Scar Revision

Scar formation is an inevitable consequence of wound healing from either a traumatic or a surgical intervention. The aesthetic appearance of a scar is the most important criteria to judge the surgical outcome. An understanding of the anatomy and wound healing along with experience, meticulous planning and technique can reduce complications and improve the surgical outcome. Scar revision does not erase a scar but helps to make it less noticeable and more acceptable. Both surgical and non-surgical techniques, used either alone or in combination can be used for revising a scar. In planning a scar revision surgeon should decide on when to act and the type of technique to use for scar revision to get an aesthetically pleasing outcome. This review article provides overview of methods applied for facial scar revision. This predominantly covers surgical methods.

A scar can be defined as a fault or blemish resulting from some former condition, wound, sore or burn. Scar formation is an inevitable consequence of wound healing in which the normal skin is replaced by a fibrous tissue. This scar tissue lacks the characteristics of the normal uninjured skin. A scar is classified into mature scar, immature scar, linear hypertrophic scar, widespread hypertrophic scar, minor keloid and major keloid. This review covers management issues related to only scars and not keloids.

• Chemical peel solutions that penetrate the skin's surface to soften irregularities in texture and color.
• Contractures are scars that restrict movement due to skin and underlying tissue that pull together during healing and usually occur when there is a large amount of tissue loss, such as after a burn.
• Dermabrasion is a mechanical polishing of the skin.
• Hyperpigmented scar is scar that is darker in color.
• Hypertropic scar is a thick clusters of scar tissue that develop directly at a wound site.
• Hypopigmented scar is a scar that is lighter in color.
• Keloids are large scars that can be painful or itchy, and may also pucker which can occur anywhere on your body, developing more commonly where there is little underlying fatty tissue, such as on the breastbone or shoulders.
• Skin grafts where healthy skin taken from other areas of your body, such as the abdomen or thigh, to revise a scar.
• Tissue expansion, the procedure that can substitute for skin grafts. An inflatable balloon called a tissue expander is placed under the skin near the scar site to stretch additional skin to be used to revise a scar. Oftentimes, multiple procedures are needed.
• Z-plasty, cutting creates angled flaps on either side of the original scar site that can completely reposition or change scar direction, interrupt scar tension or improve scar flexibility

There are a large number of tools available for scar assessment. The most important features which should be assessed are: colour, vascularity, light reflection, texture, contour, pliability, height, distortion, relation to the relaxed skin tension lines (RSTL), the natural skin lines and creases of the face and neck, which are the preferred lines of incision in surgery of those areas and relation with important landmarks in the area of the body. 

The characteristics of an ideal scar which makes it cosmetically favourable are:

• It should be a fine line
• It should be parallel to skin creases, folds and RSTLs
• It should have similar colour and contour as the surrounding skin
• There should be no distortion of the adjacent structures
• It should be at the level of the skin
• A scar that limits the mobility is functionally unfavourable.
• Less than ideal scars may be wide, red or pigmented, raised or depressed.
• The goal of scar revision is to create an ideal scar.

The various factors which should be considered before doing scar revision are:

1. Unrealistic expectation It is important to understand that scar revision will improve and not erase the scar and it may require multiple surgical procedures along with adjunct treatment in order to obtain an optimal result over a period of many months or years.
2. Time of scar revision Due to continuous collagen remodelling it takes around 12-18 months for the scar to mature and gain tensile strength of 70-80% of uninjured skin. Immature scars are prone to hypertrophy and give poor results after scar revision. Adjunct treatments like use of silicone sheet and intralesional steroid injections can be given during this period. However, if early intervention is needed it is wiser to do it only after 8-12 weeks in adults and 6 months in children smaller than 7 years of age.
3. Nutritional status and medical history of the patient A well-balanced diet is essential for good protein synthesis. Vitamin A, C, E and zinc help in wound healing. Herbal supplements and medicines which increase bleeding should be stopped 3 days to 2 weeks before scar revision. Medical conditions like diabetes mellitus, cortisone and immunosuppression negatively effects wound healing and be addressed beforehand.
4. Tobacco usage Tobacco use causes hypoxia, narrowing of arteries, aberrant cell function and delays wound healing. It is preferable to abstain the patients from smoking from 4 weeks before to 6 weeks after scar revision.

