Absorbable Polyglactin vs. Non-Cross-linked Porcine Biological Mesh for the Surgical Treatment of Infected Incisional Hernia

Emerging materials and technologies for advancing bioresorbable surgical meshes

Surgical meshes play a significant role in the treatment of various medical conditions, such as hernias, pelvic floor issues, guided bone regeneration, and wound healing. To date, commercial surgical meshes are typically made of non-absorbable synthetic polymers, notably polypropylene and polytetrafluoroethylene, which are associated with postoperative complications, such as infections. Biological meshes, based on native tissues, have been employed to overcome such complications, though mechanical strength has been a main disadvantage. The right balance in mechanical and biological performances has been achieved by the advent of bioresorbable meshes. Despite improvements, recurrence of clinical complications associated with surgical meshes raises significant concerns regarding the technical adequacy of current materials and designs, pointing to a crucial need for further development. To this end, current research focuses on the design of meshes capable of biomimicking native tissue and facilitating the healing process without post-operative complications. Researchers are actively investigating advanced bioresorbable materials, both synthetic polymers and natural biopolymers, while also exploring the performance of therapeutic agents, surface modification methods and advanced manufacturing technologies such as 4D printing. This review seeks to evaluate emerging biomaterials and technologies for enhancing the performance and clinical applicability of the next-generation surgical meshes. STATEMENT OF SIGNIFICANCE: In the ever-transforming landscape of regenerative medicine, the embracing of engineered bioabsorbable surgical meshes stands as a key milestone in addressing persistent challenges and complications associated with existing treatments. The urgency to move beyond conventional non-absorbable meshes, fraught with post-surgery complications, emphasises the necessity of using advanced biomaterials for engineered tissue regeneration. This review critically examines the growing field of absorbable surgical meshes, considering their potential to transform clinical practice. By strategically combining mechanical strength with bioresorbable characteristics, these innovative meshes hold the promise of mitigating complications and improving patient outcomes across diverse medical applications. As we navigate the complexities of modern medicine, this exploration of engineered absorbable meshes emerges as a promising approach, offering an overall perspective on biomaterials, technologies, and strategies adopted to redefine the future of surgical meshes.

The Effects of Tissue Healing Factors in Wound Repair Involving Absorbable Meshes: A Narrative Review

Wound healing is a complex and meticulously orchestrated process involving multiple phases and cellular interactions. This narrative review explores the intricate mechanisms behind wound healing, emphasizing the significance of cellular processes and molecular factors. The phases of wound healing are discussed, focusing on the roles of immune cells, growth factors, and extracellular matrix components. Cellular shape alterations driven by cytoskeletal modulation and the influence of the 'Formin' protein family are highlighted for their impact on wound healing processes. This review delves into the use of absorbable meshes in wound repair, discussing their categories and applications in different surgical scenarios. Interleukins (IL-2 and IL-6), CD31, CD34, platelet rich plasma (PRP), and adipose tissue-derived mesenchymal stem cells (ADSCs) are discussed in their respective roles in wound healing. The interactions between these factors and their potential synergies with absorbable meshes are explored, shedding light on how these combinations might enhance the healing process. Recent advances and challenges in the field are also presented, including insights into mesh integration, biocompatibility, infection prevention, and postoperative complications. This review underscores the importance of patient-specific factors and surgical techniques in optimizing mesh placement and healing outcomes. As wound healing remains a dynamic field, this narrative review provides a comprehensive overview of the current understanding and potential avenues for future research and clinical applications.

Management of enteroatmospheric fistula: A ten-year experience following fifteen years of learning

BACKGROUND

Enteroatmospheric fistulas are a serious complication of Open Abdomen. The goal of this study was to present the strategy and results of enteroatmospheric fistulas treatment during the last 10 years, after a long learning period.

