Introduction
Choosing the wrong wound closure technique can lead to dehiscence, prolonged healing, or poor cosmetic outcomes. Surgeons face critical decisions when selecting from multiple closure methods based on wound characteristics, contamination level, and patient factors.
This article explains the three main categories of wound closure—primary, secondary, and tertiary intention—the specific techniques used within each category, and guidance on selecting the appropriate method for optimal surgical outcomes.
TLDR
- Closure techniques fall into three categories: primary (direct), secondary (granulation), and tertiary (delayed)
- Primary closure uses sutures, staples, tissue adhesives, or bioabsorbable subcutaneous systems
- Selection depends on wound classification (clean vs. contaminated), tissue loss, infection risk, and cosmetic considerations
- These techniques minimize complications and improve both functional and cosmetic outcomes
What Are Wound Closure Techniques?
Wound closure techniques are the methods surgeons use to bring wound edges together or facilitate healing after surgery or injury. These approaches range from direct surgical closure using sutures, staples, or adhesives to allowing natural healing processes through granulation tissue formation.
Selecting the right approach requires careful assessment. The technique must be tailored to specific wound characteristics, patient factors, and clinical goals.
Key factors influencing closure method selection include:
- Wound depth and tissue layer involvement
- Contamination level and infection risk
- Tissue viability and blood supply
- Anatomical location and tension forces
- Patient healing capacity and comorbidities
Each of these variables guides surgeons toward the closure method that will deliver optimal healing and cosmetic outcomes.
Why Are Wound Closure Techniques Important in Surgery?
Proper wound closure directly impacts healing time, infection rates, functional outcomes, and cosmetic results.
Surgical site infections (SSIs) affect 2% to 4% of patients undergoing surgical procedures annually in the United States, with the closure method playing a significant role in infection risk.
When surgeons select inappropriate closure methods, several serious complications can arise:
Common complications include:
- Increased infection risk when contaminated wounds are closed immediately
- Wound dehiscence (separation of wound edges), which carries a 9.6% attributable mortality rate
- Excessive scarring from poor technique or inappropriate method selection
- Prolonged healing time when the wrong approach is chosen
- Patient discomfort from suboptimal closure methods
Choosing the right technique balances multiple factors: speed of closure, strength of repair, cosmetic outcome, and risk of complications. Understanding these trade-offs is essential for surgical decision-making.
Types of Wound Closure by Intention
Wound closure is categorized by "intention"—the planned mechanism and timeline of healing. Understanding these three fundamental categories is essential before selecting specific closure techniques.
Primary Intention (Primary Closure)
Primary intention is the direct approximation of wound edges immediately after creation, resulting in the fastest healing with minimal scarring.
This method is used for clean or clean-contaminated wounds with minimal tissue loss that can be closed without tension. Primary closure typically uses sutures, staples, adhesives, or bioabsorbable systems like SubQ It! and should occur within 4-8 hours of wound creation for optimal results. Wounds closed by primary intention typically heal within 2 weeks in healthy individuals.
Ideal candidates for primary intention:
- Surgical incisions in sterile environments
- Clean lacerations with well-approximated edges
- Wounds with well-vascularized tissue beds
- Injuries presenting within the "golden period" (typically 12-24 hours)
Secondary Intention (Healing by Granulation)
Secondary intention allows a wound to heal naturally from the base upward through granulation tissue formation and epithelialization (new skin cell growth).
This method is chosen when wound edges cannot be approximated due to tissue loss, high infection risk, or contamination. Healing time is significantly longer—weeks to months depending on wound size—and results in broader, contracted scars. Despite these drawbacks, this approach is sometimes the safest option when immediate closure would trap bacteria or compromise healing.
When secondary intention is preferred:
- Contaminated or dirty wounds with high infection risk
- Wounds with significant tissue loss preventing approximation
- Delayed presentation (>24 hours for most wounds)
- Abscess cavities or chronic wounds
- Areas where infection risk outweighs closure benefits
Tertiary Intention (Delayed Primary Closure)
Tertiary intention involves intentionally leaving a wound open initially, then surgically closing it after a planned observation period of 3-7 days.
This technique combines both approaches: initial open management to reduce infection and edema risk, followed by formal closure.
A 2024 meta-analysis of 12 RCTs (n=903) demonstrated that delayed primary closure significantly reduced surgical site infection rates in patients with gastrointestinal perforation (OR 0.31, 95% CI 0.15-0.63) compared to immediate primary closure.
