Operative Technique in Plastic Surgery – Kevin C.Chung

thoracodorsal (TD) system is planned, an ipsilateral SIEA flap is used (FIG
3).
FIG 3 • A. If anastomosis to the internal mammary
vessels is planned, a contralateral SIEA flap is used. B.
If anastomosis to the thoracodorsal system is planned,
an ipsilateral SIEA flap is used.

FIG 4 • Our decision-making algorithm for free
abdominal flap breast reconstruction.
■ We base our selection of SIEA flap reconstruction based on a simple
intraoperative algorithm (FIG 4).
• Assess the SIEV
• If the SIEV is present and ≥1.5 cm, then the SIEA is assessed.
• Assess the SIEA
• If the SIEA pulsation is palpable and a hemiabdomen is sufficient for
reconstruction, then a SIEA flap is used.
• If the SIEA is not present or palpable, then a DIEP or MS-TRAM is
performed.
■ Many authors have used the caliber of the SIEA to as a criterion of suitability
for the SIEA flap. In our experience, if the SIEA is palpable at the incision
and the SIEV is ≥1.5 cm, the SIEA flap can be used even if the SIEA artery is
less than 1 mm. In our consecutive series of 500 abdominal-based flaps, we
have found the SIEA to be of use in 123 cases (29%).14
■ We do not advocate the routine use of preoperative imaging for SIEA flap
reconstruction.
■ Marking
■ Patient marking is similar to that of the DIEP and free TRAM, with the
lateral borders of the abdominal ellipse ending at the right and left ASIS (FIG

5).
■ The superior transverse incision of the abdominal ellipse is designed to
include the periumbilical perforators.
■ The major difference is the location of the inferior incision of the transverse
ellipse. To encounter the SIEA at a larger caliber and optimize it as an option,
it is recommended to lower the inferior incision, and we frequently mark this
5 cm above the mons pubis.
Positioning
■ Positioning is similar to the free DIEP and TRAM.
■ The patient is placed supine with hips positioned at the flex point of the
operating table to enable a “jack-knife” position which aids in the closure of
the abdominal incision.
■ Calf compression pumps are placed for mechanical DVT prophylaxis.
Approach
■ Intravenous antibiotics are given 30 minutes before skin incision.
■ Whenever possible, the procedure is done by two teams, with one team
harvesting the flap and the other preparing the recipient pocket and vessels.
■ The IM vessels are the first choice for SIEA flap reconstruction. Use of the TD
system leads to difficult microsurgical anastomosis and in cases where the
SIEA pedicle is of insufficient length may necessitate vein grafts which
increase the complexity of the procedure.
FIG 5 • Superficial inferior epigastric artery flap marking.

T E C H N I Q U E S
■ SIEA Flap
Incision and Exposure
■ The lower incision is sharply incised, and careful dissection proceeds as the
SIEA and SIEV are in the superficial fat layer of the flap. The SIEV in
particular can be very superficial and lie just beneath the dermis (TECH FIG
1).
■ The SIEV is located at approximately a point one-third between the pubic
tubercle and the ASIS.
■ The SIEA lies in an area up to 3 cm lateral to the SIEV and can be found
deeper in the superficial fat compartment.
■ The SIEV and SIEA are exposed and suitability determined as previously
described. If suitable, the procedure proceeds with pedicle dissection.
Dissection
■ Anterior dissection of the pedicle proceeds initially without circumferential
isolation. This protects the artery from traction injury and prevents spasm.
■ Gentle cephalad retraction of the flap coupled with vertical retraction of the
lower groin skin will give clear access to anterior dissection of the pedicle
(TECH FIG 2A).
■ The route of the SIEV is straightforward and it can be easily dissected
caudally toward the femoral vein.
■ When the SCIV is identified at the lower lateral edge of the flap and can be
traced to a common origin with the SIEV at the femoral vein, the common
branch is taken. This helps to improve venous drainage of the flap (see FIG
2).
■ If more than one superficial vein is found draining the flap and entering
into separate source veins, these should be dissected out and clamped prior
to pedicle ligation to determine dominancy.

TECH FIG 1 • Exposure of the SIEV and SIEA.
■ The path of the SIEA from the flap to its origin at the femoral artery is more
complex.6
■ The SIEA initially travels caudally from the flap.
■ Prior to entering the femoral sheath, the SIEA sharply turns
superomedially.
■ To increase the length and caliber of the artery, the cribriform fascia should
be fully opened and the vessel traced all the way to its origin at the
common femoral artery. This increases SIEA length by 1 to 2 cm and yields
a larger diameter vessel (TECH FIG 2B–D, Video 1).
■ Any branches close to the origin from the femoral artery are clipped long
for potential use as a point at which to spatulate the artery to address size
mismatch.
■ Caution should be taken in cases where the SCIA merges with the SIEA to
form a common pedicle at the take-off from the femoral artery. In these
cases, both the SCIA and SIEA can be taken together with the flap.

TECH FIG 2 • A. Dissection of the right SIEV and
SIEA with cephalad retraction of the flap and vertical
retraction of the lower groin skin. B. Dissection of the
right superficial inferior epigastric artery (SIEA) to the
cribriform fascia. C. Opening of the cribriform fascia to
maximize exposure of the origin of the SIEA. D. Close
up of the cribriform fascia outlined in blue ink. E.
Completion of harvest a right sided SIEA flap. F.
Harvest of the superficial groin lymph nodes lateral to
the SIEV (yellow microvascular clamp) together with a
left-sided SIEA (green microvascular clamp) flap.
■ Once the anterior dissection is complete along the full length of the vessel,
posterior dissection of the pedicle can proceed. This is done carefully to
avoid traction on the vessels (TECH FIG 2E).
■ Concomitant vascularized lymph node transfer (VLNT).

■ The superficial groin lymph nodes lie lateral to the SIEV and can be
harvested together with the pedicle (TECH FIG 2F). To avoid harvesting
the deeper lymph nodes, which can lead to lower limb lymphedema, we
recommend the use of reverse lymphatic mapping with radioisotope to
identify the sentinel lymph node.15
Completion of Flap Harvest
■ Once pedicle dissection is completed, harvest of the abdominal tissue
proceeds.
■ The superior incision is completed sparing the umbilicus, and the flap is
dissected off the abdominal muscular fascia in the avascular plane.
■ Any intercostal perforators encountered along the way are carefully
ligated.
■ When dissection reaches the borders of the rectus muscle at the semilunaris,
care must be taken to identify the DIEP perforators.
■ If there is any question of SIEA perfusion of the flap, microvascular clamps
can be applied to the DIEP perforators to assess the perfusion based upon the
superficial system.
■ Once it is determined that the flap can survive on the SIEA alone, the DIEP
perforators are securely ligated.
■ Because the SIEA has a short pedicle, we recommend de-epithelializing the
majority of the flap in situ on the abdomen to avoid injuring the
microanastomosis once the flap has been delivered to the mastectomy defect.
This is especially important for larger flaps with the small aperture of a skin-
sparing mastectomy.
Recipient Vessels and Microanastomosis
■ Our order of choice of recipient vessels are:
■ Pulsatile IM artery (IMA) perforator with adequate IM vein (IMV)
perforator
■ IMA and IMV—the rib can usually be spared with an intercostal space of 3
cm. We typically target the 2nd or 3rd intercostal space.
■ If lymph nodes are required in the axilla, or on the rare occasion where the
internal mammary vessels are not available, the thoracodorsal system is
used.
■ If the flap pedicle is too short, vein grafts have to be used to prevent tension
on the anastomosis.

