Critical analysis of Strattice performance in complex abdominal wall reconstruction: intermediate-risk patients and early complications

Skin substitutes: from conventional to 3D bioprinting

Three-dimensional bioprinting is getting enormous attention among the scientific community for its application in complex regenerative tissue engineering applications. One of the focus areas of 3-D bioprinting is Skin tissue engineering. Skin is the largest external organ and also the outer protective layer is prone to injuries due to accidents, burns, pathologic diseases like diabetes, and immobilization of patients due to other health conditions, etc. The demand for skin tissue and the need for an off-the-shelf skin construct to treat patients is increasing on an alarming basis. Conventional approaches like skin grafting increase morbidity. Other approaches include acellular grafts, where integration with the host tissue is a major concern. The emerging technology of the future is 3D bioprinting, where different biopolymers or hybrid polymers together provide the properties of extracellular matrix (ECM) and tissue microenvironment needed for cellular growth and proliferation. This raises the hope for the possibility of a shelf skin construct, which can be used on demand or even skin can be printed directly on the wound site (in-situ printing) based on the depth and complex structure of the wound site. In the present review article, we have tried to provide an overview of Skin tissue engineering, Conventional advancement in technology, 3D bioprinting and bioprinters for skin 3D printing, different biomaterials for skin 3D bioprinting applications, desirable properties of biomaterials and future challenges.

Pioneering a paradigm shift in tissue engineering and regeneration with polysaccharides and proteins-based scaffolds: A comprehensive review

In the realm of modern medicine, tissue engineering and regeneration stands as a beacon of hope, offering the promise of restoring form and function to damaged or diseased organs and tissues. Central to this revolutionary field are biological macromolecules-nature's own blueprints for regeneration. The growing interest in bio-derived macromolecules and their composites is driven by their environmentally friendly qualities, renewable nature, minimal carbon footprint, and widespread availability in our ecosystem. Capitalizing on these unique attributes, specific composites can be tailored and enhanced for potential utilization in the realm of tissue engineering (TE). This review predominantly concentrates on the present research trends involving TE scaffolds constructed from polysaccharides, proteins and glycosaminoglycans. It provides an overview of the prerequisites, production methods, and TE applications associated with a range of biological macromolecules. Furthermore, it tackles the challenges and opportunities arising from the adoption of these biomaterials in the field of TE. This review also presents a novel perspective on the development of functional biomaterials with broad applicability across various biomedical applications.

Outcomes of Abdominal Wall Reconstruction with a Bovine versus a Porcine Acellular Dermal Matrix: A Propensity Score-Matched Analysis

BACKGROUND

Abdominal wall reconstruction (AWR) is one of the most commonly performed procedures, yet large comparative studies comparing outcomes of AWR using bovine acellular dermal matrix (BADM) and porcine acellular dermal matrix (PADM) are lacking.

METHODS

In this retrospective cohort study of patients who underwent AWR from March of 2005 to June of 2019, the primary comparative outcome measure was hernia recurrence with BADM versus PADM. The secondary outcome was the incidence of surgical-site occurrence (SSO) and surgical-site infection. A propensity score matching approach was applied to compare the clinical outcomes between the two study groups.

RESULTS

The authors identified 725 patients who underwent AWR using BADM (50.5%) or PADM (49.5%). Their mean ± SD age was 59.8 ± 11.5 years, mean body mass index was 31.4 ± 6.7 kg/m 2 , and mean follow-up time was 42 ± 29 months. With propensity score matching, 219 matched pairs were identified. Hernia recurrence rates in BADM (11.4%) and PADM (13.7%) groups did not differ significantly ( P = 0.793). SSO (26.5% versus 29.2%; P = 0.518) and SSI (13.2% versus 11%; P = 0.456) rates did not differ significantly in the PADM and BADM groups, respectively. Conditional logistic regression model and marginal Cox proportional hazards regression model determined that type of acellular dermal matrix was not significantly associated with SSOs (adjusted OR, 1.11; 95% CI, 0.74 to 1.70; P = 0.589) or hernia recurrence (adjusted hazard ratio, 0.85; 95% CI, 0.50 to 1.42; P = 0.52).

CONCLUSIONS

Both BADMs and PADMs provide durable, long-term outcomes. The hernia recurrence and postoperative surgical complication rates were not significantly different between BADM and PADM.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Semiresorbable biologic hybrid meshes for ventral abdominal hernia repair in potentially contaminated settings: lower risk of recurrence

In case of potential contamination, implantation of synthetic meshes in hernia and abdominal wall surgery is problematic due to a higher risk of mesh infection. As an alternative, a variety of different biologic meshes have been used. However, relevant data comparing outcome after implantation of these meshes are lacking. Between January 2012 and October 2021, biologic meshes were used for reconstruction of the abdominal wall in 71 patients with preoperative or intraoperative abdominal contamination. In this retrospective study, semiresorbable biologic hybrid meshes (BHM) and completely resorbable meshes (CRM) were compared and analyzed using a Castor EDC database. In 28 patients, semiresorbable biologic hybrid meshes were used; in 43 patients, completely resorbable meshes were used. Both groups showed no difference in age, gender, BMI, operation duration, hernia size and Charlson comorbidity index. The risk degree of surgical-site occurrences was graded according to the Ventral Hernia Working Group (VHWG) classification, and the median value was 3 (range 2-4) in the BHM group and 3 (range 2-4) in the CRM group. Hernia recurrence within 24 months after hernia repair was significantly lower in the BHM group (3.6% vs. 28.9%; p = 0.03), while postoperative complication rate, with respect to seromas in need of therapy (61.4% vs. 55.5%, p = 0.43) and operative revision (28.6% vs. 16.3%, p = 0.22) was not different in either group. Biologic hybrid meshes can be used safely in case of possible contamination. BHM seems to reduce the risk of hernia recurrence compared to completely resorbable biologic meshes, but this has to be investigated further.

