Plastic surgery 19 Graft and Flaps Brachial plexus

• Split thickness
• - Thin (Thiersch-Ollier) - 0.005-0.012 inch
• - Intermediate (Blair-Brown) - 0.012-0.018 inch
• - Thick (Padgett) - 0.018-0.030 inch

Full thickness - Entire dermis (Wolfe- Krause)

Composite tissue - Full-thickness skin with additional tissue (subcutaneous fat, cartilage, muscle). e.g - graft used in nasal reconstruction, ear lobe composite graft

• Also called as Wolfe grafts. Epidermis and the full thickness of dermis. The subcutaneous tissue is carefully removed from the deep surface of the dermis to maximize the potential for engraftment.
• Donor site defect closed by suturing or SSG. 
• Full-thickness grafts are associated with the least secondary contraction upon healing, the best cosmetic appearance, and the highest durability. As a result, they are frequently used in reconstructing superficial wounds of the face and the hands.
• These grafts require pristine, well-vascularized recipient beds without bacterial colonization, previous irradiation, or atrophic wound tissue.

• Also called Thiersch graft. 
• Epidermis and part of dermis 
• Thin, intermediate or thick
• Leaves adnexal remnants (pilosebaceous follicles, sweat gland apparatus) from which the donor site can resurface. 
• Contract subsequently if circumstances permit, e.g. across a flexure. Thinner a graft the more it contracts secondarily.

• Primary contraction - the degree to which a
• graft shrinks in surface area after harvesting and before grafting
• Secondary contraction - shrinking during healing

Skin graft take occurs in three phases: imbibition, inosculation, and revascularization.

Plasmatic imbibition refers to the first 24 to 48 hours after skin grafting, during which time a thin film of fibrin and plasma separates the graft from the underlying wound bed. It remains controversial whether this film provides nutrients and oxygen to the graft or merely a moist environment to maintain the ischemic cells temporarily until a vascular supply is reestablished.

After 48 hours, a fine vascular network begins to form within the fibrin layer. These new capillary buds interface with the deep surface of the dermis and allow for transfer of some nutrients and oxygen. This phase, called inosculation, transitions into revascularization, the process by which new blood vessels either directly invade the graft or anastomose to open dermal vascular channels and restore the pink hue of skin. These phases are generally complete by 4 to 5 days after graft placement. During these initial few days, the graft is most susceptible to interference in engraftment caused by infection, mechanical shear forces, and hematoma or seroma.

Streptococcus pyogenes, probably by virtue of its potent fibrinolysin- breaks down fribin

• Blair knife after the American plastic surgeon 
• Humby, an English plastic surgeon added a roller mechanism
• Watson modification is currently the bestscaled-down
• The silver knife: scaled-down version

• Thickness of graft - 0.25 mm - 0.55 mm
• The use of a number 10 or 15 scalpel blade as a feeler gauge to measure the appropriate setting for the hand-held knife has been used and would serve as a useful guide to surgeons who harvest skin grafts infrequently.
• The standard Swann-Morton number 15  scalpel blade measures 0.39 mm in thickness and the number 10 blade 0.37 mm.
• The skin graft knife is adjusted to a setting just wide enough to permit the scalpel blade to fit snugly between the roller guard and the skin graft blade

A flap is a vascularized block of tissue that is mobilized from its donor site and transferred to another location, adjacent or remote, for reconstructive purposes. The difference between a graft and a flap is that a graft brings no vascular pedicle and derives its blood flow from recipient site revascularization, whereas a flap arrives with its blood supply intact.

On the basis of their anatomical content and the nature of their vascular patterns flaps:

• - Cutaneous flap contains skin accompanied by a variable amount of subcutaneous fat
• - Fasciocutaneous flap contains skin and fascia
• - Muscle flap contains muscle only
• - Myocutaneous flap also contains the overlying skin and intervening tissues
• - Osseous flap contains vascularized bone only
• - Osteomyocutaneous flap contains, in addition, muscle, skin, and subcutaneous tissues

The classification of flaps based on blood supply - 

1. Random - Random pattern flaps have a blood supply based on tiny blood vessels in the dermal-subdermal plexus. Random flaps are typically used to reconstruct relatively small, full-thickness defects that are not amenable to skin grafting. Unlike axial pattern flaps, random flaps are limited by their geometry. The generally accepted reliable length-to-width ratio for a random flap is 3:1.

• Types of random flap
• a. Transposition flap is rotated about a pivot point into an adjacent defect.
• i. Z-plasty is a type of transposition flap in which two flaps are rotated, each into the donor site of the other, to achieve central limb lengthening.
• ii. Rhomboid (Limberg) flap
• b. Rotational flaps - similar to transposition flaps but differ in that they are semicircular
• c. Advancement flaps slide forward or backward along the flap’s long axis
• d. Interpolation flaps rotate about a pivot point

2. Axial - Discrete, well-described vessels. Axial flaps can be classified as

a. Local flaps - transferred from a position adjacent to the defect.

b. Regional flaps - from the same anatomic region of the body as the defect (e.g., the lower extremity region or the head and neck region).

c. Distant flaps - transferred from a different anatomic region to the defect. They may remain attached to the source anatomic region (pedicled flaps) or may be transferred as free flaps by microsurgery. These are completely detached from the body, and their blood supply is reinstated by microvascular anastomoses to recipient vessels close to the defect.