Typical scenarios for tertiary intention:
- Traumatic wounds with questionable contamination
- Bite wounds with high infection potential
- Wounds with significant edema requiring resolution
- Perforated viscus repairs where only fascia is initially closed
- Contaminated wounds requiring observation before definitive closure
Primary Closure Techniques
Within primary intention closure, surgeons have multiple technical options. The choice depends on wound location, tension, desired cosmetic outcome, and practical considerations.
Sutures
Sutures remain the most versatile closure method, available in absorbable and non-absorbable materials with various needle configurations. They offer precise tissue approximation and excellent cosmetic potential when properly placed.
Suture techniques include:
- Simple interrupted: Most secure option allowing individual suture adjustment; if one fails, others maintain closure integrity
- Running continuous: Faster placement with even tension distribution, but a break at any point can compromise the entire suture line
- Vertical/horizontal mattress: Maximum strength for high-tension areas; excellent for everting wound edges
- Running subcuticular: Superior cosmetic outcomes compared to interrupted sutures, with reduced superficial wound dehiscence (RR 0.56)
Sutures provide versatility and precise tissue approximation with excellent cosmetic potential for all body areas. However, they're time-consuming (42 seconds per subcuticular interrupted stitch), require technical skill, and non-absorbable types need removal.
Staples
Staples are rapid mechanical closure devices that approximate wound edges with metal fasteners. They penetrate the skin surface (percutaneous), creating characteristic "train track" scars if not removed promptly.
Staples are approximately 3 to 4 times faster to apply than sutures, making them valuable in high-volume or emergency settings. This speed comes with trade-offs.
While staples offer speed, ease of use, and cost-effectiveness for long incisions, they carry significant drawbacks. Studies show over three times greater risk of superficial wound infection in orthopedic surgery (RR 3.83, 95% CI 1.38-10.68). They also provide less precise tissue approximation, create more visible scarring, cause patient discomfort during removal, and aren't suitable for facial or cosmetically sensitive areas.
Tissue Adhesives
Tissue adhesives (surgical glue) are topical bonding agents that hold wound edges together without penetrating tissue. Clinical trials indicate that tissue adhesives offer comparable cosmetic outcomes to sutures for low-tension wounds.
Tissue adhesives work best for small, low-tension wounds, pediatric lacerations, and areas where suture removal would be difficult. They offer painless application with no removal required, making them ideal for anxious patients or children.
The main limitation is lower tensile strength than sutures, making them unsuitable for high-tension areas, infected or heavily contaminated wounds, mucosal surfaces, or high-moisture areas.
Bioabsorbable Subcutaneous Closure Systems
Beyond traditional methods, modern bioabsorbable systems represent an evolution in closure technology. These systems place fasteners in the subcutaneous layer rather than through the skin surface, combining the speed of staples with the cosmetic benefits of subcuticular sutures.
SubQ It! uses bioabsorbable fasteners that are absorbed by the body after healing, eliminating removal procedures.
The SubQ It! system deploys fasteners in approximately 7 seconds each—7 times faster than manual sutures—while achieving the cosmetic benefits of subcuticular closure. Each fastener weighs only 0.0064 grams and is made from PLGA (polylactic-co-glycolic acid), which maintains 80% strength for 21 days before natural absorption.
Key advantages include:
- Rapid closure time—7X faster than manual sutures
- Superior cosmetic outcomes with no train track scarring
- No removal required, eliminating patient discomfort and follow-up costs
- Never pierces external skin surface
- FDA-cleared for abdominal, thoracic, gynecologic, orthopedic, plastic, and reconstructive surgery
The system requires proper training and is designed for incisions up to 10 cm (SU-10 model) or 25 cm (SU-25 model).
How to Choose the Right Wound Closure Technique
Selecting the optimal closure technique requires evaluating wound-specific factors and patient circumstances rather than defaulting to familiar methods.
Wound Classification and Contamination Level
The CDC surgical wound classification system classifies infection risk:
| Wound Class | SSI Risk | Recommended Closure |
|---|---|---|
| Clean | 1-5% | Primary Closure |
| Clean-Contaminated | 3-11% | Primary Closure |
| Contaminated | 10-17% | Often Delayed Primary Closure |
| Dirty/Infected | >27% | Secondary Intention or Delayed Closure |
Clean and clean-contaminated wounds are candidates for immediate primary closure. Contaminated and dirty wounds may require secondary intention or delayed closure when infection risk outweighs immediate closure benefits.
Wound Characteristics
Beyond contamination level, the wound's physical characteristics guide closure method selection. Tissue loss extent, edge approximation ability, wound depth, and tissue viability all determine whether primary, secondary, or tertiary intention is appropriate.
Key considerations:
- Can edges be approximated without excessive tension?
- Is there significant tissue loss?