■ When there is significant vessel size mismatch between the IMA and the
SIEA, manipulation via back cuts or spatulation can be performed. The back-
cut on the antimesenteric side of the vessel allows for a technically easier
anastomosis. Alternatively, if there are any distal branches, the pedicle could
be spatulated at a branch point to increase vessel diameter.14 Finally, end-to-
side anastomosis between the SIEA and the IMA has been described.
■ The SIEV is usually of sufficient size and there is rarely any mismatch with
the IMV. Use of a venous coupler usually facilitates any venous anastomosis
size mismatch and short pedicle. We hand sew the vein if the SIEV is greater
than 4 mm in diameter as use of a coupler can cause redundancy of the thick
SIEV within the lumen and cause occlusion.
■ Overall, the SIEA is particularly prone to spasm and careful dissection, as
well as minimizing the amount of anastomotic revisions, is paramount to
successful execution of this flap.
Flap Inset
■ The main issue when insetting the SIEA flap is the short pedicle length. Care
must be taken not to cause traction on the vessels, especially in the setting of
an immediate reconstruction with a skin-sparing mastectomy and small
aperture.
■ As mentioned previously, we perform the majority of flap de-
epithelialization with the flap in situ in the abdomen before ligation of the
pedicle and transfer. Any de-epithelialization performed with the flap in the
chest must be undertaken with the utmost care. Remember the superficial
nature of the SIEV when de-epithelizing, insetting, and securing the flap.
■ Insetting the flap in the superomedial direction first takes the tension off the
pedicle. The remainder of the mastectomy skin can then be carefully draped
around the flap.
■ The mastectomy skin envelope to flap relationship must be evaluated. If the
flap is relatively small within a large skin envelope:
■ Reduce the skin envelope
■ Consider a contralateral breast reduction
■ Place anchoring sutures from the flap to the chest wall
■ Use external support such as a surgical brassiere that is fitted carefully to
prevent compression while giving inferior and lateral support.
■ A closed suction drain is placed exiting at the lateral IMF and draining the
superior portion of the flap, ending just away from the microanastomoses

site.
Donor Site Closure
■ Donor-site closure is similar to that of the free DIEP and TRAM, except that
the abdominal muscular fascia remains untouched and no closure of this is
required.
■ The upper abdominal flap is undermined to the border of the ribs laterally
and the xiphoid process superiorly, being careful to ligate any significant
perforators along the way.
■ Once the microanastomosis is complete and de-epithelialization is complete
and the flap has been secured in position in the breast defect, the operating
table can be adjusted into a “jack-knife” position with the patient’s hips
flexed to allow tension-free abdominal closure.
■ Skin staples are used to temporarily approximate the skin edges, usually
requiring some adjustment from lateral to medial.
■ Key to donor-site closure is approximating the Scarpa fascia from the upper
and lower abdominal flaps with absorbable 2-0 polyfilament sutures. Once
this is done, skin closure can be done with technique of choice. Abdominal
closed suction drains should be used.
PEARLS AND PITFALLS
Preoperative
preparation
■ Caution in patients who are heavy, active smokers for
increased risk of vasospasm
Exposure
■ Lower the abdominal incision to encounter the SIEA at a
larger caliber.
Pedicle dissection
■ Perform anterior rather than circumferential dissection of the
artery first to minimize vasospasm.
■ Dissect the artery completely to the femoral artery.
■ Avoiding unnecessary periarterial lymph node harvest
increases pedicle length.
Raising the flap
■ De-epithelialize the flap in situ on the abdomen.
Microanastomosis
■ Maximize recipient vessel length.
■ Back-cut or spatulate the SIEA for cases where there is

vessel mismatch.
■ Intraoperative papavarine is useful to address any arterial
spasm.
Inset
■ Careful support of the flap to prevent ptosis
Postoperative
care
■ Keep the patient warm and reduce pain and anxiety to
prevent vasospasm.
POSTOPERATIVE CARE
■ General care for the SIEA flap is similar to the postoperative care for other
free tissue reconstruction of the breast. At our institution:
■ A near infrared (NIRS) tissue spectroscopy monitor is placed on the flap and
the patient is sent to the postoperative care unit for a period of monitoring.
■ Once the patient is stable, she is sent to the floor. The flap is monitored
clinically for color, temperature, capillary refill, turgor, and handheld Doppler
signal as well as continuous tissue oximetry.
■ Incentive spirometry as well as chemical and mechanical DVT prophylaxis is
started.
■ Patients are kept NPO for the approximately the first 24 hours. If the patient
and flap are doing well by the first postoperative day (POD) morning, the diet
is advanced after evaluation on morning rounds. The urinary catheter is
removed and the patient is advised to sit out of bed in a chair and encouraged
to ambulate later in the day. Intravenous antibiotics are converted to oral
antibiotics after the first 24 hours.
■ POD 2 and 3 are spent with continuation of ambulation and converting all
pain control to oral medications. Patients are usually discharged on POD 3.
■ Specific considerations regarding the postoperative care of the SIEA flap
center around arterial spasm, which can happen up to more than 48 hours
postoperatively.
■ This can manifest in a variety of ways:
• A clinically cool, pale flap
• Absent Doppler signal
• Steady drop in NIRS tissue spectroscopy of 15 to 20 points and leveling off
■ Arterial spasm can result from any combination of factors including:
• Ptosis of the flap placing stretch on the vascular anastomosis
• Patient pain and anxiety

• Dehydration
• Reduced patient core temperature
■ Maneuvers to alleviate arterial spasm include the following:
• A surgical brassiere can be placed to give support.
• Adequate treatment of pain, warming, and antianxiolytics can be
administered as necessary.
■ If the spasm does not resolve after these measures, operative exploration is
warranted.
FIG 6 • Preoperative (above) and postoperative (below)
photos of a right breast reconstructed with a left
abdominal SIEA flap.
OUTCOMES
■ The SIEA flap has similar aesthetic outcomes to the other abdominal-based
flaps (FIG 6).
■ There is a steep learning curve associated with the flap and high conversion
rate to another free flap.16
■ There are no risks of hernia or bulge because the rectus fascia and motor

nerves to the rectus muscles are not disturbed.
■ In our series of 145 free abdominal flaps based on the superficial system,
overall success rates were 95%.14
COMPLICATIONS
■ Vascular thrombosis and flap loss
■ An analysis of 99 SIEA flaps performed in 82 patients showed an overall
arterial thrombosis rate of 6.1%, venous congestion rate of 2%, partial flap
loss of 5.1%, and total flap loss of 5.1%.17
■ In an analysis of 69 SIEA flaps, the rate of venous or arterial thrombosis was
17.4%, with 2.9% total flap loss, significantly greater numbers than in a
comparative DIEP flap group.18
■ Another study of outcomes of 44 SIEA flaps against 125 DIEP flaps showed
significantly higher re-exploration rates in the SIEA group (20%) vs the DIEP
group (7%). A subset analysis showed arterial problems to be significantly
higher among SIEA flaps (14%) vs DIEP flaps (1%). None of the arterial
thrombosis were salvageable.19
■ In our series, there were nine cases of re-exploration for vascular problems
(6.2%), three with purely venous thrombosis and six with arterial
thromboses. Two of the flaps with venous thromboses were salvaged,
whereas none of the flaps with arterial thromboses were salvaged. Eighty
percent of the flaps with arterial thromboses lost had arterial revisions at the
initial operation. SIEA spatulation did not correlate with increased
thromboses rate.14
■ Fat necrosis
■ In a large series of 99 free SIEA flaps, fat necrosis rates were found to be 1%.
These authors routinely used tissue across the midline, discarding zone IV of
the flap and any tissue assessed to have poor perfusion intraoperatively.17
■ In a case series of 228 patients, it was found that the fat necrosis rates for free
SIEA, DIEP, and MS-TRAM flaps were 14%, 25%, and 5%, respectively.20
■ A further systemic review of fat necrosis rates in abdominal free flaps
reinforced this and showed the SIEA to have a mean fat necrosis rate of 8.1%
(range 5.7% to 13.5%). This was lower than the free DIEP flap and slightly
higher than the free MS-TRAM. Risk factors for necrosis included obesity,
pre-existing abdominal scars, pre- and postoperative irradiation, and
smoking.21
■ In a more recent study of a single center’s experience of SIEA flaps vs DIEP

flaps, the flap necrosis requiring debridement in the SIEA group was 14%
(6/44 patients) vs 3% (4/125 patients) in the DIEP group.19
■ An analysis of our series of 145 free flaps based on the superficial system,
the fat necrosis rate was 10.3%.14
REFERENCES
1. Chevray PM. Breast reconstruction with superficial inferior epigastric artery
flaps: a prospective comparison with TRAM and DIEP Flaps. Plast Reconstr
Surg. 2004;114(5):1077-1083.
2. Ulusal BG, Cheng MH, Wei FC, et al. Breast reconstruction using the entire
transverse abdominal adipocutaneous flap based on unilateral superficial or
deep inferior epigastric vessels. Plast Reconstr Surg. 2006;117(5):1395-1403.
3. Kim BJ, Choi JH, Kim TH, et al. The superficial inferior epigastric artery flap
and its relevant vascular anatomy in Korean women. Arch Plast Surg.
2014;41(6):702-708.
4. Rizzuto RP, Allen RJ. Reconstruction of a partial mastectomy defect with the
superficial inferior epigastric artery (SIEA) flap. J Reconstr Microsurg.
2004;20(6):441-445.
5. Arnez ZM, Smith RW, Eder E, et al. Breast reconstruction by the free lower
transverse rectus abdominis musculocutaneous flap. Br J Plast Surg.
1988;41(5):500-505.
6. Dorafshar A, Januszyk M, Song D. Anatomical and technical tips for use of
the superficial inferior epigastric artery (SIEA) flap in breast reconstructive
surgery. J Reconstr Microsurg. 2010;26(06):381-389.
7. Holmström H. The free abdominoplasty flap and its use in breast
reconstruction: an experimental study and clinical case report. Scand J Plast
Reconstr Surg. 1979;13(3):423-427.
8. Hartrampf CR, Scheflan M, Black PW. Breast reconstruction with a transverse
abdominal island flap. Plast Reconstr Surg. 1982;69(2):216-224.
9. Friedman RJ, Argenta LC, Anderson R. Deep inferior epigastric free flap for
breast reconstruction after radical mastectomy. Plast Reconstr Surg.
1985;76(3):455-458.
10. Antia NH, Buch VI. Transfer of an abdominal dermo-fat graft by direct
anastomosis of blood vessels. Br J Plast Surg. 1971;24:15-19.
11. Grotting JC. The free abdominoplasty flap for immediate breast
reconstruction. Ann Plast Surg. 1991;27(4):351-354.
12. Taylor GI, Daniel RK. The anatomy of several free flap donor sites. Plast

