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increases risk of psychological problems, including
suicide attempts.
Studies have demonstrated accelerated facial
aging associated with reduction of bone and
nonfat subcutaneous soft tissues.
ABDOMINAL WALL
TRANSPLANTATION
Background
Involves transplantation of the abdominal wall to close the
abdomen.
All cases reported to date have been in conjunction with
intestinal or multivisceral transplantation in both pediatric
and adult patients.
Indications and Patient Selection
Traditional methods of abdominal wall closure are not
possible following intestinal or multivisceral transplantation.
Desire to avoid donor site morbidity associated with
autologous free flap.
Need to avoid risk of infection with open abdomen or
prosthetics.
Need to prevent abdominal compartment syndrome by
achieving tension-free closure.
Surgical Procedure
Surgical planning
Composite tissue allograft to assess abdominal wall
vessels.
ABO matching is common. Some studies report that
HLA matching may not be needed but sample sizes
are small.
Donor abdominal wall is typically harvested from the
same donor as the solid organ/intestinal grafts.
Surgical technique
Partial thickness grafts involve donor rectus fascia only.
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Nonvascularized: rectus fascia incorporated as
scar tissue overtime.
Vascularized: rectus fascia harvested en bloc with
falciform ligament and liver grafts. Uses hepatic
artery as blood supply.
Full thickness grafts may involve peritoneum, rectus
muscle, oblique muscle, transversalis muscle,
subcutaneous fat, and skin (vascularized
myocutaneous abdominal wall flap).
Flap pedicle based off the deep inferior epigastric
vessels, deep circumflex iliac vessels, internal
mammary vessels, or various intra-abdominal
vessels.
Direct orthotopic revascularization: anastomosis is
done directly after completion of visceral
transplantation.
Indirect orthotopic revascularization: used in cases
of prolonged cold ischemia time over 5 hours. The
abdominal wall graft is first revascularized to the
recipient’s forearm vessels. Then following
completion of the visceral transplant, the graft is
disconnected from the forearm and revascularized
to the recipient abdominal vessels.
Outcomes
An area of ongoing research.
Abdominal wall transplant skin is a good monitor for visceral
graft rejection.
Skin changes occur prior to bowel or organ dysfunction so
patients can be treated earlier.
Potentially higher rate of graft vs host disease.
Some studies suggest no increased risk of rejection when
abdominal wall transplant is included with intestinal
transplant.
Neurotization of abdominal wall grafts has not been
performed but cadaveric study shows adequate length and
caliber of thoracolumbar nerves to achieve tension-free
coaptation.
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GENITOURINARY TRANSPLANTATION
Background
Goal of penile transplantation is to restore urinary and
sexual function.
Five total penis/genitourinary transplants attempted
worldwide since 2006. Two in the United States, two in
South Africa, and one in China.
Indications and Patient Selection
Loss of phallus due to trauma, cancer, or infection.
Lack of donor site for phalloplasty using autologous tissue
such as the radial forearm free flap.
Extensive perineal loss at the recipient site.
Surgical Procedure
The graft includes urethra, erectile tissue (corpus
cavernosum and corpora spongiosum), penile skin, dorsal
penile nerve, and groin lymph node basins.
Graft pedicle is mainly based on the dorsal penile artery but
can also include external pudendal artery and cavernosal
artery.
Recipient vessels include native dorsal artery, femoral
artery, and deep inferior epigastric artery.
Outcomes
Four out of five penile transplants have been successful.
The failed transplant was due to psychological concerns.
Two of the successful cases have resulted in recovery of
full urinary and sexual function.
The hypervascular nature of erectile tissue may lead to
increased risk of congestion, thrombosis, or hematomas.
Epithelial lining of the urethra may undergo early rejection.
Chronic rejection could present as erectile dysfunction.
ETHICAL CONSIDERATIONS
Historical Background
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In the early days of VCA, the ethical debate was focused on
the morality of these procedures.
Over two decades since the first successful hand
transplant, VCAs have proven to be feasible and
successful, with clear benefits to patients.
The ethical considerations are now focused on how to
perform these procedures ethically.
Ethical Value of VCA
VCAs are life enhancing. Solid organ transplants are
lifesaving.
