsulated fluid accumulation, CT-controlled drainage and daily infusion of antiseptics via the drain is a good option. For dermal necrosis, mesh fistula, exposed mesh or enterocutaneous fistula, a precise CT evaluation is necessary to tailor the operation. Vacuum systems are gaining increased acceptance in conditioning the local findings. For most patients the therapeutic concept will be based on individual decisions. If parts of a formerly infected mesh remain in the patient, a lifelong follow-up is necessary.