Reconstr Surg. 1975;56(3):243-253.
13. Chang DW. Breast reconstruction with microvascular MS-TRAM and DIEP
flaps. Arch Plast Surg. 2012;39(1):3-10.
14. Park JE, Shenaq DS, Silva AK, et al. Breast reconstruction with SIEA flaps.
Plast Reconstr Surg. 2016;137(6):1682-1689.
15. Dayan JH, Dayan E, Smith ML. Reverse lymphatic mapping. Plast Reconstr
Surg. 2015;135(1):277-285.
16. Thoma A, Jansen L, Sprague S, Stat EDP. A comparison of the superficial
inferior epigastric artery flap and deep inferior epigastric perforator flap in
postmastectomy reconstruction: a cost-effectiveness analysis. Can J Plast
Surg. 2008;16(2):77-84.
17. Spiegel AJ, Khan FN. An intraoperative algorithm for use of the SIEA flap
for breast reconstruction. Plast Reconstr Surg. 2007;120(6):1450-1459.
18. Selber JC, Samra F, Bristol M, et al. A head-to-head comparison between the
muscle-sparing free TRAM and the SIEA flaps: is the rate of flap loss worth
the gain in abdominal wall function? Plast Reconstr Surg. 2008;122(2):348-
355.
19. Coroneos CJ, Heller AM, Voineskos SH, Avram R. SIEA versus DIEP arterial
complications: a cohort study. Plast Reconstr Surg. 2015;135(5):802e-807e.
20. Baumann DP, Lin HY, Chevray PM. Perforator number predicts fat necrosis
in a prospective analysis of breast reconstruction with free TRAM, DIEP, and
SIEA flaps. Plast Reconstr Surg. 2010;125(5):1335-1341.
21. Khansa I, Momoh AO, Patel PP, et al. Fat necrosis in autologous abdomen-
based breast reconstruction: a systematic review. Plast Reconstr Surg.
2013;131(3):443-452.

24
CHAPTER
Recipient Vessel Exposure
—Internal Mammary and
Thoracodorsal
Theodore A. Kung and Adeyiza O. Momoh
DEFINITION
■ Recipient vessels for microsurgical breast reconstruction are required to re-
establish perfusion in transferred free flaps.
■ Perfusion through these vessels is most critical early on after free tissue
transfers, when flaps are entirely dependent on the recipient vessels for inflow
and outflow. Over time, collateral perfusion is typically established from the
surrounding soft tissue bed.
■ The primary recipient vessels for breast reconstruction are the internal
mammary and thoracodorsal vessels.
ANATOMY
Internal Mammary Vessels
■ The internal mammary artery (IMA) is a paired artery on both sides of the
sternum that arises from the subclavian artery. It transitions into the superior
epigastric vessels at about the sixth intercostal space.
■ The internal mammary vein (IMV) is also paired, runs parallel to the IMA,
arising from the superior epigastric vein and ending in the brachiocephalic
vein.
■ The vessels are 1 to 2 cm lateral to the sternum and run deep to the intercostal
muscles and ribs.
■ Both vessels give off intercostal branches laterally that run inferior to the first
six ribs. Perforators to the overlying breast and skin are also given off by the
IMA and IMV in the first 5 to 6 intercostal spaces.

■ The right and left IMAs are of similar diameter (1.9–2.1 mm) at 3rd and 4th
intercostal spaces where they are typically used.1,2 At the level of the 3rd
intercostal space, the IMA lies lateral to the IMV or between two IMVs.
■ The left IMV bifurcates at a higher level than does the right IMV (3rd rib on
the left vs 4th rib on the right). At the level of the 3rd ICS, the left IMV is on
average smaller than the right (2.5 mm vs 3 mm).3
Thoracodorsal Vessels
■ The thoracodorsal artery (TDA) and the circumflex scapular artery are the two
main branches of the subscapular artery, which arises from the third division of
the axillary artery (FIG 1).
■ The TDA travels along the lateral thoracic wall before diving into the
latissimus dorsi muscle about 9 from its origin. Prior to its entry into the
muscle, the TDA consistently (99%) gives off a branch to the serratus anterior
muscle.4
■ The TD vessels are commonly divided for microvascular anastomosis just
proximal to the serratus branch where the diameter of the artery is
approximately 3 mm.5 Preservation of the serratus branch also allows for the
use of a pedicled latissimus dorsi flap and an implant for breast reconstruction
in case free tissue transfer is unsuccessful.

FIG 1 • Illustration of the thoracodorsal vessels arising
from the subscapular system.
■ Proximally, there are often two veins that unify into a single TD vein. The TD
vein travels with the TD artery and has an average diameter of 3.4 mm at its
origin and 1.6 mm where it enters the latissimus dorsi muscle.6
■ The TD nerve enters the axilla deep to the axillary vein at a point several
centimeters medial to the origin of the subscapular vessels. The nerve then
continues toward the subscapular system and eventually travels parallel with
the TD vessels along the lateral thoracic wall (FIG 2).

FIG 2 • Exposure of the thoracodorsal artery, vein, and
nerve prior to their entry into the latissimus dorsi
muscle. The nerve should be dissected free to prevent
any kinking of the vessels after anastomosis.
FIG 3 • A. A CT angiogram of the chest with sagittal
slices showing continuity of the IM. B. TD arteries. C.
Additional 3D reconstruction provides an overall view of
the thoracic vessel anatomy.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ A thorough history of prior thoracic and breast procedures including axillary
lymph node dissections and prior chest wall radiation are important to
determine possible compromise to the IM or TD vessels.
■ The continuity of IM vessels is seldom affected by oncologic breast
procedures; however, a history of radical chest wall tumor resections or
coronary bypass procedures may prevent use of the IM vessels as recipients.
■ Thoracodorsal vessels are at greater risk of injury during axillary lymph node

dissections and should be approached with caution in the setting of delayed
reconstruction in such patients.
■ A history of radiation should prompt an anticipation of friable recipient
vessels. IM vessel friability introduces technical challenges with exposure and
anastomosis but can be consistently overcome with careful vessel handling.
IMAGING
■ There is limited value to routine preoperative imaging of IM or TD vessels in
the absence of a history that suggests potential compromise.
■ If a patient has had a preoperative breast MRI, that status of the mammary
vessels may be evident.
■ When needed, CT angiography provides detailed information on the vascular
anatomy for surgical planning (FIG 3).
SURGICAL MANAGEMENT
■ The decision on which recipient vessel is to be used is made preoperatively.
The internal mammary vessels are the authors’ preferred option for immediate
and delayed microsurgical breast reconstruction with the TD vessels serving as
a backup option.
■ If immediate reconstruction following mastectomy and axillary lymph node
dissection is performed, the TD vessels are often already partially exposed and
may be considered for anastomosis. However, the vessels must be carefully
inspected for any injury or spasm resulting from the extirpation surgery.
Additionally, the flap pedicle must be of sufficient length to reach the TD
vessels for anastomosis.
■ In contrast, with delayed breast reconstruction and especially following
radiation therapy, significant scarring can be expected within the axilla.
Dissection of the thoracodorsal vessels in this setting is usually more time-
consuming and has a higher risk of vessel injury.
Preoperative Planning
■ The risks and benefits of costal cartilage resection with IM vessel exposure
should be discussed in addition to the rare potential for a pneumothorax during
vessel exposure.
Positioning
■ When the IM vessels are selected for anastomosis, the patient is positioned

supine with arms either tucked at the sides or abducted at 90 degrees.
■ When the TD vessels are used, the ipsilateral arm should be prepped to allow
for adjustments in position during the operation. The arm boards should be
kept under sterile drapes in order to adjust arm abduction during the operation.
It is most ergonomic for the surgeon to be positioned above the arm board on
the side of the anastomosis while the assistant is positioned below the
contralateral arm board (FIG 4).
Approach
■ IM vessels are either exposed with costal cartilage resection or in the
intercostal space through a rib-sparing approach. The former is the authors’
preferred approach.
FIG 4 • Ergonomic surgeon and assistant positioning
with use of the TD vessels as recipients.