Some patients may experience “social death” if there are
significant social and psychological consequences as a
result of severe disfigurement.
VCA can be considered lifesaving if it allows the individual
to reintegrate back into society and regain self-identity.
Patient Selection
How should patients be selected for transplantation?
Currently no consensus on inclusion and exclusion
criteria.
Providers must make judgment based on the patients’
physical condition, comorbidities, potential benefit
gained from VCA, motivation to successfully manage a
VCA graft, and amount of social support available.
How should mental health be assessed in the perioperative
period?
Assessment of mental health in VCA candidates is not
standardized.
The level of involvement and the use of assessment
tools vary vastly among mental health providers.
Some centers consider self-inflicted gunshot wound an
absolute contraindication. Yet these less-than-ideal
patients may potentially benefit the most.
How should biases be addressed in the selection process?
Institutions and providers might choose the “easier”
patient while denying VCA to another patient who
qualifies for the procedure but is at a higher risk for
negative outcomes.
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Negative outcomes could potentially lead to financial
and reputational consequences for institutions and
providers.
Informed Consent
How can providers ensure that patients understand the full
scope of the procedure and its potential complications?
In additional to information about the operation and its
complications, patients must understand the need for
intense therapy (especially for hand transplantation),
importance of compliance to immunosuppression, and
the consequence of noncompliance.
Patient advocates and support groups may be useful in
assessing patients’ understanding and motivation
preoperatively as well as provide ongoing support and
advocacy postoperatively.
Donation
How can we inform the public about the benefits of VCA?
Studies show that there is less public awareness and
greater hesitancy to donate associated with VCA
compared to solid organ transplantation. Similarly,
people also express less willingness to receive a VCA.
The public has many misconceptions about VCA, such
as VCA is used for cosmetic reasons or the recipient
will assume the identity of the donor.
How can we ensure proper consent to donate in VCA?
Individuals provide first-person consent when they
register as an organ donor obtaining a driver’s license
under the Uniform Anatomical Gift Act (UAGA).
However, the UAGA and state/national registries do not
provide any explicit information regarding VCAs. As a
result, consent to VCA donation has required surrogate
family consent to date.
Procurement
How can we ensure that procurement of VCAs does not
interfere with solid organ procurement?
Close coordination with all members of the solid organ
team is important to optimize procurement.
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How can we avoid disfigurement to the deceased donor?
Prosthesis for the donor have been used.
Quality of Life After Transplant
How do we compare quality of life before and after
transplant?
Very difficult to quantify success after VCA.
What are the implications if a VCA is rejected and
necessitates graft removal?
Consider the implications of removing the face.
ECONOMIC CONSIDERATIONS
Cost of Disability
This is an emerging area of research with respect to
general reconstruction. Understanding the costs of specific
disabilities is complicated by various factors specific to the
defect and the patient characteristics.
How does the type of injury correspond with economic
disability?
Does occupation of the recipient affect economic cost of
transplantation (eg, farmer who lost a hand vs actor with
facial defect from cancer)?
How should the economic burden of physical disfigurement
be assessed?
Cost of VCA
Total cost of VCA is related to procurement, surgical cost,
anesthesia cost, immunosuppression, rehabilitation,
complications, equipment, and personnel cost.
Analysis of the total cost of VCA should include comparing
it to the cost of care associated with traditional
reconstructive methods.
Funding for VCA
Most VCA programs in the United States have been funded
by research grants.
Insurance typically only pays for immunosuppression and
routine postoperative care.
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With the transition of VCA as an experimental treatment to
standard of care, the way in which VCAs are funded is likely
to change in the future.
Who should shoulder the costs associated with VCA?
Should it depend on the type of allograft performed?
Should different economic costs of patient care be
shouldered by separate institutions (eg, surgery vs
immunosuppression vs complications vs rehabilitation)?
Who are the potential payers for this procedure (eg, patient,
worker’s compensation/government/Medicare/Medicaid,
hospital, employer, private insurers, NIH, military)?
PEARLS
1. Performing VCAs requires a multidisciplinary team, including
surgery, anesthesiology, transplantation medicine, pathology,
radiology, nursing, occupation and physical therapy, psychology,
social work, patient advocate, and organ procurement
organizations.
