Operative Technique in Plastic Surgery – Kevin C.Chung

■ The number of implants to be placed should be decided with an
anaplastologist to ensure adequate fixation. This decision will be affected by
the location of the prosthesis as well as the type of fixation (magnet vs bar-and-
clip). Magnet fixation may require additional implants to be placed.
FIG 4 • Custom 3D printed drill guide for precise implant
placement.
■ The anaplastologist, with the craniofacial surgeon, will prepare a template of
the area to be reconstructed with implant locations designated to guide surgical
placement. In the case of the ear, this template is usually made from the
position of the contralateral ear and centered around the external auditory
meatus or tragus if present.
■ The implant depth is often decided prior to implant placement but can be
decided intraoperatively based on clinical assessment of bone depth and
density. Most craniofacial implant systems come in 3 and 4 mm depths.
Positioning
■ Standard supine positioning with a head drape and general endotracheal
anesthesia is used for most implant placements. For uncomplicated implant
placement, some surgeons may prefer local anesthesia with sedation.
■ Hair in the operative area is trimmed in a limited fashion.
■ If surgical drapes will obscure visualization of a contralateral normal structure,
marking should be performed prior to draping to ensure symmetry.
Approach

■ A one- or two-stage technique can be utilized for implant placement. In a one-
stage technique, the implant is positioned and an abutment is immediately
placed through the skin. The one-stage approach is appropriate in a majority of
scenarios.
■ In a two-stage technique, skin is reclosed over implants capped with a cover
screw. The implants are then allowed to integrate into bone (approximately 3
months). Exposure of implants and abutment placement occurs at a later stage.
A two-stage approach is generally indicated if bone is irradiated or of poor
quality, in children, or in the orbital or maxillary region.8,9 We typically favor a
more conservative two-stage approach for many of our patients rather than
early loading of the implant.
Osseointegration and healing time may range from 3 to 9 months depending on
patient comorbidities and bone quality. This is typically based on intraoperative
assessment.
T E C H N I Q U E S
■ General Technique of Implant Placement
■ Using the template created by anaplastology, the sites for implant placement
are marked utilizing a needle dipped in methylene blue buried through skin
and into bone.
■ After a skin flap is raised (see specific anatomic areas for skin flap design),
the skin is thinned to an ideal thickness of 2 to 3 mm (TECH FIG 1A). The
skin flap is depilated through thinning or electrocautery of hair follicles or
prior laser treatment. Periosteum is elevated (TECH FIG 1B).

■ The sites for implant placement are identified. A guide drill with depth stop
is used to drill a pilot hole in the correct vector (TECH FIG 1C). If the 3-mm
depth stop results in complete drilling through bone, the 3-mm depth stop
widening bit should be used and a 3-mm depth implant placed. If significant
bone remains with the 3-mm depth stop, the 4-mm depth stop and implant
can be used.
■ A wider drill bit with countersink is used to widen and countersink the pilot
hole at the appropriate depth.
■ Outer table particulate bone is harvested and placed within the depth of the
cranial bone at the dural interface when it is drilled full thickness.

TECH FIG 1 • A. Skin flap is thinned to an ideal
thickness of approximately 3 mm. B. Periosteum
elevated. C. Drill with depth stop at predetermined
implant locations. D. The implant is tightened with a
torque wrench. E. Biopsy Punch used to perforate skin
at location of implants in one-stage technique.
■ Implants are placed into the holes with a handpiece set at slow speed of 2000
rpm at 25 N-cm handpiece. The torque of 25 N-cm can be increased
depending on the density of the bone.
■ Tighten implant with torque device by the hand to recommended torque
level of the implant system (TECH FIG 1D).
■ At this point, if a one-stage technique is planned, a biopsy punch is used to
make skin holes directly over each implant (TECH FIG 1E).
■ Healing or standard abutments are placed into each implant in the one-stage
technique.
■ If a two-stage technique is used, cover screws are placed over each implant
and skin is closed.

■ The skin incision is closed in layers, including the periosteum.
■ Implants for Auricular Prostheses
■ A skin flap is designed in the proposed area of implant placement by
avoiding pre-existing scars if possible. Typically, this is an anteriorly based
single flap encompassing the area of all implants. Implants are ideally placed
2 cm from proposed or actual external auditory meatus, at least 1 cm apart
from each other, with at least one implant above and one below the meatus.
Incision is planned 1 to 2 cm posterior to the implants (TECH FIG 2A).
■ Two implants are usually adequate for fixation of a bar-and-clip prosthesis.
These are placed within the confines of the planned ear prosthesis, with
positions above, below, and posterior to the external auditory meatus10
(TECH FIG 2B,C).
■ If an anchor for a bone-anchored hearing aid is to be placed, this is placed
posterior to the planned auricular prosthesis into the temporal bone. If a
magnetic-type implant is planned, it is 30 mm in diameter and thus must be
located further from the ear.

TECH FIG 2 • A. Skin flap design for auricular
prosthesis. Incision planned 1 to 2 cm posterior to
planned implants, which are placed 2 cm from
external auditory meatus, at 2 and 4 o’clock position,
or 8 and 10 o’clock position. B. Auricular prosthesis.
(Left) Contralateral native ear. (Right) Prosthetic
reconstruction. C. (Left) Bar-and-clip mechanism of
implant attachment. (Right) Prosthetic in place. (Inset)
Prosthesis showing clips for attachment.
■ Implants for Nasal Prostheses
■ Ideally, at least three implants are utilized for fixation of a nasal prosthetic.
■ Incisions are designed to be hidden by the eventual prosthesis, and flaps are
raised anteriorly and posteriorly (TECH FIG 3A).
■ Good-quality bone is limited around the nasal cavity. The frontal process of

the maxilla (medial buttress) or premaxilla are sources of reasonable bone for
fixation. The radix can also be used (TECH FIG 3B).
■ Correlation with dental anatomy is essential to avoid the maxillary tooth
roots if placing implants into the premaxilla.
TECH FIG 3 • A. Curvilinear incision used to access
premaxilla for nasal implant placement. This incision
will be completely hidden by the prosthesis. B. Implant
locations for nasal prosthesis. C. (Left) Implants in
place for magnet-retained nasal prosthesis. (Right)
Prosthesis in place.
■ Implants for Orbital Prostheses
■ Typically, three to five implants are adequate for fixation of an orbital
prosthesis. Extra implants are often placed as it is assumed that an implant
will be lost at some point.
■ Incision is made at the orbital rim, under the area of the planned prosthesis.
Flaps are raised in both directions from the incision, with the majority of the
dissection deep to the rim (TECH FIG 4A).
■ Implant location is generally designed in the superolateral orbital rim, if
present, due to thicker bone in this area and for consideration of prosthetic
appearance. If the lateral orbital rim is unavailable, the inferior and superior

rims are selected for implant placement. The medial orbital bone is thin and
of limited utility for fixation (TECH FIG 4B).
■ Longer length implants should be used if possible given higher rates of
implant loss in the orbit.
TECH FIG 4 • A. Orbital exposure for implant
placement. Note rim incision and subperiosteal
dissection into orbit. B. Surgical planning for orbital
implant placement. Lateral orbital rim is the location
for the majority of implants. Multiple implants placed
due to higher instability of orbital implants. C. (Left)
Orbital exenteration defect with implants in place.
(Right) Defect with prosthesis in place.