■ TD vessels may be accessed through the mastectomy incision. From this
approach, adequate exposure is often difficult and requires retraction of the
lateral border of the pectoralis major muscle or the use of additional
instruments.7 Alternatively, the authors favor a separate incision in the axilla.
In many breast cancer patients, a previous scar from sentinel lymph node
biopsy may already be present. Slight abduction of the arm and the use of self-
retaining retractors facilitate microsurgical anastomosis even in overweight
patients.8
T E C H N I Q U E S
■ Internal Mammary Vessel Exposure
■ In the setting of an immediate reconstruction following a skin-sparing
mastectomy, the breast pocket is first irrigated and hemostasis achieved with
electrocautery as needed.
■ An Army-Navy retractor is temporarily introduced to retract medial
mastectomy skin for visualization of the medial anterior chest wall.
■ The cartilaginous portion of the 3rd rib is palpated through the pectoralis
major muscle. The muscle fibers over this medial aspect of the rib are split
along the fibers with electrocautery and a Weitlaner retractor is introduced
between the muscle fibers (handles lateral) to provide exposure of the
underlying rib. The muscle split is performed from the lateral edge of the
sternum to a point approximately 6 cm lateral to the sternum.
■ The anterior costal perichondrium is scored along its length with the
electrocautery and also perpendicular to the lengthwise incision at the medial
and lateral extents of the exposed cartilage.
■ A Freer elevator is then used to elevate the perichondrium off the underlying
cartilage on its superficial surface, around the superior and inferior borders of
the rib (TECH FIG 1A).
■ The lateral cartilage is then excised with a rongeur down to the posterior
perichondrium, taking care not to violate this posterior plane at this time.
■ A second Weitlaner retractor is introduced perpendicular to the first (handles
cephalad), anchored laterally at the cut edge of the rib, and used to retract the
medial mastectomy skin out of the field. At this point, the Army-Navy

retractor is no longer needed. In patients with large skin flaps, a few skin
hooks might be necessary to adequately retract redundant mastectomy skin.
■ Excision of the remainder of the cartilage proceeds from lateral to medial to
expose the posterior perichondrium. The IMA and vein are sometimes visible
through the posterior perichondrium at this point.
■ An incision parallel to the cut edge of the rib is made laterally through the
posterior perichondrium with a scalpel. A Freer is then introduced underneath
the perichondrium and used to push all soft tissue and vessel downward,
proceeding toward the sternum.
■ The posterior perichondrium is then split with a tenotomy scissor from
lateral to medial exposing the underlying IMA and IMV.
■ The posterior perichondrium is bluntly dissected off the underlying vessels
with a Freer.
■ Small vessel branches from the IMA and IMV are identified, ligated with
microsurgical clips, and cut.
■ The posterior perichondrium is then excised completely with a cautery at
low settings to provide optimal exposure of the recipient vessels.
■ If additional length is desired, the intercostal muscles cephalad and caudal to
the vessels can be excised. To gain size in the exposed vessels, the intercostal
muscles cephalad to the vessels can be excised.
■ The IMA and IMV are dissected circumferentially with a Freer elevator. All
side branches are ligated with microsurgical clips and cut with tenotomy
scissors.
■ A background mat with attached suction (authors’ preference) is then placed
beneath both vessels (TECH FIG 1B).
■ Papaverine is applied, and a warm moist gauze is placed over the vessels
until they are ready to be used.

TECH FIG 1 • A. The 3rd rib exposed deep to the
pectoralis major muscle (fibers retracted with a
Weitlaner retractor). Elevation of perichondrium over
medial segment of the rib with a Freer. B. Exposure of
the internal mammary vessels with a background in
place.
■ Thoracodorsal Vessel Exposure
■ A 6-cm curvilinear incision is made within the axillary fossa just inferior to
the axillary crease. The incision should not extend anteriorly beyond the
anterior axillary fold. If present, a previous scar from sentinel lymph node
biopsy should be incorporated into the incision.
■ Dissection is performed through the subcutaneous fat using the
electrocautery until the axillary fat is reached. The axillary fat pad is more
yellow in color than the subcutaneous fat.
■ Two Weitlaner retractors are positioned within the incision to spread the
axillary fat pad apart.
■ Branches of the intercostobrachial nerve are encountered within the axillary
fat pad and should be preserved if possible.
■ At this point, nontoothed forceps and bipolar cautery should be used.

■ The TD vessels can be found by two approaches:
■ Locating the anterolateral edge of the latissimus dorsi first and then
performing dissection along its deep surface to identify the TD
neurovascular bundle
■ Locating the axillary vein first and then exposing the takeoff of the
subscapular vessels. Dissection is then carried distally to identify the TD
vessels.
■ With the first method, the lateral edge of the latissimus dorsi muscle can be
found by gentle tapping of the electrocautery tip to bring about muscle
contractions. The point at which the neurovascular hilum enters the
undersurface of the muscle is approximately 2 to 3 cm away from its
anterolateral edge. The TD vessels are identified, separated from the TD
nerve, and followed proximally.
■ With the second method, blunt dissection with a finger through the axillary
fat pad is performed in the direction of the axillary vessels. The pulsations of
the axillary artery can easily be appreciated by palpation, and this can guide
the direction of dissection. The axillary vein is anterior to the axillary artery;
when it is encountered, meticulous dissection should proceed along its length
to identify branches traveling inferiorly. Once the subscapular artery and vein
are identified, they are dissected distally to locate the branch point of the
circumflex scapular vessels and their continuation as the TD vessels.
■ Often, the circumflex scapular branch needs to be ligated to achieve
adequate pedicle length and to prevent kinking of the pedicle.
■ The branch to the serratus anterior muscle should be identified and
preserved. The TD vessels are usually divided just proximal to the serratus
anterior branch point.
■ When sufficient pedicle length has been obtained, a McCabe dissector is
used to separate the TD artery, vein, and nerve. Once divided, the TD vessels
should be positioned superficial to the nerve to prevent a “clotheslining
effect” of the nerve on the pedicle.
■ Particularly in larger patients, performing the anastomosis deep within the
axilla can be quite difficult. To ameliorate this problem, a moist gauze is
packed into the axilla and the divided TD vessels may subsequently be
positioned more superficially.

PEARLS AND PITFALLS
Technique
■ IMA and IMV size at the level of the 3rd rib are consistently well
matched with the commonly utilized deep inferior epigastric
vessels; as often as possible, this is the ideal site for recipient
vessel.
■ The 4th rib in some cases is in a central location within
mastectomy defects and might be easier to access than the 3rd rib.
The IMVs on the left are appreciably smaller at the level of the
4th rib; plan to dissect proximal through the intercostal muscles to
improve on IMV size.
■ Plan for additional length of the IM vessels with possible
proximal and distal dissection extending to the ribs above and
below in cases with a traditionally short flap pedicle or in
morbidly obese patients with very large flaps.
■ To avoid injury to the IM vessels, it is critical to begin rib
resection and elevation of the posterior perichondrium lateral to
the vessel location. Dissect from lateral to medial.
■ Keep vessel handling and cleaning of the adventitia to a
minimum in radiated fields to avoid vessel injury.
■ In some patients, exposed to radiation or with a low BMI, there
may be very little adipose tissue between the posterior
perichondrium and the pleura. Careful blunt dissection is needed
to avoid an injury to the pleura.
Pleural injury
■ During exposure of the IM vessels, small tears in the parietal
pleura may occur. These rents may either be left unrepaired or
carefully closed with fine absorbable suture.
■ To evaluate for a pneumothorax, a positive pressure test may be
performed. The rent is completely submerged in normal saline
and the anesthesiologist delivers a breath of positive pressure
ventilation. When the injury is limited to the parietal pleura, a
positive pressure test will not result in air escape.
Pneumothorax
■ A pneumothorax results when the injury extends through the
parietal pleura, through the visceral pleura, and into the lung
parenchyma.
■ A positive pressure test will result in bubbles appearing from the
injury.
■ When this is detected in the operating room, the air within the
pleural space must be evacuated and an airtight closure of the
parietal pleura should be performed. A small red rubber catheter