METHODS

Seventy-seven patients with enteroatmospheric fistulas were treated and the data recorded between 2012 and 2021. For local treatment, 3 negative pressure methods were used, according to the wound characteristics. The results of conservative and surgical treatments were retrospectively identified and described, including nutritional recovery, morbidity and mortality. Predictors of spontaneous closure, as well as risk factors for the fistula's recurrence and mortality were analyzed.

RESULTS

Nutritional and clinical recovery was achieved in 66 patients (85.7%). Fourteen patients (18%) were healed without surgery after a median of 57 days (range 35-426 days). Unique lesions (13/46; P = .02, OR 10.23), initial output ≤700 mL/day (9/28; P = .0035, OR 3.79) and deep fistulas (9/12; P = .00001, OR 33.6) were encountered and acknowledged to be as spontaneous closure factors. Fifty-six patients (72.7%) required reconstructive surgery of the intestinal tract after a median of 187 days since last laparotomy (range: 63-455 days). There were 9 postoperative recurrences (16%), 5 of them closed with conservative treatment. No significant risk factors for recurrence nor postoperative mortality were found. Fistula complete closure was achieved in 63 of the 77 patients studied (81.8%), and 7 patients died (9%).

CONCLUSION

The combination of 3 vacuum methods used for enteroatmospheric fistula management was effective. Spontaneous closure of an enteroatmospheric fistula is unlikely but feasible when lesions are single, deep, with limited output, and when intestinal continuity is preserved. Surgical indications are well defined, although mortality and recurrence rates are still high.

In Situ Cross-Linked Collagen-Based Biological Patch Integrating Anti-Infection and Anti-Calcification Properties

Acellular dermal matrix (ADM) can be used as collagen-based biological patches for regeneration and repair of soft tissues in vivo. However, the problems of calcification and infection during treatment with patches can lead to premature patch failure and even to a severely increased risk of recurrence. In this study, first, porcine ADM (pADM) grafted with vinyl underwent an in situ cross-linking reaction in the presence of an initiator, while quaternary ammonium groups were introduced into the pADM during the cross-linking process to obtain MA-DMC-pADM, which is a biological patch with anti-infection and anti-calcification properties. The results of physicochemical property tests of the material showed that the pADM after cross-linking had better physical and mechanical properties. Importantly, antibacterial and anti-calcification experiments showed that MA-DMC-pADM had a good antibacterial and anti-calcification effect. Therefore, the MA-DMC-pADM biological patch facilitates their longer-lasting effectiveness, allowing pADM to be used in a wider range of applications.

Ventral hernia repair in high-risk patients and contaminated fields using a single mesh: proportional meta-analysis

PURPOSE

The use of mesh is a common practice in ventral hernia repair (VHR). Lack of consensus on which prosthetic material works better in different settings remains. This meta-analysis aims to summarize the available evidence on hernia recurrence and complications after repair with synthetic, biologic, or biosynthetic/bioabsorbable meshes in hernias grade 2-3 of the Ventral Hernia Working Group modified classification.

METHODS

A literature search was conducted in January 2021 using Web of Science (WoS), Scopus, and MEDLINE (via PubMed) databases. Randomized Controlled Trials (RCTs) and observational studies with adult patients undergoing VHR with either synthetic, biologic, or biosynthetic/bioabsorbable mesh were included. Outcomes were hernia recurrence, Surgical Site Occurrence (SSO), Surgical Site Infection (SSI), 30 days re-intervention, and infected mesh removal. Random-effects meta-analyses of pooled proportions were performed. Quality of the studies was assessed, and heterogeneity was explored through sensitivity analyses.

RESULTS

25 articles were eligible for inclusion. Mean age ranged from 47 to 64 years and participants' follow-up ranged from 1 to 36 months. Biosynthetic/bioabsorbable mesh reported a 9% (95% CI 2-19%) rate of hernia recurrence, lower than synthetic and biologic meshes. Biosynthetic/bioabsorbable mesh repair also showed a lower incidence of SSI, with a 14% (95% CI 6-24%) rate, and there was no evidence of infected mesh removal. Rates of seroma were similar for the different materials.