PEARLS AND PITFALLS
Communication/education
■ Educating the patient and family is critical to a
successful outcome for the patient and for the
treating team. Patients need to understand of the
details of the steps involved to achieving the desired
outcome. Expectations are best managed from the
beginning. The psychologist and nurse are critical to
this dialogue.
Implant vector
■ Implants should be placed to full depth and ideally
perpendicular to both bone and soft tissue.
■ The guide drill must be used completely down to
the depth stop to ensure proper seating.
Soft tissue contour
■ Soft tissue should be thinned in a gentle taper
around the implant area to avoid a step-off.
Hair at site of implants
■ If hair remains after surgery, this can be treated
with a laser depilation at a later time.
Postoperative
maintenance
■ It is critical that patients with the support of their
family establish a daily routine for the management
of the peri-implant soft tissue and care of the
prosthesis. Failure to provide adequate care will
lead to loss of implant.
Follow-up
■ Patients with prostheses should be followed
frequently at a minimum of an annual visit to assess
the peri-implant tissue and the quality of the
prosthesis. It is important for the team to assess its
own outcomes and understand the patient’s
satisfaction or dissatisfaction with the treatment.

FIG 5 • Head wrap dressing used postoperatively after
auricular implant placement.
POSTOPERATIVE CARE
■ The area of reconstruction is covered with a pressure dressing and then a head
wrap dressing (FIG 5), which is left in place for a period of 2 to 3 days. After
this point, abutment site care is initiated and showering is permitted.
■ The abutment site is cleaned daily with mild soap and a soft bristle brush to
prevent crusting or buildup. Peri-implant hair should be trimmed and ideally
removed permanently.
■ If a one-stage technique is utilized, healing abutments are left in place for 10
to 12 weeks until the final abutment is positioned. In a two-stage technique, a
period of 12 or more weeks is allowed for osseointegration. Once the final
abutment is in place, the prosthesis fabrication can begin.
OUTCOMES
■ Craniofacial implant–anchored prosthetics are well tolerated and have a long
history of success. A majority of patients are able to wear their prosthesis for
greater than 12 hours/d.1,11,12 Implant anchoring tends to improve patient-
reported quality of life overall.
■ Implant failure rates are low in nonirradiated patients, with failure rates of 5%
to 20% in nonirradiated sites in long-term studies.7,11,13,14
■ Failure rates are higher in irradiated patients.15 Large studies have shown
failure rates of 23% to 54% over time in irradiated fields.7,13,14,16,17 Studies are
mixed on whether high-dose radiation increases implant failure rates over low-
dose radiation.

■ The role of hyperbaric oxygen (HBO) on implant survival in irradiated fields
is as of yet unclear.15 Some studies suggest that HBO used after implant
placement may decrease failure in irradiated bone,13,17 whereas others have
seen no differences in outcomes.16
■ Prostheses themselves have a limited life. Many studies cite a 2- to 5-year life
span.18 However, prostheses may last significantly less time depending on the
patient’s tolerance of discoloration or level of activity with prosthetics in place
due to tearing or damage.19
COMPLICATIONS
■ The most common complication with osseointegrated implants are soft tissue–
related reactions due to inflammation.15,20,21 Reactions are typically graded on
a scale of 1 to 4 (Holgers scale). One is slight local erythema. Two is
erythematous and slightly moist, 3 is moist with granulation tissue, and 4 is
infection.21 Rates of reactions overall range from 3% to 26%, with grade 1
reactions being by far the most common.9,14,21 Device removal due to infection
is extremely rare. The vast majority of skin reactions can be treated with
medication. In cases of exuberant granulation tissue, local tissue around the
abutment can be removed surgically (FIG 6). Aggressive thinning of peri-
implant soft tissues at the time of placement in order to eliminate skin mobility
around the implant is the best way of limiting peri-implant soft tissue reaction.
FIG 6 • Exuberant granulation tissue reaction around
abutments.
■ Implant failure can occur early because of inadequate osseointegration with

poor bone quality and can occur late due to chronic soft tissue infection
affecting the peri-implant bone interface.
■ During drilling for auricular implants, occasionally the dura of the middle
cranial fossa or the sigmoid sinus will be exposed or perforated. In these cases,
if bone stock is good, the implant can be placed as normal and the leak will
seal. If the bone stock is poor, the leak should be sealed with pericranial tissue
followed by autogenous particulate bone harvested from the same operative
field and packed densely into the defect with fibrin sealant. The implant should
be relocated.
REFERENCES
1. Chang TL, Garrett N, Roumanas E, Beumer J III. Treatment satisfaction with
facial prostheses. J Prosthet Dent. 2005;94:275-280.
2. Nemli SK, Aydin C, Yilmaz H, et al. Quality of life of patients with implant-
retained maxillofacial prostheses: a prospective and retrospective study. J
Prosthet Dent. 2013;109:44-52.
3. Greig AV, Jones S, Haylock C, et al. Reconstruction of the exenterated orbit
with osseointegrated implants. J Plast Reconstr Aesthet Surg. 2010;63:1656-
1665.
4. Thiele OC, Brom J, Dunsche A, et al. The current state of facial prosthetics—
a multicenter analysis. J Craniomaxillofac Surg. 2015;43:1038-1041.
5. Albrektsson T, Branemark PI, Hansson HA, Lindstrom J. Osseointegrated
titanium implants. Requirements for ensuring a long-lasting, direct bone-to-
implant anchorage in man. Acta Orthop Scand. 1981;52:155-170.
6. Meltzer NE, Garcia JR, Byrne PJ, Boahene DK. Image-guided titanium
implantation for craniofacial prosthetics. Arch Facial Plast Surg. 2009;11:58-
61.
7. Cohen M, Reisberg D, Patel P, et al. Facial rehabilitation with implant-
retained prostheses: a 16-year perspective. Plast Reconstr Surg. 2009; 124:1-2.
8. Habal MB, Davilla E. Facial rehabilitation by the application of
osseointegrated craniofacial implants. J Craniofac Surg. 1998;9:388-393.
9. Sinn DP, Bedrossian E, Vest AK. Craniofacial implant surgery. Oral
Maxillofac Surg Clin North Am. 2011;23:321-335, vi-vii.
10. Lundgren S, Moy PK, Beumer J III, Lewis S. Surgical considerations for
endosseous implants in the craniofacial region: a 3-year report. Int J Oral
Maxillofac Surg. 1993;22:272-277.
11. Westin T, Tjellstrom A, Hammerlid E, et al. Long-term study of quality and

safety of osseointegration for the retention of auricular prostheses. Otolaryngol
Head Neck Surg. 1999;121:133-143.
12. Han K, Son D. Osseointegrated alloplastic ear reconstruction with the
implant-carrying plate system in children. Plast Reconstr Surg. 2002;109:496-
503.
13. Granstrom G. Osseointegration in irradiated cancer patients: an analysis with
respect to implant failures. J Oral Maxillofac Surg. 2005;63:579-585.
14. Karakoca S, Aydin C, Yilmaz H, Bal BT. Survival rates and periimplant soft
tissue evaluation of extraoral implants over a mean follow-up period of three
years. J Prosthet Dent. 2008;100:458-464.
15. Abu-Serriah MM, McGowan DA, Moos KF, Bagg J. Extra-oral craniofacial
endosseous implants and radiotherapy. Int J Oral Maxillofac Surg.
2003;32:585-592.
16. Toljanic JA, Eckert SE, Roumanas E, et al. Osseointegrated craniofacial
implants in the rehabilitation of orbital defects: an update of a retrospective
experience in the United States. J Prosthet Dent. 2005;94:177-182.
17. Granstrom G, Tjellstrom A, Branemark PI. Osseointegrated implants in
irradiated bone: a case-controlled study using adjunctive hyperbaric oxygen
therapy. J Oral Maxillofac Surg. 1999;57:493-499.
18. Wilkes GH, Wolfaardt JF. Osseointegrated alloplastic versus autogenous ear
reconstruction: criteria for treatment selection. Plast Reconstr Surg.
1994;93:967-979.
19. Karakoca S, Aydin C, Yilmaz H, Bal BT. Retrospective study of treatment
outcomes with implant-retained extraoral prostheses: survival rates and
prosthetic complications. J Prosthet Dent. 2010;103:118-126.
20. Balik A, Ozdemir-Karatas M, Peker K, et al. Soft tissue response and survival
of extraoral implants: a long-term follow-up. J Oral Implantol. 2016;42:41-45.
21. Holgers KM, Tjellstrom A, Bjursten LM, Erlandsson BE. Soft tissue
reactions around percutaneous implants: a clinical study of soft tissue
conditions around skin-penetrating titanium implants for bone-anchored
hearing aids. Am J Otol. 1988;9:56-59.