on suction is placed into the pleural space and a purse-string
suture is thrown around the pleural rent but left untied. As the
anesthesiologist delivers a breath of positive pressure ventilation,
the catheter is removed and the purse string is tied securely. The
positive pressure test is repeated to check for air escape.
Postoperatively, a chest x-ray is performed. Any significant lung
collapse warrants a chest tube.
POSTOPERATIVE CARE
■ Based primarily on postoperative flap care or protocol
OUTCOMES
■ Flap complication and survival rates with use of the internal mammary or
thoracodorsal vessels are similar.9,10
■ Conversions from TD vessels to IM vessels tend to be more common in
radiated patients with previous axillary lymph node dissections.11
■ Occasional contour deformities and temporary discomfort at the site of rib
resection are experienced by patients with IM vessel exposure. When present,
contour deformities are easily addressed with autologous fat grafting, and chest
wall discomfort resolves with time.
COMPLICATIONS
■ Hematomas in the early postoperative period can be experienced with potential
rapid enlargement of the breast mound with an arterial bleed. Large hematomas
place pressure on the vascular pedicle and increase the risk of vascular
compromise. Clinically significant hematomas are taken back to the operating
room for evacuation and hemostasis.
■ The axillary artery and vein are in close approximation to the brachial plexus.
Careful dissection using bipolar cautery will prevent iatrogenic nerve injury.
■ Arms should be well padded to avoid pressure-related complications.
■ Neuropraxia due to prolonged arm abduction may be treated expectantly, but
prevention is the best strategy.
REFERENCES
1. Rozen WM, Ye X, Guio-Aguilar PL, et al. Autologous microsurgical breast
reconstruction and coronary artery bypass grafting: an anatomical study and
clinical implications. Breast Cancer Res Treat. 2012;134(1):181-198.
2. Tan O, Yuce I, Aydin OE, Kantarci M. A radioanatomic study of the internal

mammary artery and its perforators using multidetector computed tomography
angiography. Microsurgery. 2014;34(4):277-282.
3. Clark CP III, Rohrich RJ, Copit S, et al. An anatomic study of the internal
mammary veins: clinical implications for free-tissue-transfer breast
reconstruction. Plast Reconstr Surg. 1997;99(2):400-404.
4. Rowsell AR, Davies DM, Eisenberg N, Taylor GI. The anatomy of the
subscapular-thoracodorsal arterial system: study of 100 cadaver dissections. Br
J Plast Surg. 1984;37(4):574-576.
5. Robb GL. Thoracodorsal vessels as a recipient site. Clin Plast Surg.
1998;25(2):207.
6. Bartlett SP, May JW Jr, Yaremchuk MJ. The latissimus dorsi muscle: a fresh
cadaver study of the primary neurovascular pedicle. Plast Reconstr Surg.
1981;67(5):631-636.
7. Mehrara BJ, Santoro T, Smith A, et al. Improving recipient vessel exposure
during microvascular breast reconstruction. Ann Plast Surg. 2003;51(4):361.
8. Gravvanis A, Caulfield RH, Ramakrishnan V, Niranjan N. Recipient vessel
exposure in the axilla during microvascular breast reconstruction. J Reconstr
Microsurg. 2008;24(8):595-598.
9. Moran SL, Nava G, Benham AB, Serletti JM. An outcome analysis comparing
the thoracodorsal and internal mammary vessels as recipient sites for
microvascular breast reconstruction: a prospective study of 100 patients. Plast
Reconstr Surg. 2003;111:1876-1882.
10. Temple CL, Strom EA, Youssef A, Langstein HN. Choice of recipient
vessels in delayed TRAM flap breast reconstruction after radiotherapy. Plast
Reconstr Surg. 2005;115:105-113.
11. Saint-Cyr M, Youssef A, Bae HW, et al. Changing trends in recipient vessel
selection for microvascular autologous breast reconstruction: an analysis of
1483 consecutive cases. Plast Reconstr Surg. 2007;119:1993-2000.

25
CHAPTER
Inferior Gluteal Artery
Perforator Flap Breast
Reconstruction
Katie E. Weichman
DEFINITION
■ Fujino et al. first popularized the gluteal donor site for breast reconstruction in
1975 as a free myocutaneous flap, and Shaw further refined it in 1983.1,2
Additional modification of this myocutaneous flap by Paletta and Le-Quang et
al. to use the inferior gluteal vessels as donor vessels was also described.
However, despite initial success, it was abandoned secondary to technical
difficulty and postoperative morbidity to the sciatic nerve.
■ After the popularization of perforator flaps by Koshima, both the inferior and
superior gluteal artery perforator flaps were described and gained popularity in
reconstructive surgery.
■ The inferior gluteal artery perforator (IGAP) flap was first described as a
pedicled flap for ischial pressure sores by Blondeel in 2002.
■ Allen further expanded the IGAP flap for breast reconstruction in 2004.3 He
further advanced this perforator flap, with a widely accepted in-crease
technique. This technique uses skin and tissue in the buttock area based on the
IGAPs and minimizes the scar in the gluteal crease.4
■ Though abdominally based free flaps remain the most common choice for
breast reconstruction secondary to sufficient skin and soft tissue, patients may
require alternative donor sites for various reasons. These reasons include lack
of abdominal donor sites secondary to prior abdominoplasty, inadequate
volume in the abdomen, and patient preference. Approximately 20% of
patients are not candidate for abdominally based free flaps.2
■ Advantages of IGAP flaps include the ability to harvest as a sensate flap
(posterior cutaneous nerve of the thigh), hidden donor site, lack of risk of

abdominal hernia/bulge, and increased breast projection based on the
consistency of the buttock fat. Additionally, IGAP has a slightly longer pedicle
when compared to SGAP, and the risks of aesthetic donor-site morbidity with
increased beveling of adjacent fat are decreased.
■ Disadvantages include difficult patient positioning in bilateral cases, tedious
dissection with a long oblique intramuscular course, potential injury to sciatic
or posterior femoral cutaneous nerves, and significant arterial and venous
mismatch of the pedicle.
ANATOMY
■ The inferior gluteal artery originates from the internal iliac artery and is the
smaller of its terminal branches. It exits the pelvis through the greater sciatic
foramen and accompanies the greater sciatic nerve, internal pudendal artery
and vein, and the posterior femoral cutaneous nerve.
■ Anatomically, after perforating the sacral fascia, the inferior gluteal vessels
exit below (caudal) to the piriformis muscle and above (cranial) to the coccyx
(FIG 1).
■ Once it exists below the piriformis, it divides into several perforators, usually
more than the SGAP flap, and then travels in an intramuscular fashion to
supply the inferior portion of the buttock.
■ The length of the perforator depends on the area of the buttock supplied.
Inferomedial perforators tend to be shorter with less intramuscular course (3–
5 cm), whereas superolateral perforators tend to have a longer intramuscular
course (4–6 cm). Therefore, lateral perforators are preferentially chosen for
longer pedicle length.
■ In 91% of patients, the inferior gluteal vessels travel with the posterior
femoral cutaneous nerve (S1-S2) to the posterior thigh.5 Therefore, if
desired, a neurosensory flap is possible if nerves are preserved.
■ The inferior gluteal vein is associated with the inferior gluteal artery; however,
it receives multiple tributaries in the subsacral fascia fibroconnective tissue.
These vessels are prone to bleeding at the level of the pelvis and are quite large
and friable. These vessels are routinely larger than superior gluteal veins.
■ The perforating vessels, which are all musculocutaneous, are located inferior
to the exit point below the piriformis muscle.
■ Several studies have looked at these perforating vessels and found IGAP flaps
have a mean number of 7 perforators (range 4–10), with an average
intramuscular length of 8.7 cm (range 6–14 cm) and a mean total pedicle

length of 13.4 cm (range 10–17 cm). Additionally, the mean main vessel
diameter was found to be 5 mm (range 4–7 mm) for the inferior gluteal artery
and 7.7 mm (range 6–10 mm) for the inferior gluteal vein.6
■ Understanding the course of the sciatic nerve and the posterior femoral
cutaneous nerve is paramount to this flap dissection. These nerves often run
together with the inferior gluteal artery as it emerges from the sciatic foramen
below the piriformis muscle. The posterior cutaneous nerve is generally more
medial in relation to both the inferior gluteal artery and sciatic nerve. Both
nerves run posterior to the gluteus maximus muscle.
FIG 1 • Location of the inferior gluteal artery in relation
to the piriformis muscle, posterior femoral cutaneous
nerve, and sciatic nerve as it penetrates the sacral
fascia, the space behind the gluteus maximus muscle.

