Anatomy of the Pedicled Anterolateral Thigh Flap for Phalloplasty in Transitioning-Males

Article (PDF Available)inClinical Anatomy 31(2) · November 2017with 959 Reads
DOI: 10.1002/ca.23017
Abstract
Incidence of transexualism and request for neophalloplasty is increasing yielding a current prevalence of trans-male in the USA of 1:2500. Surgeons have explored various techniques to improve desirable outcomes of neophallic construction, decrease the length of surgery, and minimize stigmatizing scars. The anterolateral thigh (ALT) flap is an alternative to the traditional radial forearm flap for patients who do not want a forearm scar. Surgical text descriptions were enhanced by the creation of new anatomic illustrations. Anatomy of the donor and recipient sites as well as the surgical technique leading to creation of the neophallus are demonstrated in detail with new relevant illustrations. The ALT flap is a skin, fat and fascia flap that is usually supplied by the descending branch of the lateral circumflex femoral vessels and the lateral femoral cutaneous nerve. However, variability in neurovascular supply does exist with important clinical implications. In the pedicled surgical procedure, neurovascular supply is left partly attached to the donor site ("pedicle") and simply transposed to the perineum, keeping the pedicle intact as a conduit to supply the tissue with blood and innervation. ALT flap offers clinical advantages of less obvious donor site concealable with clothing, decreased surgical time, preservation of erogenous sensation and vascular supply of the flap without microsurgical anastomosis of nerves and vessels, and good potential for urethroplasty. This surgery may be difficult in patients with thicker skin and more subcutaneous thigh fat. Clin. Anat, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
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ORIGINAL COMMUNICATION
Anatomy of the Pedicled Anterolateral Thigh
Flap for Phalloplasty in Transitioning-Males
MARK TERRELL,
1
WALLISA ROBERTS,
2
CHARLES WESLEY PRICE,
2
MICHAEL SLATER,
3
MARIOS LOUKAS ,
2
AND JUSTINE SCHOBER
4
*
1
Lake Erie College of Osteopathic Medicine, Erie, Pennsylvania
2
St. George’s University, Grenada, West Indies
3
Lake Erie College of Osteopathic Medicine-Bradenton, Bradenton, Florida
4
Department of Urology, UPMC Hamot, Erie, Pennsylvania
Incidence of transexualism and request for neophalloplasty is increasing yield-
ing a current prevalence of trans-male in the USA of 1:2500. Surgeons have
explored various techniques to improve desirable outcomes of neophallic con-
struction, decrease the length of surgery, and minimize stigmatizing scars. The
anterolateral thigh (ALT) flap is an alternative to the traditional radial forearm
flap for patients who do not want a forearm scar. Surgical text descriptions
were enhanced by the creation of new anatomic illustrations. Anatomy of the
donor and recipient sites as well as the surgical technique leading to creation
of the neophallus are demonstrated in detail with new relevant illustrations.
The ALT flap is a skin, fat and fascia flap that is usually supplied by the
descending branch of the lateral circumflex femoral vessels and the lateral
femoral cutaneous nerve. However, variability in neurovascular supply does
exist with important clinical implications. In the pedicled surgical procedure,
neurovascular supply is left partly attached to the donor site (“pedicle”) and
simply transposed to the perineum, keeping the pedicle intact as a conduit to
supply the tissue with blood and innervation. ALT flap offers clinical advantages
of less obvious donor site concealable with clothing, decreased surgical time,
preservation of erogenous sensation and vascular supply of the flap without
microsurgical anastomosis of nerves and vessels, and good potential for ure-
throplasty. This surgery may be difficult in patients with thicker skin and more
subcutaneous thigh fat. Clin. Anat. 31:160–168, 2018. V
C2017 Wiley Periodi-
cals, Inc. V
C2017 Wiley Periodicals, Inc.
Key words: phalloplasty; neophallus; scar; graft; anterolateral thigh flap;
radial forearm flap alternative
INTRODUCTION
Penile reconstruction is a complex surgical task and
various techniques of phalloplasty have been devel-
oped since the first operation, which was performed in
1936. Bogoras (1936) used a pedicled abdominal
tubed flap implanted with rib cartilage to construct a
penis that could functionally achieve coitus. However,
this procedure required four stages of surgery, lacked
a competent neourethra, and was not esthetically
pleasing (Hasegawa et al., 2013; Golpanian et al.,
2016). Eventually, a neophallus with a urethra was
constructed using an outside-in tubed flap within a
tubed abdominal pedicle graft (Maltz, 1946). Gillies
(1948) improved and popularized the Maltz procedure
by performing the first female-to-male gender reas-
signment; previously, phalloplasty had only been
*Correspondence to: Justine Schober, Department of Urology,
UPMC Hamot, Erie, PA, Email: Schobermd@aol.com
Received 13 November 2017; Accepted 22 November 2017
Published online 27 December 2017 in Wiley Online Library
(wileyonlinelibrary.com). DOI: 10.1002/ca.23017
V
V
C2017 Wiley Periodicals, Inc.
Clinical Anatomy 31:160–168 (2018)
performed for congenital absence or traumatic loss of
the penis (Golpanian et al., 2016). Later, a sensitive
neophallus was surgically developed through a four-
step process using a pedicled medial thigh flap con-
taining femoral branches of the genitofemoral nerve
(Kaplan, 1971). To advance to one-stage surgery, the
radial forearm free flap (RFFF) for phalloplasty was
developed using microneurovascular surgical techni-
ques and rib cartilage to achieve more esthetically
pleasing results (Chang and Hwang, 1984). The rigid-
ity of the neophallus produced by the RFFF technique
was improved by introducing the radial forearm osteo-
cutaneous flap, which contains skin, fascia, bone, and
radial artery perforators (Biemer, 1988) and is one of
the most widely used techniques for penile recon-
struction (Golpanian et al., 2016).
