A DETAILED DESCRIPTION OF THE LATISSIMUS DORSI MUSCLE FLAP FOR RECONSTRUCTION FOR PLASTIC SURGERY RESIDENTS

1. LATISSIMUS DORSI
FLAP
DR G SWAMY VIVEK
SENIOR RESIDENT
DEPT OF PLASTIC SURGERY
GMCH, GUWAHATI

2. HISTORY
 The latissimus dorsi flap was introduced by Tansini in 1906 for the
coverage of extensive mastectomy defects.

3. FLAP ANATOMY
 The latissimus dorsi muscle is the mirror image of the pectoralis major
muscle

5. ORIGIN AND INSERTION
 ORIGIN:
 Spinous process of vertebrae T7-L5,
 Thoracolumbar fascia,
 Iliac crest,
 Inferior 3-4 ribs,
 Inferior angle of scapula.
 INSERTION:
 Floor of intertubercular groove of the humerus.

6.  The superior portion of the medial aspect of the latissimus muscle is
covered by the trapezius muscle; otherwise, the latissimus muscle is
superficial to all other muscles in the back.
 The latissimus muscle covers a portion of the paraspinal muscle and the
majority of the serratus anterior muscle.
 In the middle portion there is a rather tight attachment to the 10th, 11th,
and 12th ribs and to the fibers that interdigitate with fibers of the serratus
anterior muscles.
 Superiorly it is adherent to the inferior border of the teres major muscle.

7.  it spirals 180° around and travels anterior to the tendon of the teres major
muscle before insertion into humerus.

8. FUNCTIONS
 There are numerous important functions of the latissimus dorsi muscle.
 Primarily it acts as an extender, adductor, and medial rotator of the
humerus.
 It holds the inferior angle of the scapula against the chest wall and
stabilizes and elevates the pelvis when bringing the lower extremity
forward.
 It aids in coughing and it pulls the arm posteriorly, directly behind the
back, a motion that is best described by the terminal action of pushing off
with a ski pole

9. ARTERIAL SUPPLY OF FLAP
 The latissimus dorsi muscle has a dual blood supply from the subscapular
artery and the posterior paraspinous perforators.
 Both circulatory systems are diffusely interconnected so that the muscle
can survive in its entirety if either pedicle is interrupted.

14.  Dominant: thoracodorsal artery, a branch of the subscapular artery
Length: 8.5 cm (range 6.5–12 cm)
Diameter: 3 mm (range 2–4 mm)
 The thoracodorsal artery courses from the axilla along the anterior border
of the latissimus dorsi muscle, enters the muscle from underneath, and
spreads into two or three major branches at the undersurface of the
muscle.

15.  The neurovascular hilus was found on the deep surface of the latissimus
dorsi muscle approximately 4 cm distal to the inferior scapular border and
2.5 cm lateral to the medial border of the latissimus muscle.
 At that point there was a constant bifurcation into a horizontal (medial or
transverse) branch and a descending (lateral or vertical) branch, but there
are interconnections between the horizontal and descending/lateral
branches.

16.  Within the muscle, both branches divide into lesser branches, which run
medially and anastomose with perforators from intercostals and lumbar
arteries.
 Both branching patterns supply the muscle with long, parallel
neurovascular branches, which run in the fascia between bundles of muscle
fibers and thereby enable the muscle to be split into independent
vascularized innervated units.

17.  All thoracodorsal cutaneous perforators originated within a distance of 8
cm distal to the neurovascular hilus.
 The thoracodorsal artery supplies predominantly the latissimus dorsi
muscle but also gives branches to the serratus anterior muscle, the axillary
skin, and the subscapular and teres major muscles.
 The subscapular artery arises in general, as a branch of the third portion of
the axillary artery.
 Usually the circumflex scapular artery is found to be the first branch of the
subscapular artery.
 The second major branch of the subscapular artery is the thoracodorsal
artery.

18.  Minor:
 perforating posterior branches of the posterior intercostal arteries.
 These vessels predominantly supply the distal part of the latissimus dorsi
muscle.
 They are found in two rows as segmental vessels 5–10 cm from the dorsal
midline.
 There are usually 4–5 vessels in each segmental row.
 The lateral row derives its blood supply from branches of the posterior
intercostal artery and the medial row derives its blood supply from the
lumbar artery.