CONCLUSIONS

This meta-analysis did not show meaningful differences among materials. However, the best proportions towards lower recurrence and complication rates after grade 2-3 VHR were after using biosynthetic/slowly absorbable mesh reinforcement. These results should be taken with caution, as head-to-head comparative studies between biosynthetic and synthetic/biologic meshes are lacking. Although, biosynthetic/bioabsorbable materials could be considered an alternative to synthetic and biologic mesh reinforcement in these settings.

Slowly absorbable mesh versus standard care in the management of contaminated midline incisional hernia (COMpACT-BIO): a multicentre randomised controlled phase III trial including a health economic evaluation

INTRODUCTION

Incisional hernia (IH) is the most frequent mid-term and long-term complication after midline laparotomy. The current standard treatment includes repair using a mesh. In a contaminated field, the use of a non-absorbable mesh increases the risk of surgical site infection and the costs. Slowly absorbable meshes are safe in contaminated fields, but no data have been reported regarding their long-term recurrence rate. COMpACT-BIO is a multicentre prospective randomised controlled phase III trial designed to compare the 3-year recurrence rate in patients undergoing contaminated IH repair with either a slowly absorbable mesh or standard care.

METHODS

In patients undergoing midline IH repair in a contaminated surgical field (grade III of the modified Ventral Hernia Working Group classification), the COMpACT-BIO study compares the use of a slowly absorbable mesh with that of conventional care according to standardised surgical procedures (primary closure, non-absorbable synthetic mesh or biologic mesh, at the discretion of the surgeon). Randomisation is done during surgery before closure the fascia with an allocation ratio of 1:1. The choice of the slowly absorbable mesh is left to the criteria of each centre. The primary endpoint is the proportion of patients with scan-confirmed IH recurrence within 3 years after repair.

ETHICS/DISSEMINATION

This trial is conducted in compliance with international standards for research practice and reporting. Written informed consent will be obtained from patients prior to inclusion. All data were identified and anonymised prior to analysis. The protocol has been approved by an Institutional Review Board (2020-A0823-36/SI:20.07.03.66831), and will be conducted in compliance with the CONSORT (Consolidated Standards of Reporting Trials) statement. Results will be submitted for publication in peer-reviewed medical journals and presented to patients and healthcare professionals.

PROTOCOL VERSION

Version 2-13 October 2020.

TRIAL REGISTRATION NUMBER

NCT04597840.

An Evaluation of the Evidence Guiding Adult Midline Ventral Hernia Repair

Purpose:  Several guidelines have been published in recent years to guide the clinician in ventral hernia repair. This review distils this advice, critically assesses their evidence base, and proposes avenues for future study. Methods:  A PUBMED search identified four guidelines addressing midline ventral hernia repair published by major surgical societies between 2016 and 2020. The studies used to inform the advice have been critically appraised, including 20 systematic reviews/meta-analyses, 10 randomized controlled trials, 32 cohort studies, and 14 case series. Results:  Despite a lack of randomized controlled trials, case heterogeneity, and variation in outcome reporting, key themes have emerged. Preoperative computed tomography scan assesses defect size, loss of domain, and the likely need for component separation. Prehabilitation, frailty assessment, and risk stratification are beneficial in complex cases. Minimally invasive component separation techniques, Botox injection, and progressive pneumoperitoneum represent novel techniques to promote closure of large fascial defects. Rives-Stoppa sublay mesh repair has become the "gold" standard for open and minimally invasive repairs. Laparoscopic repair promotes early return to functional status. The enhanced-view totally extraperitoneal approach facilitates laparoscopic sublay mesh placement, avoiding mesh contact with viscera. Robotic techniques continue to evolve, although the evidence at present remains immature. Synthetic mesh is recommended for use in clean and clean-contaminated cases. However, optimism regarding the use of biologic and biosynthetic meshes in the contaminated setting has waned. Conclusions:  Surgical techniques in ventral hernia repair have advanced in recent years. High-quality data has struggled to keep pace; rigorous clinical trials are required to support the surgical innovation.

