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Key Techniques in Plastic Surgery

     

  

The topic of this article spans an area of knowledge which, even if a book of a thousand pages was written,would not suffice to elucidate the key techniques within this field. However the reconstructive ladder (discussed below) provides a framework upon which the plastic surgical apprentice may base his or her studies. Thus the aim of this article is to provide the reader with an understanding of each rung on the reconstructive ladder and by this give him or her a broad yet clear view of what are the fundamental techniques of plastic surgery consist of. The interested student could build upon this knowledge by delving deeper into the intricacies within each rung on the reconstructive ladder.

 

 

The reconstructive ladder

 

The reconstructive ladder is a term developed by plastic surgeons to describe increasingly complex methods of wound closure, [1]. From the least complex to the most complex it involves:

 

1. Healing by secondary intention

2. Healing by primary intention

3. Delayed primary closure

4. Split thickness skin grafts

5. Full thickness skin grafts

6. Tissue expansion

7. Random flaps

8. Axial flaps

9. Free flaps

 

The aim of this article, as mentioned above, has been to provide a clear understanding of each rung on the reconstructive ladder, and based on this template, to teach the aspiring plastic surgeon what the fundamental techniques of plastic surgery involves.

 

The first three levels on the ladder are not discussed in depth and will be briefly explained here. Healing by secondary intention simply refers to a wound healing by itself without apposition of the wound edges. It heals via contraction and the formulation of granulation tissue from the wound base upwards.

Healing by primary intention on the other hand refers to wound healing where the wound edges are brought together by either stitches, glue, steri-strips or any other technique where the wound edges are held together.

Delayed primary closure is self-explanatory, and is where the wound edges are not opposed for a particular time of length and then following this period it is closed up by one of the techniques mentioned above. The delay in closure enables swelling or bleeding to diminish.

 

Following this we will look at the next rung on the ladder which is skin grafting. After skin grafting we will move onto tissue expansion and then cover the different types of flaps including random flaps, axial flaps and free flaps. We will then end the article with a brief look at the importance of incision placement and a brief introduction to suturing techniques.

 

 

Skin Grafts

 

A skin graft consists of epidermis together with a variable quantity of dermis which is used to cover a skin defect, [2]. Once transferred to its recipient site the skin graft establishes a blood supply. There are two types of skin grafts:

 

1) Spilt thickness skin graft (SSG) – which consists of epidermis and a variable quantity of dermis. Depending on the thickness of the dermis a split thickness skin graft can be divided into thin, intermediate or thick.

 

2) Full thickness skin graft (FTSG) – which consists of epidermis and the entire thickness of dermis.

 

The mechanism by which the skin graft adheres to its recipient site is termed “take”. Graft take involves, most importantly, vascular ingrowth into the graft from the recipient bed and fibrous tissue fixation. To a lesser degree it also involves establishing a lymphatic and neural supply to the newly grafted skin, however this is not as important and progresses at a much slower pace than the establishment of a vascular supply. The speed with which vascularisation and fibrous tissue fixation occur are dependent upon three things:

1) the graft bed,

2) the graft itself,

3) the conditions under which the graft is applied to its bed.

 

The graft bed is important because vascularisation is achieved via the outgrowth of capillary buds into the graft from the bed. The more rapid this process, the better the take. Certain tissues like muscle, fascia, bone, cartilage and tendon are able to easily take grafts as these tissues produce capillary buds which grow into the graft rapidly hence making graft take more successful. On the other hand fat is a tissue with poor vascularity (apart from on the face) and hence this makes it a less than ideal surface to graft.

 

Apart from bed vascularity, another important condition in terms of the graft bed is the presence of fibrinogen and the presence of enzymes in sufficient quantities which convert it into fibrin. Fibrin provides the necessary adhesion between the graft and its bed during the initial stages of grafting. Thus it is essential that the bed does not harbour any organisms such as streptococcus pyogenes which produce enzymes such as fibrolysin which destroy fibrin.

 

The graft itself is important because the thickness of the graft affects take. This is due to the fact that the dermis becomes progressively less vascular the deeper you go. Thus the number of exposed cut capillaries following extraction of the graft decreases as the thickness of the dermis included with the graft increases. This in turn means the thinner the graft the better the take because thinner grafts have a greater number of exposed capillary ends which promote graft take onto its bed.

