Fascial closure refers to the surgical repair of the deep fibrous tissue layer (fascia) of the abdominal wall after laparotomy or port-site incisions. This critical step in wound closure provides structural support and prevents herniation, yet traditional techniques have yielded inconsistent results. Recent evidence-based innovations, particularly the small bites technique, have demonstrated dramatic reductions in hernia rates when implemented correctly.
This article explores fascial anatomy and healing physiology, compares suture materials and techniques, examines the landmark STITCH trial findings on small bites closure, and reviews prophylactic mesh reinforcement strategies for high-risk patients.
TLDR:
- Incisional hernia affects 10–23% of patients after midline laparotomy, costing billions annually
- Small bites technique (5mm spacing) reduces hernia rates from 21% to 13% compared to traditional closure
- Slowly absorbable monofilament sutures (PDS 2-0) match fascial healing timelines better than fast-absorbing options
- Prophylactic mesh reinforcement cuts hernia risk by half in high-risk patients (BMI ≥27, AAA repair)
- All laparoscopic port sites ≥10mm require formal fascial closure to prevent herniation
Understanding Fascial Anatomy and Wound Healing
Abdominal Wall Fascial Layers
The abdominal wall fascia consists of multiple aponeurotic layers that converge at the midline to form the linea alba. These layers arise from the fusion of aponeuroses from three lateral muscle groups:
- External oblique - the outermost layer
- Internal oblique - the middle muscular layer
- Transversus abdominis - the deepest lateral muscle
Proper closure of the linea alba is critical because this avascular fibrous tissue provides the primary structural support for the abdominal wall. Unlike muscle tissue, fascia heals slowly and never fully regains its original tensile strength.
Wound Healing Timeline and Strength Recovery
Fascial healing progresses through three distinct phases, each with specific implications for closure technique:
Inflammatory Phase (Days 0-7): The wound is at its weakest point on postoperative day 3. During this period, the fascia relies almost entirely on suture material for support.
Proliferative Phase (Days 8-60): Rapid strength gain begins around the 8th postoperative day and continues through the second month. By 2 weeks, fascia regains only approximately 20% of its original strength. At 2 months, recovery reaches approximately 50%.
Remodeling Phase (Months 2-12+): Strength continues to increase gradually. By 3 months, the fascia achieves roughly 80% of baseline strength.
Even after complete healing, fascial tissue never fully recovers—maximum strength plateaus at 70-90% of uninjured tissue.
Because of this extended recovery period, suture material selection is critical. The fascia depends on suture support for at least 6-8 weeks, making slowly absorbable materials essential for preventing early breakdown and subsequent hernia formation.
Suture Materials and Selection for Fascial Closure
Absorbable vs. Non-Absorbable Sutures
Current evidence-based guidelines recommend slowly absorbable monofilament sutures for elective midline laparotomy. These materials provide structural support during the critical 6-8 week healing period while eventually absorbing to avoid long-term foreign body reactions.
Slowly Absorbable Sutures:
- Retain strength through the proliferative healing phase
- Gradually absorb after fascia has regained adequate tensile strength
- Minimize chronic inflammation and suture sinus formation
- Preferred for most midline closures
Non-Absorbable Sutures:
- Provide permanent support but carry risk of chronic pain
- May be considered in severely contaminated fields
- Associated with higher rates of suture sinus formation
- Generally not recommended for routine fascial closure
Understanding these material categories helps when selecting specific suture products, each with distinct performance profiles.
Specific Suture Material Characteristics
| Suture Material | Type | Complete Absorption | Strength at 2 Weeks | Strength at 6 Weeks |
|---|---|---|---|---|
| PDS II (Polydioxanone) | Monofilament | 182–238 days | ~80% | ~60% |
| Vicryl (Polyglactin 910) | Braided | 56–70 days | 75% | <25% |
| Prolene (Polypropylene) | Monofilament | Non-absorbable | Indefinite | Indefinite |
Clinical Implication: PDS retains over 60% tensile strength at 6 weeks, matching the fascial healing curve. Vicryl loses nearly all strength by 5 weeks—insufficient for fascial support given that the fascia only recovers ~50% strength by 8 weeks.
Suture Size Selection
Common sizes for fascial closure:
- Size 0 or 1: Used with traditional large bites technique
- Size 2-0: Preferred for small bites technique
Smaller diameter sutures (2-0) reduce the risk of tissue strangulation and ischemia when placed with appropriate spacing. The small bites technique specifically calls for 2-0 slowly absorbable monofilament on a small needle (31-36mm).
Innovations in Suture Technology
Barbed Sutures (Stratafix, V-Loc):These knotless sutures distribute tension evenly along the wound through directional barbs. A randomized trial in gynecological surgery showed 0% incisional hernia at 1 year with barbed sutures versus 1.4% with conventional sutures. The difference was not statistically significant, but the technology continues to gain adoption.
Triclosan-Coated Sutures (PDS Plus, Vicryl Plus):Meta-analysis evidence indicates that triclosan-coated sutures reduce surgical site infection rates in abdominal gastrointestinal surgery. Since infection is a known risk factor for hernia development, these materials offer dual benefit.
