Overview
Definition:
An incisional hernia is a protrusion of abdominal contents through a surgically created or weakened abdominal wall defect
Open onlay mesh repair involves placing a synthetic mesh prosthetic directly over the fascia of the abdominal wall defect, on top of the repaired fascia, and securing it in place
This technique aims to reinforce the weakened area and reduce recurrence rates.
Epidemiology:
Incisional hernias occur in 5-20% of abdominal surgical wounds
Risk factors include wound infection, dehiscence, obesity, smoking, malnutrition, prolonged steroid use, and multiple previous surgeries
They are more common in midline incisions.
Clinical Significance:
Incisional hernias can cause significant morbidity, including pain, discomfort, cosmetic deformity, and risk of strangulation or incarceration
Accurate diagnosis and effective surgical repair are crucial for patient quality of life and preventing life-threatening complications
Proficiency in various repair techniques, including open onlay mesh, is essential for surgical trainees preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
A bulge at or near a previous surgical scar, often more prominent when standing, coughing, or straining
Pain or discomfort at the hernia site
A dragging or heavy sensation in the abdomen
Nausea or vomiting if incarcerated or strangulated.
Signs:
Visible or palpable bulge in the abdominal wall, which may be reducible
Palpable defect in the fascia
Reducible hernia contents typically disappear when the patient lies down
Signs of incarceration or strangulation include a non-reducible, tender bulge, redness of the overlying skin, fever, and signs of bowel obstruction.
Diagnostic Criteria:
Diagnosis is primarily clinical based on history and physical examination
Imaging may be used to confirm complex or recurrent hernias, or to assess for complications
No formal diagnostic criteria exist beyond clinical suspicion and confirmation.
Diagnostic Approach
History Taking:
Detailed history of previous surgeries (type, location, complications)
Onset and progression of the bulge
Associated symptoms (pain, bowel changes, nausea)
Risk factors (obesity, smoking, comorbidities)
Previous hernia repairs.
Physical Examination:
Palpation of the abdominal wall with attention to previous surgical scars
Ask patient to cough or strain to elicit hernia bulge
Assess reducibility, size, and tenderness of the bulge
Examine for signs of incarceration or strangulation
Assess overall nutritional status and comorbidities.
Investigations:
Ultrasound of the abdominal wall can confirm the presence of a hernia and assess for complications
CT scan is useful for large, complex, or recurrent hernias, and to evaluate surrounding structures and potential adhesions
MRI may also be used
Routine laboratory investigations are generally not required unless complications are suspected.
Differential Diagnosis:
Lipoma, desmoid tumor, hematoma, abscess, endometrioma, rectus sheath hematoma, seroma, normal postoperative swelling.
Management
Indications:
Symptomatic incisional hernias
Asymptomatic hernias in patients at high risk of complications or with large defects
Hernias that are incarcerated or strangulated require urgent surgical intervention.
Preoperative Preparation:
Optimizing nutritional status
Smoking cessation at least 4 weeks prior to surgery
Weight loss if significantly obese
Optimization of comorbidities (diabetes, hypertension)
Antibiotic prophylaxis (e.g., cefazolin)
Hair removal at the surgical site.
Surgical Management:
Open onlay mesh repair: The patient is positioned supine
A midline or curvilinear incision is made over the hernia
The subcutaneous tissue is dissected down to the fascial defect
The hernia sac is opened, contents reduced, and the sac is excised or imbricated
The fascial defect is approximated with sutures
A synthetic mesh (e.g., polypropylene, dual-layer) is then placed over the repaired fascia (onlay position) and secured with sutures or tacks
The subcutaneous tissue is closed in layers
Laparoscopic repair is an alternative for selected patients.
Postoperative Care:
Pain management with analgesics
Monitoring for wound complications (infection, seroma, hematoma)
Early ambulation
Gradual return to normal diet
Restriction of heavy lifting for 4-6 weeks
Patients should be advised on signs of recurrence or complications.
Supportive Care:
Adequate hydration and nutrition
Management of pain and nausea
Monitoring vital signs and urine output
Prophylaxis for deep vein thrombosis if indicated.
Complications
Early Complications:
Wound infection
Seroma
Hematoma
Mesh infection
Acute mesh migration or displacement
Early recurrence
Bowel obstruction
Injury to abdominal organs.
Late Complications:
Chronic mesh infection
Meshoma
Adhesions
Chronic pain
Mesh erosion
Late recurrence
Fistula formation.
Prevention Strategies:
Meticulous surgical technique to minimize tissue trauma and achieve adequate hemostasis
Strict aseptic precautions
Appropriate selection of mesh material and fixation
Smoking cessation and optimization of comorbidities
Prophylactic antibiotics
Proper wound closure techniques
Patient education on activity restrictions.
Prognosis
Factors Affecting Prognosis:
Size and complexity of the hernia
Presence of comorbidities
Surgical technique and surgeon experience
Risk of recurrence is higher in patients with previous failed repairs or multiple risk factors.
Outcomes:
Open onlay mesh repair generally offers good outcomes with low recurrence rates when performed correctly
Recurrence rates can vary from 2% to 10% depending on patient factors and technique.
Follow Up:
Regular follow-up appointments are recommended at 1 week, 1 month, 3 months, and 6 months post-operatively, and then annually or as needed
Patients should be instructed to report any new bulges, pain, or signs of infection promptly
Long-term monitoring is crucial for early detection of recurrence.
Key Points
Exam Focus:
Understand the indications and contraindications for open onlay mesh repair
Be familiar with the surgical steps, mesh fixation techniques, and potential complications
Differentiate between onlay, inlay, and sublay mesh placements
Know the risk factors for incisional hernia development and recurrence.
Clinical Pearls:
Incisional hernias are often best repaired electively when asymptomatic or minimally symptomatic to avoid emergency surgery
Meticulous dissection and hemostasis are key to preventing early postoperative complications like seroma and hematoma
Consider patient comorbidities and lifestyle factors when planning repair.
Common Mistakes:
Inadequate fascial approximation leading to tension on the mesh
Improper mesh placement (too small, inadequate overlap)
Failure to address risk factors like obesity or smoking
Inadequate postoperative patient education regarding activity restrictions
Ignoring signs of infection or mesh complication.