■ Sciatic nerve
• The nerve is generally visualized during the submuscular dissection below
the sacral fascia, as it exits the sciatic foramen below the piriformis muscle
and travels posterior to the gluteus maximus muscle and anterior to the
inferior gemellus muscle.
• Provides motor and sensory control to almost the entire posterior leg and
foot
• Derived from spinal nerves L4-S3 and is the largest, widest, single nerve in
the body
■ Posterior femoral cutaneous nerve (S1-S2)
• Can be observed at two points during the dissection
• First, along the inferior incision of the skin paddle, in the gluteal crease, in
the subfascial plane, where the investing muscular fascia of the gluteus
maximus muscle and fascia lata coalesce
• Second, during submusclar/subfascial dissection proximally with the
inferior gluteal artery pedicle and sciatic nerve
❍ Provides sensation to the posterior thigh, leg, and perineum
❍ Derived from the sacral plexus and has three main branches:
■ Inferior cluneal nerves (most likely encountered on inferior skin
paddle incision)
• Three of four in number
• Turn upward around the lower border of the gluteus maximus
• Provide sensibility to the skin covering the lower lateral portion of the
gluteus maximus
■ Perineal branches
• Supply the skin covering the perineum
■ Main continuation in the posterior thigh
• Travels posterior to fascia lata anterior to long head of biceps femoris
• In mid leg, pierces fascia and travels with the lesser saphenous vein in
the subcutaneous plane
• Provides sensation to posterior and medial thigh, popliteal fossa, and
superior leg
■ There are several muscles that are highlighted for IGAP dissection in the
posterior gluteal area.
■ Gluteus maximus
• Origin: Gluteal surface of the ilium, lumbar fascia, sacrum, and

sacrotuberous ligament
• Insertion: Gluteal tuberosity of the femur and iliotibial tract
• Action: External rotation and extension of the hip joint
• Arterial supply: Superior and inferior gluteal arteries
• Innervation: Inferior gluteal nerve (L5, S1, and S2)
■ Gluteus medius (deep to the gluteus maximus)
• Origin: Gluteal surface of the ilium
• Insertion: Greater trochanter of the femur forming the iliotibial tract
• Action: Abduction of the hip, preventing adduction of the hip, and medial
rotation of the thigh
■ Piriformis (deep to the gluteus maximus)
• Origin: Anterior portion of the sacrum
• Insertion: Greater trochanter of the femur forming the iliotibial tract
• Action: External rotator of the thigh
• Arterial supply: Interior gluteal artery, superior gluteal artery, and lateral
sacral artery
• Innervation: Nerve to the piriformis (L5, S1, and S2)
■ Gluteus minimus (deep to gluteus maximus and gluteus medius)
• Origin: ilium under the gluteus minimus
• Insertion: greater trochanter of the femur forming the iliotibial tract
• Action—works in concert with gluteus medius: abduction of the hip,
preventing adduction of the hip, and medial rotation of the thigh
• Arterial supply: superior gluteal artery
• Innervation: superior gluteal nerve (L4, L5, S1)
PATIENT HISTORY AND PHYSICAL FINDINGS
■ This includes patients with a history of breast cancer, patients undergoing
prophylactic mastectomy, patients with congenital abnormalities, and
transgender patients.
■ Physical examination includes examination of the abdomen, medial thighs,
and buttock to assess availability of excess tissue.
■ Patients who are candidates for IGAP flap are generally nulliparous, with
inadequate abdominal soft tissue, prior abdominoplasty, prior abdominal flap
harvest, or prior abdominal liposuction.
■ Patients should have estimated mastectomy specimen weights of no more than

350 to 400 g and cup size no greater than C cup.
■ Timing of reconstruction should be planned in patients with prior history of
breast irradiation. The authors prefer to wait 6 months after the completion of
radiation therapy prior to completing delayed reconstruction.
■ Smoking status is assessed also.
■ Additionally, tamoxifen should be withheld 3 weeks prior to surgery.
IMAGING
■ Patients considering IGAP flap reconstruction should undergo preoperative
imaging with either computed tomography angiogram (CTA) or magnetic
resonance angiography (MRA) of the pelvis and lower extremity.
■ Imaging is performed in the prone position and coordinating with the
radiologist for appropriate evaluation of images.
■ Perforators should be described as they exit the deep muscular fascia and
described based on location in an x-y axis. The gluteal fold will be set as zero
on the y-axis, and the midline will be set as zero on the x-axis. Important bony
landmarks that should be noted including the coccyx, the summit of the
posterosuperior iliac crest, and the most lateral point of the greater trochanter7
(FIG 2).
■ The description of the perforator should include the size of perforator as it
exits the fascia and length of course to the inferior gluteal artery as it travels
through the gluteus maximus and inferior to the piriformis back to the origin
on the internal iliac artery. This should be described in relation to the coccyx,
posterior superior iliac crest, and the most lateral point of the greater
trochanter.
FIG 2 • Locations of IGAP perforator on axial CT scan

including the gluteus maximus muscle and piriformis
muscle.
SURGICAL MANAGEMENT
■ The authors perform IGAP flaps on patients either undergoing immediate or
delayed breast reconstruction.
■ Additionally, this procedure can be performed on patients who required
multiple flaps secondary to volume and skin deficit and require reconstruction
in a stacked fashion.8 This includes both patients having immediate stacked
reconstruction and patients who have autologous reconstruction that requires
secondary augmentation in a delayed fashion.
■ Unilateral breast reconstruction with bilateral IGAP flaps has been
described.9
■ Flap weights have been seen between 148 and 833 g.4
■ The operation requires loupe magnification for perforator dissection and
microsurgical instruments.
■ Although the microsurgical anastomosis can be performed under loupe
magnification, the authors prefer the use of the operative microscope.
Positioning
■ Patient is positioned in the lateral decubitus position for unilateral flaps and in
the prone position for bilateral flaps.
■ The perforator location should be double checked with the patient in the lateral
decubitus position.
Approach
■ A two-team approach can be used for IGAP flap harvest.
■ After intubation, the patient is placed in lateral decubitus position, and
ipsilateral chest wall, buttock, arm, and leg are prepped into the field.
■ The second microsurgeon prepares the recipient site and vessels.
■ The primary microsurgeon will start with flap harvest.
T E C H N I Q U E S

■ Flap Design and Markings
■ Patients are marked in the standing position.10
■ The flap is designed as a horizontal ellipse with the axis centered over the
gluteal fold.
■ The inferior border of the flap is marked in the gluteal fold (TECH FIG 1A).
■ Based on preoperative images, using a handheld 5- to 8-MHz Doppler, the
main perforators are marked clearly on the skin.
■ Dissection can be performed in a clockwise or counterclockwise fashion to
determine the best perforators.
■ No more than two perforators should be chosen.
■ The superior aspect of the skin island ellipse is marked to capture these
perforators, and the direction that parallels the gluteal crease is determined by
the pinch test.
■ Flap dimensions have been described as large as 8 × 18 cm but can be as
long as 25 cm. The desired width of the flap is based on judgment to avoid
excessive tension on the closure.
■ Additional fat to be captured in the flap harvest should also be noted during
marking (TECH FIG 1B).
TECH FIG 1 • A. Inferior gluteal artery perforator flap
markings in relation to the greater trochanter, red line
represents the inferior border of the piriformis muscle

(midpoint of the line connecting posterosuperior iliac
spine and coccyx to the apex of the greater
trochanter). Inferior incision lies within the gluteal fold
and superior incision incorporates perforators. B.
Inferior gluteal artery perforator flap marked on patient
noting incorporation of surrounding fat to increase bulk
of flap.
■ Flap Harvest
■ Harvest of the flap should be done under loupe magnification.
■ Incision of the skin ellipse is made inferiorly and medially first.
■ Posterior cutaneous nerve of the thigh is identified and preserved along the
inferior border of the incision.
■ Superior and lateral incisions are then made and superior and inferior
beveling to include the maximum amount of fat and soft tissue.
■ Lateral fat can also be captured additionally to include the saddlebags.
■ Care should be taken to preserve medial fat over the ischium to prevent pain
and pressure in the postoperative period. The fat in this area is notable with
lighter color and larger globule ration overlying the iliotibial tract.
■ Flap elevation begins in a lateral to medial fashion and gluteal fascia is
incised early (TECH FIG 2A).
■ Subfascial dissection proceeds until perforators are identified.
■ Once the chosen perforator has been identified, dissection proceeds with the
use of bipolar cautery through the gluteus maximus muscle using standard
perforator dissection techniques.