The radial forearm flap has a number of disadvan-
tages. First, the formation of an unsightly, conspicuous
scar at the flap harvest site yields a “donor site stigma”
(Hasegawa et al., 2013) and presents as a tell-tale sign
of gender reassignment (Descamps et al., 2009). This
is potentially a source of distress for transgender
patients who wish to control the disclosure of their
reassignment. Second, a stiffener or prosthesis is
needed (Blaschke et al., 2014) and the size of the phal-
lus is limited owing to tissue availability at the donor
site (Rashid et al., 2011). Although tissue expanders
can be used to increase graft size, this has the disad-
vantage of making the procedure two-stage. Third,
phalloplasties from radial forearm flaps are associated
with a high fistula rate of up to 75% due to the vascular
insufficiency of the flap or the small-caliber lumen of
the neophallic urethra (Nikolavsky et al., 2017).
The ideal phalloplasty should be a single-stage pro-
cedure that can be predictably reproduced and produ-
ces a functional phallus capable of tactile and erogenous
sensation, with a watertight neourethra permitting
voiding in the standing position, sufficient bulk to toler-
ate insertion of a prosthetic stiffener, and an esthetically
acceptable appearance (Hage and De Graaf, 1993). The
flap donor site should produce low morbidity with a
small, inconspicuous scar while full functionality is
retained. The anterolateral thigh (ALT) flap is versatile
(Song et al., 1984) and can be used in its pedicled form
or as a free tissue transfer. The free ALT flap was intro-
duced for penile reconstruction with these ideals (Felici
and Felici, 2006). However, free flaps often require
microsurgical attachment of neurovascular structures,
which are highly variable anatomically and therefore
have an associated risk of total failure (Hasegawa et al.,
2013). Consequently, pedicled ALT flaps were devel-
oped as a single flap surgical technique for phalloplasty
without the need for microsurgery (Lee et al., 2009).
Pedicled ALT flaps are easily raised with a long vascular
pedicle and good vessel diameter, provide different tis-
sues with large amounts of skin, produce minimal mor-
bidity at the donor site, and represent a viable option for
patients looking to avoid a conspicuous scar. They can
also be used for patients who present with a negative
Allen’s test (that is, patients who lack a dual blood sup-
ply to the hand), as a forearm graft harvest can lead to
ischemia. However, the lateral circumflex femoral arte-
rial system and the perforators nourishing the antero-
lateral thigh flap are significantly variable, so analysis of
the anatomical pattern of the neurovascular supply is
needed to improve surgical utility and patient outcomes
of the pedicled ALT.
METHODS
A comprehensive literature review of the PubMed
and Google Scholar databases was conducted. Several
database searches were performed using different
nomenclatures to identify articles that documented the
anterolateral thigh flap phalloplasty. The following
search terms were used: “anterolateral thigh flap
phalloplasty,” “phalloplasty,” “pedicled anterolateral
thigh flap,” and “perforators of the lateral circumflex
femoral artery”. The data were then assessed for rele-
vance to the study. Surgical text descriptions were then
produced and were enhanced by the creation of new
anatomical illustrations. The anatomy of the ALT flap
with a focus on vascular variation at the donor and
recipient sites, and an anatomical description of the
phalloplasty surgical technique for the neophallus, are
depicted in detail with the new relevant illustrations.
ANATOMY
Muscle Anatomy
The anterolateral thigh flap lies on the axis of the
intermuscular septum dividing the vastus lateralis and
rectus femoris muscles of the anterior compartment
of the thigh. This compartment consists of the quadri-
ceps femoris, iliopsoas, and sartorius muscles. The
quadriceps femoris is a group of muscles comprising
the vastus medialis, vastus lateralis, rectus femoris
muscle, and vastus intermedius, which is located deep
to the rectus femoris. The quadriceps are overlain by
the sartorius, a long strap-like muscle spanning from
the anterior superior iliac spine to the medial surface
of the proximal shaft of the tibia. The muscles of the
thigh are enveloped by a particularly thick deep fascia
known as the fascia lata (Fig. 1a). Extensive neuro-
vascular structures course within the intermuscular
septum and perforate through the muscle tissue and
fascia to supply the skin.
Vascular Anatomy
The region of the ALT flap is typically supplied by
multiple arterial perforator vessels originating from
the descending branch of the lateral circumflex fem-
oral artery. This artery normally originates from the
lateral side of the deep femoral artery but can some-
times arise directly from the femoral artery. In the
femoral triangle, the femoral artery branches 3.5 cm
distal to where it passes deep to the inguinal liga-
ment to give the deep femoral artery (Standring,
2008), which then provides lateral and medial
branches known as the lateral and medial circumflex
femoral arteries, respectively. The lateral circumflex
femoral artery courses laterally from the deep femo-
ral artery, deep to the sartorius and rectus femoris
muscles, and divides into three terminal branches:
Anatomy of the Pedicled Anterolateral Thigh Flap 161
ascending, descending, and transverse. The ascend-
ing branch ascends on the lateral side of the proxi-
mal thigh deep to the tensor fascia lata muscle and
connects via a branch to the medial circumflex femo-
ral artery, thereby forming a channel around the
neck of the femur. The transverse branch courses
laterally to pierce through the vastus lateralis muscle
and dives deep to encircle the proximal shaft of the
femur. The descending branch descends within the
anterolateral thigh deep in the fascia of the inter-
muscular septum between the rectus femoris and
vastus lateralis muscles, and connects distally with a
branch of the popliteal artery near the knee. This
branch is the main supplier of the ALT flap and can
be located surgically by measuring the midpoint of a
line drawn from the anterior superior iliac spine
(ASIS) to the superolateral border of the patella
(Kim et al., 2016). Two types of perforating branch
originate directly from the descending branch of the
lateral circumflex femoral artery within the inter-
muscular septum; they terminate in supplying the
overlying skin and subcutaneous tissue of the ALT
flap region. Musculocutaneous perforating branches
course laterally from the intermuscular septum to
penetrate through the vastus lateralis muscle before
coursing superficially to the skin. Septocutaneous
perforating branches course superficially directly
within the intermuscular septum to supply the
overlying skin of the anterolateral thigh without
piercing through the adjacent muscle. The middle
septocutaneous perforator vessel is located at a
fixed point at the junction between the middle and
upper thirds of the thigh (Fig. 1b). The diameter of
the descending branch of the lateral circumflex fem-
oral artery is in the range 1–3 mm (Wong et al.,
2009).
