The fascia is a strong, fibrous sheath beneath the skin and fat that encases muscle groups and organs. Surgeons focus on closing this layer for structural integrity after a major incision. Secure closure is the most effective action to prevent incisional hernias and wound dehiscence (splitting open of the wound). The choice of suture is highly specialized, determined by biomechanical requirements to withstand the immense forces placed on the wound after surgery.
The Critical Role of Fascia in Surgical Strength
The abdominal fascia, particularly the anterior rectus sheath, serves as the primary load-bearing structure of the body wall. This dense connective tissue maintains the integrity of the abdomen against constant internal pressure from breathing, coughing, and movement. Because of its dense composition, fascia has a low metabolic rate and is poorly supplied with blood vessels, which changes its healing timeline.
Fascia heals slowly, regaining strength over a prolonged period that can take 12 to 18 months to achieve full native tensile strength. Initial wound strength is entirely dependent on the suture material, as the tissue itself provides very little support in the first few weeks. The suture must therefore maintain its own tensile strength for several months to bridge the gap until the body’s own collagen remodeling process provides adequate stability. This prolonged dependency on the suture makes the material choice uniquely important for fascial closure.
Essential Biomechanical Criteria for Fascial Sutures
A suture chosen for fascial closure must meet several specific engineering and biological criteria to ensure a successful long-term outcome. The material must possess high initial tensile strength to immediately resist the mechanical forces of the abdominal cavity, which can be intense, especially during coughing or vomiting. This strength is necessary to prevent the wound edges from separating under tension.
The material must also have a controlled and predictable absorption profile. An acceptable material should retain sufficient strength, typically around 50%, for at least 60 days to support the fascia during its most vulnerable phase of healing. Rapidly absorbing sutures, which lose strength in a matter of weeks, are avoided because they leave the healing fascia unprotected too early.
Sutures are classified as either monofilament or braided (multifilament); monofilament is often preferred for fascial closure. The single-strand design reduces the risk of harboring bacteria, which is an advantage in potentially contaminated surgical fields. Monofilament sutures, such as polydioxanone, also demonstrate excellent handling properties and provide reliable knot security under tension.
Standard Materials and Techniques for Fascial Closure
The most commonly used materials for fascial closure are synthetic, slow-absorbing monofilaments, with Polydioxanone (PDS) being the archetype. PDS maintains its structural integrity for an extended time, often retaining significant tensile strength for up to six weeks and being completely absorbed over six months. The typical size, or gauge, used for abdominal fascial closure is size 0 or size 1, which provides the necessary bulk and strength to resist tissue pull-through.
While slow-absorbing sutures are the standard, non-absorbable materials like polypropylene may be used in high-risk patients or for secondary closures where maximum permanent support is desired. However, non-absorbable sutures carry a slightly higher risk of long-term complications like suture sinuses or chronic pain. The preferred surgical technique is the continuous mass closure, which passes the suture through all layers of the abdominal wall except the skin, distributing tension evenly across the entire incision.
A specific detail of the mass closure technique is the adherence to a minimum suture-to-wound length ratio of 4:1, meaning the total length of suture material used must be at least four times the length of the incision. Achieving this ratio is accomplished through a “small-bites” technique, where the surgeon takes short, closely spaced stitches, typically no more than one centimeter from the wound edge and one centimeter apart. This technique minimizes the risk of tissue strangulation and significantly reduces the incidence of incisional hernia formation.
Patient and Procedural Factors Modifying Suture Selection
The standard choice of suture material and technique may be modified based on patient risk factors and the nature of the surgical procedure. Patients with conditions that impair wound healing, such as obesity, diabetes, chronic steroid use, or malnutrition, place greater stress on the closure. In these cases, a surgeon might opt for a non-absorbable suture or a material with a more extended absorption profile to guarantee support for a longer recovery period.
Wound contamination also significantly affects material choice, as braided sutures are generally avoided in infected fields due to their ability to harbor bacteria. The monofilament structure of PDS makes it the preferred material in contaminated cases. The location of the fascia is also a consideration; while abdominal fascia requires a strong, slow-absorbing material, the closure of fascia in other areas, such as an extremity, may allow for a different choice because the mechanical stress is much lower.