There are non-surgical techniques for scar management.

• Camouflage
  Make-up, hair, accessories like scarves and tattooing can help to camouflage the scar.
• Topical therapy
  Hyperpigmented scars can be lightened by using hydroquinone, kojic acid, alpha hydroxyl acid, hydrocortisone and retinoic acid. Use of topical silicone gel or silicone sheet improves the contour, texture and the colour of the scar.
• Intralesional agents
  Intralesional corticosteroids: They reduce scar formation by inhibition of inflammatory mediators, collagen synthesis. In hypertrophic scars a low dose is injected into the bulkiest area of the scar at 3-weeks interval for a maximum of 6 injections and is started 1 month post-operatively. This treatment does not decrease the width of the scar, but helps to flatten it. Adverse effects like hypopigmentation, atrophy, telangiectasia fine veins, delayed wound healing and scar widening has been reported.
• Intralesional 5-Flurouracil
  Intralesional 5-FU has been shown to be effective in many studies though most of these studies are of limited value due to lack of adequate controls. Botulinum toxin type A can help in improving the outcome for facial scars. It acts by causing temporary ??????
• Soft tissue fillers
  Bovine collagen, homologous human collagen, fat and hyaluronic acid and other synthetic fillers can be used for elevating depressed and pitted scars]. Depressed scars on face due to lupus. Good temporary or longer can improvement after your body fat.

A fundamental principle of surgical scar revision is to minimize as much as possible both incorporation and deformation of the normal tissue. 

• IncisionMost commonly the incision is made perpendicular to the skin surface with the exception being the hair-bearing areas where the incision is in the direction of the hair follicle in order to prevent permanent loss of hair. Also, the incision should be parallel to RSTLs.
  The various surgical techniques of revising the scar are:
  Fusiform elliptical excision, in this technique a fusiform elliptical incision is made to excise the scar. The ratio of length to breadth is kept as 3:1 and the ends of the fusiform should have an angle of 30° or less in order to prevent ‘dog-ear’ formation. The ends of the fusiform are placed parallel to the RSTLs in order to promote blending.
  Serial excisions done at intervals of 6-12 weeks is used for revising a wide and/or rounded scar (caused by burn or ulcer) that cannot be excised completely in one sitting, in scars with surrounding inextensible skin and if the length of the ellipse creates an unfavourable scar. This method is particularly useful for facial scars where aim is to preserve normal skin as much as possible.
• Z-plastyThis technique has several advantages: it irregularises a linear scar, making it less noticeable; changes the direction of the scars and aligns them to the RSTLs; helps in lengthening of the webbed or contracted scar; and it helps changing the position of a displaced anatomical point by elevating or depressing it. Multiple Z-plasty, if single Z-plasty is not suitable for due to the longer length the multiple Z-plasty, gives camouflage and breaks the linear scar.
• V-Y and Y-V AdvancementThese techniques are indicated in scar lengthening in case of a small contracted scar, improving ‘trapdoor’ deformity, and elevation or depression of a free margin such as eyes and mouth in case of a scar.
• Dermabrasion and MicrodermabrasionDermabrasion is used for smoothing and levelling the textural abnormalities of the scar surface and its uneven edges, to improve the appearance of raised flaps and grafts and for blending the scar with its surroundings.

• Infection
• Anaesthesia risks
• Bleeding (haematoma)
• Change in skin sensation
• Damage to deeper structures including nerves, blood vessels, muscles and lungs can occur and may be temporary or permanent
• Allergies to tape, suture materials and glues, blood products, topical preparations or injected agents
• Delayed healing
• Skin contour irregularities
• Skin discolouration and swelling
• Skin sensitivity
• Pain, which may persist
• The potential need for additional surgical procedures or staged procedures