Ch 77 - Tension Relieving Techniques

Question 1

What happens to a wound under excessive tension?

Answer 1

Tissue ischaemia and pressure necrosis will result, followed by suture cutout and inevitably incisional dehiscense

Question 2

What determines skin tension?

Answer 2

The predominant pull of the collagen and elastin fibers in dermal and hypodermal tissues

Question 3

Which area of the body are most at risk of shear stresses at a wound edge?

Answer 3

Highly mobile areas
- Axilla
- Inguinal area
- Over joints
- Tail base
- Foot pad lacerations
- COmmisure of the lip

Question 4

What components of the skin are central to its ability to be mobilised / its viscoelastic nature?

Answer 4

• Collagen fibers
• Elastin fibers
• Lubricating extracellular matrix

Question 5

List Halsteads Principles

Answer 5

• 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

Question 6

When present, what layer should undermining be deep to?

Answer 6

The panniculus carnosus layer
- Cutaneous trunci
- Platysma
- Sphincter colli superficialis

Deep to this muscle to preserve the deep subdermal plexus

Question 7

List some tension-relieving suturing techniques

Answer 7

• Strong subcutaneous sutures
• Stent or bolster sutures
• Far-Near-Near-Far and Far-Far-Near-Near
• Walking sutures
• Horizontal and vertical mattress

Question 8

Why are horizontal and vertical matress sutures not recommended as tension relieveing suture techniques?

Answer 8

• 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

Question 9

What materials are NOT recommended as stents?

Answer 9

Buttons and red rubber drains - do not adequately disperse tension and can cut through the skin

Question 10

List some methods of skin stretching techniques

Answer 10

• Pretensioning suture
• Posttensioning
• Presuturing
• Acute Intraoperative Skin Stretching
• Chronic skin expansion

Question 11

What phenomena of skins viscoelasticity are taken advantage of for skin stretching?

Answer 11

• 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

Question 12

What structural changes occur to allow for mechanical creep?

Answer 12

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

Question 13

List three methods of pretensioning suture application?
How often and for how long should these be tightened prior to wound closure?

Answer 13

• Simple continuous suture line
• Continuous horizontal intradermal running pattern
• Extenally applies skin stretching device (Velcro)

Tightened every 8-24hr for 2-3 days

Question 14

What can be used to maintain suture tension in pretensioning sutures?

Answer 14

Split shot sinker (used for fishing!)

Question 15

What suture pattern is used for pre-suturing for skin stretching

Answer 15

Lembert, for plicating the skin over an area of planned excision

Question 16

What phenomenon does chronic skin expansion take advantage of?

Answer 16

Biological creep - The creation of new dermal and epidermal components following prolonged constant loading

Question 17

What changes occur in the skin overlying an explandable tissue stretcher?
What is the recommended rate of expansion?

Answer 17

• 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

Question 18

List options of relaxing incisions

Answer 18

• 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)

Question 19

What is the “half bow-tie technique”?

Answer 19

Question 20

What suture is recommended where multiple points of skin come together?

Answer 20

Half-buried mattress suture

Question 21

List options for closing a large circular defect

Answer 21

• 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