Abdominal Wall Reconstruction: Update Course 2017

Over 300 meshes are available on the market, spanning synthetics, bioabsorbables, and biologics.

FDA Class 2 device clearance for mesh requires only equivalence to Marlex mesh, allowing easy market entry.

Patients with more comorbidities have higher rates of wound complications after hernia surgery.

Prehabilitation (smoking cessation, weight loss, glycemic control) is now required before offering elective hernia surgery to optimize outcomes.

PTFE mesh is no longer used in abdominal wall reconstruction due to poor integration and requirement for complete removal if infected.

In a rat model, composite meshes with anti-adhesive layers performed worst, acting like agar plates for MRSA overgrowth.

Monofilament macroporous polypropylene mesh (medium-weight) performed equivalent to biologic mesh in MRSA-contaminated rat model; 70% of animals cleared bacteria.

Clinical series of 100 patients with retromuscular synthetic mesh in contaminated fields: 9% clean-contaminated wound morbidity, 19% contaminated wound morbidity, 7% recurrence at 10 months, 4 partial mesh excisions, zero complete excisions.

Gold standard for hernia repair follow-up is 2 years; 10-month follow-up is short-term.

Biologic mesh was initially touted as 'magic mesh' that would remodel into fascia, but histology shows minimal cellular penetration and no regeneration.

Cross-linked biologic mesh (terminally cross-linked = leather) shows zero cellular penetration and poor performance in infection.

Five-year series of biologic mesh in contaminated cases (128 patients, mean defect 431 cm²): 47% wound morbidity, 31% recurrence at 2 years, 50% recurrence by 3 years.

Biologic mesh costs $25,000–$30,000 versus <$200 for synthetic mesh.

Biologic mesh placed as a bridge repair (without fascial closure) for definitive abdominal wall reconstruction results in 100% recurrence by 4 years (Butler, MD Anderson data).

Biologic mesh with fascial closure (reinforcement) has ~20% recurrence rate, versus 100% with bridge repair.

Retromuscular mesh placement has 10% recurrence at 1 year versus 30% for intraperitoneal placement (RIC trial, industry-sponsored).

Posterior component separation involves incising the posterior lamella of the internal oblique just medial to the neurovascular bundles at the rib edge, then incising the transversus abdominis to enter the preperitoneal plane.

The upper third of the abdominal wall does have a transversus abdominis extending under the rectus muscle, contrary to Netter's atlas description.

Posterior component separation is becoming the standard approach in abdominal wall reconstruction because it avoids large subcutaneous flaps required for anterior component separation, reducing wound morbidity.

Posterior component separation achieves equivalent fascial advancement to anterior component separation.

Laparoscopic ventral hernia repair is reserved for non-functional patients to prevent incarceration, not for definitive reconstruction.

Recreating the linea alba is functionally important; core abdominal muscle function is critical for daily activities, and tendon incision leads to muscle scarring and loss of function.

For gastroschisis, sutureless closure (umbilical cord stump coverage) is preferred; most umbilical hernias close spontaneously, and biologic mesh is not indicated.

For subxiphoid hernias, posterior component separation allows mesh placement in an envelope extending to the central tendon of the diaphragm, providing better fixation without needing to tack mesh directly to the diaphragm.

If fascial closure cannot be achieved, bridge repair with heavyweight synthetic mesh plus a subcutaneous drain is an acceptable approach.