19. VENOUS DRIANAGE OF THE FLAP
 Accompanying veins follow the arteries
 Primary:
thoracodorsal vein
 Length: 9 cm (range 7.5–10 cm)
 Diameter: 3.5 mm (range 2–5 mm)
Usually, the thoracodorsal vein originates from the subscapular vein

20.  Secondary: concomitant veins, running with the perforating arterial
vessels, provide secondary venous drainage
 Length: 2 cm (range 1.5–2.5 cm)
 Diameter: 2 mm (range 1.1–2.7 mm)
 The lower and medial parts of the muscle preferentially drain through the
intercostals and lumbar venous system and not via the thoracodorsal
system.
 the circumflex scapular vein can provide secondary drainage of the flap.

21. FLAP INNERVATION
 Sensory: the posterior branches of the lateral cutaneous branches of the
intercostal nerves provide cutaneous sensibility laterally, and lateral
branches of the posterior rami (VI through XII) posteriorly
 Usually these branches are not used to reinnervate the flap, but in the
special case when a reverse pedicled flap is performed based on the
posterior intercostal vessels, its sensory innervation can be preserved and
so the sensory innervation can be maintained.

22.  Motor: the thoracodorsal nerve arises from the posterior cord of the
brachial plexus and travels latero-inferiorly behind the axillary artery and
vein
 Even if only a small portion of muscle is included, the entire muscle is
denervated.
 The nerve divides into lateral and medial branches approximately 1.3 cm
proximal to the neurovascular hilus and each branch runs with its vascular
counterpart

24.  if the intention is to split the muscle and retain half of it on the chest with
an intact nerve supply, then the dissection is more complicated.

25. FLAP COMPONENTS
 The latissimus dorsi flap can be raised as a muscle, or a musculocutaneous,
an osteomusculocutaneous, or even a perforator flap (TDAP).
 Combinations and extensions are possible with any component from the
subscapular system (i.e., bone, skin, fascia, muscle).
 On the same pedicle, it can be elevated with the serratus fascia or the
serratus muscle, the accompanying rib or part of the scapula, or with a
scapular or parascapular flap.
 In this way it is possible to harvest multicomponent flaps to simultaneously
reconstruct complex defects with several flaps based on a single pedicle

26. ADVANTAGES
 Latissimus dorsi dissection is rapid, easy, and safe because of the reliable
anatomy of the thoracodorsal and subscapular vessels.
 Microvascular transfer is facilitated by the long pedicle and large caliber of
the vessels.
 A skin island can be orientated vertically, obliquely, or transversely as
desired or required by the defect.
 It can be tailored to almost any size and shape. The flap can extend from
the axilla to almost the iliac crest.
 As a pedicled flap, it is certainly one of the most versatile flaps for
reconstructive problems of the chest wall and the upper arm. The pedicled
muscle flap alone will also supply coverage for massive defects of the head
and neck area as well as the shoulder.

27.  The musculocutaneous latissimus flap may be advantageous in providing
bulk for the correction of contour defects.
 Combined (“chimeric”) flaps with other components from the subscapular
system can be designed, vascularized bone can be harvested as rib grafts
with the latissimus, or on a common pedicle from the scapula, fascia can
be added from the serratus muscle.
 The thoracodorsal nerve can be included so that the muscle can be
reinnervated for restoration of motor function.

28. DISADVANTAGES
 This flap, especially the musculocutaneous type, is generally bulky,
depending on the general physical constitution of the patient.
 Even though the muscle atrophies to some degree, skin islands in
musculocutaneous flaps are usually also bulky and require secondary
thinning and contour correction for satisfactory aesthetic results.
 If all the other muscles of the shoulder girdle are intact, the loss of the
latissimus dorsi muscular function is rarely noticeable in normal activities.

