Simple Interrupted Suture Technique: Step-by-Step Surgical Guide

The deep dermal stitch is a surgical technique used to relieve tension on wounds before closing the superficial skin layer, involving alternating bites from deep to superficial on each side of the wound to bury the knot within the tissue, and always requires absorbable sutures since they cannot be removed later.

This section addresses advanced wound closure strategies including cosmetic subcuticular techniques and complex layered approaches for deep wounds. Subcuticular closure is purely cosmetic, running sutures entirely under the skin at the deep dermis level with horizontal bites, leaving no visible sutures in the wound while holding everything together beneath the surface. Complex wound closure requires addressing multiple tissue layers because closing only the skin creates potential spaces for fluid collection or excessive tension, especially over joints. Start with fascia closure using interrupted simple sutures, then close the deep dermis with buried knots. Close the ends first (least tension) working toward the middle which gapes open the most. Skin stapling offers rapid closure with automatic edge eversion; position skin properly with pickups, center the stapler, and staple down. Staples are removed by grabbing the staple, unbending the tines, aligning them straight, and allowing them to pop out easily. These techniques demonstrate the progression from basic to advanced surgical wound management.

Subcuticular suturing is a surgical technique where the needle passes through the dermis layer (the white layer beneath the epidermis) rather than the epidermis itself, with stitches placed parallel to the skin surface and knots tied deep within the dermis to create an invisible closure; the technique requires consistent depth, proper suture exit on the same side for interrupted sutures, pulling lengthwise along the incision rather than perpendicular, and can be performed as either interrupted or running sutures depending on incision length.

Plastic suture and subcuticular suture are advanced wound closure techniques used in cosmetic suturing to minimize visible scarring and promote optimal healing by placing sutures beneath the skin surface.

Deep tension relief sutures (similar to inverted sutures but in the deep dermis) are used to reduce tension on wound edges before superficial closure. This technique is particularly important in plastic surgery to prevent visible scarring. By relieving tension in the deep dermis, subsequent superficial sutures (like intradermal or simple sutures) can be placed more easily without causing tissue strangulation or visible marks.

Suture materials can be remembered using mnemonics: PMV for absorbable synthetic (Polyglactin, Polypropylene, Vicryl), PEN for non-absorbable (Polypropylene, Nylon, Ethicon). Monocryl is polyglycomer, a synthetic absorbable monofilament. Suture numbers indicate thickness: 3-0 for subcuticular, 2-0/3-0 for skin closure. Different surgical sites require different sutures: Vicryl for bladder/bowel, Monocryl for subcuticular. Absorption timelines vary: Vicryl absorbs in 180 days.

This video provides a comprehensive guide to selecting appropriate suture materials and sizes based on anatomical location and tissue characteristics. Suture materials are classified by observability (absorbable/non-absorbable), structure (monofilament/multifilament), and origin (natural/synthetic). Key selection principles include: scalp and chest skin (hard tissues) require stronger non-absorbable sutures (3-0/4-0 Nylon/Prolene); face requires careful cosmetic consideration with 5-0/6-0 sutures; delicate tissues like cornea (10-0 Nylon) and conjunctiva (8-0) need finer options; oral mucosa uses 3-0/4-0; abdominal and pelvic organs use absorbable sutures (4-0/5-0); extremities vary by location (hand 4-0/5-0, foot/leg 3-0); tendons require 2-0 strong sutures; nerves need 6-0 fine sutures; vascular repairs use 6-0/8-0 non-absorbable; bone repairs use steel wire. General rule: internal procedures use absorbable sutures, external/skin procedures use non-absorbable.

Suture selection depends on the clinical scenario: braided sutures offer better handling and knot security but have less tensile strength, while monofilament sutures provide smoother tissue passage but are more brittle; absorbable sutures (like Vicryl or PDS) dissolve over time and are ideal for skin closures where minimal scarring is desired, whereas non-absorbable sutures (like nylon or prolene) maintain constant strength and are preferred for areas with high tension or swelling; the numbering system indicates size with smaller numbers (e.g., 3-0, 4-0) representing thinner sutures, and proper needle selection (cutting vs. taper) should match the tissue being sutured.

This segment provides a comprehensive overview of suture material classification and selection criteria. The instructor explains the fundamental distinction between absorbable (reabsorbible) and non-absorbable sutures, with absorbable sutures being suitable for deep tissues where re-opening would be difficult. Nylon sutures are presented as the primary example of non-absorbable materials, noted for their economy, resistance, and black color providing good contrast. The suture size designation system is explained, where the number of zeros indicates thickness (higher number = thinner suture). The instructor emphasizes that suture selection depends on tissue type, anatomical location, and whether sutures need to be removed. Examples include using absorbable sutures for cesarean section uterine closure and non-absorbable sutures for skin. The segment concludes with the characteristics of catgut sutures as organic absorbable materials.

Sutures are classified as absorbable (dissolve in body) or non-absorbable (remain permanently). Absorbable sutures contain 'G' in spelling: Polyglycolic acid, Polyglactin, Polydioxanone (collagen), Chromic catgut. Non-absorbable sutures lack 'G': Polypropylene, Nylon, Monocryl, Stainless steel. Monofilament sutures (single thread) require 6-8 knots, are weaker but have fewer infection risks. Multifilament sutures (braided) require 2-3 knots, are stronger but have higher infection risks. Selection depends on wound location and healing requirements.