TECH FIG 2 • A. Elevation of IGAP flap in a lateral to
medial fashion in subfascial plane over the gluteus
maximus muscle. Inferior gluteal artery perforator is
present and seen coming through the muscle to the
flap. B. Intraoperative photo of dissection of inferior
gluteal artery perforator and vena comitans with
splitting of gluteus maximus muscle in the direction of
the fibers.
■ It is important to split the gluteus maximus muscle in the direction of the
fiber along the septum to avoid technical error (TECH FIG 2B).
■ Unlike the SGAP flap, it is often unnecessary to open the sacral fascia to
dissect in the submuscular or subgluteal flap plane for increased pedicle
length.
■ This is secondary to the risk of intraoperative damage to the sciatic nerve
and posterior cutaneous nerve of the thigh.
■ However, as compared to SGAP flaps, the submuscular/subsacral fascia
dissection and venous confluence are easier with less variability.
■ Significant mismatch of the inferior gluteal artery and vein is seen under the
sacral fascia. There are multiple communications and branches that require
ligation near the pedicle.
■ Flaps are then harvested with either tie or double clip in the pelvis and
placed on ice on the back table.
■ Closure of the donor site proceeds in layers and over closed suction drains.
Care is taken to avoid raising the gluteal fold by more than 1 cm.
■ Patient is then repositioned into the supine position for microsurgical

anastomosis.
■ Recipient Vessel Exposure
■ Exposure of the recipient vessels proceeds in the standard technique.
■ Both rib-sparing and rib-sacrificing techniques have been described.11
PEARLS AND PITFALLS
Physical
findings
■ This flap is really a tertiary flap choice; therefore, abdomen and
thigh donor sites should be used preferentially based on high
incidence of flap failure and technical difficulty associate with
IGAP flaps.
■ Scar position in the gluteal crease should be marked
preoperatively in the standing position.
Technique
■ Two-surgeon approach is helpful when harvesting the flap and
preparing the recipient site.
■ Choice of number of perforators and perforators selected should
be aided by imaging and difficulty of intramuscular dissection.
More than 2 perforators should not be selected.
■ Beveling superiorly, inferiorly, and laterally can help add
additional tissue to the flap and is imperative for increasing flap
volume. However, light-colored medial fat must be spared to
prevent donor-site discomfort when sitting secondary to pressure
over the ischium.
■ As the inferior gluteal artery perforator dissection moves
proximally, the sciatic nerve is palpated to avoid injury. When the
perforator enters the main trunk of the descending inferior gluteal
artery, the sciatic nerve is separated and not visualized.
■ Dissection of the submuscular/subfascial pedicle is not always
required and can prevent injury to posterior cutaneous nerve of the
thigh and sciatic nerve.
■ Venous thrombotic complications are most common and size
mismatch is possible. Therefore, avoiding kinking during inset is
imperative.
Postoperative
■ Compression garment should be worn for 1 month
postoperatively.

Complications
■ Postoperative donor-site problems remain the most common
complication.
■ If venous thrombosis occurs, vein graft will likely be required for
salvage, and possible vein donor sites include the dorsal foot,
hand, and turn down from proximal cephalic vein.
POSTOPERATIVE CARE
■ Patients routinely stay in the hospital for 3 to 4 days postoperatively.
■ Pain control can be augmented with intraoperative subcutaneous bupivacaine
(Exparel) administration in addition to scheduled ibuprofen/Toradol.
■ Patients have routine transcutaneous Doppler checks, and monitoring can be
further augmented by ViOptix technology. The authors prefer flap checks q 15
minutes × 2 hours, q 30 minutes × 1 hour, q 1 hour × 24 hours, and q 4 hours
until discharge.
■ Postoperatively, sitting can be initiated on POD no. 1 and ambulation on POD
no. 2.
■ Patients routinely stay in the hospital for 3 days and then are discharged home
on postoperative aspirin × 30 days.
■ Drains remain in place until less than 30 mL × 24 hours.
OUTCOMES
■ IGAP flap for breast reconstruction provides an adequate reconstruction. The
buttock fat is less pliable with a greater skin to fat ratio as compared to a
natural breast due to a developed reticular system. This flap gives increased
projection of the breast secondary to this quality.
■ The IGAP flap offers a successful reconstruction in 90% to 96% of patients.
■ Secondary revision with fat grafting to the breast and local tissue
rearrangement to the donor site is common.
■ Should be used as a tertiary flap in breast reconstruction, with abdominal and
thigh donor site preferred (FIG 3)
COMPLICATIONS
■ Donor-site complications remain the most common complications associated
with IGAP flap dissection. These complications include:
■ Seroma is common and reported in as many as 25% of patients.
■ Hematoma
■ Wound healing problems (including dehiscence and wound infection)

• Avoid tension across the incision with minimal skin paddle height and focus
on undermining superiorly, inferiorly, and laterally to gain additional fatty
tissue.
■ Total flap loss is a dreaded complication of breast reconstruction with IGAP
flap. Based on available series, the failure rate is likely between 2.5% and
6.5%.12
■ These complications can be associated with arterial or venous thrombosis or
difficulty with perforator dissection but most commonly associated with
venous thrombosis in a delayed fashion with that being observed in up to 13%
of flaps.
■ This can be attributed to kinking of the vein and significantly size mismatch.
Prompt take back to the operating room is required for either revision of
arterial anastomosis or venous anastomosis in the cases of arterial or venous
insufficiency. Vein grafts are often necessary for salvage.
■ These complications often present in the first 24 to 48 hours.
■ Fat necrosis in fasciocutaneous flaps for breast reconstruction is
commonplace. However, the fat necrosis rate in IGAP flaps has been seen to be
between 3.5% and 10%. Treatment of fat necrosis is variable and can include
revision with direct excision or liposuction.
■ Sciatic nerve injury is possible; however, reapproximation to the gluteus
maximus muscle helps to avoid significant sequelae.
■ Persistent sensory disturbances greater than 3 months can be seen in 19% of
patients in their posterior leg. This complication is associated with injury or
sacrifice of the posterior cutaneous nerve of the thigh, due to intimate
association with the pedicle.13 However, most of these complications diminish
over time.

FIG 3 • Preoperative and postoperative results. A.
Preoperative AP view of a 42-year-old female with
history of right breast DCIS and size 34A breasts. B.
Preoperative PA view of patient. C. Postoperative AP
view of patient after bilateral mastectomy and
immediate IGAP reconstruction. D. Postoperative PA
view of patient after bilateral IGAP harvest.
REFERENCES
1. Fujino T, Harasina T, Aoyagi F. Reconstruction for aplasia of the breast and
pectoral region by microvascular transfer of a free flap from the buttock. Plast
Reconstr Surg. 1975;56(2):178-181.
2. Shaw WW. Breast reconstruction by superior gluteal microvascular free flaps
without silicone implants. Plast Reconstr Surg. 1983;72(4):490-501.
3. Guerra AB, Metzinger SE, Bidros RS, et al. Breast reconstruction with gluteal
artery perforator (GAP) flaps: a critical analysis of 142 cases. Ann Plast Surg.
2004;52(2):118-125.
4. Allen RJ, Levine JL, Granzow JW. The in-the-crease inferior gluteal artery
perforator flap for breast reconstruction. Plast Reconstr Surg. 2006;118(2):333-
339.
5. Boustred MA. Inferior gluteal free flap breast reconstruction. Clin Plast Surg.

1998;25:275.
6. Georgantopoulou A, Papadodima S, Vlachodimitropoulos D, et al. The
microvascular anatomy of superior and inferior gluteal artery perforator (SGAP
and IGAP) flaps: a fresh cadaveric study and clinical implications. Aesthetic
Plast Surg. 2014;38(6):1156-1163.
7. Fade G, Gobel F, Pele E, et al. Anatomical basis of the lateral superior gluteal
artery perforator (LSGAP) flap and role in bilateral breast reconstruction. J
Plast Reconstr Aesthet Surg. 2013;66(6):756-762.
8. Blum CA, Frank D, Scott S, et al. Composite superior gluteal artery perforator
flaps for unilateral breast reconstruction: a case report. J Reconstr Microsurg.
2015;31(7):541-543.
9. Satake T, Muto M, Ogawa M, et al. Unilateral breast reconstruction using
bilateral inferior gluteal artery perforator flaps. Plast Reconstr Surg Glob
Open. 2015;3(3):e314.
10. LoTempio MM, Allen RJ. Breast reconstruction with SGAP and IGAP flaps.
Plast Reconstr Surg. 2010;126(2):393-401.
11. Haddock NT, Teotia SS. Five steps to internal mammary vessel preparation in
less than 15 minutes. Plast Reconstr Surg. 2017;140(5):884-886.
12. Mirzabeigi MN, Au A, Jandali S, et al. Trials and tribulations with the
inferior gluteal artery perforator flap in autologous breast reconstruction. Plast
Reconstr Surg. 2011;128(6):614e-624e.
13. Windhofer C, Brenner E, Moriggl B, Papp C. Relationship between the
descending branch of the inferior gluteal artery and the posterior femoral
cutaneous nerve applicable to flap surgery. Surg Radiol Anat. 2002;24(5):253-
257.