29.  Occasionally, the harvest of this muscle will result in some winging of the
scapula, even though the serratus anterior muscle is intact. It can also
compromise the motion of “posterior push,” an important function in
skiing, where the hand is pulling the body weight forward.
 Loss of the latissimus in paraplegics may also seriously weaken upper
extremity function such as crutch-walking or bed-to-wheelchair transfer.
 Similarly, in patients with poliomyelitis or other neuromuscular diseases,
loss of the latissimus dorsi muscle may seriously weaken pelvic stability
 Pains at the donor site and seroma formations are occasionally seen

30. PREOPERATIVE PREPARATION
 No preoperative vessel identification is necessary.
 In cases of previous axilla dissection or radiation, muscle function has to be
evaluated preoperatively.
 If muscle function is intact, the vessels are likely not violated.
 If the muscle function does not seem to be good or if the suspicion is high
for vessel injury, further studies such as tracing the vessel course with high
resolution ultrasound may be performed to see if adequate perfusion is
available.
 A donor site for possible skin grafting is also prepped and draped.

31. FLAP DESIGN
 ANATOMIC LANDMARKS

32. SPECIAL CONSIDERATIONS
 BREAST RECONSTRUCTION
 the island over the upper free muscle border should be designed in a way
that closure of the secondary defect leaves a transverse scar that is easily
concealed by a brassiere.

35.  HEAD AND NECK RECONSTRUCTION
 if the flap is to be pedicled, a skin island along the anterolateral margin of
the muscle is necessary because the transverse island will not reach.

36.  SOFT TISSUE DEFECT OF THE LOWER EXTREMITY WITH A BONE DEFECT

39. FLAP DIMENSIONS
 Muscle Dimensions
 Length: 35 cm (range 21–42 cm)
 Width: 20 cm (range 14–26 cm)
 Thickness: 1.5 cm (range 0.5–4.5 cm)
 The average dimensions are 4–6 cm more in male patients than in female patients.
 Skin Island Dimensions
 Length: 18 cm (range up to 35 cm)
 Width: 7 cm (range up to 20 cm), maximum to close primarily: 8–9 cm
 Thickness: 2.5 cm (range 1–5 cm)
 The latissimus dorsi flap can be tailored to almost any size with a maximum dimension of
20×35 cm. Primary closure of the donor site can be achieved when the width is <8–9 cm.

40.  Bone Dimensions
 Length: 5 cm (range 1.5–8 cm)
 Width: 2 cm (range 1–5 cm)
 Thickness: 2 cm (range 1–3 cm)

41. FLAP MARKINGS

43. PATIENT POSITIONING
 Most surgeons would agree that a lateral decubitus position is ideal for
flap harvest, although it is possible with the patient in a prone or even a
supine position with a 45° lateral tilt.
 The arm is abducted to 90°, the elbow also flexed 90°.
 More abduction may stretch the brachial plexus
 In cases of a free transfer to the lower extremity, the flap is usually
harvested from the contralateral side

44. ANESTHETIC CONSIDERATIONS
General anesthesia is needed to harvest the latissimus dorsi
flap

45. TECHNIQUE OF FLAP HARVEST

49. DONOR SITE CLOSURE AND
MANAGEMENT
 For standard flap designs, the donor site is closed as a direct closure after
at least two drains are inserted. No special dressing is needed. Because of
the high incidence of seroma formation, which occurs even with adequate
suction, drainage of the donor site has constituted the biggest
disadvantage of this flap.
 The donor site itself does not create any significant surface depression or
excessive prominence of the ribs, but if more than 5 cm of skin is carried
with the muscle, a widened scar can be expected.
 If a skin graft is required for the donor site, the resulting contour deformity
can be remarkably unattractive, particularly in the obese patient

50. ARC OF ROTATION
 The latissimus dorsi, based on the major pedicle in the axilla, has a wide
arc of rotation.
 Anterior arc: will cover the lateral abdomen (musculofascial flap), chest
wall, and head and neck region.
 Posterior arc: will cover the lumbar, thoracic, and cervical vertebrae and will
reach the posterior neck.

