The FDA continuously monitors the safety of hernia surgical mesh products for repair by assessing the adverse event reports it receives from multiple sources, including medical device manufacturers, distributors, medical facilities, medical providers, and patients. The FDA is committed to improving public access to accurate and transparent medical device reports and to quickly address any data or entry errors. The FDA closely monitors medical device reports and manufacturers’ compliance with accurate and timely reporting of adverse events.
Although reports of adverse events are a valuable source of information, this passive surveillance system has limitations, including the potential submission of incomplete, inaccurate, late, unverified or biased data. The FDA uses a variety of other methods to monitor the safety of a device after it has been approved, including inspections and ongoing research and data analysis of medical journals, electronic health records systems, patient registries and administrative and insurance claims. Reports of adverse events alone are rarely able to confirm a direct cause and effect between an adverse event report and a specific medical device. We continue to assess information from these sources and will communicate to the public if significant new information becomes available.
FDA Review of Adverse Event Reports Associated with Hernia Mesh
The FDA conducted a comprehensive review of reports of adverse events that include hernia mesh or similar terms submitted over the past 22 years. The most frequently cited patient problems were:
- Unspecified Infection
- Additional Surgical Procedure
- Unspecified Tissue Injury
When filtered to identify events for inguinal, ventral, incisional, hiatal, umbilical, and unspecified hernias, this search produced over 55,000 adverse event reports. In these reports, approximately 60% referred to ventral or incisional hernia surgery or an equivalent term. And in approximately 20% of these reports, the type of surgery was not specified.
FDA Review of Literature on Hernia Repair with Mesh
The FDA also conducted a literature review of barrier coated and hybrid mesh used in hernia repair to assess the reported experience with these devices. Barrier coated meshes are meshes coated with collagen, or other absorbable substances that resist attachment to tissue or organ, while hybrid meshes are combination mesh or mesh with a smooth side and a rough side, the former resisting attachment to tissue and the latter allowing ingrowth of tissue.
Forty-five (45) full text articles published over 11 years were found to provide sufficient detail for further review. These articles described results from 9 randomized controlled trials (RCTs), 7 prospective cohorts, 20 retrospective cohorts, and 9 case reports and series. The search terms included types of hernia meshes and types of hernias (ventral incisional umbilical, inguinal). The complications that were analyzed in these articles included hernia recurrence, reoperation for recurrence, reoperation for mesh related complications, surgical site infections, mesh infections, chronic pain, bowel adhesions, bowel obstruction, bowel fistula, hematoma, seroma, abscess, organ space infection, wound dehiscence/fascial disruption (separation and opening of a deep surgical wound), and death.
Estimates of the incidence of the most common complications associated with barrier coated and hybrid mesh reported in the literature are summarized below:
- Incidence of hernia recurrence ranged from 0-11.1%
- Incidence of hematoma ranged from 0.5% to 2.3%.
- Incidence of seroma ranged from 0-52.5%
- For mesh bowel adhesion, the incidence reported varies, but does not exceed 3.2%.
- For bowel obstruction, the incidence reported does not exceed 3.8%; however, it is not possible to determine whether bowel obstruction was related to the mesh or the procedure.
- For fistula formation, the incidence of fistula formation reported was estimated at less than 1%.
- For abdominal organ space infection, the incidence reported varies between 0.22%-1.1%.
- The incidence of surgical site infections ranged from 0-21%.
- The incidence of mesh infection ranged from 0-1.4%
- The definition of chronic pain in the studies varied, which resulted in a wide range of incidence (0.3-68%). However, the incidence resulting in significant impact on quality of life does not exceed 3.8%.
Although barrier coated and hybrid meshes were involved in the majority of adverse events reported to the FDA, the literature did not report a significant difference in barrier coated and hybrid meshes compared with other hernia meshes.