Updating mesh material: The tissue matrix

Tela Bio explains the alternative to mesh that can be used in hernia repair procedures.

With an estimated 20 million repaired each year worldwide, hernias are common and represent a major source of disability and morbidity in patients. Today, mesh is used in almost 90% of hernia procedures to prevent a recurrence. But it’s the “how” and “with what material” used in hernia repair procedures that may mean the difference between a potential surgical complication and a smooth recovery. With healthcare resources already stretched thin due to COVID-19, it’s critical that each patient and their provider select the right hernia reinforcement material, based on the patient’s needs and clinical research.

Plastic mesh used today

A significant advancement in the surgical treatments of hernias came in the 1950s after the invention of a permanent synthetic polymer-based mesh. The reinforced strength provided by this advancement meant overall fewer revision surgeries. In fact, in a 2004 prospective, randomised controlled trial published in the Annals of Surgery, the authors demonstrated a 10-year cumulative incisional hernia recurrence rate of 63% for suture repairs with no mesh reinforcement and a 32% recurrence rate for repairs using permanent synthetic mesh. While permanent synthetic mesh materials have been used safely in most procedures over the years, the application of these types of mesh has been associated with serious complications, which include mesh contracture, adhesions, fistulae, and others. Many of these related complications can be attributed to the prolonged foreign body exposure inherent to the amount, density, and type of permanent synthetic polymer in the mesh implant. Despite these potential complications, surgeons continue to choose polymeric meshes for most hernia repairs due to long-standing clinical experience, their relative low cost, and ability to withstand intra-abdominal wall pressures, helping to reduce the risk of reherniation.

Limitations of biologic mesh

Biologic materials are an alternative to synthetic materials due to their inherently lower inflammatory response and resilience, particularly for high-risk patients. Harvested from xenogeneic or allogeneic organs, the extracellular matrix (ECM) creates a scaffold for remodelling once processed to remove cells and DNA from the tissue. However, quality can vary, depending upon processing methods. In addition, while these materials show promise, unfortunately, they are expensive and due to the retention of the protein elastin, may weaken over time. 

Next-gen hernia reinforcement material 

If neither fully synthetic nor fully biologic meshes are ideal, what is the answer? A more recently developed material used in hernia repairs is a reinforced tissue matrix called OviTex.

The new material, consisting of polypropylene or polyglycolic acid polymer, interwoven within layers of xenograft tissue, has shown promise as a suitable alternative both pre-clinically and clinically.

OviTex Reinforced Tissue Matrix creates a three-dimensional scaffold, interweaving low levels of polymer suture throughout layers of ovine (sheep) forestomach (rumen)-derived ECM. This construction creates a permeable, tissue-based scaffold that allows fluids and cells to flow throughout the device enabling neovascularisation and functional tissue remodelling as demonstrated in multiple preclinical models. The polymer enhances the strength of the layers of biologic tissue providing overall compliance comparable to that of the human abdominal wall, which is critical in offloading tension of the sutured hernia repair during the acute healing phase.

Utilising input from over 100 general and plastic surgeons, OviTex’s embroidered design of OviTex is interwoven through layers of biologic material in a “lockstitch” pattern, creating an embroidered construction. This offers a technology intended to surpass the performance of all existing hernia repair and abdominal wall reconstruction mesh products.

The biologic material in OviTex, derived from ovine rumen, serves as the natural building block, is optimised to reduce foreign body response, and enable functional tissue remodelling. The interwoven polymer fibres provide additional reinforcement, along with improved handling and load-sharing capability to support natural abdominal wall function. The polymer fibre is available in resorbable or permanent variations and comprises less than 5% of the final product.

OviTex Reinforced Tissue Matrix aims to combine the benefits of biologic material and polymer reinforcement to provide a more natural hernia repair.

Recently published in the journal Polymers, an early clinical assessment of OviTex Reinforced Tissue Matrix described a decrease in chronic postoperative inguinal pain, improvement of preoperative hiatal hernia symptoms, and a lower incidence of recurrence compared to use of synthetic mesh in a more challenging ventral hernia repair population.

The future of hernia repair

Hernia mesh material is overdue for an update and now is the time for healthcare providers and patients to consider alternatives to long-standing hernia mesh options. While the healthcare system and resources have been stretched thin and overworked during the pandemic, it is critical that providers understand the drawbacks of plastic mesh and the limitations of biologics. Considering a next-gen hernia reinforcement material may help address patient concerns surrounding permanent synthetic mesh and decrease the foreign body exposure while facilitating functional tissue remodelling.