One to two venae comitantes accompany the
descending branch of the lateral circumflex femoral
artery. Their diameters are larger than that of the
artery so they provide sufficient drainage to the ALT
flap. Usually the two veins merge into one at the deep
femoral vein junction. The lateral femoral vein, which
drains into the great saphenous vein, can supplement
the venae comitantes if needed (Koshima et al.,
1989).
Anatomical variations in the ALT’s vascular pedicle
have complicated surgical practice and have dimin-
ished its usefulness for various surgeries in the United
States (Wong et al., 2009; Yu, 2004; Valdatta et al.,
2002). The vascular pedicle varies in several anatomi-
cal ways and the patterns of this variability need to be
clarified spatially to improve ap elevation during sur-
gery. The origin of the perforating arteries supplying
the ALT flap is from the descending branch of the lat-
eral circumflex femoral artery in as many as 90% of
cases. However, perforators have been found in a
Fig. 1. (a) The muscles of the thigh are covered by a
thick deep fascia which is referred to as the fascia lata.
(b) Neurovascular anatomy of the anterior thigh. The
descending branch of the lateral circumflex femoral artery
gives off the cutaneous perforating arteries which are tar-
geted as the vascular supply of the flap. (Used with per-
mission of Charles Wesley Price, 2017). [Color figure can
be viewed at wileyonlinelibrary.com]
162 Terrell et al.
third of cases originating from the transverse branch
and a few directly off the deep femoral artery (Kim
et al., 2016). Other perforators have been found origi-
nating from the oblique branch of the lateral circum-
flex femoral artery, a unique branch that when
present runs inferolaterally across the vastus lateralis
muscle between the descending and the transverse
branches of the lateral circumflex femoral artery. The
oblique branch has been observed in 32% (eight of
25) of Brazilian cadavers (da Costa and Lancelotti,
2009) and was observed in another study in 35% of
cases (31 of 88), where it functioned as the primary
origin of the dominant perforator supplying the ALT
flap region in 14% (Wong et al., 2009).
The type of perforator also varies. Musculocutaneous
perforators constitute the majority of perforating arter-
ies serving the ALT region and tend to cluster in two
locations along the intermuscular septum between the
rectus femoris and vastus lateralis muscles. The mid-
point between ASIS and the patella’s superolateral cor-
ner contains the most common and sizable perforators
(Yu, 2004). Perforators in this location are musculocu-
taneous, perforating the vastus lateralis muscle within
1 cm lateral to the intermuscular septum. They have a
characteristically short and superficial intramuscular
course toward their origin, making them easier to ele-
vate. More laterally-sited musculocutaneous perfora-
tors are longer and tend to take a more tortuous
course, making them much more difficult to elevate
(Wong et al., 2009). Distal musculocutaneous perfora-
tors have also been observed in as many as 62% of
cases (Valdatta et al., 2002) and are located in the dis-
tal 2
=
3portion of the intermuscular septum. They pierce
more laterally on the vastus lateralis muscle, making
them very long and very difficult to dissect or elevate
(Wong et al., 2009). Septocutaneous perforators have
been observed in 15% of cases (Wong et al., 2009;
Song et al., 1984). Most septocutaneous perforators
are clustered more proximally in the intermuscular sep-
tum and are short, making them easiest to dissect and
elevate. However, the septum is sometimes heavily
infiltrated with fat, particularly in the elderly patient,
making the surgical dissections arduous and prone to
bleeding.
The number of perforators is also highly variable,
ranging from zero to eight. Some studies have
reported a range of one to three perforators with an
average of 2.1 (Yu, 2004; Valdatta et al., 2002); in
one case, no cutaneous perforator could be identified
(Valdatta et al., 2002), while another study reported
an average of 4.2 perforators (Choi et al., 2007). Yet
another clinical study reported that perforators were
absent in five of 13 cases (Koshima et al., 1989). If
perforators are absent, a tensor fasciae latae muscu-
locutaneous flap or anteromedial thigh flap can be
used with only minor changes in flap outline (Koshima
et al., 1989). Therefore, surgeons should be aware of
this high prevalence of anatomical variations in the
origin, type, and number of perforators when conduct-
ing the ALT flap surgery and should be ready to per-
form alternative flaps if there is a lack of perforators.