 

The conditions for uptake, apart from including sufficient capillary outgrowth into the graft and a bed that is clean and does not consist of fibrin destroying agents as already discussed above also include a close, immobile, non-shearing contact between the graft and the bed.

 

 

Full-thickness skin graft

 

As discussed above a full thickness skin graft consists of the epidermis and entire thickness of dermis.

 

Full thickness skin grafts are used most commonly for small defects on the face, scalp and hands, [2,3].

 

The donor sites for FTSGs usually include:

 

Figure 2. A full-thickness skin graft where the entire depth of dermis is extracted along with the e

 

  • upper eyelid skin – usually for defects of the other eyelid as it provides the best colour and texture match.

 

  • postauricular skin – the best donor site for defects of the face giving an excellent skin colour and texture match. The graft and the area to which it is applied both have very good vascularity which make it one of the easiest full thickness skin grafts to get to take.

 

  • supraclavicular skin – gives a reasonable colour and texture match for defects of the face. It is more inferior to that of postauricular skin for defects of the face. The advantage however is that it provides a greater surface area of skin for larger defects of the face.

 

  • skin of the upper arm, antecubital fossa, wrist crease, medial forearm – all of which are potential donor sites. Grafts from the antecubital fossa are mainly used for managing flexion contractures of the hand.

 

  • skin in the thigh and abdominal area – these are usually poor areas for facial grafts as they do not provide a good colour and texture match for facial skin. However they are useful sites for grafts used in treating defects of the palms of the hands.

 

 

Harvesting of the FTSG usually involves using a template of the recipient defect. The template could be made prior to creating the defect or it could be made once the defect has been made. The shape of the template is then transferred to the donor site and the required graft is excised. The donor site is closed directly. The excised graft may then be defatted using a pair of scissors.

 

The graft is then placed into the defect with the dermis side down and trimmed in order to fit the defect site. Once the graft is trimmed and fits exactly into the recipient defect, the graft is secured via sutures. A pressure dressing may then be placed over the graft in order to maximise contact between the graft and its bed, hence maximising the capacity of vascularisation and reducing the chances of heamatoma and shear between the graft and its bed.

 

 

Split skin graft

 

Split skin grafts are much more widely used than full thickness skin grafts. 

 

They consists of epidermis with a variable thickness of dermis, [2]. The thickness of the graft can be varied within limits by the surgeon depending on the instrument he uses to obtain the graft, [3].

 

The thickness of the graft in turn affects the clinical behaviour and characteristics of the graft.

 

Figure 1. A split thickness skin graft: the entire epidermis with a variable depth of dermis is extr

 

The term primary contraction is used to describe the immediate recoil that a freshly harvested graft undergoes while the term secondary recoil is used to describe contraction of the graft following application of the graft to its bed. The thinner a graft is, the greater the degree of secondary contraction it undergoes.

 

Split skin grafts are obtained most commonly from the following donor sites:

 

  • the thigh and upper arm
  • the entire surface of the torso
  • the flexor aspect of the forearm including sometimes the other aspects of the forearm
  • the lower leg in situations where the above mentioned sites are not available.

 

 

Split skin grafts are harvested using either a:

 

  • power-driven dermatome – which is an electrical device with the appearance of a large hair clipper which enables the harvest of grafts with a precise uniform thickness.

 

  • graft knife e.g. Humby (to which Watson added a roller to enable a more precise thickness of graft to be excised), Sliver knife.

 

 

Power driven dermatome with a set of cutting blades Humby graft knive

 

 

Harvest of the graft requires the application of an even tension on the surrounding skin. The skin is then lubricated either with water, liquid paraffin or Cetavlon. The graft instruments are then set to the required thickness setting and the graft obtained.

 

If a graft knife is used, a back and forth slicing motion is used to obtain the graft, while if a dermatome is used the back and forth movement occurs automatically, the surgeon only having to advance the device forward with a constant pressure while maintaining skin tension in front of the machine.

 

A split-thickness skin graft taken from the thigh of a child via a power-driven dermatome.

The graft could then either be left as a sheet, perforated via a scalpel or meshed using a device that places equidistant holes in the graft. Meshing has the advantages of increasing graft surface area and hence increasing the area covered by it, allowing the free drainage of blood and exudate and resulting in a smaller donor site.

