Overview

Definition:
-Infected mesh explant refers to the surgical removal of a prosthetic mesh that has become infected, often following procedures like hernia repair, abdominal wall reconstruction, or breast reconstruction
-Reconstruction may be necessary to restore structural integrity and function.
Epidemiology:
-Mesh infections are a significant complication, with reported rates varying from 1% to 5% for inguinal hernia repairs and higher for complex abdominal wall reconstructions
-Factors like mesh type, surgical technique, patient comorbidities, and perioperative antibiotic use influence incidence.
Clinical Significance:
-Mesh infections can lead to significant morbidity, including chronic pain, recurrent hernias, enterocutaneous fistulas, sepsis, and abdominal wall defects requiring complex reconstruction
-Early diagnosis and management are crucial to prevent severe outcomes and optimize patient recovery.

Clinical Presentation

Symptoms:
-Increasing incisional pain and tenderness at the mesh site
-Redness, warmth, and swelling of the overlying skin
-Purulent wound discharge
-Fever and chills
-Possible systemic signs of infection such as malaise and anorexia
-Development of a palpable fluctuant collection
-In late stages, recurrent hernia symptoms or bowel obstruction may occur.
Signs:
-Erythema and edema of the surgical wound
-Tenderness to palpation over the mesh area
-Purulent drainage from the incision
-Boggy or fluctuant mass in the operative site
-Palpable mesh remnants
-Signs of sepsis: tachycardia, hypotension, tachypnea, fever.
Diagnostic Criteria:
-Diagnosis is primarily clinical, supported by imaging and laboratory findings
-Criteria often include: 1
-Presence of local signs of infection (erythema, warmth, tenderness, discharge) at the mesh site
-2
-Systemic signs of infection (fever, elevated WBC)
-3
-Imaging evidence of mesh infection or fluid collection
-4
-Positive microbiological culture from wound drainage or explanted mesh.

Diagnostic Approach

History Taking:
-Detailed history of the index surgery (type of mesh, procedure, complications)
-Onset and progression of symptoms
-Presence of fever, chills, or systemic illness
-Previous antibiotic use
-Comorbidities such as diabetes, immunosuppression, obesity, or smoking
-History of recurrent infections or wound healing issues.
Physical Examination:
-Thorough examination of the abdominal wall or surgical site
-Assess for erythema, warmth, edema, induration, and tenderness
-Palpate for any fluctuant collections or sinus tracts
-Evaluate the integrity of the abdominal wall and check for signs of hernia recurrence
-Examine for signs of sepsis.
Investigations:
-Complete Blood Count (CBC) with differential to assess for leukocytosis
-C-reactive protein (CRP) and Erythrocyte Sedimentation Rate (ESR) for inflammatory markers
-Blood cultures if sepsis is suspected
-Wound culture and sensitivity of any purulent drainage
-Imaging: Ultrasound can detect fluid collections
-CT scan of the abdomen/pelvis is essential to delineate the extent of infection, identify abscesses, assess mesh involvement, and detect potential fistulas or bowel complications
-MRI may provide more detailed soft tissue characterization.
Differential Diagnosis:
-Seroma formation without infection
-Wound dehiscence without infection
-Abscess unrelated to mesh
-Cellulitis of the abdominal wall
-Recurrent hernia
-Enterocutaneous fistula from other causes
-Postoperative hematoma.

Management

Initial Management:
-Prompt broad-spectrum intravenous antibiotics covering common Gram-positive and Gram-negative organisms, and anaerobes
-Analgesia and antipyretics
-Wound care: sterile dressing changes
-Consultation with surgery department for urgent assessment.
Medical Management:
-Antibiotic therapy should be guided by culture and sensitivity results
-For established infection, parenteral antibiotics are typically required for at least 2-6 weeks, potentially longer based on clinical response and extent of infection
-Long-term oral suppressive antibiotics may be considered in select cases or while awaiting definitive reconstruction.
Surgical Management:
-Surgical explantation of the infected mesh is the definitive treatment
-This involves debridement of all necrotic tissue, pus, and infected mesh material
-The approach can be open or laparoscopic, depending on the extent of infection and surgeon expertise
-Once the mesh is removed, thorough irrigation and drainage of the wound are critical
-Reconstruction of the abdominal wall defect is often required, using autologous tissue (e.g., rectus abdominis flaps) or synthetic grafts in a non-infected field at a later stage
-Primary closure of the defect or staged reconstruction may be performed.
Supportive Care:
-Nutritional support to promote healing
-Close monitoring of vital signs and laboratory parameters
-Strict wound care and dressing protocols
-Management of comorbidities
-Pain management
-Patient education regarding wound care and signs of recurrence.

Complications

Early Complications:
-Wound dehiscence
-Abscess recurrence
-Sepsis
-Hemorrhage
-Injury to adjacent organs (bowel, bladder, major vessels) during explantation
-Pneumothorax if laparoscopic approach used without proper precautions.
Late Complications:
-Chronic wound drainage
-Enterocutaneous fistula formation
-Incisional hernia recurrence
-Chronic pain syndrome
-Adhesion formation
-Formation of enterocutaneous fistula
-Scarring and cosmetic deformities
-Need for further reconstructive surgeries.
Prevention Strategies:
-Meticulous aseptic technique during mesh implantation
-Judicious use of mesh, especially in contaminated fields
-Appropriate perioperative antibiotic prophylaxis
-Patient optimization (smoking cessation, diabetes control)
-Early recognition and management of wound complications
-Use of biologic meshes or alternative techniques in high-risk patients
-Minimizing mesh surface area and ensuring adequate tissue coverage.

Prognosis

Factors Affecting Prognosis:
-Extent of infection
-Presence of systemic sepsis
-Comorbidities of the patient
-The ability to achieve complete debridement of infected material
-The success of subsequent reconstruction
-Timing of intervention
-Virulence of the infecting organism.
Outcomes:
-With timely and aggressive management (explantation and antibiotics), outcomes can be favorable, leading to resolution of infection
-However, recurrence of hernia is common if reconstruction is inadequate or delayed
-Chronic pain and functional deficits can persist
-Complete recovery may require multiple surgical interventions
-Morbidity and mortality are significantly higher in patients with sepsis or delayed treatment.
Follow Up:
-Regular follow-up is essential, typically for several months to a year or more
-This involves serial clinical examinations to monitor for signs of recurrent infection, hernia recurrence, or wound healing issues
-Imaging (ultrasound, CT) may be performed periodically to assess the reconstructed area and rule out complications
-Patients should be educated on self-monitoring for warning signs.

Key Points

Exam Focus:
-Infected mesh explantation is a common complication after hernia repair and abdominal wall reconstruction
-CT scan is the gold standard for diagnosis
-The mainstay of treatment is surgical removal of the mesh and antibiotics
-Reconstruction is often staged and uses autologous tissue
-Early recognition and management are key to reducing morbidity.
Clinical Pearls:
-Always consider mesh infection in patients with persistent or worsening wound pain, discharge, or fever post-mesh implantation
-Thorough debridement is paramount during explantation
-leave no residual foreign material
-Consider a staged approach for reconstruction, allowing the infected field to fully resolve before reimplanting synthetic material
-Autologous tissue reconstruction is preferred for definitive closure in infected fields.
Common Mistakes:
-Delaying surgical explantation in favor of prolonged antibiotics alone
-Inadequate debridement of all infected mesh and tissue
-Attempting primary reconstruction with synthetic material in a recently infected field
-Underestimating the extent of infection
-Not considering bowel involvement or fistula formation.