Ch 77 - Tension Relieving Techniques Flashcards
What happens to a wound under excessive tension?
Tissue ischaemia and pressure necrosis will result, followed by suture cutout and inevitably incisional dehiscense
What determines skin tension?
The predominant pull of the collagen and elastin fibers in dermal and hypodermal tissues
Which area of the body are most at risk of shear stresses at a wound edge?
Highly mobile areas
- Axilla
- Inguinal area
- Over joints
- Tail base
- Foot pad lacerations
- COmmisure of the lip
What components of the skin are central to its ability to be mobilised / its viscoelastic nature?
- Collagen fibers
- Elastin fibers
- Lubricating extracellular matrix
List Halsteads Principles
- Strict aseptic technique
- Gentle tissue handling
- Meticulous haemostasis
- Preservation of blood supply
- Obliteration of dead space
- Accurate apposition of tissue planes
- Minimisation of tension on tissue
When present, what layer should undermining be deep to?
The panniculus carnosus layer
- Cutaneous trunci
- Platysma
- Sphincter colli superficialis
Deep to this muscle to preserve the deep subdermal plexus
List some tension-relieving suturing techniques
- Strong subcutaneous sutures
- Stent or bolster sutures
- Far-Near-Near-Far and Far-Far-Near-Near
- Walking sutures
- Horizontal and vertical mattress
Why are horizontal and vertical matress sutures not recommended as tension relieveing suture techniques?
- Horizontal mattress may compromise the blood supply to the wound edge
- Vertical mattress does not compromise the blood supply but causes significant eversion of wound edges.
Far-Near-Near-Far and Far-Far-Near-Near are just as functional and more cosmetically acceptable
What materials are NOT recommended as stents?
Buttons and red rubber drains - do not adequately disperse tension and can cut through the skin
List some methods of skin stretching techniques
- Pretensioning suture
- Posttensioning
- Presuturing
- Acute Intraoperative Skin Stretching
- Chronic skin expansion
What phenomena of skins viscoelasticity are taken advantage of for skin stretching?
- Mechanical creep - elongation under constant short-term loading
- Stress relaxation - Delicate elastic fibers fracture and lose their tendancy to recoil once the load is removed
What structural changes occur to allow for mechanical creep?
Within the extracellular matrix, the convoulter superhelices of the coiled triple helix collagen fibers will readily straighten and realign in a more parallel orientation, releasing water molecules and increasing skin viscosity
List three methods of pretensioning suture application?
How often and for how long should these be tightened prior to wound closure?
- Simple continuous suture line
- Continuous horizontal intradermal running pattern
- Extenally applies skin stretching device (Velcro)
Tightened every 8-24hr for 2-3 days
What can be used to maintain suture tension in pretensioning sutures?
Split shot sinker (used for fishing!)
What suture pattern is used for pre-suturing for skin stretching
Lembert, for plicating the skin over an area of planned excision
What phenomenon does chronic skin expansion take advantage of?
Biological creep - The creation of new dermal and epidermal components following prolonged constant loading
What changes occur in the skin overlying an explandable tissue stretcher?
What is the recommended rate of expansion?
- SQ fat and dermal thickness decrease and epidermal proliferation occurs
- Dense fibrous capsule forms over the expander
- Skin is not as pliable
- However, skin perfusion is enhanced
Explanded by 10-15% of final volume every 2-3 days
List options of relaxing incisions
- Mesh expansion (1cm incision, 1cm appart in scattered rows)
- Simple relaxing incision (Bipedicle flap) - must not exceed 4:1 length-to-width ratio
- V-Y plasty
- Z-plasty
- M-plasty (at 1 or both ends of the end of a fusiform incision)
What is the “half bow-tie technique”?
What suture is recommended where multiple points of skin come together?
Half-buried mattress suture
List options for closing a large circular defect
- Closed in linear fashion with correction of dog ears
- Revised to fusiform incision and closed
- Divide into three equal arcs and performe three-point closure
- Combined V-plasty
- O- to S-plasty