 

The SSG is then applied to the recipient site, which should be heamostatically as dry as possible with the dermis side down. It is then trimmed to fit the defect and secured to the wound edge with either sutures, staples or cyanoacrylate glue welds. A pressure dressing including tulle gras and moist gauze wrapped with a crepe bandage over the graft site is used to compress the graft into its bed and prevent shear.

 

The donor site also requires a dressing. Perforated adhesive tape such as Mefix can be applied directly to the donor site until the wound heals and the tape drops off. Alternatively alginate dressings covered with absorbent gauze maybe used.

 

 

Graft healing

 

The healing of a graft is divided into four phases, [2-4]:

 

  1. Adherence – is the formation of fibrin bonds between the graft and its bed immediately on application of the graft to its bed.

  2. Serum imbibition – about 2-4 days following application of the graft to its bed, serum starts to enter the graft via imbibition resulting in swelling of the graft. It is thought that serum imbibition helps maintain graft viability, however this is debated.

  3. Revascularisation – on about day 4 vessels start to grow into the graft. The mechanism by which vessels grow into the graft is uncertain and may include:

    - Inosculation: direct anastomosis between the vessels on the recipient bed and those within the graft.

    - Revascularisation: the ingrowth of new vessels from the recipient bed along the vascular channels of the graft.

    - Neovascularisation: the ingrowth of new vessels from the recipient bed along new vascular channels in the graft.

  4. Remodelling – the process via which the histological architecture of the graft returns to that of normal skin.

 

 

Graft failure

 

The following are all reasons which could lead to graft failure, [4]:

 

  • Haematoma – which is the most common cause of graft failure. The risk of haematoma formation is reduced by meticulous haemostasis, the use of a meshed graft and the application of a pressure dressing.

 

  • Infection – as mentioned above the graft bed should be clear of any organisms which could get in the way of graft adherence and take. If the graft bed has a bacterial count greater than 100,000 organisms per gram, the graft usually will not take. On the other hand the organisms such as haemolytic streptococcus could prevent graft take when present in much smaller numbers.

 

  • Shear – this occurs when a lateral force is applied to the graft resulting small movements of the graft which disrupt the delicate connections between the graft and its bed. Disruption of these connections makes it less likely that graft take would occur.

 

  • Seroma – is the collection of serous fluid under the graft which reduce the likelihood of graft take.

 

  • Inappropriate bed – for example when grafting onto bone, it is essential that the periosteum of the bone is intact. A graft will not survive on bone denuded of periostuem as it contains blood vessels which are essential for graft take.

 

  • Technical error – these include placing the graft on the recipient site with the wrong surface in contact with the bed and applying the graft to it bed prior to allowing sufficient time for the bed to dry out.

 

 

Tissue expansion

  

Tissue expansion can be defined as an increase in the surface area of tissue brought about by exerting a mechanical force on the tissue, [3,4]. This causes the tissue to expand via a combination of two processes, namely, creep and stress relaxation. Creep is the time-dependent plastic deformation that any material or tissue undergoes on application of a constant mechanical stress to it. Stress relaxation , on the other hand, occurs when the force required to stretch the material or tissue reduces over time. This reduction in force is due to the tissue having expanded over time.

 

Tissue expansion occurs mainly by new tissue growth due to the processes of creep and stress relaxation, but also due to recruitment from surrounding skin and thinning of the skin underneath the expander. A tissue expander is essentially a saline filled bag placed underneath the skin which expands the more you fill it with saline.  

 

Expanders differ in terms of their size, shape (oval, round, rectangular etc.), port location (integrated port or remote port) and the composition of the layer surrounding their outer surface (thin smooth shell or a thick rough shell). 

 

Note the grey tip of the port used to inject saline into the expander compartment.

 

 

Tissue-expanded skin have the following characteristics, [3]:

 

1) The epidermis – thickness of the epidermis usually increases due to cellular hyperplasia, although in certain cases it can remain the same as in unexpanded skin.

2) The dermis – becomes thinner as the skin expands, probably due to collagen fibre realignment along the new tension lines created by the tissue expansion process.

3) The mitotic rate of skin increases due to the application of traction.

4) Skin appendages and nerves become increasingly separated from each other during expansion meaning that for example hair density on the scalp,a common site of tissue expansion,will reduce.

