Local and Regional FlapsFlap Principles*Flaps differ from grafts in that they maintain their blood supply as they are moved.*Some defects are amenable to closure with a single flap, but others require a combination of flaps for optimal results *An advantage of using multiple flaps is that they can be harvested from separate esthetic units. This decreases the size of the secondary defect and may allow placement of scars between esthetic units, thus improving scar camouflage leading to better cosmesis.*As local flaps heal, regaining of blood flow and cutaneous sensibility increases.*Relaxed skin tension lines (RSTLs) result from vectors within the skin that reflect the intrinsic tension of the skin at rest. They are due to the microarchitecture of the skin and represent the directional pull on wounds. *The RSTLs are generally parallel to the facial rhytids. *Lines of minimal tension (rhytids) result from repeated bending of the skin from muscular contraction. *A permanent crease results from the adhesions between the dermis and deeper tissues. These natural skin creases run perpendicular to the direction of muscle pull and can guide incision orientation for optimal scar camouflage and cosmesis.*The face is composed of esthetic subunits. The areas where these subunits meet are referred to as anatomic borders.Scars that are located at the junction of two adjacent anatomic subunits are inconspicuous because one expects to see a delineation between these areas.

Flap NomenclatureThere are many methods described for classifying cutaneous flaps: by the arrangement of their blood supply, their configuration, location, tissue content, and method of transferring the flap.Blood SupplyThese include random pattern, axial pattern, and pedicle flapsRandom flaps

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are supplied by the dermal and subdermal plexus alone and are the most common type of flap used for reconstructing facial defects.Axial pattern flaps are supplied by more dominant superficial vessels that are oriented longitudinally along the flap axis.Pedicle flaps are supplied by large named arteries that supply the skin paddle through muscular perforating vessels.

N.B:-Free tissue transferrefers to flaps that are harvested from a remote region and have the vascular connection reestablished at the recipient site.

LocationThis includes local, regional, and distant flapsLocal flaps: imply use of tissue adjacent to the defect

regional flaps : refer to those flaps recruited from different areas of the same part of the body.Distant flaps : are harvested from different parts of the body.ConfigurationExamples of these flaps include bilobed, rhombic, and Z-plasty.Tissue ContentCutaneous flap : refers to those flaps that contain the skin only.When other layers are incorporated into the flap they are classified accordingly. Examples includemyocutaneous and fasciocutanous flaps.Method of TransferAdvancement flaps: are mobilized along a linear axis toward the defectRotation flaps :pivot around a point at the base of the flap

Transposition flap : refers to one that is mobilized toward an adjacent defect over an incomplete bridge of skin. Examples of transposition flaps include rhombic flaps and bilobed flapsInterposition flaps: differ from transposition flaps in that the incomplete bridge of adjacent skin is also elevated and mobilized. An example of an interposition flap is a Z -plasty

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Interpolated flaps : are those flaps that are mobilized either over or beneath a complete bridge of intact skin via a pedicle.Designing the Flap**The characteristics of the defect and adjacent tissue must be analyzed. :These include color, elasticity, and texture of the missing tissue. The defect size, depth, and location are evaluated as well as the availability and characteristics of adjacent or regional tissue. It is important to determine the mobility of adjacent structures and to identify those anatomic landmarksthat must not be distorted. **The orientation of the RSTLs and esthetic units should by analyzed closely.**Potential flap designs :should be drawn on the skin surface being careful to avoid those designs that obliterate or distort anatomic landmarks.**The final location: of the resultant scar should be anti-cipated by previsualizing suture lines and choosing flaps that place the lines in normal creases.**The secondary defect: that is created as the tissue is transferred into the primary defect must be able to be closed easily.**avoid secondary deformities: that distort important facial landmarks or affect function.**Avoid obliterating critical anatomic lines that are essential for normal function and appearance.**Proper surgical technique involves: *gentle handling of the tissue by grasping the skin margins with skin hooks or fine-toothed tissue forceps. *Avoid traumatizing the vascular supply by twisting or kinking the base of the flap. *Deep pexing sutures minimize tension on the flap and eliminate dead space. *Excessive tension on the flap may decrease blood flow and cause flap necrosis. *Meticulous hemostasis should be achieved prior to final suturing so that a hematoma does not develop beneath the flap.*adequately mobilize and extend the flap, which should be of adequate size to remain in place without tension to minimize the chance of dehiscence, scarring, or ectropion.

