Treating Small Hernias with Bigger Mesh Sizes in EDS Patients May Lead to Low Recurrence Rates, Study Says

Patients with Ehlers-Danlos syndrome (EDS) showed a low recurrence rate after hernia surgery, possibly due to the large mesh size used in the procedure, according to researchers.

Their study, “Complications and recurrence rates of patients with Ehlers-Danlos syndrome undergoing ventral hernioplasty: a case series,” was published in the journal Hernia.

Scientists hypothesize that an imbalance between mature and immature collagen may lead to hernias, which happen when an organ pushes through an opening in the tissue that holds it in place.

Collagen is a major component of the extracellular matrix, which provides cells with the necessary structural and biochemical support.

Tenascin, a group of glycoproteins — proteins with a sugar chemical group attached — have also been linked to the formation of hernias.

Taken together, these mechanisms suggest that patients with a connective tissue disease such as EDS could have a greater risk of recurrence after their hernia is repaired.

Ehlers-Danlos syndrome has been classified into six subtypes based on clinical features and biochemical and genetic characteristics. Different EDS subtypes have been linked to collagen or tenascin disorders.

As a result, surgeons fear a high recurrence rate after hernia surgery in people with EDS. But studies are scarce on the association between Ehlers-Danlos and the development of hernias.

Now, a research team from the Netherlands and Belgium assessed the outcomes of ventral hernioplasty, a surgical technique for the repair of hernias, in EDS patients. The investigators evaluated hernia recurrence and postoperative complications.

They analyzed hospital registries from January 2000 to January 2017. Fourteen EDS patients (seven men and seven women) with a median age of 45 were analyzed. They were seen three weeks after their hernia surgery, then every six months afterward. The median follow-up period was 50 months, or a little over four years.

Researchers collected data about the patients’ age, sex, body mass index (BMI), medical history, type of EDS, details about the hernia and the surgical procedure, as well as complications and follow-up.

Their results showed that 10 patients had an incisional hernia, which is formed through the scar of a previous operation, while four had a primary ventral hernia.

The median BMI of the Ehlers-Danlos patients was 24.82, which is at the upper limit of normal weight levels. Four patients smoked, one had diabetes, and five had an aneurysm (an abnormal bulge) of the abdominal aorta.

All patients underwent elective open hernioplasty, with various brands  of surgical mesh used as reinforcement. This is a standard strategy for abdominal hernias, in which the hernia is removed, the abnormal opening is stitched closed by the surgeon, and the weak area is strengthened using a mesh.

Three patients experienced a postoperative complication, two of which were infections and one a seroma — a buildup of fluid beneath the surface of the skin.

One patient experienced a hernia recurrence, representing a 7.1 percent recurrence rate among this group of Ehlers-Danlos patients.

The researchers observed that the hernia recurrence rate is lower than the 12 percent reported for the general population of hernia patients. The team believes this difference is likely due to the large mesh size (16×23 cm — or 6.3×9 inches ) used in the EDS patients.

“The low recurrence rate could be explained by the use of large meshes that reinforce the entire midline to compensate for the reduced collagen strength in EDS patients,” the researchers wrote.

They also hypothesized that the surgeon, knowing the EDS diagnosis of the patient before the procedure, could have had a higher awareness, which might have led to more conservative choices and a more tailored care approach. But this could not be confirmed.

As one of the study’s limitations, the researchers mentioned the small number of patients, which meant that a detailed analysis of the possible associations between EDS subtypes and clinical outcomes could not be made.

Researchers recommend that establishing a diagnosis of Ehlers-Danlos syndrome is the first step for specific care of these patients. In case a hernioplasty is needed, surgeons should “treat ‘small’ ventral abdominal wall hernias as if they were bigger,” using larger mesh sizes, they added.