 

 

Once the tissue expander is inserted, four zones described by Paysk, form around the expander. They include:

 

1) An inner zone consisting of fibrin and machrophages

2) A central zone which contains elongated fibroblasts and myofibroblasts

3) A transitional zone composed of loose collagen

4) An outer zone consisting of blood vessels and collagen.

 

  

Tissue expansion occurs best in areas of the body where the expander can rest upon a bony base. Thus they are best suited to areas such as the breast (for reconstruction) and scalp, and less so to areas such as the neck, abdomen and limbs.

 

Note the difference in the placement of the expander ports. In one expander the port is placed away from the body of the expander itself while the other expander has the port situated on its surface.

 

 

 

 

 

 

Advantages of tissue expansion include, [3]:

 

1) It can be used to expand skin adjacent to a defect or lesion thus providing skin of a goodcolour,texture and hair match.

2) A limited degree of donor-site deformity.

3) The defect is reconstructed with sensate skin containing skin appendages.

 

 

Disadvantages of tissue expansion include:

 

1) Possible complications of tissue expansion includinginfection,extrusion,haematoma,seroma, implant rupture,rotation or loss of port site,necrosisof overlying skin,pain,neuropraxia,erosion of bone,muscle and fat.

2) Inconvenience caused to patient due to repeated need to inject saline for continuousexpansion for periods of 4 weeks to 4 months.

3) At times there is a failure to achieve sufficient expansion.

4) Pain associated with injection of saline for expansion.

5) Expansion site unsightly to the insertion of expander underneath tissue.

 

Tissue expanders are contraindicated at sites of infection, under skin grafts, under irradiated tissue and in the vicinity of an immature scar.

 

 

Flaps

  

A flap can be defined as a unit of tissue of variable composition that is transferred from one region of the body (donor site) to another (recipient) while maintaining its own blood supply, [5,6]. There are many methods by which flaps are classified, in this article we will restrict ourselves to the four most common methods:

 

  • Circulation / blood supply
  • Composition / tissue to be transferred
  • Contiguity / location of donor site
  • Contour / method of flap transfer

 

 

Circulation

 

Flaps can be classified according to their circulation as either, [5]:

 

  • random
  • axial

 

Random

 

These flaps have no known vessel supplying them, unlike axial flaps. They are dependent upon the subdermal plexus entering the flap from the pedicle for their blood supply. Due to this reason random flaps do not have as reliable a blood supply as axial flaps and hence have strict length:breadth ratios. For example random flaps have a length to breadth ratio of 1:1 in the lower extremity where the blood supply is especially poor and a length:breadth ratio of 1:6 in the face where the blood supply is much better.

 

Axial

 

Unlike random flaps, are based upon specific identifiable vessels. Axial flaps can be divided into:

 

* Direct: where the flap has a known /identified artery (and vein) responsible for the circulation to a particular area of skin. Examples include the skin of the volar aspect of the forearm supplied by the radial artery and the skin on the back supplied by the circumflex scapular artery.

 

* Fasciocutaneous: flaps are based on vessels running either within or close to the fascia. These flaps receive their blood supply from fasciocutaneous vessels which branch out from the deeper arteries of the body to the fascia. Most fasciocutaneous flaps are located on the limbs as this is their predominant destination. Cormack and Lamberty have classified fasciocutaneous vessels into the following types, [6]:

 

-> Type A: dependent upon multiple non-named fasciocutaneous vessels at the base of the flap with the vessels orientated longitudinally along flap axis. The lower leg “super flaps” are examples of type A flaps.

 -> Type B: based on a single perforator vessel feeding a fascial vascular plexus which may run along the axis of the flap. Examples include the scapular and parascapular flaps.

 -> Type C: a longitudinal deep artery running along the a fascial septum between muscles sends small multiple perforators which supple the flap. Examples include the radial forearm flap (RFF) and the lateral arm flap.

 -> Type D: these are type C flaps fasciocutaneous flaps which contain bone.

 

* Musculocutaneous: flaps are based on blood vessels (perforators) that reach the skin through the muscle. Mathes and Nahai classified musculocutaneous flaps as follows[6]:

 

-> Type 1: supplied by one vascular pedicle. Examples include the tensor fascia lata (TFL), gastrocnemius and the abductor digiti minimi (ADM).