73
CHAPTER
Section XXI: Conjoined
Twins
Conjoined Twin Separation
Michael R. Bykowski, Joseph E. Losee, and Lorelei J.
Grunwaldt
DEFINITION
■ Conjoined twins are individuals who are physically connected by their
anatomy and share one or more organs. The site of fusion and orientation of the
twins characterize the different types of conjoined twins. Although some
conjoined twins can live functional lives, surgical separation is often performed
for religious beliefs, cultural beliefs, parental wishes, and/or to promote
survival of one or both twins.
■ Conjoined twin separation is the procedure of surgically dividing the
conjoined twins, allocation and reconstruction of shared organs, and soft tissue
coverage. The challenge of the complex anatomy and physiology requires
comprehensive preoperative planning and coordination by a multidisciplinary
team often lead by the plastic surgeon.
■ Because there is great variability of fusion patterns of conjoined twins,
surgical management cannot be reliably predicted and is not amendable to
treatment within fixed protocols. As such, this chapter discusses the general
key principles for planning and executing separation of conjoined twins.
ANATOMY
■ The detailed anatomy of conjoined twins is dependent on each set of twins. In
general, however, the larger the connecting bridge between twins, the more
complex its contents.
■ The tissues of conjoined twins are normal but the anatomy is not. The anatomy

is always abnormal but not in a reliably predictable manner. Nonetheless, there
are general patterns to the anatomy based on the fusion type. The anatomical
arrangements may be such that one twin may be incapable of independent
existence.
■ Classification is based on terminology according to the most prominent site of
connection plus the suffix “pagus,” which is the Greek word meaning “that
which is fixed”.1 Some forms are described below:
■ Thoracopagus (40 cases; FIG 1A): junction primarily at the chest with
varying amount of fusion of the heart, pericardium, and diaphragm.
■ Omphalopagus (34 cases; FIG 1B): joined at the abdomen and often have
fusion of the liver and gastrointestinal (GI) tracts.
■ Pygopagus (18 cases; FIG 1C): connection at the sacrum/perineum and
commonly face away from each other. May have fusion of the terminal spinal
cord and associated meninges.
■ Ischiopagus (6 cases; FIG 1D): connected at the pelvic level. Each twin may
have a normal leg and a common fused leg (ischiopagus tripus) or each has
two normal legs (ischiopagus tetrapus). Often have fusion of distal small
intestine/large intestine and genitourinary system.
■ Craniopagus (2 cases; FIG 1E): fusion of the skull and meninges. (The
separation of craniopagus twins is often driven by the neurosurgical team and
is not discussed in detail in this chapter.)
PATHOGENESIS
■ Conjoined twins are monozygotic, monoamniotic, and monochorionic.
■ There are two leading theories for the pathogenesis of conjoined twin
formation.2
■ Failure of separation of the embryonic plate approximately 15 to 17 days of
gestation
■ Union of two separate embryonic discs
NATURAL HISTORY
■ Conjoined twinning occurs in 1.5 per 100 000 births.3
■ Other congenital anomalies that are not related to conjoining frequently occur
and impact survival with cardiac abnormalities occurring in greater than 60%.4
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The minimal diagnostic criterion is the fusion of some portion of monozygotic

twins.
■ The main physical finding—ie, the site at which the twins are connected—
provides insight to the internal anatomy. Predictable patterns of fusion occur
and are associated with shared organs and organ abnormalities (see FIG 1).
IMAGING
■ From the time of prenatal diagnosis to the time of surgical separation, imaging
is the most important aspect of conjoined twin management.
■ Prenatal and postnatal imaging evaluations are critical for predicting
prognosis, obstetrical planning, medical management, and ultimately surgical
separation.
■ Conjoined twins can be first diagnosed by prenatal ultrasound by the 12th
week of gestation.5
■ Specific diagnostic ultrasound findings include fixed position of the twin
bodies on repeated examinations over time, lack of a separating membrane
between the twins, and an inability to visualize a separation between the fetal
bodies and skin contours.
■ Once the presence of conjoined twins is diagnosed prenatally, further imaging
is crucial to delineate the anatomy and extent of shared organs; both of which
are important for obstetrical purposes and prognosis.
■ Due to the high incidence of cardiac abnormalities, fetal echocardiography is
the most important prenatal evaluation.
■ All conjoined twins (irrespective of the site of connection, but especially for
those with a ventral union pattern)4 should undergo fetal echocardiography.
■ The degree of cardiac fusion and the severity of associated cardiac anomalies
can help predict the postnatal viability and thus provide information for
parental counseling.
■ Prenatal computed tomography (CT) is useful to delineate the anatomic
arrangement of the twins, primarily bony anatomy.
■ Magnetic resonance imaging (MRI) is the best modality to provide the most
detailed imaging of the fetuses as well as their associated anomalies and extent
of union.
■ Ultrafast T2-weighted MRI sequences eliminate the need for maternal
sedation and allow precise anatomical assessment of fetal organs avoiding the
artifact due to fetal movement.
■ Once the fetuses are determined to be viable and subsequently survive birth

and the neonatal period, elective surgery can be planned with a team approach
and with repeat postnatal imaging (discussed in detail below under
“Preoperative Planning”).

Thoracopagus Heart Shared pericardium Sternum Omphalopagus Stomach Pyopagus Liver • Liver Spleen Shared spinal column Shared intestine from mid-duodenum to distal ileum

FIG 1 • Five most common classifications. A.
Thoracopagus. B. Omphalopagus. C. Pygopagus. D.
Ischiopagus. E. Craniopagus.