While traditional suture-based fascial closure remains the standard approach, surgeons increasingly have access to alternative closure technologies. For skin closure above the fascial layer, bioabsorbable stapling systems offer speed advantages while eliminating removal procedures—an evolving complement to the suture techniques discussed here.
Continuous vs. Interrupted Suture Techniques
Technique Comparison
Continuous (Running) Suture:
- Single strand runs the entire length of the incision
- Distributes tension evenly across the wound
- Faster to perform (average 10-14 minutes for midline closure)
- Preferred for most elective midline closures
Interrupted Suture:
- Individual sutures placed separately along the incision
- Each stitch functions independently
- Theoretical advantage if one suture fails
- May be indicated in contaminated fields or immunocompromised patients
Meta-analysis shows no significant difference in incisional hernia rates between continuous and interrupted techniques when suture type and bite size are controlled.
Continuous suturing does offer practical advantages in operating time without compromising outcomes.
The Critical 4:1 Suture-to-Wound Length Ratio
One of the most important technical factors in preventing dehiscence and hernia is achieving a suture length to wound length (SL:WL) ratio of at least 4:1.
What this means in practice:
- A 10cm wound requires at least 40cm of suture material
- A 20cm wound needs at least 80cm of suture
According to biomechanical research on suture materials that achieving this ratio with small bites and small spacing produces higher tensile forces than large bites. The ratio is achieved through close bite spacing (5-7mm intervals) rather than large tissue bites.
How to ensure adequate ratio:
- Measure wound length before closure and calculate required suture length (multiply by 4)
- Achieve the ratio through appropriate bite spacing (5-7mm intervals)
- Avoid excessive tension that shortens the effective suture length
The Small Bites Technique: Evidence and Application
The STITCH Trial: Landmark Evidence
The STITCH trial published in Lancet 2015 provided Level 1 evidence that fundamentally changed fascial closure practice. This multicenter, double-blind randomized controlled trial compared two techniques in 560 patients:
Small Bites Technique:
- 5-7mm tissue bites
- 5-7mm spacing between bites
- USP 2-0 suture with small needle (31mm)
Traditional Large Bites:
- 1cm tissue bites
- 1cm spacing
- USP 1 suture
Results at 1 Year:
- Incisional hernia rate: 13% (small bites) vs. 21% (large bites)
- Adjusted odds ratio: 0.52 (95% CI 0.31–0.87, p=0.0220)
- No significant difference in adverse events between groups
- Small bites took slightly longer (mean 14 min vs 10 min)
These findings held up under further scrutiny. A 2024 validation study in colorectal cancer surgery confirmed the superiority of small bites, reporting even more dramatic results: 7% hernia rate with small bites versus 27% with conventional technique (p < 0.001).
Biomechanical Rationale
The small bites technique works by:
- Reducing tissue ischemia: Smaller bites preserve blood supply to fascial edges
- Distributing tension more evenly: Frequent bite points spread mechanical load
- Minimizing tissue strangulation: Less tissue incorporated in each bite
- Achieving optimal SL:WL ratio: Close spacing consumes more suture length
Traditional large bites incorporate more tissue but create zones of ischemia and concentrate tension at fewer points. This increases the risk of suture pull-through and tissue necrosis.
Step-by-Step Small Bites Technique
- Select appropriate suture: Use 2-0 slowly absorbable monofilament (PDS) on a 31-36mm needle
- Begin 1cm from wound edge: Start continuous suture at one end
- Take 5-7mm bites: Pass needle through fascia 5-7mm from the cut edge
- Space bites 5-7mm apart: Advance 5-7mm before the next bite
- Maintain consistent tension: Avoid excessive tightness that causes tissue blanching
- Achieve 4:1 ratio: Total suture length should equal 4 times the wound length
- End 1cm from opposite edge: Secure with multiple throws
Limitations and Considerations
Learning Curve
Surgeons accustomed to large bites require practice to achieve consistent 5-7mm spacing. Training on simulation models can build skill faster.
Time Investment
Small bites add approximately 4 minutes to closure time compared to large bites. This is a worthwhile trade-off for 40% reduction in hernia risk.
Patient Selection
Studies validate the technique primarily in elective midline laparotomy. Application in emergency surgery or contaminated fields requires clinical judgment.
Mesh Augmentation and Prophylactic Reinforcement
When to Consider Prophylactic Mesh
For certain high-risk patient populations, primary suture closure—even with optimal technique—may be insufficient. Current guidelines suggest considering prophylactic mesh for patients with:
- Abdominal aortic aneurysm (AAA) repair
- BMI ≥27 kg/m² (PRIMA trial threshold)
- Chronic immunosuppression (steroids, transplant patients)
- Advanced age with poor tissue quality
- Previous hernia or multiple prior laparotomies
Mesh Placement Options
Surgeons have three primary mesh placement options, each with distinct advantages:
Onlay Position:
- Placed superficial to fascia, deep to subcutaneous fat
- Simpler surgical technique
- Higher seroma rates but effective hernia prevention
Sublay (Retrorectus) Position:
- Placed posterior to rectus muscle, anterior to posterior sheath
- More complex dissection required
- Lower seroma rates with excellent biomechanical positioning
Intraperitoneal Position:
- Generally avoided for prophylactic reinforcement
- Reserved for ventral hernia repair scenarios
PRIMA Trial Evidence
The PRIMA trial compared primary suture alone versus prophylactic mesh reinforcement in high-risk patients (BMI ≥27 or AAA). Results showed significant hernia rate reductions with mesh:
2-Year Hernia Rates:
- Primary suture alone: ~30%
- Onlay mesh reinforcement: 13%
- Sublay mesh reinforcement: 18%
Both mesh positions significantly reduced hernia rates compared to suture alone. However, onlay mesh was associated with increased seroma formation (relative risk 2.23), though surgical site infection rates remained comparable.