Incisional Hernia Repaired Using Thigh Muscle Fascia After Kidney Transplantation: A Case Report

BACKGROUND

Although monofilament mesh-based repair is a safe and effective procedure for incisional hernia (IH) in organ transplant patients, there is no definite evidence of IH treatment for patients with graft rejection and enhanced immunosuppressive therapy. We report a successful case of large IH repair using an autologous thigh muscle fascia sheet in a kidney transplant patient.

CASE PRESENTATION

A 69-year-old man had IH from the incision of kidney transplantation, which was performed 6 years ago. He had a large right lower abdominal distension hanging down to the inguinal portion. A computed tomography scan revealed a large IH with a maximum abdominal defect diameter of 15 cm. The hernia sac contained the intestine, colon, and transplanted kidney, which had pulled out along with the retroperitoneum and protruded into the abdominal wall. He had chronic active acute antibody-mediated rejection, which required frequent steroid pulse therapy and additional or adjusted immunosuppressive drugs. After total circumferential exposure of the hernia sac and abdominal fascia, the abdominal wall defect was closed using a horizontal mattress suture. The sutured line was covered with a thigh muscle fascia sheet harvested from the patient's right femur and attached to the closed fascia. He was discharged on postoperative day 13 without any complications, and no IH recurrence was observed 10 months after surgery.

CONCLUSIONS

Hernia repair using autologous tissue could be a treatment option for post-transplant IH with a higher risk of infection.

Clinical applications of acellular dermal matrices: A review

INTRODUCTION

The extracellular matrix (ECM) plays an integral role in wound healing. It provides both structure and growth factors that allow for the organised cell proliferation. Large or complex tissue defects may compromise host ECM, creating an environment that is unfavourable for the recovery of anatomical function and appearance. Acellular dermal matrices (ADMs) have been developed from a variety of sources, including human (HADM), porcine (PADM) and bovine (BADM), with multiple different processing protocols. The objective of this report is to provide an overview of current literature assessing the clinical utility of ADMs across a broad spectrum of applications.

METHODS

PubMed, MEDLINE, EMBASE, Scopus, Cochrane and Web of Science were searched using keywords 'acellular dermal matrix', 'acellular dermal matrices' and brand names for commercially available ADMs. Our search was limited to English language articles published from 1999 to 2020 and focused on clinical data.

RESULTS

A total of 2443 records underwent screening. After removing non-clinical studies and correspondence, 222 were assessed for eligibility. Of these, 170 were included in our synthesis of the literature. While the earliest ADMs were used in severe burn injuries, usage has expanded to a number of surgical subspecialties and procedures, including orthopaedic surgery (e.g. tendon and ligament reconstructions), otolaryngology, oral surgery (e.g. treating gingival recession), abdominal wall surgery (e.g. hernia repair), plastic surgery (e.g. breast reconstruction and penile augmentation), and chronic wounds (e.g. diabetic ulcers).

CONCLUSION

Our understanding of ADM's clinical utility continues to evolve. More research is needed to determine which ADM has the best outcomes for each clinical scenario.

LAY SUMMARY

Large or complex wounds present unique reconstructive and healing challenges. In normal healing, the extracellular matrix (ECM) provides both structural and growth factors that allow tissue to regenerate in an organised fashion to close the wound. In difficult or large soft-tissue defects, however, the ECM is often compromised. Acellular dermal matrix (ADM) products have been developed to mimic the benefits of host ECM, allowing for improved outcomes in a variety of clinical scenarios. This review summarises the current clinical evidence regarding commercially available ADMs in a wide variety of clinical contexts.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

Failure of Abdominal Wall Closure: Prevention and Management

This article reviews evidence-based techniques for abdominal closure and management strategies when abdominal wall closures fail. In particular, optimal primary fascial closure techniques, the role of prophylactic mesh, considerations for combined hernia repair, closure techniques when the fascia cannot be closed primarily, and management approaches for fascial dehiscence are reviewed.

