Overview

Definition:
-Abdominal wall reconstruction with mesh in the preperitoneal space involves placing a synthetic or biological mesh between the posterior rectus sheath (or transversalis fascia) and the peritoneum to reinforce a weakened abdominal wall, most commonly for large incisional or ventral hernias
-This technique aims to restore structural integrity and prevent recurrence by allowing tissue ingrowth into the mesh, creating a strong, tension-free repair.
Epidemiology:
-Incisional hernias occur in 10-20% of patients after abdominal surgery, with higher rates after emergency procedures or midline incisions
-Large or recurrent ventral hernias present significant reconstruction challenges
-The preperitoneal approach is particularly favored for hernias exceeding 10 cm in diameter and those involving significant fascial defect.
Clinical Significance:
-Effective abdominal wall reconstruction is critical for patient quality of life, preventing complications like bowel obstruction or incarceration, and reducing chronic pain
-The preperitoneal mesh technique offers a tension-free repair with lower recurrence rates compared to some other methods, especially for complex defects
-Understanding this approach is vital for surgical residents preparing for DNB and NEET SS examinations, as it is a common and important procedure.

Indications

Primary Indications:
-Recurrent incisional hernias
-Large (>10 cm) primary incisional or ventral hernias
-Defects with tissue loss or significant fascial retraction
-Hernias associated with enterocutaneous fistulas (in selected cases)
-Cases requiring wide mesh coverage.
Contraindications:
-Active infection at the surgical site or systemic sepsis
-Uncontrolled coagulopathy
-Severe malnutrition or cachexia
-Patient refusal or inability to tolerate surgery
-Certain extensive abdominal wall tumors requiring radical resection.
Relative Contraindications:
-Previous mesh infection
-Significant abdominal contamination
-Patient with poor wound healing potential.

Preoperative Preparation

Patient Assessment:
-Thorough history and physical examination to assess hernia size, location, and associated comorbidities
-Nutritional assessment and optimization
-Smoking cessation counseling
-Optimization of comorbidities like diabetes or hypertension.
Imaging Studies:
-Ultrasound or CT scan of the abdomen to precisely delineate hernia anatomy, defect size, fascial planes, and identify any intra-abdominal adhesions or pathology
-MRI may be useful in select cases for better soft tissue visualization.
Surgical Planning:
-Decision between open versus laparoscopic approach based on defect size, patient factors, and surgeon expertise
-Choice of mesh material (synthetic polypropylene, ePTFE, or biological grafts) considering factors like infection risk and mesh cost
-Preoperative antibiotic prophylaxis.

Surgical Management

Open Preperitoneal Technique:
-A curvilinear or transverse incision is made above or below the hernia defect, creating a plane between the posterior rectus sheath and the peritoneum
-The peritoneum is dissected away from the posterior rectus sheath to create adequate space for mesh placement
-The mesh is then secured using sutures, tacks, or fibrin glue, overlapping the defect margins by at least 5-10 cm
-The rectus muscles are then approximated, and the anterior fascia and skin are closed.
Laparoscopic Preperitoneal Technique:
-Performed laparoscopically, typically using the Trans-Abdominal Pre-Peritoneal (TAPP) or Extraperitoneal (IPOM – Inlay Onlay Mesh) approach
-For TAPP, ports are placed, and the peritoneum is incised and dissected to create a preperitoneal space
-For IPOM, dissection is performed directly in the preperitoneal space without entering the peritoneal cavity
-Mesh is introduced and secured with tacks or sutures
-The peritoneal flap is then closed if necessary (TAPP).
Mesh Selection:
-Synthetic meshes (e.g., polypropylene, ePTFE) are durable and cost-effective but have a higher risk of infection
-Biological meshes offer better tissue integration and reduced infection risk but are more expensive and can retract or lose strength over time
-Combination meshes may be used in contaminated fields
-The choice depends on hernia complexity, patient factors, and surgeon preference.
Fixation Methods:
-Sutures for secure fixation, especially in open procedures
-Tacks (e.g., spinal needles, spiral tacks) for laparoscopic procedures to minimize tissue trauma
-Fibrin glue can be used as an adjunct or primary fixation in select cases
-The goal is to ensure adequate mesh coverage and prevent migration.

Postoperative Care

Pain Management:
-Adequate analgesia is crucial, often involving multimodal approaches including parenteral opioids, NSAIDs, and patient-controlled analgesia (PCA)
-Epidural anesthesia can be considered for open procedures
-Regional blocks may also be beneficial.
Monitoring:
-Close monitoring for signs of infection (fever, wound redness, discharge), hematoma formation, seroma, or mesh-related complications
-Vital signs monitoring
-Assessment for bowel function recovery.
Mobility And Activity:
-Early ambulation is encouraged to prevent deep vein thrombosis (DVT) and pulmonary complications
-Restrictions on heavy lifting and strenuous activity are typically advised for 6-8 weeks, with gradual return to normal activities as tolerated
-Graduated exercise programs may be recommended.
Wound Care:
-Standard wound care, including keeping the incision clean and dry
-Dressing changes as per protocol
-Monitoring for wound dehiscence or signs of infection
-Follow-up appointments to assess wound healing and patient recovery.

Complications

Early Complications:
-Wound infection
-Hematoma or seroma formation
-Mesh infection
-Urinary retention
-Ileus
-Pneumonia
-Deep vein thrombosis (DVT) or pulmonary embolism (PE).
Late Complications:
-Chronic pain (neuropathic or mesh-related)
-Mesh migration or shrinkage
-Bowel obstruction due to adhesions
-Enterocutaneous fistula (rare with preperitoneal placement)
-Recurrence of hernia
-Persistent seroma.
Prevention Strategies:
-Meticulous surgical technique to minimize tissue trauma and ensure proper mesh placement
-Use of prophylactic antibiotics
-Appropriate mesh selection for the defect
-Adequate wound closure and drainage if necessary
-Patient education on activity restrictions
-Optimization of patient comorbidities.

Prognosis

Factors Affecting Prognosis:
-Hernia size and complexity
-Patient comorbidities
-Surgeon's experience
-Mesh type and fixation
-Presence of infection
-Adherence to postoperative instructions.
Outcomes:
-Successful abdominal wall reconstruction with preperitoneal mesh typically leads to a significant reduction in hernia recurrence rates and improvement in quality of life
-Long-term success rates are generally high, especially with large mesh overlap and secure fixation.
Follow Up:
-Regular follow-up appointments are essential for at least 1-2 years postoperatively to monitor for recurrence, assess wound healing, and manage any long-term complications
-Patient education on recognizing signs of recurrence is crucial.

Key Points

Exam Focus:
-Preperitoneal mesh placement provides a tension-free repair for large ventral and incisional hernias
-Key advantage: reduced recurrence compared to purely intraperitoneal or underlay repairs
-Differentiate between open and laparoscopic approaches (TAPP vs
-IPOM)
-Understand mesh types and fixation methods and their implications for complications like infection and migration.
Clinical Pearls:
-Ensure adequate mesh overlap (at least 5-10 cm) in all dimensions for optimal results
-Careful dissection in the preperitoneal plane is crucial to avoid injury to the peritoneum, bowel, or bladder
-Consider biologic mesh in contaminated fields or in patients with high infection risk
-Postoperative pain control is paramount for early mobilization and recovery.
Common Mistakes:
-Inadequate mesh overlap
-Incomplete dissection of the preperitoneal space
-Poor fixation leading to mesh migration
-Ignoring patient comorbidities that can impair wound healing
-Premature return to strenuous activity
-Failure to recognize and manage early signs of infection or seroma.