Effects of macroporous monofilament mesh on infection in a contaminated field

'Flip-flap' hernia sac sandwich mesh hernioplasty for giant incisional hernia

Purpose: The treatment of giant ventral hernia (GVH) with domain loss is a challenge for surgeons. This modified and simplified form of sandwich technique in a form of flip-flap repair was done to assess the outcomes of GVH repair by using the hernia sac taking into account the late complications in terms of recurrence, mesh explantation and early: SSO (surgical site occurrence). Material and method: A total of 21 patients of GVH were treated with flip-flap repair technique in the department of surgery in a teaching hospital in the central India between December 16 to June 21. In flip-flap technique the hernia sac is tailored in the best possible way, by making multiple layered flaps encasing the Polypropylene mesh in between, separating it from intraperitoneal contents and subcutaneous tissue. Results: In this prospective and interventional study, the collected data revealed the mean follow up period of 22.3 months (7months to 48months). Mean age was 44.2years (27-65 years). SSO was seen in 38% of cases mainly in the form of SSI. No explantation of mesh and recurrence was seen in any patient. Conclusion: The flip-flap repair technique is safe and effective surgical technique that can be used for the treatment of GVH regardless of the size, BMI or position of hernia.

Simultaneous Treatment of Complex Incisional Hernia and Stoma Reversal

Purpose: The simultaneous repair of incisional hernias (IH) and the reconstruction of the intestinal transit may pose a challenge for many surgeons. Collaboration between units specialized in abdominal wall and colorectal surgery can favor simultaneous treatment. Methods: Descriptive study of patients undergoing simultaneous surgery of complex IH repair and intestinal transit reconstruction from the start of treatment in a joint team. All interventions were performed electively and with the collaboration of surgeons experts in abdominal wall and colorectal surgery. Results: 23 patients are included. 11 end colostomies, 1 loop colostomy, 6 end ileostomies and 5 loop ileostomies. Seven (30%) patients presented with a medial laparotomy incisional hernia, 3 (13%) with a parastomal incisional hernia, and 13 (56%) with a medial and parastomal incisional hernia. Closure of the hernial defect was achieved in 100% of cases, and reconstruction of the intestinal tract was achieved in 22 (95%). Component separation was required in 17 patients (74%), which were 11 (48%) posterior and 6 (26%) anterior. In-hospital morbidity was 9%, and only two patients presented Clavien-Dindo morbidity > III when requiring reoperation, one due to hemorrhage of the surgical bed and another due to dehiscence of the coloproctostomy. The mean follow-up was 11 months, with 20 (87%) patients having no complications. Mesh had to be removed in one patient with anastomotic dehiscence, no mesh had to be removed due to surgical site infection.

Surgical site infection in mesh repair for ventral hernia in contaminated field: A systematic review and meta-analysis

BACKGROUND

Given the risk of surgical site infection (SSI), the use of mesh in contaminated ventral hernia repair (VHR) is not standardized and still a clinical dilemma. This meta-analysis aimed to assess whether mesh use increased the risk of SSI in patients following VHR in contaminated field.

METHODS

We performed a systematic review of published literature. Studies comparing the mesh repair and anatomic repair, the use of mesh in different Center for Disease Control and Prevention (CDC) wound classes and mesh repair with synthetic mesh or other type of meshes to treat complicated and contaminated VHR were considered for analysis. The main outcome was SSI incidence.

RESULTS

Six studies compared mesh and suture repairs. No significant difference in SSI incidence was observed between patients with complicated VHR in the mesh and suture repair groups.Five studies analyzed mesh repair in patients by field contamination level. There was no significant difference between the use of mesh in clean-contaminated, contaminated and dirty field versus clean wound class. Moreover, there was no significant difference between the use of mesh in clean-contaminated and contaminated cases.Four studies compared mesh repair technique with synthetic mesh or other type of meshes were included. The incidence of SSI was significantly lower in the synthetic mesh group.

CONCLUSIONS

The use of mesh repair in the management of complicated VHR compared to suture repair is not associated with an increased incidence of SSI even in potentially contaminated fields.

Evaluation of a Biocomposite Mesh Modified with Decellularized Human Amniotic Membrane for Intraperitoneal Onlay Mesh Repair

Various materials and approaches have been used to optimize the biocompatibility of mesh to reduce the implant-induced host response in intraperitoneal onlay mesh (IPOM) repair. Ineffective host integration, limited resistance to contamination, and untargeted administration hinder the wider application of the currently available clinical options. In this study, human amniotic membrane (HAM) was decellularized, fully characterized, and compared with porcine small intestinal submucosa (SIS) in terms of its structure, components, and bioactivity. In an in vivo study, HAM was reinforced with silk fibroin (SF) membrane, which was fabricated as a biodegradable submicroscale template by electrospinning, to construct a bilayer composite mesh. The independent SF membrane, associated with HAM and SIS, was evaluated for tissue remodeling in vitro. The HAM-SF and SIS meshes were then characterized morphologically and implanted intraperitoneally into Sprague-Dawley rats for 28 days for macroscopic investigation of their integration into the host via interactions of regulatory factors. After decellularization, HAM formed a bioagent-rich collagen-based acellular structure. HAM was superior to SIS in concurrently suppressing the expression of transforming growth factor β1 (TGF-β1) and proangiogenic proliferation. When HAM, SF, and SIS were used as regenerative scaffolds, they showed qualified biocompatibility, cell infiltration, and degradation in vitro. Comparatively, macroscopic observation after implantation indicated that HAM-SF induced less-intensive intraperitoneal adhesion and weaker inflammatory responses at the interface but greater angiogenesis in the explant than SIS. Analysis of the expression of regulatory factors showed a greater quantity of hepatocyte growth factor (HGF) in HAM, which partly inhibited the expression of TGF-β1 and promoted vascular endothelial growth factor (VEGF)-induced angiogenesis. This bioactive interaction appeared to be responsible for the better host integration, making HAM more biocompatible than SIS in IPOM repair. When combined with SF, HAM displayed similar mechanical properties to SIS. In conclusion, HAM displayed better bioactivity and biocompatibility than SIS. After its reinforcement with SF, HAM-SF is a promising biocomposite mesh for IPOM repair.