Comparative study of biological versus synthetic prostheses in the treatment of ventral hernias classified as grade II/III by the Ventral Hernia Working Group

AIM OF THE STUDY

The implantation of biological prostheses in an at-risk environment has seen increasing use. Their markedly higher cost compared to synthetic prostheses makes it important to analyse their usefulness in terms of actual benefit and cost-effectiveness. This study aims to examine the relevance of bioprostheses during surgical repair of Grade II/III ventral hernias as classified by the Ventral hernia working group (VHWG).

MATERIALS AND METHODS

This study analysed the data of 119 patients requiring non-emergency repair of VHWG II/III grade hernias between 2010 and 2017. The results of patients who were treated with a bioprosthesis (n=59) were compared to those receiving a synthetic prosthesis (n=60). The primary outcome was surgical site infection (SSI) at 90 days. The secondary endpoints were hernia recurrence rate, cost of the prosthesis, duration of hospital stay and re-hospitalisation rate.

RESULTS

The two groups were shown to be comparable by analysis of demographic, pre- and intraoperative data. The SSI rate was significantly higher in the bioprosthesis group (20% vs. 7%; P=0.010), as was the recurrence rate (56% vs. 28%; P=0.003) with a median follow-up of 40 months. The cost of the bioprosthesis was significantly higher than that of the synthetic prosthesis (€3363 vs. €249; P<0.010).

CONCLUSION

In this retrospective study, the use of a bioprosthesis for repair of VHWG II/III ventral hernias was associated with a higher rate of both SSI and hernia recurrence at a cost 13 times greater than the use of a synthetic prosthesis.

A systematic review of outcome reporting in incisional hernia surgery

Background

The incidence of incisional hernia is up to 20 per cent after abdominal surgery. The management of patients with incisional hernia can be complex with an array of techniques and meshes available. Ensuring consistency in reporting outcomes across studies on incisional hernia is important and will enable appropriate interpretation, comparison and data synthesis across a range of clinical and operative treatment strategies.

Methods

Literature searches were performed in MEDLINE and EMBASE (from 1 January 2010 to 31 December 2019) and the Cochrane Central Register of Controlled Trials. All studies documenting clinical and patient-reported outcomes for incisional hernia were included.

Results

In total, 1340 studies were screened, of which 92 were included, reporting outcomes on 12 292 patients undergoing incisional hernia repair. Eight broad-based outcome domains were identified, including patient and clinical demographics, hernia-related symptoms, hernia morphology, recurrent incisional hernia, operative variables, postoperative variables, follow-up and patient-reported outcomes. Clinical outcomes such as hernia recurrence rates were reported in 80 studies (87 per cent). A total of nine different definitions for detecting hernia recurrence were identified. Patient-reported outcomes were reported in 31 studies (34 per cent), with 18 different assessment measures used.

Conclusions

This review demonstrates the significant heterogeneity in outcome reporting in incisional hernia studies, with significant variation in outcome assessment and definitions. This is coupled with significant under-reporting of patient-reported outcomes.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in emergency colorectal surgery

AIM

There is a requirement for an expansive and up to date review of the management of emergency colorectal conditions seen in adults. The primary objective is to provide detailed evidence-based guidelines for the target audience of general and colorectal surgeons who are responsible for an adult population and who practise in Great Britain and Ireland.

METHODS

Surgeons who are elected members of the Association of Coloproctology of Great Britain and Ireland Emergency Surgery Subcommittee were invited to contribute various sections to the guidelines. They were directed to produce a pathology-based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. Each author was asked to provide a set of recommendations which were evidence-based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after two votes were included in the guidelines.