-> Type 2: these flaps have a single dominant pedicle which enters the muscle at either its origin or insertion with several smaller vascular pedicles entering the muscle belly. Examples include the trapezius, temporalis and gracilis flaps.

 -> Type 3: these flaps have two dominant pedicles which originate from two different sources, either of which is capable of supporting the entire muscle. Examples include the trapezius, temporalis and gracilis flaps.

 -> Type 4: these flaps are supplied by multiple segmental pedicles which only supplies its segment and an immediately adjacent segment.

 -> Type 5: have one dominant pedicle at the origin of the muscle which can support the entire muscle and several minor pedicles at the insertion which can also support the muscle. Examples include the latissimum dorsi and pectoralis major.

 

 

Mathes and Nahai's classification of musculocutaneous flaps, [8].

 

* Venous: flaps are based venous pedicles rather than arterial ones i.e. the flap is based on the venous supply to it rather than the arterial supply. Due to post-operative congestion venous flaps have not been universally accepted. Thatte and Thatte classified venous flaps as follows, [6]:

 

-> Type 1: these flaps have a single venous pedicle.

-> Type 2: have veins which flow through the flap i.e. veins enter the flap from one side and then exit from the other.

-> Type 3: these are arterialised venous flaps.

 

 

Composition

 

Apart from the blood supply, flaps can also be classified according to the tissues which comprise it:

 

  • Cutaneous
  • Fasciocutaneous
  • Fascial
  • Musculocutaneous
  • Muscle only
  • Osseocutaneous
  • Osseous

 

 

Contiguity

 

The term contiguity is used to describe the location of the flap donor site with respect to the recipient site:

 

  • Local flaps: these flaps are composed of tissue directly next to the defect.

 

  • Regional flaps: these consist of tissue from the same region of the body as the defect e.g. lower limb,head and neck.

 

  • Distant flaps: can be divided in pedicled and free flaps. Pedicled distant flaps are from a distant region of the body to which they still remain attached. Free flaps on the other hand are completely detached from the site of their origin and anastomosed (via microsurgical techniques) to vessels close to the defect.

 

 

Contour

 

Flaps can also be classified according to the way they are transferred into the defect. Flaps can be transferred via a number of techniques which include:

 

* Advancement: of the flap into the defect which involves the following methods:

 

  • Stretching of the flap
  • V-Y advancement
  • Z-plasty at its base
  • A combination of the above techiques

 

* Transposition: where the flap is moved into the defect from an adjacent position which leaves a defect which must be closed by another method.

 

* Interpolation: where the flaps are moved into a defect either under or above an intervening bridge of tissue.

 

* Rotation: where the flap is rotated into the defect. Infact several flaps have elements of both rotation and transposition and hence are described as pivot flaps.

 

Note: these are the four most important methods whereby flaps are classified. In addition to these four C's there are another 2-3 which are beyond the scope of this article. They include conditioning, conformation and construction and are covered in flap manuals and textbooks of plastic surgery.

 

 

Local flaps

 

Knowledge of the common local flaps which can be employed to fill defects is of primary importance to the budding plastic surgeon[4]. Local flaps maybe either:

 

  • Advancement flaps: simple,modified, V-Y,or bipedicled
  • Pivot flaps: transposition, interpolation, rotation or bilobed

 

 

Advancement flaps:

 

* Simple

 

Simple advancement flaps depend on the laxity of skin. Here skin is more or less pulled into the defect as shown below.

 

Note the small triangles excised in flap A, these are referred to as Burrow's triangles (see below) and enable a greater degree of advancement of the flap, [8].

 

Figure 2

 

* Modified

 

A modified advancement flap uses one of the following techniques at its base to enable a greater degree of advancement:

 

  • A counter incision
  • A Burrow's triangle
  • A Z-plasty

 

 

 * V-Y flap

 

A V-Y flap consists of incisions along each of its cutaneous borders. The blood supply to a V-Y flap arises from the deep tissue and passes to the flap through a subcutaneous pedicle. It is designed as shown below.

 

In the case of a defect of the fingertip this is an ideal flap as it there is the capacity for the flap to provide sensation like a normal fingertip, [8].

 

 

Figure 3

 * Bipedicled

 

These flaps receive a blood supply from either end which makes them less prone to necrosis than flaps of similar diemensions which have only a single attachment.