DIFFERENTIAL DIAGNOSIS
■ Teratoma
■ Lymphatic malformation
NONOPERATIVE MANAGEMENT
■ In determining operative vs nonoperative management of conjoined twins, a
pragmatic approach is necessary to balance:
■ What is technically feasible by the health care team.
■ The parental wishes.
■ The likely outcome for the children with or without separation. (The issue of
parental consent is beyond the scope of this chapter.) The technical feasibility
and prognosis are issues that depend on each other and are dictated by which
organs are connected and the extent of their connections.
■ An extreme example demonstrating successful nonoperative management of a
set of conjoined twins is the famous Eng and Chang Bunker. These twins—
born in Siam in 1811—gained notoriety while traveling with the Barnum &
Bailey Circus under the exhibition name “Siamese Twins.” Despite their
abdominal connection, Eng and Chang married sisters, fathered 22 children,
and lived together for 63 years.
■ Separation of conjoined twins is contraindicated in the following
circumstances:
■ Thoracopagus twins with complex cardiac fusion
■ Craniopagus twins with extensive cerebral fusion
■ Separation that would result in physical disability, which is unacceptable to
the parents. This is often associated with shared organ systems with
compromise of one or both twins when the organ system is removed from one
twin (often seen in parapagus, extensive ischiopagus, and craniopagus).
SURGICAL MANAGEMENT
■ The discussion of this chapter focuses on elective separation, but the
management of conjoined twins can be characterized as three distinct groups:
■ Nonoperative
■ Emergency separation
■ Elective separation
■ The objective of the operation is to separate the conjoined twins while
adequately allocating each individual with organs for survival and to obtain
soft tissue coverage over the resulting defect. In general, the anatomy of the

junction and the shared organs and structures dictate the technical details of the
procedure.
■ A multidisciplinary approach is required along with frequent planning
meetings, involving all of the staff necessary before, during, and after surgical
separation.
■ The staff should include nursing, neonatologists, pediatricians, critical care
physicians, anesthesiologists, and a variety of surgical specialists. Because a
critical factor in conjoined separation is soft tissue coverage, the plastic
surgeon is often the team leader and coordinates all activity.
■ Elective separation should be delayed until at least 2 months of age if
possible.6 The timing of separation varies widely from 2 months to 2 years of
age. The critical factor is to allow time for extensive preoperative planning and
simultaneous medical optimization.
■ Occasionally, conjoined twins require mechanical ventilation to preserve
respiratory functioning toward the end of tissue expansion of the abdomen or
thorax, as there may be decreased tidal volume from external compression.7
■ Due to the varied anatomy of conjoined twins, it is usually not possible to
follow a predetermined protocol for surgical separation. In general, the main
steps of the procedure are as follows:
■ Exposure of shared organs
■ Division, allocation, and reconstruction of shared organs
■ Identification and ligation of cross-circulation
■ Abdominal wall reconstruction and wound closure with rotational flaps,
previously expanded tissues, and skin substitute materials
Preoperative Planning
■ Although the health care team is large and multidisciplinary, it must be clear
that there is a lead surgeon who is in charge and makes the final decisions on
preoperative evaluations and treatment.
■ Conjoined twin separation is technically challenging due to the various organs
that can be fused. The most important factor for successful separation is
preoperative planning through postnatal multimodal imaging modalities.
■ Postnatal imaging is the keystone of preoperative planning to, firstly, assess
operability and, secondly, to understand the shared anatomy and help with
surgical planning.
■ Three features are key to determining survival and thus should be a focus of

preoperative planning:
■ Major vascular connections
• CT angiogram: this modality is necessary to visualize vascular connections.
■ Management of the body wall closure: without adequate soft tissue coverage,
the patient is at risk for exposure of viscera, evisceration, and sepsis. CT
imaging allows sufficient assessment of the anticipated soft tissue deficiency
and can help determine reconstructive options. If closure is too tight, cardiac
and pulmonary functioning can be compromised. Therefore, additional soft
tissue coverage needs to be created or temporizing measures must be
employed.
• Tissue expansion.
• Mesh or dermal substitutes.
• Rotational flaps can be used as an adjunct to tissue expansion and skin
substitutes.
■ Performance of both hearts after separation: cardiovascular performance after
separation is not predictable given potential changes in cardiac functioning
and changes in circulation.
■ Even with extensive postnatal imaging, close monitoring and treatment in the
intensive care unit is necessary.
■ Because congenital anomalies (unrelated to conjoined twinning) are common,3
all patients regardless of the form of conjoined twin should undergo cranial
ultrasound, abdominal ultrasound, CT, and MRI. Three-dimensional models
can be created to aid in surgical planning.
■ As stated above, each type of union is associated with specific structural
abnormalities, so preoperative evaluation and planning will vary.
■ Each organ system should be preoperatively evaluated in a systematic manner.
■ Cardiovascular system: due to the high rate of cardiac abnormalities in all
forms of conjoined twins, all twins should undergo postnatal
echocardiography to characterize cardiac anomalies. Thoracopagus twins
should undergo electrocardiographic-gated cardiac CT or cardiac MRI for
detailed assessment of cardiac anatomy.
■ Respiratory system: CT is performed to demonstrate the anatomy of the lungs
and airways. Parapagus twins often have abnormalities of the
tracheobronchial tree. Although the respiratory systems in thoracopagus and
omphalopagus twins develop separately, there may be associated
abnormalities (eg, hypoplastic lobes secondary to diaphragmatic hernia or

asymmetric chest union).
■ Hepatobiliary tree: the number of gallbladders, liver, and pancreas should be
known. Furthermore, liver vascularity and hepatic venous drainage for each
twin must be ascertained. The liver is fused in all parapagus twins, most
thoracopagus and omphalopagus twins, and less frequently in ischiopagus
twins. Cross-sectional imaging will demonstrate the degree of fusion and
visualize the intrahepatic vessels. MRI or CT scan with contrast injected into
one twin can help to delineate the plane of liver separation. Overall, 25% of
thoracopagus twins share a biliary system. Magnetic resonance
cholangiopancreatography (MRCP) provides a detailed assessment of biliary
anatomy.
■ GI system: the length of the alimentary tract should be evaluated. Though
laparoscopy or upper GI contrast studies have been used to evaluate bowel
distribution, much of the anatomy can be determined and managed during the
separation procedure by the general surgeons. The lower GI tract is shared
most often in ischiopagus twins (70% of cases) and in 25% of pygopagus
twins. Pygopagus twins often have varying degrees of rectal fusion and
common anuses. Contrast enema along with MRI will demonstrate complex
anorectal abnormalities.
■ Urinary tract: imaging studies are performed to assess the number, reflux
status, and anatomy of the kidneys, ureters, urinary bladders, and urethras.
Cystograms can identify small fistulae not revealed by cross-sectional
imaging. In 15% of pygopagus cases, the bladder is shared. Half of
ischiopagus twins share pelvic organs.
■ Genital system: in pygopagus and ischiopagus twins, vaginoscopy is
mandatory to assess vaginal and cervical anatomy. MRI can demonstrate the
number of uteri, ovaries, vaginas, and testes.

FIG 2 • Markings prior to chest and abdominal tissue
expander placement and subsequent removal due to
restrictive lung disease.
■ Central nervous system: the nature and extent of spinal cord fusion is
assessed in pygopagus, ischiopagus, and parapagus twins with spinal MRI.
■ Integumentary system: the soft tissue deficiency that will occur following
separation can be estimated with CT scan. This information can be used to
plan for the number of and placement of tissue expanders. Vascular territories
of the skin can be mapped by intravenous fluorescein dye.
■ Musculoskeletal system: CT scan provides detailed assessment of bony
anatomy, which is especially useful to determine pelvic and spinal bony
anatomy in cases of caudal union. MR angiography can be used as an adjunct
to determine blood supply when vascularized muscle flaps are planned—eg,
when a shared limb will be used for wound closure.
■ The primary goal of the plastic surgeon is to provide coverage overlying the
newly created defect following separation.
■ Tissue expanders have been placed intraperitoneally and in subcutaneous
positions throughout the bodies of conjoined twins.
■ The size of the defect following separation can be extensive and require
multiple strategies in addition to tissue expanders, including meshes or dermal
substitutes.
• Tissue expansion overlying the abdomen/thorax can compress the compliant

chest wall and immature respiratory muscles of young children, leading to
restrictive lung disease7 (FIGS 2 and 3). As such, tissue expanders should
be minimized around the thorax (FIG 4).
FIG 3 • Top row. CT cross-section view through
ischiopagus twins with and without tissue expanders.
Bottom row. Lind drawing of chest cavity showing
deformation of anterior chest wall with tissue expanders
in place. (Left) Preoperative chest CT scan. (Center)
Chest scan with tissue expanders inflated and resultant
chest deformation. (Right) Chest scan 6 months after
tissue expander removal and resolution of clinical
respiratory symptoms.

