A DETAILED DESCRIPTION OF RECTUS ABDOMINIS FLAP AND ITS APPLICATIONS IN PLASTIC SURGERY AND ONCOLOGY

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

2. HISTORY
 The rectus abdominis muscle (RAM) flap and its variations are some of the
most important flaps used in reconstructive surgery.
 The RAM flap was first described by Holmstron in 1979, who based the flap
on its inferior pedicle, the deep inferior epigastric artery (DIEA).
 The RAM flap gained popularity with the work of Hartrampf, with its
utilization as a pedicled flap based on its superior pedicle, the superior
epigastric artery (DSEA), in breast reconstructions.

3. FLAP ANATOMY

4. ARTERIAL SUPPLY OF THE FLAP
 The rectus muscle exhibits double nourishment (type III Mathes/Nahai)
and is supplied superiorly by the superior epigastric artery, a branch of the
internal thoracic artery, and by the deep inferior epigastric artery, a branch
of the external iliac artery.
 These two vessels comprise an intramuscular anastomotic network with
each other above the level of the umbilicus.

5.  DOMINANT:
 DEEP INFERIOR EPIGASTRIC ARTERY
 DEEP SUPERIOR EPIGASTRIC ARTERY
 MINOR:
 SUBCOSTAL AND INTERCOSTAL ARTERIES
 SUPERFICIAL SUPERIOR EPIGASTRIC ARTERY AND SUPERFICIAL
CIRCUMFLEX ARTERY

7. VENOUS DRIANAGE OF FLAP
 Veins accompany the arteries and are present in pairs.
 PRIMARY:
 deep inferior epigastric vein
 deep superior epigastric vein
 SECONDARY:
 superficial inferior epigastric vein
 This drains to the saphenous bulb and cooperates in skin drainage of the
anterior abdomen.

8. FLAP INNERVATION
 SENSORY:
 The 7th–12th intercostal nerves enter the RAM at various points and divide
into motor and sensory branches.
 The sensory branches join the perforators that supply the overlying skin.
 MOTOR:
 Segmental motor branches of the 7th–12th intercostal nerves.

10. FLAP COMPONENTS
 The flap can be dissected
 as a pure muscle flap;
 as a segmental muscle flap with preservation of part of the muscle;
 as a myocutaneous flap with a transverse, oblique, or vertical skin island
flap;
 as a myocutaneous flap with muscle preservation; or
 as a perforator flap, with preservation of the muscle and its innervation.
 The 7th, 8th, 9th, and/or 10th ribs can be included in a rectus abdominis
flap.

11. ADVANTAGES
 The position of this flap’s skin island in the inferior abdomen, especially in
women who have already been pregnant, is advantageous.
 Since the flap is dissected in the supine position, reconstruction of defects
in the anterior trunk as well as the upper and lower extremities can be
performed without a change in position during the procedure.
 The vascular anatomy is uniform and reliable.

12.  If it is transferred based on its superior pedicle, the whole length of the
pedicle included in the rectus muscle will greatly increase its rotational arc.
 The design of the skin island is very versatile. It can be transverse, vertical,
and/or oblique.
 In large three-dimensional defects, the flap can be folded on itself,
providing good coverage particularly in complex head and neck resections.
 A muscle flap, without a skin island, can be harvested through a low
transverse abdominal incision.

13. DISADVANTAGES
 Weakening of the abdominal wall after flap harvest may be seen. If only a
small part of the anterior fascia and the abdominal wall layers is closed
appropriately, weakening of the abdominal wall and bulgings or hernia will
be less likely to happen.
 The removal or denervation of the RAM can create a slight functional
deficit, especially upon flexing the trunk.
 In obese patients, the myocutaneous form of the rectus flap is very likely
to be bulky for resurfacing objectives.

14.  This muscle does not function well as a functional muscle transfer since its
excursion is minimal and its innervation is segmental.

15. PREOPERATIVE MANAGMENT
 Preoperative evaluation is of fundamental importance.
 A detailed history and physical examination can reveal important aspects
of the surgical procedure.
 Previous abdominal or pelvic surgeries can damage the vascularization of
the flap.
 Previous irradiation of the internal thoracic vessels can diminish its blood
flow. If one suspects injury of the pedicles, additional studies should be
performed.

16.  CT angiography can help determine availability and location of
perforators. Also, careful delay procedures can be helpful.
 In obese patients, fat necrosis is a major probability when the superiorly
based pedicled form is utilized.
 Supercharging and superdraining, microsurgical inferiorly based flaps or
delay procedures can be indicated in this situation.
 One should look for abdominal muscle weakness or herniations that
should be dealt with intraoperatively.
 Patients in whom the internal mammary artery has been used for cardiac
revascularization should not use a superiorly based flap.