 

Illustrated is a bipedicled flap used to cover a scalp defect. The flap has two pedicles on either side which reduce the chances of flap necrosis. In this case the defect following flap advancement will be closed directly, [8].

 

 

Figure 4

Pivot flaps

 

 

* Transposition flaps

 

Such flaps are transposed into the defect which in-turn leaves a donor site which is closed by some other means such as a skin graft for example.

 

Here, the defect is covered by raising a local flap and transposing it into the defect, [8].

 

 

Figure 5

Transpsition flaps with direct closure of donor site include the rhomboid flap and the Dufourmontel flap. Both flaps are based on the same concept, however their geometry varies. It is essential that these flaps are designed in order that the donor scar lies parallel to the resting skin tension lines (RSTL's) which will be discussed later on in this article.

 

 

* Interpolation flaps

 

In an interpolation flap, where the flap is not directly adjacent to the defect, the pedicle of the flap passes over or under an intervening skin bridge upon a pivot point, as done here to cover a nasal defect, before being sutured into the defect. After the base of the flap is sufficiently vascularised it can be divided during a second procedure (C) and the donor site closed directly, [8].

 

 

* Rotation flaps

 

A rotation flap involves the movement of tissue in a defect via a rotatory movement as shown below. It is recommended that the circumference of the flap should be 5-8 times the width of the defect. These flaps are most commonly used on the scalp or for pressure ulcers, where the lesion is excised and and a flap of adjacent tissue is raised and rotated into the defect, [8]. The donor defect is usually closed directly without any problems.

 

 

 

* Bilobed flap

 

A bilobed flap essentially consists of two transposition flaps where the first flap is transposed into the original defect and the second flap is transposed into the defect produced by the first flap. The tertiary defect produced by raising of the second flap is usually small enough to be closed directly.

 

The flap needs to be designed in a manner such that the suture line of the directly closed tertiary defect lies parallel to the RSTLs as shown below. 

 

 

Plasty techniques

 

The term plasty is a medical suffix which refers to repair or restoration of a body part or its function. It is also used to describe the moulding or shaping of a body part through surgical techniques. In this instance the second definition is probably more reflective of what is meant by “plasty techniques”.

 

The most classic plasty technique and the one upon which almost all other plasty techniques are based on is the z-plasty. We will discuss the z-plasty in some detail and then also discuss a few of the other plasty techniques which are an improvisation of the classic z-plasty, [4].

 

 

* Z-plasty

 

A z-plasty involves the transposition of two interdigitating triangular flaps.

 

E moves to position D, while F moves to position C, as indicated by the arrows, [10].

 

 

 

The term “z-plasty” derives from the Z shape seen when the three limbs of the flaps are drawn out on the skin surface. A z-plasty has several important effects following transposition of the flaps, however two of them are of special relevance:

 

  • It results in an increase in length of an area of tissue, along what is known as the “common” limb.
  • The second effect of transposition is to change the direction of the common limb.

 

 

These two effects mean that the Z-plasty is an essential technique in three situations:

 

1) The treatment of contracted scars e.g. contracture of scar following a burn where the first effect of lengthening is used to release contracture of the scar.

2) Facial scars where the second effect of change in direction of the common limb is used to break up facial scars and to reduce their cosmetic impact.

3) In the prevention of scar contracture in certain emergency and elective procedures, most importantly of the hand.

 

 

The degree of elongation of the longitudinal axis of the z-plasty is directly proportional to the angle of its constituent flaps. Theoretically, for a 30 degree angle there is a 25% increase in length. This increases to 50% with a 45 degree angle and to 75% with a 60 degree angle. Simply put, a 15 degree increase in the angle gives a 25% increase in length.

 

The angle however cannot usually exceed 60 degrees as the shortening produced along the opposite plane produces tension which makes it difficult to transpose the flaps. Hence the angle is rarely increased to beyond 60 degrees. Apart from the difficulty in transposing the flaps, tension is also an important cause of flap necrosis, especially at the tip of the flap.

 

 

 

 

Apart from the angle of the limb, the other variable is the length of the limb. This is dependent upon the amount of tissue present. If there is a large quantity of tissue, this allows a Z with large limbs, while the presence of a small amount of tissue enables only a Z with small limbs.