52. TYPICAL INDICATIONS FOR THE USE
OF THIS FLAP
 AS PEDICLED FLAP
 BASED ON ANTERIOR ARC OF ROTATION
 Anterior and posterior chest wall defects
 Sternum osteitis
 Major coverage problems of the axilla, shoulder, and neck
 Less often for intraoral defects
 Massive defects of the temporal area
 Breast reconstruction
 Correction of surface coverage problems of the upper arm extending to
the elbow

53.  BASED ON POSTERIOR ARC OF ROTATION
 Proximally based obvious flap of choice for major upper back and scapular
defects
 As a reversed flap for defects of the lower thoracic and lumbar areas
 Bilaterally, especially for soft tissue coverage in spina bifida patients

54.  AS FREE FLAP
 HEAD AND NECK
 Major coverage problems. Coverage of intraoral defects, including
mandibular reconstruction with a free rib.Functional muscle transfer for
facial reanimation with the thoracodorsal nerve connected to the
contralateral normal facial nerve in a one-stage procedure.

55.  TRUNK
 Major coverage problems.
 UPPER EXTREMITY
 Major coverage problems. Free functional muscle transfer.
 LOWER EXTREMITY
 Major coverage problems. Treatment of chronic infections because of its
excellent vascular supply.

56. ATYPICAL INDICATIONS FOR THE USE
OF THIS FLAP
 PEDICLED TRANSFERS
 Pedicled innervated latissimus muscle transfer may be used for restoration
of biceps or triceps function.
 FREE MICROVASCULAR TRANSFERS
 A free latissimus muscle or myocutaneous flap may be used for forearm
flexion with or without finger flexion, or for forearm extension with or
without finger extension.

58. POSTOPERATIVE CARE

59. GENERAL
 VASCULAR COMPLICATIONS
 Venous thrombosis
 Arterial thrombosis
 Vascular spasm

60. RECIPIENT SITE
 The suction drains are removed after 3–5 days, or when they accumulate
<50 mL of fluid in 24 h.
 The skin clips or sutures are left for at least 14 days.
 Mesh grafts are dressed until the 5th day after the operation, and
thereafter the dressings are changed every 2nd day.
 After 10 days, the wound can usually be left without dressing. Depending
on the flap’s healing process, the patient’s stay in hospital will be about 2–
3 weeks

61. DONOR SITE
 The suction drains are removed after 3–5 days, or when they accumulate
<50 mL of fluid in 24 h.
 The skin clips or sutures are left for at least 14 days because of the tension.
 Mesh grafts are dressed until the 5th day after the operation, and
thereafter the dressings changed every 2nd day.
 After 10 days, the wound can usually be left without dressings.
 If the donor site has been closed under tension, careful exercise of the
affected shoulder can be started on the 3rd day, because limitation in
movement quickly sets in owing to protective posturing, and not only in
older patients.

62. UNTOWARD OUTCOMES
 Complications are those that are general and likely to be seen with any
muscle flap.
 These include planning errors, technical intraoperative errors, and
postoperative care errors, all of which can contribute to flap failure.
 The arc of rotation of the flap is limited by the location of the vascular
pedicle and length of the flap.
 In thin patients, the flap will reach much farther.
 These factors have to be taken into account in preoperative planning.
 Furthermore, the orientation of the overlying skin on the muscle is less
precise in obese patients

63.  DONOR SITE
 The donor site itself does not create any significant surface depression or
any excessive prominence of the ribs, but if >5 cm of the skin is carried
with the muscle, a widened scar can be expected. If a skin graft is required
for closure of the donor site, the resulting contour deformity can be
remarkably unattractive, and it is difficult to achieve aesthetic closure of
these donor sites, particularly in obese patients.Loss of function is not
noticeable in normal individuals. In patients requiring the use of crutches,
the effect is noticeable. Removal of the muscle can also affect pelvic
stability in paraplegic patients. Winging of the scapula is also present in
some patients

64.  . To avoid this, care must be taken not to damage innervation to the
serratus anterior muscle.The donor site constitutes the biggest
disadvantage of this flap because of the high incidence of seroma
formation, which occurs even with adequate suction drainage. These
seromas are occasionally difficult to eradicate and can result in the
formation of a bursa. If this happens, it is usually possible to collapse the
cavity with a Penrose drain. After 4–6 weeks, this becomes an intractable
problem, and it may be necessary to abrade or excise the two surfaces of
the bursa to obtain healing.

65. THANK YOU