Innervation
The sensate anterolateral thigh flap is innervated
by the lateral cutaneous femoral nerve (Rubino et al.,
2009). This nerve originates from the posterior divi-
sion of L2 and L3 and emerges from the lateral border
of the psoas major muscle, inferior to the iliolumbar
ligament. It then courses on the anterior surface of
the iliacus muscle, deep to the iliac fascia, and pro-
ceeds to enter the thigh by passing under or through
the inguinal ligament, traversing within a fibrous com-
partment medial to the anterior superior iliac spine,
passing over the sartorius, and running on the surface
of the deep fascia. This nerve is preserved with the
flap in order to produce a phallus with erogenous sen-
sation. Two other nerves, the superior and median
perforator nerves, which are cutaneous sensory
branches of the femoral nerve, were found in 25/29
and 24/29 cadavers, respectively (Ribuffo et al.,
2005). They enter the flap at its medial border in its
Fig. 2. The preoperative phase of the pedicled anterolateral thigh flap phalloplasty
shows a rectangular skin island drawn to include distal perforators located by doppler.
Markings are extended laterally to include the fascia lata to provide adequate lining for
the penile prosthesis. (Used with permission of Charles Wesley Price, 2017). [Color fig-
ure can be viewed at wileyonlinelibrary.com]
Anatomy of the Pedicled Anterolateral Thigh Flap 163
proximal half by emerging through the sartorius mus-
cle or at its lateral margin (Luenam et al., 2015).
Although the lateral cutaneous femoral nerve lies
deep, the superior and median perforator nerves lie
more superficially and have a role in anterolateral
thigh flap innervation (Ribuffo et al., 2005).
Most of the anterior muscles of the thigh are inner-
vated by the femoral nerve, which is formed by the
L2-L4 plexus. Immediately after traversing the ingui-
nal ligament to enter the femoral triangle, the femoral
nerve branches into the anterior cutaneous branches,
numerous motor branches, and the saphenous nerve.
Given the harvest site of this pedicle, care must be
taken to avoid ligation of the femoral nerve.
Surgical Procedure
The first documented pedicled anterolateral flap
phalloplasty consisted of preoperative, operative and
postoperative phases (Rubino et al., 2009). The pre-
operative phase involved localization of the perforator
vessels from the descending branch of the lateral cir-
cumflex femoral artery using ultrasound. This is
Fig. 3. The second phase is flap harvest. Once the origin of the descending branch
of the lateral cutaneous femoral artery and lateral cutaneous nerve have been identi-
fied, the surgeon can locate and preserve the necessary perforators for the flap. (Used
with permission of Charles Wesley Price, 2017). [Color figure can be viewed at
wileyonlinelibrary.com]
Fig. 4. After the flap has been dissected, it is transferred to the pubic region under
the insertion of the rectus femoris. With the flap in the desired anatomic place, a penile
prosthesis is then inserted and covered by the fascia lata. (Used with permission of
Charles Wesley Price, 2017). [Color figure can be viewed at wileyonlinelibrary.com]
164 Terrell et al.
particularly important because the perforator vessels
that maintain the vascular integrity of this flap are
variable, as discussed. During this phase, a reference
line is drawn from the anterior superior iliac spine to
the superolateral border of the patella. The perforator
vessels are located lateral to this line using a hand-
held Doppler probe. In order to increase the pedicle
length, only vessels located distal to the midpoint of
the reference line are used. A rectangular skin island
is then drawn on the distal two thirds of the thigh,
with the reference line forming the medial border and
its mid-level indicating the proximal border. The flap
marking is extended laterally to include the fascia lata
to provide adequate lining for the penile prosthesis
(Rubino et al., 2009) (Fig. 2).
The second phase of the operation is the flap har-
vest. Initially, a cut is made along the proximal border
of the flap. After this incision, the origins of the
descending branch of the lateral circumflex femoral
artery and the lateral cutaneous femoral nerve are
established. Once these are identified, the surgeon
can proceed to identify and maintain the perforator or
perforators suitable for the flap (Fig. 3). The flap is
then dissected to its origin while retaining its neuro-
vascular pedicle. A W-shaped incision is made in the
pubic skin, through which the flap is transferred to the
pubic region under the insertion of the rectus femoris
muscle to its origin. With the flap in the desired ana-
tomical location, a penile prosthesis can be inserted
and covered by the fascia lata, around which the flap
is then wrapped (Fig. 4). In an effort to maintain tac-
tile sensation in the phallus, the lateral cutaneous
femoral nerve of the flap is then coapted to the dorsal
nerve of the clitoris, which is dissected deeply on the
sides of the corpora cavernosa. Finally, the prosthesis
and flap are sutured to the periosteum of the pubis,
and superficially to the epithelium of the pubic region.
The flap donor site is closed using a split-skin graft
from the contralateral thigh (Rubino et al., 2009).
DISCUSSION
As a result of social progress, the incidence of
transgender males is increasing. Currently there is an
estimated prevalence of 1:2500 trans-males in the
United States (Conway, 2002). Among trans-men,
there is a 98% preference for the ability to void while
standing (Nikolavsky et al., 2017). To address this,
the female to male transgender patient is offered two
surgical options - Metoidioplasty and Phalloplasty.
Metoidioplasty is an older procedure that involves
creating a neophallus from the female clitoris after it
has been enlarged by hormonal stimulation. The
patient’s native urethra is lengthened by vaginal and
labial flaps in order to construct a neophallus long
enough to allow voiding in a standing position. This is
a viable option for those who would prefer to avoid
more invasive phalloplasty procedures involving large
distant tissue flaps and grafts. The advantages of this
procedure include a limited local donor site and the
ability to achieve an erection without a prosthesis,
while the main disadvantage is size, as the limited
size and girth of the resultant neophallus can preclude
its use for sexual intercourse (Frey et al., 2016.).
