Microbiologists uncover possible hidden culprit of hernia repair failure

Researchers at The Queen Elizabeth Hospital (TQEH) have uncovered a potential hidden contributor to chronic pain and hernia mesh failure.

In hernia meshes removed due to pain or failure, the team identified colonies of bacteria, known as biofilms, in 95 per cent of the samples.

Biofilms: a global enemy

A hernia happens when an internal organ pushes through a weak spot in a patient’s muscle or tissue.

If left untreated, the buldge can cause loss of blood supply, become septic, and life-threatening.

Hernia repair surgery is one of the most frequently performed surgeries in the world, and in most cases surgeons use a flexible mesh to strengthen the area.

Like other surgical devices, a hernia mesh is a foreign object without its own immune system, and is prone to bacterial attachment, according to Dr Katharina Richter working in the Discipline of Surgery at the Basil Hetzel Institute, TQEH.

When bacteria cluster they can form a biofilm, which protects them from treatments such as antibiotics.

“Once they attach to a foreign body, it’s only a matter of time before bacteria then multiply and form a biofilm, and may cause an infection weeks to months after the surgery,” said Dr Richter.

After analysing 20 hernia meshes that were removed from patients who experienced chronic pain or mesh failure, the team found evidence of biofilms in an alarming 19 of the 20 samples.

“These meshes weren’t removed due to infection. This shows that there is likely a link between biofilms and the reason for removal (e.g. chronic pain), though we don’t understand it yet.”

The results suggest that a silent, undetected biofilm infection could contribute to mesh complications, chronic pain and exacerbation of disease.

Just the beginning

Professor Guy Maddern and Dr Richter are seeking collaborators to expand this small study to a larger scale to further investigate the link between biofilms and chronic pain.

“We need better materials that prevent bacterial attachment, so bacteria don’t form a biofilm, or materials that better integrate with our own tissue, so our immune system protects the mesh from bacteria.”

Dr Richter’s lab is also working on a treatment that is embedded inside the mesh, which kills bacteria that try to attach themselves, and are ready to take it into pre-clinical trials.

This work was supported by the Royal Australasian College of Surgeons through a Small Project Grant, the National Health and Medical Research Council (GNT1163634, GNT2004036), the University of Adelaide and The Hospital Research Foundation.

Read the research

Click here to read the published paper.