Types of FlapsLocal Flaps

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Advancement Flaps : *Advancement flaps have a linear configuration and are advancedinto the defect along a single vector. *These flaps can be single or double. *Advancement flaps are often chosen when the surrounding skin exhibits good tissue laxity and the resulting incision lines can be hidden in natural creases. *Advancement flaps limit wound tension to a single vector with minimal perpendicular tension. *They are often helpful in reconstructing defects involving the forehead, helical rim, lips, and cheek.*Advancement flaps are created by parallel incisions approximately the width of the defect.*Standing cutaneous deformities (“dog ears”) are usually created and are managed with excision. A Z -plasty incision or Burow’s triangle may be performed at the base of the flap, reducing the standing cutaneous deformities*A variation of the advancement flap is the V-Y flap .:- A triangular island of tissue adjacent to the defect is isolated and attached only to the subcutaneous tissue.-It relies on a subcutaneous pedicle for blood supply.INDICATIONS:1-Intraoral uses of advancement flaps: include covering oroantral fistulas and alveolar clefts2- extraoral: for cheek defects along the alar facial groove .3- reconstructing defects involving the forehead, helical rim, lips, and cheek

**disadvantage of buccal advancement flaps: *1- is the decrease in vestibular sulcus depth*2-avoided where there are superficial nerves because of the depth of the incisions.Rotation Flaps: *Rotation flaps have a curvilinear configuration. *Defects reconstructed with rotation flaps should be somewhat triangular or modified by removing normal tissue to create a triangular defect. *These flaps have a large base and are usually random in their vascularity but may be axial. *One or more rotation flaps are often used to reconstruct scalp defects. *Because of the relative inelasticity of the scalp tissue, these flaps must be large relative to the size of the defect. Scoring of the galea is helpful in gaining additional rotation and advancement

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The axial frontonasal flap: is a modified simple rotation flap with a back cut.USES: closing nasal defectsThe flap is based on a vascular pedicle at the level of the medial canthus. This pedicle consists of a branch of the angular artery and thesupraorbital artery.Rotated palatal flaps : are helpful for closing large oroantral fistulasTransposition Flaps : *These flaps are rotated and advanced over adjacent skin to close a defect. *Examples of transposition flaps include rhombic flaps and bilobed flapsUSES:-*in areas where it is desired to transfer the tension away from closure of the primary defect and into the repair of the secondary defect.Transposition flaps have a straight linear axis and are usually designed so that one border of the flap is also a border of the defect. An advantage of this type of flap is that it can be developed at variabledistances. Areas where these flaps are often used include the nasal tip and ala, the inferior eyelid, and the lipsA-The rhombic flap : *is a precise geometric flap that is useful for many defects of the face. *The traditional rhombic (“Limberg”) flap is designed with 60 and 120° angles and equal-length sides. *The angle of the leading edge of the rhombic flap is approximately 120° but may vary.*The flap is begun by extending an incision along the short axis of the defect that is equal to the length of one side of the rhombic defect. Another incision is then made at 60° to the first and of equal length*Disadvantages of the rhombic flap are the significant tension at the closure point as well as the amount of discarded tissue to transform a circular defectinto a rhombus.

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B-The bilobed flap: * is a transposition flap with two circular skin paddles . It is useful for skin repairing of lateral nose and nasal tip defects up to 1.5cm. The bilobed flap has a random pattern blood supply. The flap is primarily rotated around a pivot point and the paddles aretransposed over an incomplete bridge of skin. The second lobe allows the transfer of tension further from the primarydefect closure. The bilobed design rotates around an arc that is usually 90 to 100°.In the bilobed flap the first lobe closes the defect and the second closes the first lobe defect. The flap is designed with a pivot point approximately a radius of the defect away from the wound margin. The first lobe is usually the same size as the defect, and the second lobe is slightly smaller with a triangular apex to allow for primary closure. The axis of the second flap is roughly 90 to 100° from the primary defect and undermined widely to distribute the tension.An advantage of the bilobed flap is that one can construct a flap at some distance from the defect with an axis that isindependent of the linear axis of the defect. A disadvantage of this flap : 1- is that it leaves a circular scar that does not blend with the existing skin creases. 2-During healing the flap may become elevated (“pin cushioning”) because of the narrow pedicle that is prone to congestion, scar tissue that impedes lymphatic drainage, and curvilinear scars that tend to bunch the flap up as they shorten.Interpolation Flaps: Interpolation flaps contain a pedicle that must pass over or under intact intervening tissue. A disadvantage: of these types of flaps is that for those passing over bridging skin, the pedicle must be detached during a second surgicalprocedure. Occasionally it is possible to perform a single-stage procedure by deepithelializing the pedicle and passing it under the intervening skin. Advantages :of interpolation flaps include their excellent vascularity, and also their skin color and texture match.The forehead flap (median and paramedian) * is a commonly used interpolation flap and remains the workhorse flap for large nasal defects. It is a robust and dependable flap.