The second option, phalloplasty, is offered to those
who desire to achieve both voiding and sexual capa-
bility. Phalloplasty is categorized as either free flap or
pedicled flap phalloplasty. There are several different
techniques within each of these two categories. Radial
forearm free flap, anterolateral thigh flap, dorsal scap-
ular flap, and fibular free flap are described and con-
trasted here.
The radial forearm free flap (RFFF) has been consid-
ered the flap of choice in female-to-male phalloplasty
for many years. It meets many of the aforementioned
criteria of the “ideal” neophallus since the donor site is
thin and pliable, allowing for a “tube-in-tube” design to
create a competent neourethra that makes it possible
to void while standing, and the sensory nerves of the
flap can be connected to the ilioinguinal and dorsal cli-
toral nerves to confer tactile and erogenous sensibility
on the phallus. Although the outcomes of the neophal-
lus using the RFFF are generally favorable and well-
received by surgeons and patients alike, this method
also has significant drawbacks. In this procedure, a tis-
sue flap nearly two-thirds the circumference of the dis-
tal forearm is harvested for phalloplasty and covered
with a graft. This creates a large conspicuous scar. A
prominent forearm scar, which can only be concealed
by long sleeves, is experienced by many transgender
individuals as a stigma, causing distress (Rashid et al.,
2011). For this reason, other surgical methods are
being explored as alternatives. One of the most popu-
lar alternative techniques currently in use is the pedi-
cled anterolateral thigh (ALT) flap.
The ALT free flap has been used extensively for
reconstructing upper and lower limb defects and is
considered a primary method of free tissue transfer of
the head and neck, but has attracted considerable
interest recently because of its use as a pedicled flap
for defects around the groin (Rashid et al., 2011). The
pedicled ALT flap, first described by Song et al. in
1984, has shifted toward greater use in many institu-
tions over the last decade (Knott et al., 2016). The
pedicled ALT flap has gained popularity owing to pri-
mary benefits such as the allowance of large amounts
of pliable tissue harvested, anatomical location at the
junction of the vastus lateralis muscle and fascia, and
ability to be harvested as cutaneous, fasciocutaneous,
myocutaneous, or as a free fascial flap (Fischer et al.,
2013).
The ALT flap has some advantages over the RFFF.
Two major benefits are a donor site that can be hid-
den by everyday clothing, and no requirement for a
microvascular anastomosis. In regard to donor-site
morbidity, most complications of the RFFF stem from
the fact that the free vascularized tissue transfer
necessitates a microsurgical anastomosis, so a micro-
vascular surgical team is required (Colebunders et al.,
2017). The fact that the RFFF is a free flap greatly
limits its wider application owing to its potential for
poor perfusion, which results in partial flap loss in 2–
11% or total flap failure in 1–5% of cases according
to larger studies (van der Sluis et al., 2017). In view
of this incidence of flap failure, the pedicled ALT flap
approach has recently become a favored alternative in
Anatomy of the Pedicled Anterolateral Thigh Flap 165
many institutions owing to the inherent preservation
of its blood supply. The variability of the cutaneous
perforators of the descending branch of the lateral cir-
cumflex femoral artery, the most commonly-used
blood supply of the flap (Yu, 2004; Valdatta et al.,
2002), could have hindered acceptance of the pedi-
cled ALT flap as the new gold standard against the
RFFF. However, as van der Sluis et al. (2017) have
demonstrated, preoperative evaluation of ALT perfora-
tors and the subcutaneous fat tissue layer using CT
angiography, in addition to Doppler ultrasound, can
help facilitate adequate perforator selection based on
the anatomical variation of the individual patient, and
thus determine a feasible flap size. One good-size
perforator is usually said to be sufficient for vasculari-
zation and adequate perfusion of the requisite large
skin paddle, so partial and total flap failures are less
common with the pedicled ALT flap method than with
RFFF (Rashid et al., 2011; van der Sluis et al., 2017).
Fischer et al. (2013) reported more donor site compli-
cations among patients undergoing RFFF than ALT
free flaps (35.4% vs.12.4%) and wound dehiscence
was significantly more frequent among patients
undergoing RFFF than ALT free flap reconstruction
(30% vs.5%).
Another anatomical benefit of the pedicled ALT flap
is its capacity to maintain its neural innervation by
inclusion of the lateral femoral cutaneous nerve. This
nerve can be coapted to the ilioinguinal and dorsal
nerves of the clitoris, providing tactile and erogenous
sensitivity to the newly constructed neophallus. How-
ever, this leads to sensation deficits typically in a
5x13cm area of the distal lateral aspect of the thigh
(Fischer et al., 2013; Colebunders et al., 2017).
Rubino et al. (2009) demonstrated that when an
innervated pedicled ALT flap was used for phalloplasty
in trans-men, tactile sensation usually returned within
6 months (Rashid et al. 2011). Unfortunately, the
pedicle containing the vascular and neural structures
is intimately associated with the femoral motor nerve
to the quadriceps muscle and, if the perforator follows
an intramuscular course, dissection of the quadriceps
muscle is necessary. In these instances, patients have
described weakness of the leg causing impairment in
their daily routine, especially when trying to stand
from a seated position (Fischer et al., 2013). The ped-
icled ALT flap also offers cosmetic benefits in compari-
son to the RFFF. In addition to a more easily hidden
scar than the forearm scar, the tissue of the anterolat-
eral thigh has an excellent color and texture match to
that of the groin area and phallus. The donor scar is
concealed when dressed, making it superior to alter-
native flap harvest sites such as RFFF, dorsal scapular
flap, and fibular free flap (Rashid et al., 2011).