FIG 4 • Tissue expanders removed for the chest of one
twin but maintained in the other. A tissue expander is
placed on the left extremity.
■ When plausible, expanders should be placed near the pelvic ring so that
counter pressure is provided to optimize tissue expansion. Caution must be
taken to avoid expanding too rapidly to avoid skin ischemia and expander
exposure.
■ Due to the thin subcutaneous layer in infants, smooth wall tissue expanders
are used. Textured implants tend to minimize capsule formation, which can
promote thinning of the skin.
• Distant ports are used rather than integrated ports. The reason is that the thin
skin overlying the expander is more prone to breakdown from repeated
injections during the expansion process.
■ Tissue expansion using pneumoperitoneum is an alternative. Sterile air is
injected (500–1500 cc) every 3 days to expand abdominal circumference.8
Ischiopagus tripus twins present with an accessory hip joint and lower
extremity, giving a tripod, or “tripus” configuration. As discussed below in
“Techniques,” the tripus (FIG 5) can provide additional coverage by filleting
it open for maximal use of the skin, subcutaneous tissues, and muscle.
Positioning
■ Positioning will depend on how the twins are conjoined. Due to the potential

for a long duration of surgery, the twins must be well padded to prevent the
development of decubitus wounds.
■ Positioning must allow adequate exposure to the planned line of separation.
■ If a posterior approach is favored, position the patient supine initially. Once
intubated and venous access secured, the twins can be turned prone. This
maneuver can be cumbersome. Circumferential sterile surgical preparation is
often required.
FIG 5 • Posterior view of the conjoined twins that
demonstrates the tripus (after bones removed), which
will be used for the abdominal wall reconstruction.
■ An important consideration is that a separate room is prepared and staffed for
once the separation is completed. One twin will be transferred from the initial
operating room to the other room while final reconstruction and wound closure
is performed for each. After separation, each individual should have its own
anesthesia team, surgical team, surgical staff, and operating room.
■ A staff member is assigned to communicate ongoing progress of the surgery
and coordinates patient transfers.
Approach
■ An anterior approach is most often performed.
■ Depending on the conjoined twin anatomy, some surgeons favor a posterior

approach.
T E C H N I Q U E S
■ Separation of Ischiopagus Conjoined Twins
Outline and Order of Procedures
■ Anterior incision extending from the chest to perineum.
■ Anterior pelvic osteotomy and “booking open” of fused pelvic ring.
■ Ligation and reimplantation of twin no. 1’s left ureter.
■ Transabdominal liver separation.
■ Separation of two ileums from the single channel into the colon.
■ Posterior pelvic osteotomy with excision of the extranumerary hip joint of
the tripus.
■ Fillet of the tripus to create two musculocutaneous flaps.
■ Repair of ventral abdominal wall and pelvic floor defects with allograft,
tissue expanded advancement flaps, and musculocutaneous flaps for each
twin.
Initial Steps
■ Plan the skin incision to provide optimal exposure of the shared internal
organs to facilitate equal allocation and reconstruction of organs. Special
attention is paid to the pelvic region where the most complex connection
occurs between the gastrointestinal and genitourinary tracts.
■ Markings: while the twins are supine, mark the most cephalad point at the
junction between the twins. Extend the marking inferiorly along the midline
(in line with the umbilicus) toward the pelvis. The marking continues to the
left of twin no. 1’s labia majora, which was preoperatively determined to go
with twin no. 1 (TECH FIG 1A).
■ Sharply incise the ventral surface along the midline through the skin between
the tissue expanders (TECH FIG 1B).
■ Continue the incision deep through subcutaneous tissue with electrocautery
to enter the abdominal cavity. Continue dissection inferiorly to the pelvic
region to directly expose the anterior aspect of the pelvic ring. Note: it is
known from preoperative imaging that the pubic symphysis is near-normal

and midline.
TECH FIG 1 • A. Inferior view of the twins
demonstrating the markings about the perineum. B.
The ventral incision is performed along the midline to
provide adequate exposure of internal anatomy. C.
The conjoined livers are exposed and separated with
electrocautery and ligation of small venous branches
that traverse the isthmus. D. The small soft tissue

bridge is the only connection of the twins. E. These
soft tissues are separated, and the twins are entirely
separate. F. The tripus of each twin is rotated medially
and laterally and tacked down to be used for pelvic
reconstruction.
■ The urologists dissect, identify, and retract the ureters and bladders to
prepare for safe division of the anterior pelvic ring at the pubic symphysis.
■ In conjunction with the orthopedic surgeon, the pubic symphysis is
visualized and divided using a combination of electrocautery and an
osteotome. This maneuver allows the pelvis to “book” open.
■ With this exposure, dissection is carried posteriorly toward the rectum,
which appears to have two blood supplies, one from each twin.
■ With focus moved more proximally, it is ascertained that each twin has an
entire length of small bowel to near the distal end where there is a common
channel of small bowel that leads into a single colon.
■ Attention is directed to the anterior chest where dissection is carried down
deep between the chest cavities of both twins. Dissection is continued along
this plane to the posterior aspect of the twins toward the operating table.
■ The connected livers are now adequately exposed, which are fused at the
midline for a broad segment encompassing an approximately 8-cm span. The
shared liver is separated with electrocautery and ligation of small venous
branches that traverse the isthmus with 3-0 Vicryl sutures (TECH FIG 1C).
■ Once the liver is divided, each twin’s liver, stomach, and proximal small
bowel can be easily retracted to the right and to the left to identify the four
kidneys in the retroperitoneum.
■ A Balfour retractor is placed to give adequate exposure.
■ Attention is then turned to separate the small bowel. At the level of the
Meckel diverticulum, an EndoGIA stapler is fired across twin no. 2’s small
bowel who will later undergo creation of an end ileostomy.
■ Twin no. 1’s small bowel, colon, and colonic mesentery are separated from
twin no. 2’s small bowel. A bulldog clamp is used to assess the vascularity of
the colon, which is determined to have two separate active blood supplies.
The colonic blood supply of twin no. 2 is divided because she will not have a
colonic conduit.