26
CHAPTER
Superior Gluteal Artery
Perforator Flap Breast
Reconstruction
Katie E. Weichman
DEFINITION
■ The superior gluteal artery perforator (SGAP) flap is a variation of the gluteal
artery myocutaneous flap initially described by Shaw and further modified by
Codner and Nahai for use in breast reconstruction.1,2 This perforator flap was
first described as a pedicled flap by Koshima and used for repair of sacral
pressure sores3 and further expanded for use as a free flap in breast
reconstruction when described by Allen and Tucker in 1995.4 This perforator
flap uses skin and tissue in the buttock area based on the SGAPs. The flap has
been further modified by Blondeel in 1999 for use in breast reconstruction as a
sensate flap.5
■ While abdominally based free flaps remain the most common choice for breast
reconstruction secondary to sufficient skin and soft tissue, patients may require
alternative donor sites for various reasons. These reasons include lack of
abdominal donor sites secondary to prior abdominoplasty, inadequate volume
in the abdomen, and patient preference.
ANATOMY
■ The superior gluteal artery originates from the internal iliac artery and is its
largest branch. It runs backward between the lumbosacral trunk and the first
sacral nerve and exits the pelvis through the sciatic foramen just above the
upper border of the piriformis muscle and inferior to the gluteus medius.
■ Anatomically, this exit point between the piriformis and the gluteus medius
has been shown to be about 6 cm from the PSIS and 4.5 cm lateral to the
midline of the sacrum or at the junction of the proximal and middle thirds of a

line connecting the PSIS to the apex of the greater trochanter of the femur
(FIG 1).
■ Once it passes out of the pelvis, it immediately divides into a superficial and
deep branch.
■ The superficial branch enters the deep surface of the gluteus maximus
muscle and divides into several branches that perforate through the gluteus
maximus muscle onto the skin. These are the perforating vessels that will be
followed in SGAP dissection.
■ The superior gluteal vein is associated with the superior gluteal artery;
however, it receives multiple tributaries as it enters the pelvis that requires
ligation during harvest.
■ The perforating vessels are located inferior to and lateral to the anatomical exit
point of the superior gluteal artery. Several studies have looked at these
perforating vessels and found SGAP flaps have a mean number of 7.2
perforators (range 5–10), with an average intramuscular length of 5.33 cm
(range 3–11 cm) and a mean total pedicle length of 9.8 cm (range 6.0–15.5
cm).6
■ There are several muscles that are highlighted for SGAP dissection in the
posterior gluteal area (FIG 2).
■ Gluteus maximus
• Origin: Gluteal surface of the ilium, lumbar fascia, sacrum, and
sacrotuberous ligament

FIG 1 • Anatomical relationships of superior gluteal
artery. Line 1 connects posterior iliac spine to apex of
greater trochanter. Superior gluteal artery is located at
the junction between the proximal and middle third of
this line. Line 2 connects the midpoint of the gluteal
crease to the superior greater trochanter. Line 3
connects the posterior iliac spine to the coccyx. Line 2
represents the inferior border of the piriformis muscle.

FIG 2 • Important musculature of the posterior trunk
involved in SGAP dissection.
• Insertion: Gluteal tuberosity of the femur and iliotibial tract
• Action: External rotation and extension of the hip joint
• Arterial supply: Superior and inferior gluteal arteries
• Innervation: Inferior gluteal nerve (L5, S1, and S2)
■ Gluteus medius (deep to the gluteus maximus)
• Origin: Gluteal surface of the ilium
• Insertion: Greater trochanter of the femur forming the iliotibial tract
• Action: Abduction of the hip, preventing adduction of the hip, and medial
rotation of the thigh
■ Piriformis (deep to the gluteus maximus)
• Origin: Anterior portion of the sacrum
• Insertion: Greater trochanter of the femur forming the iliotibial tract
• Action: External rotator of the thigh
• Arterial supply: Interior gluteal artery, superior gluteal artery, and lateral
sacral artery
• Innervation: Nerve to the piriformis (L5, S1, and S2)
■ Gluteus minimus (deep to gluteus maximus and gluteus medius)

• Origin: Ilium under the gluteus minimus
• Insertion: Greater trochanter of the femur forming the iliotibial tract
• Action: Works in concert with gluteus medius: abduction of the hip,
preventing adduction of the hip, and medial rotation of the thigh
• Arterial supply: Superior gluteal artery
• Innervation: Superior gluteal nerve (L4, L5, S1)
PATIENT HISTORY AND PHYSICAL FINDINGS
■ This includes patients with a history of breast cancer, patients undergoing
prophylactic mastectomy, patients with congenital abnormalities, and
transgender patients.
■ Physical examination includes examination of the abdomen, medial thighs,
and buttock to assess availability of excess tissue.
■ Timing of reconstruction should be planned in patients with prior history of
breast irradiation. The authors prefer to wait 6 months after the completion of
radiation therapy prior to completing delayed reconstruction.
■ Smoking status is also assessed.
■ Additionally, tamoxifen should be held 3 weeks prior to surgery.
IMAGING
■ Patients considering SGAP flap reconstruction should undergo preoperative
imaging with either computed tomography angiogram (CTA) or magnetic
resonance angiography (MRA) of the pelvis and lower extremity.
■ Imaging is performed in the prone position and coordinating with the
radiologist for appropriate evaluation of images.
■ Perforators should be described as they exit the deep muscular fascia and
described based on location in an x-y axis. The gluteal fold will be set as zero
on the y-axis, and the midline will be set as zero on the x-axis. Important bony
landmarks that should be noted include the coccyx, the summit of the
posterosuperior iliac crest, and the most lateral point of the greater trochanter7
(FIG 3).

FIG 3 • Locations of SGAP perforator on axial CT scan
including the gluteus maximus muscle and piriformis
muscle.
■ The description of the perforator should include the size of perforator as it
exits the fascia and length of course to the superior gluteal artery as it travels
through the gluteus maximus and superior to the piriformis back to the origin
on the internal iliac artery. This should be described in relation to the coccyx,
posterosuperior iliac crest, and the most lateral point of the greater trochanter.
SURGICAL MANAGEMENT
■ The authors perform SGAP flap on patients either undergoing immediate or
delayed breast reconstruction.
■ Additionally, this procedure can be performed on patients who required
multiple flaps secondary to volume and skin deficit and require reconstruction
in a stacked fashion.8 This includes both patients having immediate stacked
reconstruction and patients who have autologous reconstruction that requires
secondary augmentation in a delayed fashion.
■ Unilateral stacked SGAP flaps have been described.8
■ PAP and augmenting prior SGAP flap have also been described. 9
■ Flap weights have been seen between 210 and 820 g.4
■ The operation requires loupe magnification for perforator dissection and
microsurgical instruments.
■ While the microsurgical anastomosis can be performed under loupe
magnification, the authors prefer the use of the operative microscope.

Preoperative Planning
■ Patients are marked in the standing or sitting position.
■ The superior gluteal artery is identified and marked as noted above at the
junction of the proximal and middle thirds of a line connecting the posterior
iliac crest to the lateral most portion of the greater trochanter of the femur. The
perforators are most likely found in a 3-cm radius of the point.
■ A second line is drawn from the PSIS to the coccyx.
■ A third line is drawn to represent the piriformis muscle from the midpoint of
the line between the PSIS and coccyx to the superior edge of the greater
trochanter.
■ Based on preoperative images, using a handheld 5- to 8-MHz Doppler, the
main perforators are marked clearly on the skin.
■ The flap is then designed and should be centered over the perforators. The skin
island should be oriented parallel to the bikini line and medially should be
marked in a fishtail to avoid a dog-ear at the gluteal crease. In general, the flap
should be at a 45-degree slant cranially from medial to lateral.
■ The apex of the flap is marked beginning two to three fingerbreaths below the
gluteal crease in the midline extending laterally and superiorly.
■ Flap dimensions have been described as large as 30 cm × 13 cm; however,
generally, it can be between 6 and 13 m wide and 20 and 25 cm in length.5 The
desired width of the flap is based on judgment to avoid excessive tension on
the closure.
■ Additional fat that you would like to capture in the flap harvest should also be
noted during marking (FIG 4).
Positioning
■ The patient is positioned in the lateral decubitus position for unilateral flaps
and in the prone position for bilateral flaps. If bilateral reconstruction, this will
have to start in the supine position for either mastectomy in immediate
reconstruction or preparation of site in delayed reconstruction and vessel
harvest. This supine position will be followed by prone positioning and finally
supine positioning again.
Approach
■ A two-team approach can be used for SGAP flap harvest. The first team is
utilized for site preparation and vessel exposure and the second team for flap