 

As mentioned previously, the extent of lengthening via increasing the angle of the limbs is usually limited to about 60 degrees due to the fact that any further increment in this angle leads to lateral tension. In addition, a large Z with long limbs would also produce significant amounts of tension. The search for techniques whereby the degree of lengthening is increased and the transverse shortening (and hence the lateral tension) is reduced has led to the development of the multiple Z-plasty.

 

The multiple Z-plasty consists of many smaller Z-plasties instead of one large Z-plasty which produces the same degree of lengthening. The transverse shortening however is significantly reduced which in turn reduces the transverse tension. The reduction in tension makes it easier for the flaps to be transposed and also reduces the likelihood of flap tip necrosis.

 

 

* Four-flap Z-plasty

 

The four-flap Z-plasty is used to elongate an area of tissue and is most commonly employed to release first webspace contractures. It consists of two Z-plasties where the two inner flaps become the outer flaps and the two outer flaps become the inner flaps i.e. the “ABCD” configuration becomes “CADB” following transposition of the flaps.

 

 

It is usually designed with an angle of 90 degrees and then divided to create four 45 degree angle flaps.

 

However it can also be designed with an angle of 120 degrees, as shown here, and divided to create four 60 degreeangle flaps, [11].

 

 

 

 

Figure 11

* Five-flap Z-plasty

 

The five-flap Z-plasty again helps to elongate tissue and is employed to clinically to release first web space contractures and epicanthal folds. The five-flap plasty consists of a V-Y advancement in the centre combined with two opposing Z-plasties.

 

 

* W-plasty

 

The W-plasty, unlike the plasty techniques discussed above, is not a technique used to elongate tissue. It is a technique used to break up the line of a scar and improve its appearance. Before a W-plasty is carried out careful planning is essential. A W-plasty consists of a number of small triangular flaps which are positioned on either side of the scar such that the two sides will interpose following scar excision.  

 

 

The triangular limbs should ideally be 3-5mm long and the ends should be less than 30 degrees in order prevent the formation of any “dog ears”. In addition the limbs of the W-plasty should be as parallel as possible to the RSTL's to enable optimal camouflage. The flaps are then brought together such that they inter-pose, [13]. 

 

 

Figure 13

Placing the incision

 

It is of vital importance that the surgeon pays meticulous attention to the placement of incisions, [2]. An incision should always be made, where possible, along skin tension lines and not across them. This is especially true of aesthetically sensitive areas such as the face. On the face, an incision should be placed, as far as possible, along the resting skin tension lines (RSTLs). This can be more easily determined by getting the patient to carry out characteristic facial expressions such as smiling, frowning, closing the eyelids tightly etc, which gives a clearer idea of which way the muscles underneath are contracting and hence which way the skin tension lines run.

 

In addition to placing incisions along skin tension lines, another aspect that can be utilized to ensure an aesthetically pleasing scar on the face is to use natural junction lines to distract the observer's eye from the scar. For example the junction between the lip and facial skin can be used to hide scars on the face close to the lips.

 

Apart from the use of natural junction lines, scars can also be hidden insides hairlines or in eyebrows where possible.

 

 

Sutures

 

An aesthetically pleasing scar has two determinants:

 

  • the precision with which the incision is placed along the skin tension line, and
  • the suturing technique used depending upon the type of wound, the anatomical area being sutured and the thickness of the skin, [2].

 

Some of the common suturing techniques include, [7]:

 

Interrupted sutures:

 

-> consist of a simple loop knotted at one end of the wound. The suture is placed by passing the needle perpendicular to the epidermis, traversing the entire epidermis and dermis on the same side and then traversing the dermis and epidermis on the opposite side of the wound, finally emerging through the opposite end of the wound in a perpendicular plane. Ideally, the bites taken at either side of the wound should be equidistant to prevent the possibility of wound height mismatch and the suture should have a flask shape when viewed in profile in order to enable a slight degree of eversion and hence complete dermal apposition. Please click on the following link in order to view a video of how to perform an interrupted suture: http://www.youtube.com/watch?v=PoORW7pQs2M

 

Continuous/running sutures:

-> a continuous suture consists of first placing a simple interrupted suture whose end is tied but not cut. The remaining length of suture is then passed through the wound edges in the form of successive simple sutures which are placed equidistantly from each other. The line of stitches is then completed by tying a knot after the last pass at the end of the suture line. Its advantages include rapid placement and even distribution of tension. Its disadvantage is that any damage to the suture may result in the entire suture coming undone. Please click on the following link in order to watch a video of how to perform a continous suture: http://www.youtube.com/watch?v=lKR6yQ59wXM