• C is pivot
• BD is 60% of AC 
• EF is parallel and equal to DC
• DE = AB, AD = EF

• Deltopectoral flap (Bakamjian flap) - first three perforating branches of the internal mammary vessels
• Forehead flap - Anterior branch of superficial temporal artery
• Groin flap - superficial circumflex iliac vessels
• Gastrocnemius flap - popliteal vessels
• Pectoralis major flap - Pectoral branch of thoraco-acromial artery and the lateral thoracic artery
• Retus abdominis (TRAM flap)
• - Superior pedicle supplied by superior epigastric artery for breast
• - Inferior pedicle supplied by inferior epigastric artery for groin and thigh
• Latissimus dorsi flap - thoracodorsal branch of subscapular artery and its associated veins

• 1. Pedicled transverse rectus abdominis myocutaneous (TRAM) flap
• - Based on the superior epigastric vessels that run on the undersurface of the rectus abdominis muscle
• - A transversely oriented skin paddle with underlying fat is isolated based on its perforating vessels that course through the rectus muscle to join the main superior epigastric pedicle.
• - The flap, along with the rectus muscle and blood supply, is tunneled under the anterior chest wall and  delivered into the mastectomy defect, where it is then shaped into a breast mound.
• - The donor site is closed in a manner similar to an abdominoplasty.

• Advantages -
• - Creation of a breast that looks and feels natural, that changes volume along with the patient’s weight (and the contralateral natural breast)
• - Avoids potential complications of breast implants.
• - The pedicled TRAM flap procedure is also relatively quick for a total autologous reconstruction. 

• Disadvantages - 
• - Potential for partial or complete flap failure
• - Fat necrosis
• - Fullness in the upper abdomen from the tunneled pedicle
• - Abdominal wall bulge or hernia
• - Abdominal wall weakness

2. Free TRAM flap is similar to the pedicled TRAM flap but is based on the deep inferior epigastric vessels, which are the dominant blood supply to the lower abdomen. The flap is  anastomosed to recipient vessels in the chest, usually the internal mammary or the thoracodorsal vessels.

Angiosome - a block of tissue that is reliably supplied by a given artery. An anatomic angiosome is defined by the limits of an artery’s ramifications, where it forms anastomoses with a neighboring anatomic angiosome. The potential angiosome of an artery is the volume of tissue that can be included in a flap that has undergone conditioning. Both the dynamic and potential angiosomes extend beyond the anatomic angiosome of an artery.

Choke vessels - The vessels that pass between these anatomic angiosomes. In life, these may open or close in response to physiologic changes to increase or decrease, respectively, an artery’s dynamic angiosome momentarily.


Conditioning - any procedure that increases the reliability of a flap by enlarging the angiosome of the pedicle artery from its dynamic toward its potential angiosome.

Delay phenomenon - Delay phenomenon improves the survival of flaps that otherwise would more frequently be complicated by unpredictable partial necrosis. One method of delay for the pedicled TRAM flap is to divide a major portion of its blood supply, the deep inferior epigastric artery on both sides, approximately 2 weeks before transfer. In response, blood from the anatomic angiosome of the superior epigastric artery appears to flow into that of the interrupted deep inferior epigastric artery via intervening choke vessels. As a result, the flap becomes conditioned to rely on the superior epigastric artery. The TRAM flap can then be transferred based on the superior epigastric artery with less risk of its distal portions becoming ischemic and possibly necrotic.

• Waltzing transfer is used when the entire defect cannot be covered by the flap in a single procedure.
• At a first stage, part of the primary defect is covered by the flap, the remainder being covered at a second stage by untubing the unused segment of the flap (pedicle), usually divided 3 weeks later. 
• If such a transfer is to be completed without necrosis, it is essential that the second stage is preceded by a formal delay stage.

The best advice for postoperative flap care for major tissue transfers is to keep the patient ‘wet, warm and comfortable’. This means that the patient should be well hydrated with a hyperdynamic circulation, a very warm body temperature and well-controlled analgesia to reduce catecholamine output.

Any surgery performed with the aid of an operative microscope - 6× and 40× magnification

• (a) complete detachment of the flap, with devascularization, from the donor site;
• (b) revascularization of the flap with anastomoses
• to blood vessels in the recipient site; and
• (c) an intervening period of flap ischemia. Flap circulation must be restored within a tolerable ischemia time.

• Clinical Sign // Arterial Compromise // Venous compromise
• Color // Becoming paler // Increasingly reddish or purplish
• Temperature // Becoming cooler // Becoming warmer
• Tissue turgor // Reducing // Increasing
• Capillary refill time // Becoming slower // Becoming faster
• Pinprick bleeding // Increasingly sluggish // Quickening (and darkening)

Surgical measures as well as by application of medicinal Hirudo medicinalis leeches (with concomitant Aeromonas hydrophila prophylaxis) or by chemical “leeching” (topical heparin combined with dermal punctures).

• Root 5 
• Trunk 3
• Division 2
• Cord 3
• Branches 5

[@ Ram Thapa Drinks Cold Beer]

• Medial cord - M4U (I am for you)
• Lateral - LML 
• Posterior - ULNAR

Ulnar Nerve innervates most Hand muscles except  “MEAT LOAF” which are all innervated by Median Nerve. 

• Lumbricals 1 &2,
• Opponens Pollicis,
• Abductor Pollicis Brevis,
• Flexor Pollicis Brevis (Superficial head)

Radial nerve innervates the BEST - 

• Brachioradialis
• Extensors
• Supinator
• Triceps