RESULTS

All aspects of care (excluding abdominal trauma) for emergency colorectal conditions have been included along with 122 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence-based summary of the current surgical knowledge in the management of emergency colorectal conditions and should serve as practical text for clinicians managing colorectal conditions in the emergency setting.

Mesh Repair in Crohn's Disease: A Case-Matched Multicenter Study in 234 Patients

BACKGROUND

There are no specific guidelines for ventral hernia management in Crohn's disease (CD) patients. We aimed to assess the risk of septic morbidity after mesh repair in CD.

METHODS

This was a retrospective multicentre study comparing CD and non-CD patients undergoing mesh repair for ventral hernia (primary or incisional hernia). Controls were matched 1:1 for the presence of a stoma, history of surgical sepsis, hernia size and Ventral Hernia Working Group (VHWG) score. All demographic, pre-, intra- and postoperative data were retrieved, including long-term data.

RESULTS

We included 234 patients, with 114 CD patients. Both groups had comparable VHWG scores (p = 0.12), hernia sizes (p = 0.11), ASA scores ≥ 3 (p = 0.70), body mass index values (p = 0.14), presence of stoma (CD 21.9% vs. controls 15%, p = 0.16), history of sepsis (14% vs. 6.7%, p = 0.23), rates of malnutrition (4.4% vs. 1.7%, p = 0.46), rates of incisional hernia (93% vs. 95%, p = 0.68) and concomitant procedures (18.4% vs. 11.7%, p = 0.12). CD patients carried a higher risk of postoperative septic morbidity (18.4% vs. 5%, p = 0.001), entero-prosthetic fistula (7% vs. 0, p < 0.01) and mesh withdrawals (5.3% vs. 0, p = 0.011). Ventral hernia recurrence rates were similar (14% vs. 8.3%, p = 0.15). In the univariate analysis, the risk factors for septic morbidity were CD (p = 0.001), malnutrition (p = 0.004), use of biological mesh (p < 0.0001) and concomitant procedure (p = 0.004). The mesh position, the means used for mesh fixation as well as the presence of a stoma were not identified as risk factors.

CONCLUSIONS

CD seems to be a risk factor for septic morbidity after mesh repair.

What results can be expected one year after complex incisional hernia repair with biosynthetic mesh?

BACKGROUND

Incisional hernia is a frequent complication after midline laparotomy. The current standard repair includes the use of a synthetic mesh to prevent recurrence. However, the use of a synthetic mesh in a contaminated field carries a higher risk of mesh infection. In this setting biologic and biosynthetic meshes can be used as they resist to infection, but these are absorbable meshes. This raises the question of the risk of recurrence as the mesh disappears. Phasix® is a biosynthetic mesh getting absorbed in 12-18 months. The aim of this study was to assess the 1-year recurrence rate after abdominal-wall repair with a Phasix® mesh.

METHODS

All patients undergoing ventral hernia repair between 2016 and 2018 at the University Hospital of Dijon using a Phasix® mesh were prospectively included in a database. They were all followed-up with a physical exam and a routine CT scan at one year. All postoperative complications were recorded.

RESULTS

Twenty-nine patients were included in the study (55.2% women), with a mean BMI of 30,25 kg/m². Nineteen meshes were sublay and 10 intraperitoneal. Complications at 1 month were mainly mild: Clavien-Dindo I and II (61.1%). No mesh was explanted. There was no chronic infection. The mean length of stay was 11.5 days. The 1-year recurrence rate was 10.3%.

CONCLUSION

Patients having undergone complex ventral hernia repair with a Phasix® mesh have a 1-year recurrence rate of 10.3%. No severe surgical site occurrence was detected. A longer follow-up in a larger number of patients could confirm the place of this mesh in abdominal-wall repair.