Bovine fetal collagen reinforcement in a small animal model of hernia with component repair

Mesenchymal Stem Cells and Regenerative Therapy with Bilateral Gracilis Flaps for Perineal Reconstruction of a Wound Infection in the Setting of Anal Squamous Cell Carcinoma

ABSTRACT

Many patients are affected by HIV/AIDS, and these conditions are highly prevalent worldwide. Patients with HIV/AIDS can experience debilitating wound infections that often require flap reconstruction and become challenging for surgeons to treat. In the past 5 years, mesenchymal stem cells have been tested and used as regenerative therapy to promote the growth of tissues throughout the body because of their ability to successfully promote cellular mitogenesis. To the authors' knowledge, the use of mesenchymal stem cell grafting following necrosis of a myocutaneous gracilis flap (as part of perineal wound reconstruction) has never been reported in the literature.In addition, the use of mesenchymal stem cells and regenerative medicine combined in the setting of squamous cell carcinoma of the anus with prior radiation (along with comorbid AIDS) has not been previously documented.In this report, the authors outline the case of a 60-year-old patient who had a recipient bed (perineum) complication from prior radiation therapy. Complicating the clinical picture, the patient also developed a Pseudomonal organ space infection of the pelvis leading to the failure of a vertical rectus abdominis myocutaneous flap and myocutaneous gracilis flaps. As a result, the patient underwent serial operative debridements for source control, with the application of mesenchymal stem cells, fetal bovine dermis, porcine urinary bladder xenograft, and other regenerative medicine products, achieving a highly successful clinical outcome. A procedural description for future use and replication of this method is provided.

A paradigm shift for diaphragmatic and chest wall reconstruction using a bovine acellular dermal matrix: an analysis versus synthetic meshes

OBJECTIVES

Recently, biologic meshes have gained increasing popularity in soft tissue reconstruction. The aim of this study was to investigate the use of a bovine acellular dermal matrix (SurgiMend, Integra LifeSciences, Princeton, NJ, USA) in diaphragmatic and chest wall reconstruction by comparing it with synthetic meshes.

METHODS

Consecutive patients who underwent diaphragmatic and/or chest wall reconstruction at a single center from 2016 to 2021 were retrospectively reviewed. Outcome measures included surgical site complications, readmission, and reoperation.

RESULTS

Sixty-six patients underwent diaphragmatic and/or chest wall reconstruction for a malignant (74.2%) or benign (25.8%) disease. SurgiMend was used in 26 (39.4%) patients and a synthetic mesh in 40 (60.6%) patients. There were no significant differences in baseline characteristics between the groups. Surgical site complications included prolonged air leak (12.1%), pleural effusion (9.1%), pneumothorax (3%), empyema (1.5%), and wound infection (1.5%). The patients in the synthetic mesh group developed a significantly higher rate of surgical site complications compared to those in the SurgiMend group (37.5% vs. 11.5%; p = 0.025). Similarly, the readmission rate was significantly higher in the synthetic mesh group (17.5% vs. 0%; p = 0.037), with causes including pleural effusion (n = 3), pneumothorax (n = 2), empyema (n = 1), and pneumonia (n = 1). Among the study cohort, only 1 patient with a synthetic mesh underwent reoperation (p > 0.99).

CONCLUSIONS

The use of surgiMend in diaphragmatic and chest wall reconstruction is associated with fewer surgical site complications and readmissions compared to synthetic meshes.

In Vivo Evaluation of a Pectin-Honey Hydrogel Coating on Polypropylene Mesh in a Rat Model of Acute Hernia

Investigations about ventral hernia repair are focused on improving the quality, resistance, and biocompatibility of mesh. This study compared plain polypropylene mesh with a pectin-honey hydrogel-coated polypropylene mesh in an acute hernia model in rats. Forty Wistar rats, randomly assigned to two groups, were submitted to laparotomy, and a 1 cm × 2 cm fascial defect was created, centered on the midline. Uncoated (group C) or coated mesh (group T) was inserted in an inlay fashion to repair the defect. After 30 days, the rats were euthanized, and the presence of adhesions to the mesh was macroscopically evaluated. Histology and measurement of COX-2 as tissue inflammation markers were used to assess fascia tissue healing. Grades of adhesion were not different between groups. Histological score and COX-2 expression were not significantly different between groups, except for the higher inflammatory response demonstrated in group T. The pectin-hydrogel coated mesh could not reduce adhesion formation compared to uncoated polypropylene mesh but improved peritoneal regeneration and tissue healing.

The worst-case scenario: Bridging repair with a biologic mesh in high-risk patients with very large abdominal wall hernias-a prospective multicenter study

BACKGROUND

While modern techniques allow midline fascial closure for most abdominal hernias, a bridge repair with mesh may be the only alternative in very large defects. When the risk of infection is high, the use of prosthetic mesh is controversial. We aim to examine outcomes after bridge repair of very large abdominal hernias at high risk for postoperative infection with a second-generation biologic mesh.

METHODS

Prospective, multicenter, single-arm study of patients with very large abdominal hernias who received bridge repair with a neonatal bovine dermis mesh. Primary outcome was hernia recurrence, as identified on computed tomography 1 year after the operation. Secondary outcomes included mesh laxity, surgical site occurrences, and any other mesh-related complications. Independent risk factors of the outcomes were determined by univariate and multivariable analyses.

