Abdominal wall hernia repair: from prosthetic meshes to smart materials

Abstract

Hernia reconstruction is one of the most frequently practiced surgical procedures worldwide. Plastic surgery plays a pivotal role in reestablishing desired abdominal wall structure and function without the drawbacks traditionally associated with general surgery as excessive tension, postoperative pain, poor repair outcomes, and frequent recurrence. Surgical meshes have been the preferential choice for abdominal wall hernia repair to achieve the physical integrity and equivalent components of musculofascial layers. Despite the relevant progress in recent years, there are still unsolved challenges in surgical mesh design and complication settlement. This review provides a systemic summary of the hernia surgical mesh development deeply related to abdominal wall hernia pathology and classification. Commercial meshes, the first-generation prosthetic materials, and the most commonly used repair materials in the clinic are described in detail, addressing constrain side effects and rational strategies to establish characteristics of ideal hernia repair meshes. The engineered prosthetics are defined as a transit to the biomimetic smart hernia repair scaffolds with specific advantages and disadvantages, including hydrogel scaffolds, electrospinning membranes, and three-dimensional patches. Lastly, this review critically outlines the future research direction for successful hernia repair solutions by combing state-of-the-art techniques and materials.

Keywords: Abdominal wall hernia; Biological tissue grafts; Electrospinning; Hydrogel scaffold; Polypropylene mesh.

Graphical abstract

Fig. 1

Schematic illustration of abdominal wall hernia repair meshes: from prosthetic meshes to smart materials.

Fig. 2

Schematic illustration of hernia pathology, hernia types and hernia surgery.

Fig. 3

Non-absorbable hernia mesh-induced complications and structural difference between various commercial meshes. A. Immunofluorescent image of mesh-tissue explant (left) and Mosson's trichrome staining result of the same mesh-tissue explant with collagen deposition (right). The results demonstrated the inflammatory cell infiltration and fibrosis within the hernia mesh implant site [167]. B. Gross observation of the explanted mesh-vagina complexes and the implant complications related with hernia mesh deformation [64]. C. Post-operative case of infection and fistula formation after hernioplasty [65]. D. Morphological characterization (thickness, porosity, and pore size) and light microscopic pictures of different non-absorbable commercial meshes [168].

Fig. 4

Adsorbable hernia meshes. A. Surgical procedure performed for large-size abdominal wall defect reconstruction with a poly-p-dioxanone mesh [171]. B. Schematic diagram of a heat-shrinkable electrospun fibrous tape for reconstructing soft tissue both structurally and functionally in a rat abdominal wall hernia [73]. C. Representative images of Masson's trichrome and dystrophin staining images of explanted grafts after 30 days of implantation. The human acellular collagen matrix group showed no adhesion with or without MSCs. There were different angiogenesis and musculogenesis between groups regarding the matrix loading with different cells [115]. D. Schematic illustration of the small intestinal submucosa (SIS) membrane that modified with fusion peptide-mediated extracellular vesicles which can promote cell migration and spreading, achieving a more successful abdominal wall tissue regeneration [103]. E. Representative pictures of the decellularized and crosslinked bovine pericardial implants, the full-thickness abdominal wall defects induced by sectioning ventral muscular tissue, and the defect reconstructing with implant [157].

Fig. 5

Engineered composite hernia meshes and surface modified hernia meshes. A. Scanning electron microscopy images and macroscopic appearance of the of the commercial and composite meshes [186]. B. The schematic diaphragm of the design, development and evaluation of a new multifunctional prosthetic mesh for abdominal wall defect treatment. The developed hernia mesh is composed of a synthetic commercial polyester fabric coated with a natural biodegradable, biocompatible and antimicrobial layer of chitosan [187]. C. Schematic description of a modified PP mesh coated with two different sides. The backside: PCL nanofiber modified with l-DOPA with adhesive properties; the front side: CECS/PVA and PCL nanofibers with different amounts of ofloxacin as an anti-adhesion barrier [188]. D. Experimental design of an enhanced hernia PP mesh through antibiotic loading [189]. E. Electron scanning microscopic images of silver-coated PP mesh and in vitro effect of presence/absence of silver on PP implants on biofilm formation by E. coli [190].

Fig. 6

Hydrogel based hernia meshes. A. Schematic illustration of preparation of CS/HA hydrogel via Schiff's base reaction for abdominal wall hernia treatment [302]. B. Rat ventral hernia repair surgery with the implantation of a type I collagen/elastin crosslinked blend (CollE) hernia mesh [284]. C. Schematic characterization of a microparticle based, sprayable adhesion prevention hernia mesh composed of decyl group modified Alaska pollock gelatin (C10-ApGltn). Characteristics of the new colloidal gel barrier to prevent postoperative adhesion [300]. D. Schematic illustration of structure and abdominal wall defect repair properties for conventional hernia meshes, and a brand-new Janus porous poly (vinyl alcohol) hydrogel patch, which is prepared through top-down solvent exchange, lyophilization, and rehydration processes [312]. E. Schematic demonstration of fabricating a dual dynamically crosslinked hydrogel to serve as a physical postoperative anti-adhesion barrier generated by alkoxyamine-terminated Pluronic F127 and oxidized hyaluronic acid [309].

Fig. 7

Electrospun fiber-based hernia meshes. A. Schematic illustration of the fabrication of a functional electrospun mesh by combining PCL with silk fibroin (SF) and decellularized human amniotic membrane (HAM) for full-thickness defect repair [331]. B. Schematic illustration of a functional “outer inner” medicated fibrous membrane preparation and the regulated early exogenous and long-term endogenous inflammation process in a rat abdominal wall hernia model. A traditional Chinese medicine was loaded onto the fiber by micro-sol electrospinning technique while a functional peptide was modified on the fiber surface [320]. C. An illustration of the design and fabrication process of a double-layer structured nanofiber membrane made by PCL, graphene oxide and chitosan with excellent mechanical strength and biocompatibility [319]. D. The electron scanning microscopic images of human vaginal fibroblast proliferation on the bFGF-modified PLLA fibers to promote hernia repair and the cell proliferation assay by cell count kit study [77].

Fig. 8

3D printing hernia meshes. A. 3D printing process of alginate and waterborne-polyurethane inks for fabricating hernia mesh implants with adequate morphological properties customizable to patient injury through computer-aided design model adaptation [343]. B. Schematic diagram of making a degradable 3D printing patch with an antiadhesive layer for hernia repair. Macropictures of hernia defect healing 4 weeks after patch implantation and HE staining microscope section [344]. C. Photographs of a 3D-printed bioscaffold composed of an in situ phosphate crosslinked poly (vinyl alcohol) polymer to capture the proinflammatory cytokines and chemokines to reduce the implant-related adhesion formation. The pictures of bioscaffolds retrieved after 2 and 4 weeks' implantation showed a much milder adhesion within the 3D printed hernia scaffold compared with the commercial PP one [345].