Suture removal timing varies based on body location. Scalp sutures should be removed in 6-8 days. Face sutures should be removed in 3-5 days. Upper extremity sutures should be removed in 8-10 days. Lower extremity sutures should be removed in 14 days. These timing guidelines ensure proper wound healing while preventing complications from prolonged suture presence.

Post-surgical wound care involves removing sutures after 10-14 days depending on body location, using waterproof tape for showering, applying ointment 5 times daily to keep wounds moist, and protecting scars from sun exposure for 2-4 months; normal symptoms include mild redness, swelling, bruising, and decreasing pain, while warning signs requiring medical attention include fever with increasing redness and pain, continuous drainage, fever above 37.5°C, or worsening pain over time.

Sutures must be removed only when the wound has healed sufficiently, with timing varying by body location: face/head (4 days), neck (7 days), arm/trunk (7-10 days), extremities (12-14 days), and joints (10-14 days); removal should only occur when wound edges are firmly attached and there are no signs of infection, as premature removal can cause wound reopening and infection.

Proper wound closure requires aligning basement membranes to ensure anatomical approximation and minimize scarring. Surgeons may gently manipulate tissue edges to achieve optimal alignment before suturing. Suture removal timing depends on location and tension: facial sutures are removed around day 4, while upper back sutures remain in place up to 2 weeks. The technique involves removing every other suture first to assess wound strength before complete removal. Patient education is critical—patients must avoid strenuous activities during healing. Complications like dehiscence result from premature activity, not surgical technique. Dermal sutures provide continued strength even after superficial sutures are removed, dissolving slowly over weeks or months.

Proper post-operative wound care involves using sterilized instruments for suture removal, where non-absorbable sutures (like ethicon) are typically removed completely while absorbable sutures may remain under the skin without causing issues; wound healing depends on the patient's immune system strength, nutrition, rest, medication adherence, and proper wound care, with complete healing typically taking 6 months to 1 year, and complications like pus, swelling, or prolonged pain may occur due to infections, poor healing conditions, or weight gain affecting the surgical site.

Wound healing complications include infection, hematoma, and wound dehiscence. Risk factors include smoking, diabetes, connective tissue disorders, and corticosteroid use. Bacteria compete with healing cells for oxygen, impairing tissue regeneration. Excessive liposuction compromises blood supply to skin flaps, increasing dehiscence risk. Areas with high moisture and bacterial load have higher complication rates.

Major wound complications include infection (appearing 2-7 days post-injury with purulent drainage, redness, swelling, warmth, elevated temperature; can lead to bone infections and sepsis), hemorrhage (excessive bleeding requiring physician notification, possible fluid replacement, and surgical intervention), dehiscence (partial/total wound separation from excessive stress, common 4-5 days postpartum or in abdominal incisions), evisceration (most serious complication where viscera protrude through separated wound, requiring immediate sterile saline coverage, supine positioning, and physician call without attempting reinsertion), and fistula formation (abnormal passages between organs or to exterior, increasing infection and healing delays).

Surgical site infection occurs within 30 days (90 days with prosthetics), caused by endogenous flora. Risk factors include age >60, immunosuppression, obesity, diabetes, malnutrition, smoking, and previous radiation. Procedures are classified by infection risk: clean (1-5%), clean-contaminated (5-10%), contaminated (up to 20%), infected. Depth classification (superficial, deep, organ-space) guides treatment. Superficial infections present with local signs without systemic symptoms; treatment involves drainage and debridement without routine antibiotics unless cellulitis or prosthetics are present. Deep infections present with systemic symptoms and require debridement plus antibiotics. Organ-space infections involve intracavitary organs and require comprehensive management. Wound dehiscence is separation of sutured tissues, classified as superficial (skin/subcutaneous) or deep (muscle/aponeurosis). Primary cause is surgical site infection; other factors include technical errors, hematoma, increased intra-abdominal pressure, obesity, corticosteroids, malnutrition, neoplasia, radiation, and chronic diseases. Evisceration is protrusion of viscera through the incision, representing the most severe form. Prevention involves optimizing patient factors (glycemic control, smoking cessation, nutrition) and proper surgical technique with layered closure using continuous suture 1 cm from edges with 1 cm spacing. Management depends on defect size: small dehiscences may be managed conservatively, while large defects require surgical revision.

Wound infection prevention requires aseptic technique, hand hygiene, proper wound cleaning, and monitoring. Signs include redness, swelling, pain, purulent drainage, warmth, fever, and lymphadenopathy. Timing patterns help identify infection source: early (within 24 hours) suggests surgical contamination, late (after 48 hours) suggests catheter-related infection. Wound dehiscence (separation of wound layers) and evisceration (protrusion of internal organs) are surgical emergencies requiring immediate provider notification, sterile dressing application, tension reduction, nutritional support, and preparation for surgical re-exploration. These complications require immediate medical attention to prevent further deterioration.

Surgical site complications: (1) Hematoma - collection of blood, (2) Seroma - collection of lymph fluid, (3) Dehiscence - separation of wound edges, (4) Infection - bacterial contamination. These complications require appropriate management including drainage, antibiotics, and wound care.