17. FLAP DESIGN
 ANATOMIC LANDMARKS
 The RAMs are located in the anterior abdomen with their medial limits
situated in the midline, except in multiparous women who present with
diastasis of the rectus muscles, separating them from the midline.
 The superior limit is the rib cage, as the muscle arises from the fifth, sixth,
and seventh costal cartilages and the inferior limit is its insertion at the
pubis.
 Palpation of the contracted muscle easily determines its location in thin
patients.

18. ANATOMIC LANDMARKS

19. FLAP DIMENSIONS
 Skin Island Dimensions: Lower Abdominal Skin Flap
 Length: 13 cm (range 10–20 cm). Maximum to close primarily: 20 cm
 Width: 25 cm (range 20–40 cm)
 Thickness: 2.5 cm (range 1–6 cm)
 Skin Island Dimensions: Vertical Skin Flap
 Length: 25 cm (range 23–29 cm)
 Width: 6 cm (range 4–8 cm)
 Thickness: 2.5 cm (range 1–6 cm)
 These dimensions are based on what would allow primary closure of the donor
site.

20.  MUSCLE DIMENSIONS
 Length: 25 cm (range 23–29 cm)
 Width: 6 cm (range 4–8 cm)
 Thickness: 1.5 cm (range 0.7–2 cm)
 BONE DIMENSIONS
 Length: 10 cm (range 3–15 cm)
 Width: 2 cm (range 2–6 cm, multiple costal cartilages)
 Thickness: 2 cm (range 1–3 cm)
 The 7th–10th cartilages can be raised with the flap

21. PATIENT POSITIONING
 Supine position

22. ANESTHETIC CONSIDERATIONS
 General anesthesia

23. FLAP DESIGN

24. TECHNIQUE OF FLAP HARVEST
 SUPERIORLY BASED PEDICLED TRAM
 MUSCLE FLAP
 FREE FLAP
 PERFORATOR FLAP

27. FLAP MODIFICATION AND HANDLING
 DELAY OF THE FLAP
 A surgical delay has been suggested to increase flap reliability in high-risk
patients as an alternative to microsurgical augmentation or supercharging,
or even free TRAM flap transfer.
 Delay of a superiorly based TRAM flap can be performed on an outpatient
basis under general anesthesia.
 The procedure should be done at least 2 weeks before the reconstruction,
whether the reconstruction is immediate or delayed.

28.  THINNING OF THE CUTANEOUS PORTION OF THE FLAP
 Based on the need at the recipient site, thinning of the DIEP flap may be
required in order to optimize the final contour.
 For this purpose, the thinning technique should be based on knowledge of
perforator vascular territories in order to avoid vascular compromise.

29.  SENSORY REINNERVATION OF THE FLAP
 the fourth intercostal nerve responsible for erogenous sensation can be
anastomosed to sensory nerve branches of the flap.

30.  FUNCTIONAL MUSCLE TRANSFER
 Due to its segmental motor innervation, dependent on multiple nerves,
and its short excursion, the use of the rectus flap as a functional muscle
does not have clear indications in clinical practice

31.  MUSCLE-SPARING FLAP
 This can be defined as a flap with maximal preservation of both lateral and
medial portions of the remaining rectus muscle.
 One might surmise that split muscle harvest results in less bulk of muscle
folding on itself and may contribute to less potential venous outflow
obstruction
 Non-innervated and poorly vascularized muscle segments lack the ability
to contract, and finally atrophy. Conversely, innervated muscle segments
will contract on stimulation and maintain muscle width and volume

32.  SPLITTING OF THE FLAP BETWEEN THE LATERAL AND MEDIAL ROW
PERFORATORS
 Some authors have described splitting the muscle between the medial and
lateral row vessels for reconstruction of two separate defects or for
creation of a valve-like mechanism (vagina reconstruction or bladder neck
reconstruction).

33.  THE RECTUS FLAP WITH VASCULARIZED RIB
 The RAM flap can be combined with vascularized 7th, 8th, 9th, and/or 10th
costal cartilages.
 These cartilages are nourished by costomarginal and musculophrenic
arteries, branches of the deep superior epigastric artery
 Care must be taken to avoid pleural injury.
 This technique is used mostly in three-dimensional reconstructions of the
face

34.  SUPERCHARGED FLAP (SUPERIORLY OR INFERIORLY BASED, ARTERIES OR
VEINS)
 In“turbocharged,” “recharged,” and “parasite” flaps, both deep inferior
epigastric vessels are anastomosed together to form a loop.