- Is the tissue bed well-vascularized?
- What is the wound depth and complexity?
Excessive tension is a primary risk factor for dehiscence. Wounds that cannot be closed without tension require alternative approaches such as secondary intention or reconstructive techniques.
Location and Cosmetic Considerations
Anatomical location significantly influences technique selection based on cosmetic expectations:
High-visibility areas (face, neck, anterior torso):
- Subcuticular sutures or bioabsorbable subcutaneous systems
- Tissue adhesives for appropriate wounds
- Continuous subcuticular sutures result in superior cosmetic appearance compared to interrupted percutaneous sutures
Lower-visibility areas (trunk, extremities, scalp):
- Surgeons often use staples on scalp lacerations due to hair coverage and speed requirements
- Interrupted sutures provide strength for high-tension areas
- Speed and strength often take priority over cosmetic refinement
Time, Resource, and Skill Considerations
Clinical realities also shape technique decisions:
- Surgeon expertise: Proficiency with specific techniques affects outcomes
- Time available: Emergency situations may require faster methods
- Patient compliance: Can the patient return for suture/staple removal?
- Cost implications: Consider both upfront device costs and removal-related expenses
Bioabsorbable systems like SubQ It! eliminate removal costs entirely, which can offset higher initial device costs when analyzing total cost of care. For institutions performing high volumes of closures, this elimination of follow-up visits can significantly impact operational efficiency.
Common Mistakes to Avoid When Selecting Wound Closure Methods
Choosing Speed Over Appropriateness
Selecting the fastest method when cosmetic outcome or wound characteristics require a different approach creates patient dissatisfaction and suboptimal results.
Facial wounds closed with staples, for example, result in prominent scarring that proper technique selection could prevent.
Ignoring Wound Contamination and Infection Risk
Attempting primary closure on contaminated wounds or wounds with high infection risk invites complications that secondary intention or delayed closure would prevent.
Delayed primary closure significantly reduces SSI rates in contaminated abdominal wounds, yet surgeons sometimes prioritize immediate closure for convenience.
Applying Excessive Tension
Closing wounds under high tension—regardless of technique—causes tissue ischemia, necrosis, dehiscence, and poor cosmetic outcomes.
When edges cannot be approximated without tension, secondary intention or reconstructive techniques (skin grafts/flaps) are more appropriate than forced primary closure.
Conclusion
Wound closure techniques encompass three main healing intentions—primary, secondary, and tertiary—with multiple methods available within primary closure. These include traditional sutures and staples, tissue adhesives, and newer bioabsorbable subcutaneous systems like SubQ It! that combine speed with superior cosmetic outcomes.
Understanding the differences between these approaches and matching them to specific wound characteristics leads to optimal healing outcomes, reduced complications, and better patient satisfaction.
Surgeons who thoughtfully consider wound classification, contamination level, tension, location, and practical factors can select the most appropriate closure method for each clinical scenario. As closure technology continues to advance, staying informed about emerging options ensures patients receive the most effective and comfortable care possible.
Frequently Asked Questions
What is a primary wound closure?
Primary wound closure involves directly approximating wound edges immediately after creation using sutures, staples, adhesives, or bioabsorbable systems. This method produces the fastest healing time and minimal scarring for clean wounds with minimal tissue loss.
What is the difference between primary and secondary intention healing?
Primary intention closes wound edges surgically for fast healing (typically within 2 weeks), while secondary intention allows wounds to heal naturally from the base upward. Secondary intention takes longer (weeks to months) but is necessary when immediate closure isn't safe due to contamination or tissue loss.
When should tertiary (delayed primary) closure be used instead of primary closure?
Tertiary intention is used when contamination, infection risk, or significant edema are concerns. The wound remains open for 3-7 days for observation before surgical closure, reducing infection rates in high-risk scenarios.
How long does it take for different types of wound closures to heal?
Primary intention typically heals in 1-2 weeks, secondary intention can take weeks to months depending on wound size, and tertiary intention falls in between as it combines an observation period (3-7 days) with eventual surgical closure and standard healing time.
Which wound closure technique leaves the least visible scar?
Running subcuticular sutures and bioabsorbable subcutaneous closure systems typically produce the best cosmetic outcomes because they don't penetrate the skin surface. Traditional staples and some suture techniques can leave more visible "train track" scarring from surface penetration points.
What factors should surgeons consider when choosing between sutures and staples?
Key factors include wound location (face requires sutures for cosmesis), incision length, tension level, and desired cosmetic outcome. Bioabsorbable subcutaneous systems like SubQ It! combine the speed of staples with superior cosmetic results and eliminate the need for removal appointments.