 

Deep dermal sutures:

–> these are placed completely below the epidermal skin layer. They can be either interrupted or continous sutures depending on the context and are not usually removed postoperatively. Please click on the following link in order to watch a video of how to perform a deep dermal suture: http://www.youtube.com/watch?v=pLrK7fZV3Lk

 

Buried sutures:

–> these are sutures which are placed in such a manner that the knot protrudes to the inside, under the layer to be closed. Please click on the following link in order to watch a video on how to perform a buried suture:http://www.youtube.com/watch?v=zOr14A_UfMs

 

Subcuticular sutures:

–> consist of either interrupted or continuous stitches placed in the dermis. Given its location in the skin, the term subcuticular is an incorrect description. It would thus more appropriately be called an intradermal suture. Please click on the following link to in order to watch a video of how to perform a subcuticular suture: http://www.youtube.com/watch?v=-osbgWMXcFE

 

For a more in-depth analysis of suturing techniques and the vast number of variations in the above mentioned techniques please refer to a manual of surgical skills.

 

 

Summary

 

In concluding, we come back to the reconstructive ladder with which we started. As mentioned there, the reconstructive ladder is the key to understanding and learning about the fundamental techniques within plastic surgery. Recently plastic surgeons have advocated that the term “ladder” be discarded as there is no stepwise progression from one method of reconstruction to another. To illustrate this point, a large defect with loss of muscle, for example, will require that we straight away consider free flap reconstruction without considering the intervening steps in this ladder.

 

We have presented Mathes and Nahia's classification of musculocutaneous free flaps but not gone into the common work-horse free flaps as this was beyond the scope of this article. At this stage what is most important is the appreciation of their classification. However the interested reader has a number of very good works on free flaps available on the market.

 

The most basic role of the plastic surgeon is to choose the most appropriate technique to reconstruct a defect, whether it be traumatic or induced by the surgeon himself, such as in the excision of a cancerous lesion. Apart from deciding the mode of reconstruction, it is also important that he gives due consideration to factors such as incision placement and suturing technique, as all of these aspects impact on the final outcome of the reconstruction. Thus this article has brought into focus the options available to a reconstructive surgeon in terms of defect reconstruction via tissue transfer and also touched upon how the surgeon should place his incisions and some of the options when suturing tissue.

 

 

References

 

1. Plastic and hand surgery in clinical practice: classifications and definitions – O'Brien M. Springer 2009.

2. Fundamental techniques of plastic surgery:and their surgical applications – McGregor AD,McGregor IA. Churchill Livingstone 2001.

3. Plastic and reconstructive surgery – Giele H, Cassell O. Oxford university press 2010.

4. Key notes in plastic surgery – Richards AM. Blackwell science 2002.

5. Practical plastic surgery for nonsurgeons – Nadine B Semar. Iuniverse 2007.

6. Flaps and reconstructive surgery – Wie FC, Mardini S. Saunders 2009.

7. Ethicon wound closure manual.

8. Anonymous. Flap classification. Available from: http://oralmaxillo-facialsurgery.blogspot.com/2010/05/flaps-classification.html

9. Cho M, Kim DW. Modification of the Zitelli bilobed flap: a comparison of flap dynamics in human cadavers. Arch Facial Plast Surg. 2006;8(6):404-409.

10. Salam GA and Amin JP. The basic z-plasty. Am Fam Physician.2000;67(11):2329-2332.

11. Fraulin FO and Thomas HG. First webspace deepening: comparing the four-flap and five-flap z-plasty. Which gives the most gain? Plast Reconstr Surg.1999;104(1):120-8.

12. Hirshowitz B, Karev A, Levy Y. A 5-flap procedure for axillary webs leaving the apex intact. Br J Plast Surg. 1977;30(1):48-51.

13. Batra RS. Surgical techniques for scar revision. Avialable from: http://www.skintherapyletter.com/2005/10.4/2.html

14. Available from:www.bapras.org.uk

15. Available from:https://www.yourbreastoptions.com/en-us/breastconstruction/Pages/reconstructionwithcombination.aspx

 

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