35. DONOR SITE CLOSURE AND
MANAGEMENT
 The donor site closure is performed as a standard technique.
 The closure is usually accomplished with interrupted figure-of-8
nonabsorbable sutures reinforced with a running suture.
 An onlay mesh is utilized when a complete secure closure cannot be
accomplished.
 Usually, mesh reinforcement is indicated for a bipedicled TRAM flap

36. FLAP USAGE
 PEDICLED – INDICATIONS
 SUPERIORLY BASED:
 Coverage: anterior and lateral thorax, abdomen, and posterior trunk
 Reconstruction: breast
 Components: muscle, musculocutaneous or cutaneous
 INFERIORLY BASED:
 Coverage: perineum, vagina, groin, and lower extremity
 Reconstruction: perineum, groin, and lower extremity
 Components: muscle, musculocutaneous or cutaneous

37.  FREE FLAP – INDICATIONS
 Coverage: head and neck, upper and lower extremities
 Components: muscle, musculocutaneous or cutaneous
 Functional muscle: head and neck and extremities

41. POST OPERATIVE OUTCOMES
 GENERAL:
 When the lower abdominal skin is included with the flap, as with breast
reconstructions, positioning the patient in a semi-Fowler position reduces
skin tension on the donor area.
 Excessive efforts, chiefly those that increase abdominal pressure such as
lifting or carrying weight, should be avoided for at least 1 month.
 Drains are kept in place for about 3 days and hospitalization is for about 5
postoperative days.

42.  RECEPIENT SITE:
 In breast reconstructions the use of a surgical brassiere is recommended
for about 1 month to avoid excessive tension on the vascular pedicle and
to provide a suitable shape to the flap.
 In lower extremity reconstructions, the patient must keep the
reconstructed limb elevated for 1 or 2 weeks and, after this period, is
encouraged to maintain the elevation when resting.
 The use of a compressive stocking helps the diminishment of edema and
bulkiness of the flap.

43.  DONOR SITE:
 In breast or facial reconstructions, the patient is encouraged to ambulate
on the first postoperative day.
 Abdominal binders are recommended for 1 month.
 In lower extremity reconstructions, the patient can ambulate for short
distances after 7 day

44. UNFAVOURABLE OUTCOMES
 GENERAL
 The RAM flap is very safe as long as one respects its vascular anatomy.
 Small necrosis of the flap are usually related to insufficient venous
drainage and are located at the margins of the flap.
 Total flap losses are related to technical problems with the vascular
anastomosis rather than problems with the dissection of the flap.
 The presence of small hard nodules in the subcutaneous tissue of the flap
is related to fat necrosis.
 They are more common in breast reconstructions with superiorly based
pedicled flaps.

45.  DONOR SITE
 Small areas of necrosis of the abdominal flap and poor umbilical scarring
rarely occur, and are probably related to extensive undermining or
aggressive dissection.
 They are usually treated with minor local debridement and dressings.
 Seromas in the undermined areas are rare due to the use of suction drains.
However, if they should occur, they can be treated by needle aspiration or
surgical drainage.

46. LONG-TERM OUTCOMES
 GENERAL
 The RAM flap is sometimes heavy. In the long term there may be a variable
degree of ptosis that may require repositioning of the flap.
 When the RAM flap is used in contour restoration, one must bear in mind
that the muscle segment of the flap will atrophy by about 20–30% due to
denervation.

47.  BREAST RECONSTRUCTION
 Surgeries for remolding or repositioning of the flap with or without reduction
or pexy of the opposite breast are eventually necessary.
 The flap tends to grow proportionally to the patient’s weight gain but there is
generally less tendency to ptosis than in the normal breast.
 Postoperative radiotherapy can reduce the size of the reconstructed breast;
therefore, it is recommended that treatment be concluded before procedures
to achieve symmetry are scheduled.
 Approximately half the patients undergoing breast reconstruction utilizing the
myocutaneous flap achieve some spontaneous return of sensibility.
 This return increases if the perforating form of the flap is dissected, even more
if sensory reinnervation by microsurgical nerve anastomosis is performed.

48.  DONOR SITE
 Hernias or bulges are not uncommon.
 A careful closure of the aponeurotic layers can diminish these problems.
 Reinforcement with a nonabsorbable mesh must be used whenever there
is tension on the sutures.
 The RAM and its aponeurotic margin possess three main functions: tensing
the abdominal wall, maintaining its contents, and providing the first 30° of
flexion when passing from the supine to the sitting position.

49. THANK YOU.