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*The forehead flap is primarily based on the supratrochlear vessel, is relatively narrow, and uses a skin paddle from the forehead region. *The flap is supplied by a rich anastomosis between the supratrochlear and angular arteries.*Because of the marked vascularity, it is possible to incorporate cartilage or tissue grafts for nasal reconstruction. *The forehead flap has abundant tissue available, allowing resurfacing of the entire nasal unit with a single flap and provides a good texture and color match to the native nose.

The technique for elevating the forehead flap is straightforward. The flap can be designed directly in the midline or in a paramidline location. A template of the defect is used to outline the flap. Elevation of the flap proceeds in either a subgaleal or subcutaneous plane. The pedicle is always elevated in such a way as to incorporatethe frontalis muscle. The width of thepe dicle is usually 1.0 to 1.5 cm, which allows for easy rotation of the pedicle.Prior to inset the skin paddle is selectively thinned to match the native skin thickness.The pedicle is divided approximately 3 weeks later, with the base of the pedicle inset into the glabellar area to reestablish brow symmetry. The incision, and resulting scar, is perpendicular to the RSTLs buttends to heal well .The nasolabial flap (melolabial) : * is useful for reconstructing defects involving the oral cavity and those involving the lower third of the nose *It can be used as an interpolation flap with either a single or staged technique. *The flap is supplied by the angular artery, intraorbital artery, and infratrochlear artery and can be based either superiorly or inferiorly. *The area of recruitment for nasal reconstruction is in closer proximity to the primary defect than is the forehead flap. A disadvantage of the nasolabial flap is that there is a limited amount of tissue available, and asymmetry can occur along the nasolabial flap folds. *When the pedicle is divided, the defect can be closed primarily by placing the scar in the nasal facial junction and the nasolabial flap fold.

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The lip-switch flap (Abbe): can be taken from either lip, but it is most commonly switched from the lower to the upper lip. This flap can be used toreconstruct as much as one-third of the upper lip. The lower lip can supply a flap of one-quarter of its length, and the Abbe flap offers immediate replacement of total lip anatomy . The labial artery supplies the flap and should be maintained with a small cuff of subcutaneous tissue and muscle surrounding the vascular pedicle. The pedicle is divided after approximately 2 to 3 weeks.Tongue flaps: are excellent flaps for intraoral reconstruction. They use adjacent tissue, have an excellent blood supply, and are associated with minimal morbidity.The tongue has excellent axial and collateral circulation, with the lingual artery providing the main blood supply. Up to onehalf of the tongue can be rotated for tissue coverage without compromising speech, mastication, or deglutition. A variety of flap designs have been described including anterior- and posterior-based tongue flaps. Some indications include: repair of oral defects and fistula closure. These flaps are helpful for providing closureof large oroantral fistulas.

Regional FlapsRegional flaps are defined as: those that are located near adefect but are not in the immediate proximity.SITE: harvested from the neck, chest, or axilla and can providecoverage of large surface areas on the face. Selection of a specific regional flap depends on: the size and location of thedefect and also on the intrinsic properties of the flap. Advantages of regional flaps include the large amount of soft tissueand skin available. Disadvantages of these types of flaps include poor color and texturematch, excessive bulkiness of the flap, and donor site morbidity.

A)Pectoralis Major Myocutaneous FlapThe pectoralis major myocutaneous flap : remains a workhorse of reconstructive surgery.*It has provided a reliable method of soft tissue reconstruction of

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bone and soft tissue defects of the mandible and maxilla. *The pectoralis major myocutaneous flap can be rotated around a pivot point 180° and is supplied by two separate blood supplies*The pectoral branch is the major artery that supplies the pectoralismajor myocutaneous flap.*The position of the vascular pedicle can be approximated by drawing a line from the shoulder point to the xiphoid. The pectoral branch descends at a right angle from the middle of the clavicle until it meets this line. *Branches of the internal mammary artery supply the medial portion of the muscle and skin over the sternum.*The flap provides good coverage for the carotid artery when combinedwith a neck dissection.B)Deltopectoral Flap : for reconstructing large ablative resections for head and neck cancer.used as an alternative to the pectoralis major myocutaneous flap for soft tissue reconstruction of the mandible and maxilla. This flap is composed of fascia, subcutaneous tissue, and skin but does not contain musclePerforators from the internal mammary artery provide vascular supplyto the flap. The secondary defect is covered with a skin graft.

C)Temporalis Flap The temporalis flap was useful for covering intraoral defects. The outer portion of the muscle is invested by the deep temporal fascia. This fascia is supplied by the middle temporal vessel, which originatesjust below the zygomatic arch. The temporalis muscle is supplied by both the anterior and posterior deep temporal arteries, which arise from the second portion of the internal maxillary artery. This dual blood supply allows for splitting of the muscle into anterior and posterior flaps.When elevating the muscle, it is important to remain on the deep temporalfascia beneath the superficial temporal fascia to avoid damage to the frontalbranch of the facial nerve. Elevation of the inferior portion of the flap is performed in a subperiosteal plane to avoid damage to the deep temporal arteries, which lie on the undersurface of the muscle.