RESULTS

A total of 117 bridge repair patients were enrolled with a mean defect size of 442.5 ± 254.2 cm². The patients were predominantly obese (mean body mass index 36.5 ± 10.5) and with multiple comorbidities (Charlson comorbidity index 3 ± 2.5). Hernia recurrence was identified in 24 (20.5%) patients. An infected mesh at the index operation was an independent predictor of hernia recurrence, whereas obesity was an independent predictor of the pooled endpoint of recurrence and mesh laxity. Surgical site occurrences were recorded in 36.8% of the patients, and no independent risk factors were identified.

CONCLUSION

In patients with very large abdominal hernias and at high risk for postoperative infection, who cannot undergo midline fascial closure, a bridge repair with neonatal bovine dermis mesh offers an acceptable profile in terms of hernia recurrence and wound occurrences.

Fundamentals of Extracellular Matrix Biomaterial Assimilation: Effect of Suture Type on Attachment Strength and Cell Repopulation

The clinical results with extracellular matrix biomaterials are confounded by expectations of material response based on years of experience with permanent or degradable synthetic polymers. However, the remodeling or assimilation of extracellular matrix biomaterials is dictated by cell-mediated processes rather than fibrous encapsulation or hydrolytic degradation. Previously, we found that tissue adherence and revascularization were dictated by proximity with de-epithelialized host tissue. We now investigate the effects of polymer and fixation type on attachment strength and rate of cell repopulation in an intra-abdominal implant model.

Clinically available reinforcing materials for soft tissue reconstruction

Navigating the rapidly evolving field of materials for soft tissue reinforcement is challenging given the volume of clinically available options. Additionally, the current generally accepted classifications of these mesh materials confound the understanding of their utility by grouping disparate materials that have attributes overlapping category boundaries and that do not fully consider their clinically functionality. This review article highlights, from a materials science perspective, the most important attributes of these materials to improve the clinical decision-making process in the selection of the most appropriate features and design for the patient, surgery and clinical need. These characteristics include the physical attributes that directly impact the surgical procedure and immediate postoperative mechanical requirements as well as the post-implantation properties such as an adequate reinforcement time, strength of the resulting tissue and infection risk profile.

Bioprosthetic Versus Synthetic Mesh: Analysis of Tissue Adherence and Revascularization in an Experimental Animal Model

Supplemental Digital Content is available in the text.

Background:

Both synthetic and bioprosthetic meshes play important roles in surgical procedures such as ventral hernia repair. Although sometimes used interchangeably, these devices have inherently different properties. We therefore sought to better understand how these materials interact with the host environment to optimize surgical techniques and to improve outcomes.

Methods:

Synthetic mesh (polypropylene, Prolene) or bioprosthetic mesh (acellular fetal/neonatal bovine dermis, SurgiMend) was implanted intraperitoneally into rats lateral to a ventral incision in a novel intra-abdominal implant model. Two variables were modified with each material: (1) tight or loose tissue apposition, altered by modifying suture placement; and (2) abdominal wall injury, altered by selective abrasion of the peritoneal lining. After 5 weeks, the meshes and abdominal wall were evaluated grossly and histologically. The analysis focused on the degree of inflammatory response, neovascularization, and mesh adherence to the surrounding tissues.

Results:

Synthetic mesh adhered to the abdominal wall and visceral organs, regardless of the degree of apposition or tissue injury, due to a foreign body–mediated inflammatory reaction. In areas of noninjured peritoneal lining, SurgiMend was adherent peri-suture. Neovascularization entered the mesh from these apposition points and spread outward. In areas of denuded peritoneal lining, the adherent and vascularized areas were significantly greater and not merely coincident with suture placement.

Conclusions:

The inflammatory and wound healing responses with bioprosthetic mesh seem fundamentally different from synthetic mesh. Understanding these differences may lead to varied outcomes in adherence and vascularization of the materials, and ultimately the efficacy of hernia repair. Additionally, these differences highlight the need for further basic research to optimize mesh selection for surgical technique.

Protocol for a Randomized Phase II Trial for Mesh Optimization by Autologous Plasma Coating in Prolapse Repair: IDEAL Stage 3

INTRODUCTION

Mesh-related complications especially after vaginal implantation have raised awareness lately because of severe adverse reactions and legal aspects. About 20% of patients suffer from complications after mesh insertion in the anterior vaginal wall. Autologous plasma coating of meshes prior to implantation has shown potential to improve the biocompatibility of meshes in vivo and in vitro. This innovative approach has been developed according to the IDEAL recommendations for surgical innovations. The method has still to be assessed at stage 3 accordingly.

METHODS

A protocol is developed for a prospective single-blinded randomized controlled phase II trial for biocompatibility optimization of anterior vaginal meshes for prolapse repair by autologous plasma coating versus non-coated meshes.

RESULTS

The protocol aims at fulfilling the requirements for stage 3 (assessment) according to IDEAL. Eligible for inclusion are women with primary cystocele, requiring a surgical procedure, suitable for randomization, and willing to be randomized. Participants will be followed up by postal questionnaires (6 months post surgery and 12 months post randomization) and will also be reviewed in clinic 12 and 24 months post surgery. Primary endpoint is the assessment of mesh-related complications following the Clavien-Dindo classifications. QoL, sexual function assessment, efficacy, and validation of an already developed long-term register are considered secondary endpoints. To afford a calculated 10% reduction of postoperative complications through plasma-coated meshes vs. non-coated meshes at 1-year follow-up, a total 214 women in each arm will be necessary to achieve 80% power at a significance level of 5%.

CONCLUSION

The protocol for this randomized clinical trial represents the conditions to assess the surgical innovation of plasma coating of meshes in order to improve the meshes' biocompatibility at stage 3 according to the IDEAL recommendations.