There are a few minor disadvantages with the pedi-
cled ALT flap. The “tube within a tube” formation, a
technique for constructing a smaller tube (the neour-
ethra) within a larger tube (the penile shaft), is only
possible for patients with a thin layer of subcutaneous
fat in the thighs. Significant subcutaneous fat in the
thighs can cause a considerable problem in tubing the
flap twice. In such cases the flap must be thinned
down, taking care not to compromise the vasculature
(Rashid et al., 2011). If this is not possible, the
pedicled ALT flap can be used to construct the penile
shaft while a second flap, usually a small RFFF, is used
to create the neourethra. This leaves a smaller and
less conspicuous donor site scar on the inner, less
exposed, side of the forearm, which can be closed pri-
marily, in contrast to RFFF total phalloplasty (van der
Sluis et al., 2017; Colebunders et al., 2017). Urethral
fistula is the most frequent urethral complication of
ALT flap phalloplasty, occurring most commonly at or
just proximal to the anastomosis between the phallic
urethra and fixed urethra due to the vascular insuffi-
ciency of the flap. However, spontaneous closures
were demonstrated in 35.7% of patients within 2
months (Nikolavsky et al., 2017).
Other currently-used donor sites for flap harvest for
phalloplasty are the parascapular (PS) and fibular free
flaps. The parascapular free flap has become one of
the most popular free flaps in reconstructive surgery
owing to the large areas of tissue that can be taken
and the relative ease with which they can be har-
vested. Vascular abnormalities/variations are seen in
only about 5% of PS flap cases, much less than in ALT
flaps, so the PS flap is favored by some surgeons. In
one study of patients who had undergone both PS flap
and ALT flap procedures, patient reports regarding
esthetic, functional, and overall satisfaction showed a
preference for the PS flap. The authors of this study
believed that this could have been because the scar is
out of the patient’s field of vision and therefore less
emotionally present than it is with the ALT flap, which
is easily visible to the patient and others. Disadvan-
tages of the PS flap include the flap being insensate,
the donor site being more prone to seroma formation
than other donor sites, and the need for a lateral
decubitus position during surgery, potentially requiring
intraoperative position changes, leading to prolonged
operating time and inability to use a two-team
approach (Fischer et al., 2013).
The fibular free flap is another viable current option
for phalloplasty. The flap itself is based around the pero-
neal artery and vein, which supply perforating vessels to
the skin island at the lateral site of the lower leg. A free
flap, rather than pedicled, has a greater risk of flap fail-
ure and dehiscence, requiring surgical revision. An
advantage of this technique is that it can make sexual
intercourse possible without a penile prosthesis, but
there is often a pointed deformity in the distal part of the
penis and the penis is permanently erect, making it
impractical (Colebunders et al., 2017).
For phalloplasty, very large tissue flaps are needed
and the donor site subsequently requires skin grafting,
leaving a noticeable hairless skin graft depression at
the site. Among transgender men, there is a subset of
patients who seek to minimize scarring and avoid
grafting altogether as these sites cannot be concealed
when undressed and are very close to the genital
area, the center of their masculinity and intimacy. A
solution to this issue is pre-expansion of the ALT flap,
aimed at thinning the flap to achieve primary closure
and avoid grafting, and improving the vascular terri-
tory of the perforating vessels of the flap. This process
involves selection of the largest perforator using pre-
operative CT angiography and the insertion of two
bags, placed medially and laterally to the perforator,
166 Terrell et al.
which are gradually filled with saline and methylene
blue. The expansion usually takes between 4 weeks
and 6 months and is therefore initiated about 6
months before phalloplasty. The patients who choose
to undergo ALT flap pre-expansion must be well
informed and highly motivated in view of the extra
effort, the longer process, additional operations, and
extra costs entailed by this course of action. Owing to
the large volume of fluid these expanders can hold
and the size they can achieve, patients can experience
discomfort and often try to conceal them partially by
wearing large, loose-fitting clothes. The results of ALT
flap pre-expansion are quite good, partial flap necrosis
being very uncommon. In contrast to some reports of
pre-expanded RFFF, which merely resulted in a reduc-
tion of the area to be grafted and an insensate phal-
lus, pre-expanded ALT flaps always allow preservation
of the flap’s innervation. To date, there have been no
specific complications regarding pre-expansion of the
ALT flap, though the thinning of the thigh tissue often
causes a depression and contour deformity at the
donor site, which eventually requires lipofilling
(D’Arpa et al., 2017).
CONCLUSION
The anterolateral thigh flap offers a good alterna-
tive to the currently popular radial forearm free flap
for phalloplasty with similar skin coloration and easy
concealment by most clothing. This procedure may
have failed to gain popularity in the United States
owing to the perceived anatomical variability of the
cutaneous perforators of the lateral circumflex femoral
artery. More studies are needed to clarify the spatial
patterns of the vascular anatomy of the lateral cir-
cumflex femoral artery and its associated branches.
When an appropriate donor site is available, the pedi-
cled anterolateral thigh flap remains a viable option
for making an almost ideal phallus.
REFERENCES
Biemer E. 1988. Penile construction by the radial arm flap. Clin Plast
Surg 15:425–430.
Blaschke E, Bales GT, Thomas S. 2014. Postoperative imaging of
phalloplasties and their complications. AJR 203:323–328.
Bogoras N. 1936. Uber die volleplastiche Wie derherstellung sines
Cum Koitus Fahigen penis (peniplastica Totalis). Zentralblat Cli-
nargie 63:1211.
Chang TS, Hwang WY. 1984. Forearm flap in one-stage reconstruc-
tion of the penis. Plast Reconstr Surg 74:251–258.