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An osteotomy of the zygomatic arch is often helpful to facilitate placement of the muscle into the mouth. The arch can be put back into place and secured with plates and screws. A disadvantage: of the temporalis flap is the minimal cosmetic deformity of hollowing in the temporal region; this can be corrected with autogenousor alloplastic materials and can be minimized by using either an anterior ora posterior flap.D)Sternocleidomastoid FlapThe muscle is invested by the deep cervical fascia and is supplied by three arteries. The dominant vessel is the occipital artery, which enters the muscle below the mastoid tip and supplies the superior portion of the muscle. The superior thyroid artery supplies the middle portion, and the thyrocervicaltrunk supplies the inferior third of the muscle.The muscle is elevated over the deep cervical fascia superior to the carotidsheath. It is recommended to maintain two of the three vessels when elevating the flap to enhance the viability of the flap. The spinal accessory nerve enters the deep portion of the muscle approximately at the carotid bifurcation and should be preserved to prevent denervation atrophy of the muscle. Advantages of the sternocleidomastoid flap include its close proximity tothe defect and minimal donor site defect

E)Trapezius Myocutaneous Flap : The trapezius myocutaneous flap is supplied by three arteries, allowing several flaps to be used. The main vessel supplying the trapezius muscle is the transverse cervical artery, which is a branch of the thyrocervical trunk. The upper portion of the muscle is supplied by the occipital artery. The trapezius myocutaneous flap is a ready source of skin of uniform thickness without excessive very large defects requiring coverage.The main disadvantages are the need to reposition the patient during the operation and morbidity from the donor site.

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ComplicationsTwo main unwanted outcomes are flap failure and unacceptable cosmetic results. Flap survival depends on early recognition of flap compromise.

Ischemia :is defined as an inadequacy of perfusion in providing tissue needs. Signs of arterial ischemia include a pale and cool flap that does not blanch with pressure and typically does not bleed with a pinprick. Flaps are somewhat ischemic initially because the original tissue perfusion has been compromised by flap elevation.necrosis depends on patient-related and surgery-related factors that influence the risk of necrosis in facial flaps.Smoking is associated with an increased risk of flap failure. The deleterious effects of smoking on flap survival include hypoxemia andvasoconstriction.Common causes of bleeding in facial reconstruction with local flaps include:inadequate hemostasis and drug-inducedcoagulopathy. Patients should be questioned carefully about the use of medications that affect coagulation such as acetylsalicylic acid, nonsteroidal anti-inflammatory drugs, and vitamin E. If possible, these medications should beavoided for 2 weeks prior to and 1 weekafter surgery.Hematoma formation : *should be identified and decompressedwithin 24 hours. *Decompression can be accomplished with aspiration using a 22- gauge needle or by taking out one or two sutures and applying gentle compressionon the flap. Hematoma formation may diminish tissue perfusion and can lead to ischemia or necrosis by inducing vasospasm, stretching the subdermal plexus, or separating the flap from its recipient bed.

Congestion is the most common vascular problem associated with facial flaps.

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Signs of a congested flap include warmth, edema, and a purple color that blanches with pressure then immediately refills. A pinprick will cause release of dark venous blood.Venous congestion can lead to arterial compromise and flap necrosis.

Management of congested flaps : may include * temporarily releasing sutures to allow decompression at the flap edges or possible impingement involving the flap pedicle.*Tight bandages around the flap pedicle should be removed. Medicinal leeches (Hirudo medicinalis) may be useful in decompressing congested flaps. Saliva from the leech contains an anticoagulant and a vasodilator that facilitate continued oozing from the site even up to 6 hours after they detach.*Hyperbaric oxygen (HBO) has been shown to be beneficial in improving the vascularity of marginal tissues. ProphylacticHBO therapy in cutaneous flap surgery in the irradiated tissue bed may be particularly helpful to combat the hypoxia and hypocellularity. HBO is beneficial in treating both venous congestion and arterial ischemia by creating a local arterial vasoconstriction through the rise in arterial oxygen content, which reduces the amount of inflow. The tissue oxygenlevels continue to rise owing to the improved diffusion even though there isvasoconstriction and a reduction in vascular perfusion. The flap can maintainviability while continued neovascularization occurs. Other options include the use of heparin and dipyridamole to help increase the survival of an ischemic flap.

Infection can complicate flap healing.The postoperative infection rate for clean wounds in facial surgery is as low as 2.8%, with higher rates in facial reconstruction with local flaps. Tissue oxygenation is an important factor in prevention of wound infection and is closely related to blood supply. Infections involving local flaps may result in flap failure or poor cosmetic outcome secondary to wound dehiscence and scarring.

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