■ Of note, because twin no. 1 had more of the perineum, it was preoperatively
decided to leave the rectum with twin no. 1.
■ The colon is retracted laterally to allow the urology team to proceed. The
balloon in each bladder is palpated to determine its location in the shared
pelvis. Twin no. 2’s left ureter, which connects to the contralateral twin’s
bladder, is ligated with 3-0 Vicryl at the ureterovesical junction.
■ Dissection is performed to create definition between the bladders.
■ Dissection is continued to isolate the uterus, fallopian tubes, and ovaries of
each twin with their respective pedicles. This dissection further delineates the
plane of cleavage for the twins.
■ The previously ligated ureter of twin no. 2 is tunneled through the
mesentery, spatulated, and closed to the neohiatus of the bladder. Good efflux
of urine is confirmed, and the bladder is irrigated easily.
■ After genitourinary reconstruction, attention is turned to the bony pelvis as it
is still connected at the posterior aspect along with the extranumerary hip
joint of the tripus.
■ From preoperative evaluation, the iliac vessels are known to feed the
conjoined connection within the single nonfunctional tripus.
■ Using an abdominal retractor, the organs of each twin are retracted laterally
to provide access to their medial shared hip structures and components.
■ The aortas are palpated, and the iliac vessels of each child are identified and
followed, which lead to either side of the hip joint. With the help of the
orthopedic surgeon, osteotomies are created on either side of the hip joint,
which is then is excised.
■ The distal portion of the femur was previously removed in a separate
procedure due to concerns with pressure necrosis on adjacent tissue expanded
skin. The proximal femur is then directly visualized and is grabbed with a
towel clip. The proximal femur is skeletonized with electrocautery and
removed in continuity.
■ After the removal of the hip joint and the proximal femur, further dissection
of the iliac vessels is performed as they course into the tripus internally. The
dissection of the iliac vessels is performed cautiously with a handheld
Doppler device until each set of iliac vessels is traced into the tripus. The
tripus is then split longitudinally to create two individual musculocutaneous
axial pattern flaps.
■ At this point, a small soft tissue bridge only connects the twins (TECH FIG

1D). These soft tissues are separated, and the twins are entirely separate
(TECH FIG 1E).
■ The tripus of each twin is rotated medially and laterally and tacked down to
be used for pelvic reconstruction (TECH FIG 1F).
■ A patient bed is brought into the operating room, and twin no. 2 is
transferred to the adjacent operating room where further reconstruction is
completed.
Twin no. 2
■ The procedure begins with the inset of the tripus, which is on the
posterolateral right side of her lower body. The hemitripus is reflected as a
musculocutaneous flap from lateral to medial at the inferior aspect of her
ventral wound recreating her pelvic floor. The hemitripus is inset into the
inferior edge of the wound initially into layers closing the deep soft tissues
with 2-0 Vicryl (Ethicon, Inc., Somerville, NJ) in interrupted buried fashion
followed by a single closure utilizing 3-0 Monocryl (Ethicon, Inc.,
Somerville, NJ) in an interrupted buried deep dermal fashion.
■ The left upper leg expander, left chest wall tissue expander, and right upper
chest wall tissue expander are removed to create the left leg inferiorly based
advancement flap. This flap is elevated in the subfascial plane while also
harvesting the capsule. The composite tissues are advanced centrally toward
the ventral defect.
■ On the left lower lateral abdomen, a wide-based rotation flap is created from
removal of its tissue expander, which is rotated medially. Similarly, on the
right upper posterior chest, the tissue expander is removed to create a wide-
based rotation flap, which is based superiorly and rotated centrally.
■ A large sheath of extra thick AlloDerm is used to close the fascial defect of
the ventral body. The AlloDerm is inset to the surrounding fascia and body
wall utilizing 2-0 PDS (Ethicon, Inc., Somerville, NJ) in a horizontal mattress
fashion.
■ On the inferior aspect of the ventral defect, the tripus remnant is used to
recreate the pelvic floor by suturing muscular elements of the tripus to the
surrounding remnants of the muscular pelvic girdle.
■ The advancement flaps are closed in layers utilizing 2-0 Vicryl in an
interrupted buried fashion within the deep tissues followed by skin closure
utilizing 4-0 plain gut in a simple running fashion.

■ The ventral defect is decreased in size using a no. 1 Maxon (Ethicon, Inc.,
Somerville, NJ) suture along the periphery of the closure to create a purse-
string effect.
■ The general surgeons re-entered the case to create a left-sided ostomy by
incising the AlloDerm. The end ileostomy is brought through the left
abdominal wall.
■ A negative suction-assisted closure device is placed on the skin defect area
directly atop the AlloDerm.
■ The patient is transferred to the intensive care unit. Over the oncoming
weeks, the vacuum-assisted suction device is used to promote formation of
granulation tissue (TECH FIG 2).
Twin no. 1
■ As with twin no. 2, the split tripus is used as an axial-based
musculocutaneous flap for pelvic floor reconstruction. A large piece of 16 ×
20-cm AlloDerm is sewn across the abdominal wall to act as a barrier and
also to act as a substitute for the anterior rectus sheath.
■ The four tissue expanders were removed. The expanders from the anterior
chest and the lateral chest wall are used as advancement flaps.
TECH FIG 2 • Postoperative photograph of twin no. 2
showing healing of soft tissue defect.

■ Back cuts are made along the lateral abdominal wall into the right axilla and
also into the left axilla in the left lateral chest wall. These flaps are advanced
into the middle and are sutured to each other.
■ A large central defect remains that measures 10 × 15 cm where the
AlloDerm is exposed. A negative suction-assisted closure device is placed
atop of the exposed AlloDerm.
■ The patient is transferred to the intensive care unit. Over the oncoming
weeks, the vacuum-assisted suction device is used to promote formation of
granulation tissue (TECH FIG 3).
TECH FIG 3 • Postoperative photograph of twin no. 1
showing healing of soft tissue defect.
PEARLS AND PITFALLS
Preoperative
imaging
■ Images obtained without anesthesia can be suboptimal. CT scans
under general anesthesia allow suspension of respiration to
minimize artifact.
■ An additional benefit is that the anesthesia team has an opportunity
to assess how each twin behaves hemodynamically while under
general anesthesia.

Abdominal
closure
■ Primary closure of the abdomen should be completed under no
tension, as tension can lead to cardiopulmonary insufficiency and
death.
■ A combination of techniques should be used to obtain tension-free
closure, including tissue expanders, pneumoperitoneum, dermal
replacement materials, and/or meshes (as a temporary measure).
Abdominal
tissue
expansion
■ Use of tissue expanders overlying the abdomen can be used to
achieve skin expansion and coverage of moderately sized soft tissue
defects. However, additional measures are often required such as
rotational flaps and/or dermal replacement materials.
■ Tissue expanders should be placed near the pelvic ring to provide
counter pressure to optimize soft tissue expansion.
Thorax
tissue
expanders
■ Circumferential placement of thorax expanders can lead to
restrictive lung disease. This problem is especially true in younger
patients with more compliant chest walls and immature respiratory
muscles.
■ Restriction of respiratory mechanics is more pronounced in twins
who are joined at the chest, which results in compressive forces on
three of the four sides of the chest wall.
Pressure
relief
■ A pressure relieving bed is critical to reduce decubitus ulcer
development.
■ Pressure relief is paramount, especially with use of posterior tissue
expanders, to avoid soft tissue necrosis and expander exposure.
Tripus fillet
procedure
■ The third leg in ischiopagus tripus twins is deformed and
nonfunctional and can even induce pressure necrosis to adjacent soft
tissues undergoing expansion.
■ The filleted tripus can be separated to create musculocutaneous
flaps for each twin for abdominal and/or pelvic floor reconstruction.
POSTOPERATIVE CARE
■ Planning of postoperative care occurs in the preoperative period. Meticulous
supportive care in the intensive care unit is mandatory. The acute physiological
changes occur after separation, especially when cardiac separation is performed
and/or extensive cross-circulation is present prior to separation.
■ Cardiovascular instability should be anticipated.
■ In most cases, elective paralysis and mechanical ventilation is necessary for 24
to 48 hours for cardiopulmonary stabilization.
■ Aside from critical care support, attention should be focused to promote
wound healing.