Choi SW, Park JY, Hur MS, Park HD, Kang HJ, Hu KS, Kim HJ. 2007.
An anatomic assessment on perforators of the lateral circumflex
femoral artery for anterolateral thigh flap. J Craniofac Surg 18:
866–871.
Colebunders B, Brondeel S, D’Arpa S, Hoebeke P, Monstrey S. 2017.
An update on the surgical treatment for transgender patients.
Sex Med Rev 5:103–109.
Conway L. 2002. How frequently does transsexualism occur? URL:
http://ai.eecs.umich.edu/people/conway/TS/TSprevalence.html .
Accessed June 2017.
D’Arpa S, Colebunders B, Stillaert F, Monstrey S. 2017. Pre-
expanded anterolateral thigh perforator flap for phalloplasty. Clin
Plast Surg 44:129–141.
da Costa AC, Penteado Lancelotti CL. 2009. Oblique branch of the
lateral circumflex femoral artery also found in 32 percent of
cadavers in Brazil. Plast Reconstr Surg 124:1011–1012.
Descamps MJL, Hayes PM, Hudson DA. 2009. Phalloplasty in com-
plete aphallia: Pedicled anterolateral thigh flap. J Plast, Reconstr
Aesthet Surg 62:e51–e54.
Felici N, Felici A. 2006. A new phalloplasty technique: The free ante-
rolateral thigh flap phalloplasty. J Plast Reconstr Aesthet Surg
JPRAS 59:153–157.
Fischer S, Klinkenberg M, Behr B, Hirsch T, Kremer T, Hernekamp F,
Kolbenschlag J, Lehnhardt M, Kneser U, Daigeler A. 2013. Com-
parison of donor-site morbidity and satisfaction between antero-
lateral thigh and parascapular free flaps in the same patient.
J ReconstrMicrosurg 29:537–544.
Frey JD, Poudrier G, Chiodo MV, Hazen A. 2016. A systematic review
of metoidioplasty and radial forearm flap phalloplasty in female-
to-male transgender genital reconstruction: Is the “ideal” neo-
phallus. an achievable goal? Plast Reconstr Surg - Global Open
4:e1131.
Gillies H. 1948. Congenital absence of the penis. Br J Plast Surg 1:
8–28.
Golpanian S, Guler KA, Tao L, Sanchez PG, Sputova K. 2016. Phallo-
plasty and urethral (re)construction: A chronological timeline.
Anaplastology 5:159.
Hage JJ, De Graaf FH. 1993. Addressing the ideal requirements by
free flap phalloplasty: Some reflections on refinements of tech-
nique. Microsurgery 14:592–598.
Hasegawa K, Namba Y, Kimata Y. 2013. Phalloplasty with an inner-
vated island pedicled anterolateral thigh flap in a female-to-male
transsexual. Acta Med Okayama 67:325–331.
Kaplan I. 1971. A rapid method for constructing a functional sensi-
tive penis. Br J Plast Surg 24:342–344.
Kim J, Kim D, Ahn K, Lee J. 2016. Surgical implications of ana-
tomical variation in anterolateral thigh flaps for the reconstruc-
tion of oral and maxillofascial soft tissue defects: focus on
perforators and pedicles. J Korean Assoc Oral Maxillofac Surg
42:265–270.
Knott PD, Seth R, Waters HH, Revenaugh PC, Alam D, Scharpf J,
Meltzer NE, Fritz MA. 2016. Short-term donor site morbidity:
A comparison of the anterolateral thigh and radial forearm
fasciocutaneous free flaps. Head Neck 38 Suppl 1:E945–
E948.
Koshima I, Fukuda H, Utunomiya R, Soeda S. 1989. The anterolat-
eral thigh flap; variations in its vascular pedicle. Br. J Plast Surg
42:260–262.
Lee GK, Lim AF, Bird ET. 2009. A novel single-flap technique for total
penile reconstruction: The pedicled anterolateral thigh flap. Plast
Reconstr Surg 124:163–166.
Luenam S, Prugsawan K, Kosiyatrakul A, Chotanaphuti T, Sriya P.
2015. Neural Anatomy of the Anterolateral Thigh Flap. J Hand
Microsurg 7:49–54. doi:10.1007/s12593-014-0167-x.
Maltz M. 1946. Maltz reparative technique for the penis; in Evolution
of Plastic Surgery, Maltz M ed, Froben Press, NY, pp 278–279.
Nikolavsky D, Yamaguchi Y, Levine JP, Zhao LC. 2017. Urologic
sequelae following phalloplasty in transgendered patients. Urol
Clin North Am 44:113–125.
Rashid M, Aslam A, Malik S, Tamimy MS, Ehtesham-ul-Haq, Aman S,
Jamy O. 2011. Clinical applications of the pedicled anterolateral
thigh flap in penile reconstruction. J Plast Reconstr Aesthet Surg
64:1075–1081.
Ribuffo D, Cigna E, Gargano F, Spalvieri C, Scuderi N. 2005. The
innervated anterolateral thigh flap: Anatomical study and clinical
implications. Plast Reconstr Surg 115:464–470.
Rubino C, Figus A, Dessy LA, Alei G, Mazzocchi M, Trignano E,
Scuderi N. 2009. Innervated island pedicled anterolateral thigh
flap for neo-phallic reconstruction in female-to-male tanssexuals.
J Plast Reconstr Aesthet Surg 62:e45–e49.
Song YG, Chen GZ, Song YL. 1984. The free thigh flap: A new free
flap concept based on the septocutaneous artery. Br J Plast Surg
37:149–159.
