Diagnosis and Initial Evaluation
Identifying a mesh infection can be challenging, as symptoms can appear weeks, months, or even years after the initial hernia repair. The clinical presentation can vary widely, from acute, severe signs of inflammation to an indolent, chronic issue. A thorough evaluation is essential for determining the most appropriate treatment path.
Common signs and symptoms
- Local symptoms: Persistent or recurring swelling, redness (erythema), tenderness, or warmth around the surgical site. A pus-draining sinus tract may also develop.
- Systemic symptoms: General signs of infection, such as fever, chills, and flu-like symptoms.
- Imaging: A computed tomography (CT) scan is often used to confirm the presence of a fluid collection (abscess) or inflammation around the mesh and to assess for more serious complications, like mesh erosion into nearby organs.
- Bacteriological culture: Fluid drained from the site or a sample of the mesh itself can be cultured to identify the specific bacteria causing the infection. Staphylococcus aureus is one of the most common pathogens involved.
Factors influencing treatment decisions
Several factors help guide a surgeon in selecting the best course of action. These include:
- The type of mesh (e.g., polypropylene, polyester, biologic)
- The location of the mesh (e.g., preperitoneal vs. intraperitoneal)
- The timing and severity of the infection (acute vs. chronic)
- Patient-specific risk factors (e.g., diabetes, smoking, obesity)
- The presence of complications like an enterocutaneous fistula
Conservative management (Mesh salvage)
In some carefully selected cases, particularly with acute infections involving certain mesh types, an attempt may be made to save the mesh. The conservative approach typically involves a combination of the following measures:
- Systemic antibiotics: A prolonged course of antibiotics is administered, often starting intravenously and then transitioning to oral medication, based on the results of bacterial culture.
- Percutaneous or surgical drainage: An abscess or fluid collection is drained by placing a pigtail drain or performing a small incision to relieve pressure and remove the infected fluid.
- Negative pressure wound therapy (NPWT): A vacuum-assisted closure (VAC) system may be used for wound care, especially if there is persistent drainage or a large open wound.
- Local irrigation: In some cases, antibiotic or saline solutions can be irrigated directly into the infected area through a drain.
This approach carries a high risk of failure, especially in chronic infections, because bacteria can form a protective biofilm on the mesh surface that is resistant to antibiotics. For certain mesh types and patient risk factors, salvage is rarely successful.
Surgical management (Mesh removal or excision)
Mesh removal is often considered the most definitive treatment for a mesh infection and is required when conservative efforts fail or if the infection is severe from the outset. Complete removal is generally considered the goal to prevent recurrence, as leaving even small fragments can harbor persistent bacteria. This surgery can be complex, and the specific technique depends on the initial repair method and the extent of the infection.
Complete mesh excision vs. partial removal
| Feature | Complete Mesh Excision | Partial Mesh Removal |
|---|---|---|
| Effectiveness | Higher rate of infection resolution, especially for chronic infections. | High rate of persistent or recurrent infection. |
| Complexity | Often more extensive surgery, potentially involving reconstruction. | Less invasive initially, but often fails and requires subsequent operations. |
| Hernia Recurrence | High risk of hernia recurrence post-removal, which may require staged repair. | High risk of both recurrent infection and hernia. |
| Risks | Higher risk of injury to surrounding structures during removal of well-incorporated mesh. | Lower initial surgical risks, but higher long-term risk of ongoing complications. |
| Best for | Most severe and chronic infections; infection involving fistula formation; most types of synthetic mesh. | Selected, less severe infections, often in conjunction with biologic mesh. |
Reconstruction after removal
After removing the infected mesh, the surgeon must decide how to manage the abdominal wall defect. The options include:
- Suture repair: Closing the defect with sutures. This has a high risk of hernia recurrence.
- Use of biologic or biosynthetic mesh: This non-permanent mesh is used in a contaminated field because it is more resistant to infection and encourages tissue growth.
- Staged repair: For complex cases, the infected mesh is removed, the area is allowed to heal, and a second surgery is planned later to address the hernia recurrence.
Potential complications of untreated mesh infections
If a mesh infection is left untreated or is not treated effectively, the consequences can be severe. The bacteria forming a biofilm on the mesh can cause chronic, persistent inflammation and further erode into surrounding tissues and organs. Long-term effects can include:
- Chronic pain and inflammation that significantly impact quality of life.
- Sepsis, a potentially life-threatening bloodstream infection.
- Organ perforation and fistula formation (abnormal connection to organs like the bowel or bladder).
- Recurrent hernia due to tissue breakdown.
- Rarely, chronic inflammation has been associated with the development of squamous-cell carcinoma in the affected tissue.
Conclusion
The management of a mesh infection is a complex and often multi-faceted process that requires expert surgical evaluation. While conservative treatment with antibiotics and drainage may be attempted for early, uncomplicated infections, the presence of a bacterial biofilm often necessitates surgical removal of the mesh for a definitive cure. Patients should be aware of the symptoms and seek prompt medical attention if they suspect an infection. Ultimately, the best treatment strategy is highly individualized, with outcomes dependent on the type of mesh, the severity of the infection, and patient-specific factors. For most severe or chronic cases, complete mesh removal combined with antibiotic therapy offers the best chance for a successful resolution and minimizes the risk of ongoing complications.
Prevention strategies
While not always preventable, several strategies can help reduce the risk of a mesh infection:
- Optimize patient health: Addressing comorbidities like diabetes and obesity, as well as encouraging smoking cessation, can significantly lower infection risk.
- Appropriate antibiotic prophylaxis: Administering antibiotics prior to surgery has been shown to reduce infection rates.
- Minimize contamination: Meticulous surgical technique and a clean operative field are critical, especially during bowel-related procedures.
- Use appropriate mesh: In patients with a high risk of infection, biologic or biosynthetic meshes may be considered, as they are less prone to infection compared to permanent synthetic meshes.
- Promptly address wound issues: Early attention to superficial wound infections can prevent them from involving the underlying mesh.
For more information on preventing surgical infections, consult the Centers for Disease Control and Prevention's guidelines.
Important considerations
- Biofilm Formation: The most significant challenge in treating mesh infections is the formation of a bacterial biofilm, which shields the microorganisms from antibiotics. This is why conservative treatments often fail in chronic infections.
- Delayed Presentation: Many mesh infections present long after surgery, making the connection to the implant less obvious to patients.
- Individualized Plan: No single approach works for all mesh infections. A surgeon must consider multiple variables, including the mesh type, patient health, and infection characteristics, to develop an effective treatment plan.