■ Nutrition must continue to be optimized postoperatively.
• Parenteral and enteral feeding should be considered.
■ Focus should be to reduce the risk of health care–associated infection with
the strict use of gowns and gloves to decrease exposure to hospital pathogens.
■ Pressure-relieving beds are required for wound healing and to prevent
development of decubitus ulcers.
■ Extremity immobilization can promote flap healing and can prevent
accidental trauma induced by the moving infants.
OUTCOMES
■ Patient outcomes depend on the extent and complexity of the connection of the
conjoined twins.9,10
■ Omphalopagus twins typically have the least extensive connection and have
the highest survival rates.
■ Due to complex cardiac connections and abnormalities, thoracopagus twins
have the lowest survival rates, with the exception of craniofacial anomalies.10
COMPLICATIONS
■ Tight closure of the abdomen or thoracic cavities can lead to cardiopulmonary
insufficiency, which can lead to abdominal compartment syndrome, restrictive
lung disease, or a cardiac low-output state.
■ Wound healing complications are common postoperatively.
■ Tissue necrosis can occur with high-tension closure, especially due to
unpredictable blood supply of soft tissues.
■ With inadequate soft tissue coverage or subsequent breakdown, abdominal
viscera can be exposed.
REFERENCES
1. Spencer R. Anatomic description of conjoined twins: a plea for standardized
terminology. J Pediatr Surg. 1996;31(7):941-944.
2. Spencer R. Conjoined twins: theoretical embryologic basis. Teratology.
1992;45(6):591-602.
3. Mutchinick OM, et al. Conjoined twins: a worldwide collaborative
epidemiological study of the International Clearinghouse for Birth Defects
Surveillance and Research. Am J Med Genet C Semin Med Genet.
2011;157C(4):274-287.
4. McMahon CJ, Spencer R. Congenital heart defects in conjoined twins:

outcome after surgical separation of thoracopagus. Pediatr Cardiol.
2006;27(1):1-12.
5. Chen CP, et al. Conjoined twins detected in the first trimester: a review.
Taiwan J Obstet Gynecol. 2011;50(4):424-431.
6. Kiely EM, Spitz L. Planning the operation. Semin Pediatr Surg.
2015;24(5):221-223.
7. Losee JE, et al. Induced restrictive lung disease secondary to tissue expansion
in ischiopagus conjoined twins. Plast Reconstr Surg. 2009;123(4):1378-1383.
8. Qazi AQ, et al. Separation of xiphi-omphalo-ischiopagus tetrapus twins with
favorable internal anatomy. J Pediatr Surg. 2002;37(5):E9.
9. Jackson OA, Low DW, Larossa D. Conjoined twin separation: lessons
learned. Plast Reconstr Surg. 2012;129(4):956-963.
10. Tannuri AC, et al. Conjoined twins: twenty years’ experience at a reference
center in Brazil. Clinics (Sao Paulo). 2013;68(3):371-377.

Index
Note: Page numbers followed by the letter “f” refer to figures;
those followed by the letter “t” refer to tables; and those
followed by the letter “b” refer to boxes.
A
Abbe flap, 2652–2653, 2652f–2653f. See also Estlander flaps
anatomy, 1063
complications, 1067
definition, 1063
donor-site preparation, 1064, 1064f
imaging, 1063
merits and demerits, 1064b
pathogenesis, 1063
patient history and physical findings, 1063
placement and closure, 1066, 1066f
raising the flap, 1065, 1065f
recipient-site preparation, 1064, 1065f
surgical management
approach, 1064
patient positioning, 1064
preoperative planning, 1063–1064
Abdominal compartment syndrome, 3031
Abdominal oblique release, external, 1574–1575
Abdominal panniculectomy
anatomy, 1602

complications, 1607
definition, 1602
flap advancement and skin resection, 1606, 1606f–1607f
imaging, 1603, 1603f
merits and demerits, 1607b
natural history, 1602
nonoperative management, 1603
outcomes, 1604f, 1607
pathogenesis, 1602
patient history and physical findings, 1602, 1603f
postoperative care, 1607
in super obese
anatomy, 1609
during closure, 1611, 1611f
complications, 1611
definition, 1609
diagnostic studies, 1609
imaging, 1609
merits and demerits, 1611b
nonoperative management, 1609
outcomes, 1611
pannus preparation and transection, 1610, 1610f
patient history and physical findings, 1609
postoperative care, 1611
surgical management, 1603–1604, 1603f
patient position and anesthesia, 1603–1604
preoperative planning, 1603
with umbilical transposition, 1605, 1605f
dissection, 1604, 1605f
markings and incision, 1604, 1604f
Abdominal wall, 1556
anatomy, 1563, 3030, 3031f
complications, 3036

definition, 3030, 3030f
imaging, 3032, 3032f
merits and demerits, 3035b
natural history, 3031–3032, 3032f
outcomes, 3036
pathogenesis, 3030–3031
patient history and physical findings, 3032
postoperative care, 3035–3036
surgical management, 3032, 3033b
Abdominal wall defects
anatomy, 1588–1589
complications, 1595
imaging, 1589
merits and demerits, 1595b
pathogenesis, 1589
patient history and physical findings, 1589
postoperative care, 1595
surgical management
approach, 1590, 1591f–1592f
patient position, 1590
preoperative planning, 1589–1590, 1589f
Abdominal wall reconstruction, rectus femoris flap for
anatomy, 1580, 1581f
complications, 1586
definition, 1580
imaging, 1580
merits and demerits, 1586b
outcomes, 1586, 1586f
patient history and physical findings, 1580
postoperative care, 1586
surgical management, 1580–1582
surgical markings, 1583, 1583f
Abdominal-based flaps, for breast reconstruction

anatomy, 1438–1439, 1438f–1439f
complications, 1445
decision-making algorithm, 1441f
definition, 1438
differential diagnosis, 1440
imaging, 1440
merits and demerits, 1442b, 1444b
natural history, 1439
outcomes, 1445
pathogenesis, 1439
patient history and physical findings, 1439
postoperative care, 1444
SIEA flap
anterior dissection, pedicle, 1442–1443, 1442f–1443f
donor site closure, 1444
flap inset, 1443–1444
harvest completion, 1443
incision and exposure, 1442, 1442f
recipient vessels and microanastomosis, 1443
surgical management
approach, 1441
patient positioning, 1441
preoperative planning, 1440–1441
Abdominoplasty
anatomy, 1596
closure and exteriorization of umbilicus, 1599, 1600f
complications, 1601
definition, 1596
flap inset, 1598–1599, 1599f
imaging, 1596
incisions and dissection, 1598, 1598f
markings, 1597
merits and demerits, 1600b

mons pubis, conjunction with, 1642, 1642f
narrower waistline, 1600, 1600f
outcomes, 1598f, 1600–1601
patient history and physical findings, 1596
postoperative care, 1600
surgical management, 1596–1597, 1597f
approach, 1597
patient position, 1597, 1597f
preoperative planning, 1596–1597
umbilical stenosis after, 3040, 3040f
Abductor digiti minimi (ADM), 1986–1987, 1986f, 2366
to abductor pollicis brevis, 2015, 2015f
opponensplasty, 2231–2232, 2232f
Abductor pollicis (AP) brevis
abductor digiti minimi, 2015, 2015f
extensor indicis proprius tendon, 2015–2016, 2016f
flexor digitorum superficialis, 2013–2015, 2014f
palmaris longus to, 2013, 2014f
Abductor pollicis longus suspensionplasty, 1965, 1965f–1967f
ABI (ankle-brachial index), 2365, 2400, 2401f
Ablative fractional resurfacing, 52f, 54
Ablative nonfractional resurfacing, 54
Above-knee amputation, 2549
Above-knee popliteal exposure, 2403, 2403f
Abscesses drainage, of lower leg and foot
anatomy, 2335, 2335f
approach, 2336
complications, 2337
definition, 2335
differential diagnosis, 2336
imaging, 2336
merits and demerits, 2336b
necrotic right lateral foot wound, 2336, 2337f