Anatomy of the Pedicled Anterolateral Thigh Flap 167
Standring S. 2008. Gray’s anatomy: The anatomical basis of clinical
practice. 40th Ed. London: Elsevier.
Valdatta L, Tuinder S, Buoro M, Thione A, Faga A, Putz R. 2002. Lat-
eral circumflex femoral arterial system and perforators of the
anterolateral thigh flap: An anatomic study. Ann Plast Surg 49:
145–150.
van der Sluis WB, Smit JM, Pigot GLS, Buncamper ME, Winters HAH,
Mullender MG, Bouman MB. 2017. Double flap phalloplasty in
transgender men: Surgical technique and outcome of pedicled
anterolateral thigh flap phalloplasty combined with radial forearm
free flap urethral reconstruction. Microsurgery 37:917–923.
Wong CH, Wei FC, Fu B, Chen YA, Lin JY. 2009. Alternative vascular
pedicle of the anterolateral thigh flap: the oblique branch of the
lateral circumflex femoral artery. Plast Reconstr Surg 123:571–
577.
Yu P. 2004. Characteristics of the anterolateral thigh flap in a west-
ern population and its application in head and neck reconstruc-
tion. Head Neck 26:759–769.
168 Terrell et al.
  • ... One solution involves free tissue transfers from healthy regions of the body to reconstruct the phallus. In fact, this phalloplasty procedure has seen a recent upsurge secondary to gender reassignment surgery [3]. Although phalloplasty in a young, healthy patient undergoing gender reassignment surgery can have satisfactory results, phalloplasty for the treatment of Fournier's gangrene has substantial risk due to the patient's likely comorbidities and vascular disease, making these patients poor microsurgical candidates with a great risk of flap failure. ...
    ... An additional well-studied flap that can be utilized during a phalloplasty procedure incorporates the anterolateral thigh (ALT) flap. This flap is appropriate for patients who would like to prevent a visible scar on their forearm and instead prefer an easily hidden donor site with no requirement for microvascular anastomosis [3,15]. Additionally, the ALT flap can also be utilized in patients in whom the radial forearm free flap is not a viable option either due to vascular or anatomic anomalies or secondary to previous forearm surgery [15]. ...
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    Objectives To gain information on anatomical variation in anterolateral thigh (ALT) flaps in a series of clinical cases, with special focus on perforators and pedicles, for potential use in reconstruction of oral and maxillofacial soft tissue defects. Materials and Methods Eight patients who underwent microvascular reconstructive surgery with ALT free flaps after ablative surgery for oral cancer were included. The number of perforators included in cutaneous flaps, location of perforators (septocutaneous or musculocutaneous), and the course of vascular pedicles were intraoperatively investigated. Results Four cases with a single perforator and four cases with multiple perforators were included in the ALT flap designed along the line from anterior superior iliac spine to patella. Three cases had perforators running the septum between the vastus lateralis and rectus femoris muscle (septocutaneous type), and five cases had perforators running in the vastus lateralis muscle (musculocutaneous type). Regarding the course of vascular pedicles, five cases were derived from the descending branch of the lateral circumflex femoral artery (type I), and three cases were from the transverse branch (type II). Conclusion Anatomical variation affecting the distribution of perforators and the course of pedicles might prevent use of an ALT free flap in various reconstruction cases. However, these issues can be overcome with an understanding of anatomical variation and meticulous surgical dissection. ALT free flaps are considered reliable options for reconstruction of soft tissue defects of the oral and maxillofacial area.
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    Introduction: As gender dysphoria is becoming increasingly accepted in the general population, the number of patients seeking gender reassignment surgery is increasing. Although not every patient with gender dysphoria requires surgery, medical practitioners taking care of these individuals should be aware of the different surgical options. Aim: To review current gender reassignment surgical techniques and update the clinician. Methods: A review of the literature was performed focusing on the most recent techniques of gender reassignment surgery. Main outcome measures: Main outcomes included a historical review of gender confirmation surgery leading to the techniques of choice in different divisions. For the vaginal lining, penile-scrotal skin flaps remain the technique of choice, and the gold standard for a phalloplasty remains the radial forearm flap. Results: Surgical techniques for male-to-female gender reassignment consist of facial feminization surgery, voice surgery, breast augmentation, orchiectomy, and vaginoplasty. Female-to-male gender reassignment surgery includes facial masculinization surgery, subcutaneous mastectomy, and phalloplasty procedures. Conclusion: Penile-scrotal skin flaps remain the technique of choice for the vaginal lining, although indications for a vaginoplasty with intestinal transfer are becoming more common. The gold standard for a phalloplasty remains the free radial forearm flap.
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    Donor site morbidity is an important consideration in the overall decision-making algorithm for fasciocutaneous free flap reconstruction of the head and neck. Retrospective case series of donor site complications occurring within 30 days of surgery among 226 consecutive ALT or RF microvascular free tissue transfers performed by multiple reconstructive surgeons between 2005 and 2010. A greater number of donor site complications occurred among patients undergoing RF versus ALT free flaps (40 (35.4%) versus 14 (12.4%), p<0.001). Wound dehiscence occurred significantly more frequently among patients undergoing RF versus ALT free flap reconstruction (34(30%) versus 6(5%), p<0.001). Tendon exposure occurred in 16 of the 113 RF flaps (14.1%). Seromas occurred more commonly in the ALT group (6(5%) versus 2(1.7%), p=0.280). While short-term donor site morbidity is low in both groups, the ALT is associated with a significantly lower incidence of wound dehiscence with or without tendon exposure. This article is protected by copyright. All rights reserved. © 2015 Wiley Periodicals, Inc.