Biomaterials-Based Regenerative Strategies for Skin Tissue Wound Healing

Skin tissue wound healing proceeds through four major stages, including hematoma formation, inflammation, and neo-tissue formation, and culminates with tissue remodeling. These four steps significantly overlap with each other and are aided by various factors such as cells, cytokines (both anti- and pro-inflammatory), and growth factors that aid in the neo-tissue formation. In all these stages, advanced biomaterials provide several functional advantages, such as removing wound exudates, providing cover, transporting oxygen to the wound site, and preventing infection from microbes. In addition, advanced biomaterials serve as vehicles to carry proteins/drug molecules/growth factors and/or antimicrobial agents to the target wound site. In this review, we report recent advancements in biomaterials-based regenerative strategies that augment the skin tissue wound healing process. In conjunction with other medical sciences, designing nanoengineered biomaterials is gaining significant attention for providing numerous functionalities to trigger wound repair. In this regard, we highlight the advent of nanomaterial-based constructs for wound healing, especially those that are being evaluated in clinical settings. Herein, we also emphasize the competence and versatility of the three-dimensional (3D) bioprinting technique for advanced wound management. Finally, we discuss the challenges and clinical perspective of various biomaterial-based wound dressings, along with prospective future directions. With regenerative strategies that utilize a cocktail of cell sources, antimicrobial agents, drugs, and/or growth factors, it is expected that significant patient-specific strategies will be developed in the near future, resulting in complete wound healing with no scar tissue formation.

What is the evidence for the use of biologic or biosynthetic meshes in abdominal wall reconstruction?

INTRODUCTION

Although many surgeons have adopted the use of biologic and biosynthetic meshes in complex abdominal wall hernia repair, others have questioned the use of these products. Criticism is addressed in several review articles on the poor standard of studies reporting on the use of biologic meshes for different abdominal wall repairs. The aim of this consensus review is to conduct an evidence-based analysis of the efficacy of biologic and biosynthetic meshes in predefined clinical situations.

METHODS

A European working group, "BioMesh Study Group", composed of invited surgeons with a special interest in surgical meshes, formulated key questions, and forwarded them for processing in subgroups. In January 2016, a workshop was held in Berlin where the findings were presented, discussed, and voted on for consensus. Findings were set out in writing by the subgroups followed by consensus being reached. For the review, 114 studies and background analyses were used.

RESULTS

The cumulative data regarding biologic mesh under contaminated conditions do not support the claim that it is better than synthetic mesh. Biologic mesh use should be avoided when bridging is needed. In inguinal hernia repair biologic and biosynthetic meshes do not have a clear advantage over the synthetic meshes. For prevention of incisional or parastomal hernias, there is no evidence to support the use of biologic/biosynthetic meshes. In complex abdominal wall hernia repairs (incarcerated hernia, parastomal hernia, infected mesh, open abdomen, enterocutaneous fistula, and component separation technique), biologic and biosynthetic meshes do not provide a superior alternative to synthetic meshes.

CONCLUSION

The routine use of biologic and biosynthetic meshes cannot be recommended.

Non-crosslinked porcine acellular dermal matrix in pediatric abdominal wall reconstruction: a case series

INTRODUCTION

The use of biologic mesh where native tissue deficiencies limit reconstructive options has been well documented in the adult population, with increasing use to address the special requirements of complex abdominal wall reconstruction. There is, however, little documented evidence as to the safety and efficacy of these products in the pediatric population.

METHODS

This retrospective case series details 5 pediatric cases of complicated abdominal hernia repair with Strattice®, a non-crosslinked porcine acellular dermal matrix. Outcomes measured include recurrence, infection, seroma formation, symptomatic bulging, and need for mesh removal. Defect size, mesh size, and history of prior abdominal operations and infection were also recorded.

RESULTS

Patients received Strattice® with an average area of 132.2 (24-250)cm² and primary closure was achieved over a mesh underlay in three (60%) patients, while the remaining required a bridging approach secondary to lateral defects. Complications included suture extrusion, requiring suture removal, hernia recurrence without bulge, noted incidentally, and seroma formation, requiring placement of drains.

DISCUSSION/CONCLUSIONS

In conclusion, the use of porcine ADM in pediatric patients appears to be potentially safe and efficacious in the context of complex abdominal wall defects, including those with substantial contamination. Our small series builds on previous reports in this difficult patient population. Although additional study, with larger subject pools, would assist in solidifying the observations seen in this and other series, initial findings suggest that porcine ADM is a valuable tool in the treatment of these complex patients.

LEVEL OF EVIDENCE

Case series: Treatment study, Level IV.