nonoperative management, 2336
patient history and physical findings, 2336
postoperative care, 2337
preoperative planning, 2336
supine position, 2336
ACB. See Amniotic constriction band (ACB) reconstruction
Acellular dermal allograft, 2656, 2656f
Acellular dermal matrix (ADM), 1221, 2698
direct-to-implant breast reconstruction, 1399–1400, 1400f, 1401f
Acetaminophen, 2414
Acetylsalicylic acid (ASA), 421
ACG. See Alar contour graft (ACG)
Achilles tendon reconstruction
anatomy, 2416, 2416f
complications, 2419
definition, 2416
differential diagnosis, 2417
flexor hallucis longus tendon, 2419, 2419f
imaging, 2416–2417, 2417f
natural history, 2416
open direct (end-to-end) suture repair, 2418, 2418f
pathogenesis, 2416
patient history, 2416
percutaneous repair, 2418, 2418f
physical findings, 2416
postoperative care, 2419
reconstruction with VY advancement, 2419
surgical management, 2417
approach, 2417
patient positioning, 2417, 2417f
preoperative planning, 2417
Acne scarring, 55
Acneform eruptions, 66

Acquired ectropion, 1103–1104
Active Movement Scale, 2949
Acute infection, 2506
Acute osteomyelitis, 2352–2353
Acute traumatic injury, repair of, 2453
Acute venous insufficiency, 2520
Acute wound, sharp debridement of, 2428–2429, 2429f
Adductor canal, 2524, 2525f
Adductor canal blocks
anatomy, 2310
complications, 2313–2314
definition, 2310
imaging, 2310
merits and demerits, 2313b
outcomes, 2313
patient history and physical findings, 2310
postoperative care, 2313
surgical management, 2310–2311
approach, 2311
patient positioning, 2311
preoperative planning, 2311
ultrasound-guided technique, 2312f
Adductor pollicis, 1986–1987, 1986f
Adductor pollicis (AdP) with tendon graft
ECRB, 2037, 2038f–2039f
Adenoid cystic carcinoma
facial nerve, 1256, 1256f
FOM, 1210
Adequate septal cartilage, 299
Adipofascial flaps, 2123
Adjunctive hyperbaric oxygen treatment, 2408
ADM. See Abductor digiti minimi (ADM)
Adrenaline

furlow palatoplasty, 2664
hard palate incisions, 2676
Advanced Trauma Life Support guidelines, 2467
Aecondary aneurysmal bone cyst of the talar body, 2343f
Aesthetic chin projection assessment
in woman vs. men, 758, 758f
Aesthetic subunits, 1122, 1122f
Aggressive wound debridement, 2408
AIA (anterior interosseous artery), 2126, 2128, 2132
Airway assessment, 2618
Airway compromise, 2682
Airway contracture, 2766, 2766f–2767f
Airway obstruction, 698, 2674, 2690, 2694
palatal fistula, 2704
two-flap palatoplasty, 2689
velopharyngeal insufficiency, 2713
Alar base, 2629, 2631
anatomy, 2606
elevation, 2610
on lateral lip element, 2608f–2609f, 2609
managing, 321–322, 321f
repositioning of, 2612, 2613f
subunits, 1146, 1147f
Alar cartilage, 2617
malposition, 289
resection, ethnic rhinoplasty, 291
Alar collapse, 377
Alar contour graft (ACG)
anatomy, 377
complications, 379
definition, 377, 377f
imaging, 377
lateral placement—open approach, 378

merits and demerits, 379b
open, medial placement, 378, 378f
outcomes, 379
patient history and physical findings, 377
postoperative care, 379
surgical management, 378
approach, 379
preoperative planning, 378
Alar rim
grafts, 319–321
reconstruction, 1182
Alar wedge resection, ethnic rhinoplasty, 292
Allen test, 1173, 1987
Allergic contact dermatitis, 973
Allergy, local anesthesia, 973
Allograft(s), 2431, 2436, 2769
cancellous chips, 2358
dermis, 358, 358f
reconstruction and femur resection, 2503, 2504f
Alloplastic chin augmentation
anatomy, 758, 758f
chin implant styles, 758, 759f
complications, 760–761
definition, 758
differential diagnosis, 758
imaging, 758
implant placement and fixation, 760
merits and demerits, 759b
natural history, 758
nonoperative management, 758
outcomes, 760
pathogenesis, 758
patient history and physical findings, 758

postoperative care, 760
surgical management
approach, 759, 759f–760f
patient positioning, 759
preoperative planning, 759
Alloplastic implants, 392
Alloplastic reconstruction, calvarium
anatomy, 519
complications, 522
definition, 519
imaging studies, 519–520, 520f
intraoperative technique, 520, 521f
left parietal skull defect, 519, 520f
merits and demerits, 520b
natural history, 519
outcomes, 522
pathogenesis, 519
patient history and physical findings, 519
postoperative care, 522
resected calvarial tumor specimen, 519, 519f
surgical management
patient positioning, 520
preoperative planning, 520
Alopecia, 990, 2803
Alveolar bone, 2616
Alveolar cleft defects
alveolar bone grafting of
anatomy, 643, 643f
complications, 649
definition, 643
dissection, 645–647, 645f, 646f, 647f
iliac crest bone graft harvest, 648, 648f
imaging studies, 644

indications, 645
merits and demerits, 645b
natural history, 644
nonoperative management, 644
outcomes, 649
pathogenesis, 643–644
patient history and physical findings, 644
postoperative care, 649
surgical management, 645, 645f
bone morphogenetic proteins
anatomy, 663, 663f–664f
gingivoperiosteoplasty with BMP-2, 666
imaging studies, 664
merits and demerits, 666b
natural history, 664
outcomes, 668
patient history and physical findings, 664
postoperative care, 668
secondary, 666
surgical management, 664, 665f
Ambiguous genitalia
anatomy, 3062
complications, 3073
definition, 3062
differential diagnosis, 3063–3064
examination, 3063
imaging, 3063
merits and demerits, 3072b
natural history, 3063
nonoperative management, 3064
outcomes, 3066f, 3072
pathogenesis, 3062–3063
patient history and physical findings, 3063

postoperative care, 3072
surgical management
approach, 3064–3065
patient position, 3064, 3065f
preoperative planning, 3064
The American Society of Regional Anesthesia (ASRA) guidelines,
2330
Amino esters, 1759
Aminoglycosides, 2466, 2471
Amniotic constriction band (ACB) reconstruction
adipofascial advancement technique, 2260–2261, 2262f, 2263f
anatomy, 2259
complications, 2264–2265
definition, 2259
differential diagnosis, 2259
fenestrated syndactyly, release of, 2263, 2263f
imaging, 2259, 2261f
merits and demerits, 2264b
natural history, 2259
nonoperative management, 2260
outcomes, 2264, 2264f
pathogenesis, 2259
patient history and physical findings, 2259, 2260f
postoperative care, 2264
surgical management, 2260–2261
patient positioning, 2261
preoperative planning, 2261
Amputation, 2372
absolute indications for, 2394
relative indications of, 2394
traumatic, fingertip, 1766–1770
Anastomosis, 2394–2396, 2394f
flap and, 2526, 2526f