2. The skin typically shows signs of acute rejection first. It
manifests as erythematous macules and diffuse redness.
Histologic analysis shows lymphocytic infiltrate consisting of T
cells.
3. Induction immunosuppression typically uses antithymocyte
antibody to deplete recipient T cells. Maintenance
immunosuppression uses a triple therapy with tacrolimus,
mycophenolate mofetil, and prednisone.
4. Prednisone is associated with hypertension, diabetes,
dyslipidemia, and risk of malignancy.
QUESTIONS YOU WILL BE ASKED
1. What is the most immunogenic tissue for transplantation?
Skin.
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1.
2.
3.
4.
2. What is the difference between allotransplantation and
autotransplantation?
Allotransplantation involves transferring tissue from one
individual to another. Autotransplantation involves transferring
tissue from one location to a different location on the same
individual.
3. What are factors to consider when deciding whether someone
should undergo VCA?
Age, current physical state, cause of disfigurement,
comorbidities, impact of disfigurement on quality of life and
function, candidacy for traditional reconstruction options, mental
health history, social support, patient motivation, and ability to
comply with maintaining a VCA.
Recommended Readings
Caplan AL, Parent B, Kahn J, et al. Emerging ethical challenges raised by the
evolution of vascularized composite allotransplantation. Transplantation.
2019;103(6):1240‐1246.
Cetrulo CL, Ng ZY, Winograd JM, et al. The advent of vascularized composite
allotransplantation. Clin Plast Surg. 2017;44:425‐429.
Mendenhall SD, Brown S, Ben-Amotz O, et al. Building a hand and upper
extremity transplantation program: lessons learned from the first 20 years of
vascularized composite allotransplantation. Hand. 2020;15(2):224‐233.
Siemionow M. The past the present and the future of face transplantation. Curr
Opin Organ Transplant. 2020;25:568‐575.
*
Denotes common in-service examination topics.
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5
Tissue Expansion
Christine S. Wang
OVERVIEW
Definition: Placement of an artificial filling device that is
gradually filled with saline or air, resulting in stretch of local soft
tissue to increase surface area to reconstruct adjacent defect
when primary closure is not possible.
Advantages
Reconstruct “like with like” by using donor tissue that offers
similar color, texture, thickness, and hair-bearing qualities.
Less donor site morbidity because the expanded tissue is
closed primarily.
Robust angiogenic response within expanded local tissue
reduces risk of tissue necrosis.
Versatile, reliable, repeatable, and can be applied to many
regions of the body.
Disadvantages
Significant time commitment with multiple operations and
outpatient visits required
Temporary but significant contour deformity at the donor
site that is often difficult to conceal
Complications associated with presence of foreign material
(eg, infection, exposure, extrusion)
BIOLOGIC PROPERTIES OF SKIN
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Physiology
Layers of skin
Epidermis: stratum corneum, lucidum, granulosum,
spinosum, basale
Dermis: papillary and reticular
Biomechanics
Creep: the tendency of tissue to deform permanently under
influence of stress; it can be an acute (mechanical) or
chronic (biological) response to sustained stretch.
Acute/mechanical creep
Acute tissue elongation as collagen fibers align
parallel to the vector force and adjacent tissue is
recruited from surrounding skin laxity zones.
Water is displaced from the ground substance and
elastic fibers microfragment.
Chronic/biological creep
Chronic tissue elongation due to new tissue
regeneration.
Sustained tissue stretch leads to new tissue within
expanded field by activation of collagenogenesis,
angiogenesis, and epidermal proliferation.
Stress relaxation
Stress is defined as the average force per unit surface
area within the tissue.
Strain is defined as the amount of tissue deformation
that occurs in response to stress.
Stress relaxation refers to the gradual decline in stress
over time at constant strain in biological tissues.
Clinically, this is important because the acutely
stretched tissue can relax before the next expansion,
thereby preventing ischemia-related complications of
the overlying soft tissue envelope.
Histology
Epidermis
*Increase in thickness through hyperkeratosis
(stratum corneum thickens) and acanthosis (stratum
spinosum thickens).
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