Meshes in a mess: Mesenchymal stem cell-based therapies for soft tissue reinforcement

Surgical meshes are frequently used for the treatment of abdominal hernias, pelvic organ prolapse, and stress urinary incontinence. Though these meshes are designed for tissue reinforcement, many complications have been reported. Both differentiated cell- and mesenchymal stem cell-based therapies have become attractive tools to improve their biocompatibility and tissue integration, minimizing adverse inflammatory reactions. However, current studies are highly heterogeneous, making it difficult to establish comparisons between cell types or cell coating methodologies. Moreover, only a few studies have been performed in clinically relevant animal models, leading to contradictory results. Finally, a thorough understanding of the biological mechanisms of mesenchymal stem cells in the context of foreign body reaction is lacking. This review aims to summarize in vitro and in vivo studies involving the use of differentiated and mesenchymal stem cells in combination with surgical meshes. According to preclinical and clinical studies and considering the therapeutic potential of mesenchymal stem cells, it is expected that these cells will become valuable tools in the treatment of pathologies requiring tissue reinforcement. STATEMENT OF SIGNIFICANCE: The implantation of surgical meshes is the standard procedure to reinforce tissue defects such as hernias. However, an adverse inflammatory response secondary to this implantation is frequently observed, leading to a strong discomfort and chronic pain in the patients. In many cases, an additional surgical intervention is needed to remove the mesh. Both differentiated cell- and stem cell-based therapies have become attractive tools to improve biocompatibility and tissue integration, minimizing adverse inflammatory reactions. However, current studies are incredibly heterogeneous and it is difficult to establish a comparison between cell types or cell coating methodologies. This review aims to summarize in vitro and in vivo studies where differentiated and stem cells have been combined with surgical meshes.

Minimally invasive techniques and indocyanine angiography in anterior abdominal wall reconstruction after multiple laparotomies

Anterior abdominal wall reconstruction surgery in patients who have undergone multiple laparotomies is associated with a high risk of complications. For this reason, minimally invasive surgery techniques are used to avoid abdominal compartment syndrome, to enhance wound healing and to reduce postoperative pain and blood loss. This paper presents a case of a patient who was admitted to the Department of General Surgery in Puck Hospital as a result of extensive anterior abdominal wall deformation with an end descending colostomy. A single-stage procedure was performed: specifically, digestive tract reconstruction followed by anterior abdominal wall reconstruction using intraoperative angiography of indocyanine green in infrared light.

A critical review of the in vitro and in vivo models for the evaluation of anti-infective meshes

BACKGROUND

Infectious complications following mesh implantation for abdominal wall repair appear in 0.7 up to 26.6% of hernia repairs and can have a detrimental impact for the patient. To prevent or to treat mesh-related infection, the scientific community is currently developing a veritable arsenal of antibacterial meshes. The numerous and increasing reports published every year describing new technologies indicate a clear clinical need, and an academic interest in solving this problem. Nevertheless, to really appreciate, to challenge, to compare and to optimize the antibacterial properties of next generation meshes, it is important to know which models are available and to understand them.

PURPOSE

We proposed for the first time, a complete overview focusing only on the in vitro and in vivo models which have been employed specifically in the field of antibacterial meshes for hernia repair.

RESULTS AND CONCLUSION

From this investigation, it is clear that there has been vast progress and breadth in new technologies and models to test them. However, it also shows that standardization or adoption of a more restricted number of models would improve comparability and be a benefit to the field of study.

Mesh Infection and Hernia Repair: A Review

BACKGROUND

The use of a prosthetic mesh to repair a tissue defect may produce a series of post-operative complications, among which infection is the most feared and one of the most devastating. When occurring, bacterial adherence and biofilm formation on the mesh surface affect the implant's tissue integration and host tissue regeneration, making preventive measures to control prosthetic infection a major goal of prosthetic mesh improvement.

METHODS

This article reviews the literature on the infection of prosthetic meshes used in hernia repair to describe the in vitro and in vivo models used to examine bacterial adherence and biofilm formation on the surface of different biomaterials. Also discussed are the prophylactic measures used to control implant infection ranging from meshes soaked in antibiotics to mesh coatings that release antimicrobial agents in a controlled manner.

RESULTS

Prosthetic architecture has a direct effect on bacterial adherence and biofilm formation. Absorbable synthetic materials are more prone to bacterial colonization than non-absorbable materials. The reported behavior of collagen biomeshes, also called xenografts, in a contaminated environment has been contradictory, and their use in this setting needs further clinical investigation. New prophylactic mesh designs include surface modifications with an anti-adhesive substance or pre-treatment with antibacterial agents or metal coatings.

CONCLUSIONS

The use of polymer coatings that slowly release non-antibiotic drugs seems to be a good strategy to prevent implant contamination and reduce the onset of resistant bacterial strains. Even though the prophylactic designs described in this review are mainly focused on hernia repair meshes, these strategies can be extrapolated to other implantable devices, regardless of their design, shape or dimension.