Surgical mesh is a commonly used medical device in hernia repair, serving to reinforce weakened tissue and reduce the likelihood of the hernia returning. The prosthetic material provides a tension-free repair, which has significantly lowered recurrence rates compared to traditional suture methods. Despite its widespread use, many patients express concern about the possibility of the mesh shifting from its original placement. This article addresses whether hernia mesh can move and details the mechanisms, symptoms, risk factors, and clinical responses associated with this complication.
Mechanisms of Device Migration
Hernia mesh migration is an uncommon event, but it can occur through two distinct physical processes: primary and secondary movement. Primary, or mechanical, migration is typically an early post-operative event resulting from inadequate surgical fixation. This occurs when the mesh is inadequately anchored, allowing it to slip along the path of least resistance. External forces, such as intra-abdominal pressure from coughing or straining, can cause the poorly secured mesh to detach and move shortly after surgery. This form of migration is characterized by the mesh displacing as a whole unit, often into an adjacent anatomical space.
Secondary migration is a gradual, late-onset process that occurs months or even years after the initial hernia repair. This movement is often triggered by a foreign body reaction, leading to chronic inflammation and the formation of scar-like granulation tissue. This inflammatory response can cause the mesh to slowly erode into adjacent organs or tissues over time, a process known as transmural migration. If exposed to a hollow organ, such as the bowel or bladder, the mesh can break down or fold up, sometimes forming a clumped mass called a meshoma.
Identifying Symptoms of Movement
The signs of mesh migration or erosion are varied and often manifest long after the surgical site has healed. Chronic pain is a frequently reported symptom, which can be localized to the original surgical area or radiate outward as the mesh irritates surrounding nerves and tissues. This discomfort often persists beyond the typical post-operative recovery period.
Patients may also notice a palpable mass or lump near the repair site, representing the migrated or crumpled prosthetic material. If the mesh has eroded into the intestines, symptoms can include unexplained changes in bowel function, signs of obstruction, or the formation of a fistula. Migration into the urinary bladder can lead to chronic urinary tract infections or blood in the urine. These symptoms warrant immediate medical evaluation, as they indicate a serious internal complication.
Contextual Factors in Mesh Stability
Several factors contribute to the likelihood of mesh migration, though the overall incidence rate remains low. The type of mesh used plays a role, as non-absorbable materials like polypropylene depend on tissue integration for long-term stability. Lightweight meshes, for instance, are designed to allow for greater tissue incorporation than older, heavier materials, potentially improving fixation.
The surgical technique and fixation method are also significant determinants of stability. An insufficient overlap of the mesh beyond the hernia defect margins, or an inadequate number of fixation points, increases the risk of mechanical displacement. Placing the mesh in the intraperitoneal position, in direct contact with the abdominal organs, may carry a higher potential for erosion over time compared to preperitoneal placement.
Patient-specific health factors can also influence the stability and integration of the mesh. Patients with chronic conditions, such as diabetes or obesity, may experience impaired wound healing, which can compromise the strength of the tissue’s bond with the mesh. Excessive post-operative strain, such as heavy lifting or chronic coughing, can place tension on the repair site, increasing the risk of early detachment.
Diagnostic Steps and Treatment Options
When mesh migration is suspected based on a patient’s symptoms, diagnostic imaging is initiated to confirm the mesh’s position and assess any organ damage. Computed Tomography (CT) scanning is considered the primary tool for evaluating the integrity and location of the mesh in relation to surrounding structures. While the prosthetic material itself may not always be clearly visible on imaging, the presence of secondary findings is often diagnostic. Radiologists look for signs like mural inflammation, abnormal bowel contour, or the displacement of surgical staples away from the original repair site. Ultrasound and Magnetic Resonance Imaging (MRI) may also be used to provide additional detail regarding soft tissue and possible fluid collections.
Treatment for confirmed mesh migration is almost always surgical, with the approach tailored to the severity of the complication. If the mesh is causing severe pain, infection, or has eroded into a hollow organ, complete surgical removal, known as explantation, is typically required. This procedure can be technically demanding, as the surgeon must carefully separate the mesh from any adhered tissue or organs.
In cases of erosion into the bowel, a portion of the intestine may need to be resected and reconnected. Following mesh removal, the surgeon performs a new hernia repair, often using native tissue repair techniques or a different type of prosthetic material, such as a biologic mesh, to reinforce the abdominal wall.