Complications and Patient Counseling
Understanding potential complications helps guide patient selection and informed consent discussions.
Seroma Formation:
- Most common complication with onlay mesh
- Usually self-limiting, resolves within weeks to months
- May require aspiration in symptomatic cases
Infection Risk:
- No significant increase in SSI with prophylactic mesh in clean cases
- Risk-benefit calculation differs in contaminated fields
Mesh Removal:
- Rare with modern synthetic meshes in prophylactic setting
- Rates typically <2% in published series
When counseling patients about prophylactic mesh, discuss these key points:
- Mesh reduces hernia risk by approximately 50%
- Small increase in seroma risk (usually minor)
- Permanent implant remains in body
- Overall benefit outweighs risk in appropriate candidates
Port-Site Fascial Closure Techniques
Laparoscopic surgery has revolutionized many procedures, but trocar sites create fascial defects that can herniate if not properly closed. While port-site hernias are less common than midline incisional hernias, they represent a preventable complication.
Indications for Port-Site Closure
Evidence-based guidelines recommend formal fascial closure for:
- Ports ≥10mm diameter (all sizes)
- Umbilical ports regardless of size (inherent weakness)
- Dilated ports subjected to manipulation or enlargement during the procedure
Ports <5mm that were not manipulated extensively generally do not require fascial closure, as herniation risk is minimal.
Once you've identified which ports require closure, selecting the appropriate technique depends on your preference for visualization and device availability.
Closure Technique Categories
Intracorporeal Assistance:
- Suture passer devices used under direct laparoscopic visualization
- Ensures full-thickness fascial closure with visual confirmation
Extracorporeal Assistance:
- External device manipulation with internal viewing
- Balances control and visual confirmation
External Closure Methods:
- Blind techniques using specialized needles or hooks
- Faster approach without direct visualization
Commonly Used Devices
Carter-Thomason CloseSure System:A comparative study found this device was faster overall and resulted in fewer port-closure-related complications compared to other techniques. The system uses a suture passer with a spring-loaded needle for controlled fascial penetration.
Endoclose Device:Allows passage of suture through the fascia under laparoscopic guidance, providing visual confirmation of proper placement.
Graham's Nerve Hook Technique:A manual technique using a standard nerve hook reported only one hernia in 493 cases when used for ports ≥10mm, demonstrating excellent outcomes with simple instrumentation.
Best Practices for Port-Site Closure
- Incorporate full-thickness fascia, not just peritoneum
- Use figure-of-eight or simple interrupted sutures
- Absorbable suture is appropriate for port-site closure (0 or 2-0)
- Verify closure under laparoscopic visualization before removing camera port when technique allows
Frequently Asked Questions
What is fascial closure?
Fascial closure repairs the deep fibrous tissue layer (fascia) of the abdominal wall following laparotomy or port-site incisions. This structural layer is distinct from skin closure, which addresses only superficial layers.
What are the three types of closure?
The three main categories are continuous (running) suture, interrupted suture, and hybrid techniques. Continuous suture uses a single strand along the entire incision and is preferred for most elective closures, while interrupted sutures are placed separately in contaminated fields or high-risk cases.
What suture is used to close fascia?
Slowly absorbable monofilaments like PDS or Maxon in sizes 0, 1, or 2-0 are most common. These materials retain strength through the critical 6-8 week healing period, unlike non-absorbable options that persist indefinitely or rapidly absorbable ones that lose strength too quickly.
What is the small bites technique and why is it preferred?
The small bites technique uses 5-7mm tissue bites placed every 5-7mm along the fascial edge. The STITCH trial showed this reduces incisional hernia rates from 21% to 13% at one year by reducing tissue ischemia and distributing tension more evenly.
How can incisional hernias be prevented after abdominal surgery?
Evidence-based prevention strategies include adopting the small bites technique, using slowly absorbable monofilament sutures, achieving a 4:1 suture-to-wound length ratio, considering prophylactic mesh in high-risk patients (BMI ≥27, AAA repair), and avoiding excessive tension during closure.
What are the most common complications of fascial closure?
Key complications include incisional hernia (10-23% incidence after midline laparotomy), wound dehiscence or evisceration (0.5-3%), surgical site infection, seroma formation (especially with mesh reinforcement), and suture-related pain or chronic suture sinus formation with non-absorbable materials.
