|
|
Hand Transplantation: Current Status
First Prepared September 2001. Position Revised November
2003.
I. Position of the American Society for Surgery of the Hand
November 2003
W.P. Andrew Lee, MD
Dennis B. Phelps, MD
David M. Lichtman, MD
Hand transplantation has been performed since September of
1998. Preliminary clinical experience based on 14 patients
has underscored the importance of patient motivation and compliance,
intensive hand therapy, and close post-transplantation
surveillance. Acceptable functional and cosmetic outcomes,
particularly for bilateral amputees, have been achieved and are similar
to hand replantation at equivalent levels. However, major return
of two-point discrimination or intrinsic muscle function is not to be
expected.
At present, ongoing heavy immunosuppression is required for allograft
survival with unknown long-term risks. Although there have
been no life-threatening adverse events, complications include allograft
rejection and loss, tissue necrosis, and osteomyelitis.
Furthermore, the effects of chronic rejection on the allograft function
and survival have not yet been determined. Because there are many
significant contraindications to both the surgical procedure and the
immunosuppressive protocol, careful pre-operative, medical and
psychological screening is mandatory.
In summary, hand transplantation is still an experimental procedure
that may enhance the function and/or appearance of carefully selected
patients. Further research and progress in transplant immunology
are needed before it can be considered a consistently safe and
efficacious practice.
II. Background
September 2001
William P. Cooney, M.D.
Vincent R. Hentz, M.D.
Past Presidents of the ASSH
Outcomes for 10 Hand Transplant Patients
At the recent conference of the International Federation of Societies
for Surgery of the Hand (IFSSH) in June 2001, information related to ten
patients with upper limb composite tissue transfer (hand
transplantation) was reported. The first patient, a 48-year-old
New Zealand businessman, had surgery in Lyon, France, in September of
1998 with an international multi-discipline team. (2) (3) However,
he failed to maintain the needed immune suppression medication
post-operatively and when chronic rejection was present, had his
transplanted hand amputated on February 2, 2001, in London by Dr. Nadley
Hakim, one of the original team members. (4) Other patients with
hand transplantations were reported from United States (N=2), China
(N=3), Italy (N=1), France (N=1), Malaysia (N=1), and Austria (N=1)
(including one bilateral hand-forearm transplant). They have had
either too short follow-up or inadequate data to evaluate the
preliminary outcomes. (5) (6) (7) Two hand transplantations
(included in those listed above) have been performed in the United
States at Louisville, Kentucky, at the Jewish Hospital, one reported
with a year follow-up. This first patient, a 38-year-old emergency
medical technician, has had continued “transplant success”
as reported in November 2000. (8) A viable limb with reported
improving function and sensation at a protective level appears to be
present. Continuation of intermittent problems related to immune
suppression has been noted. The second limb transplant has also
been successful from a viability perspective, but continues to be faced
with ongoing evidence of chronic rejection, currently controlled with
immunologic suppressive medication.
Expected Outcomes and Risks
As hand surgeons and members of the American Society for Surgery of
the Hand, we must ask, “What do we currently know of the expected
outcome and risks associated with hand transplantation?”
“Is this an operative procedure that we should recommend to an
inquiring patient?”
In addressing these questions, we recognize several factors:
1. Hand surgeons clearly possess the needed technical skills to
perform a successful hand or upper limb transplantation as evidenced by
the experience in limb replantation.
2. Upper limb transplantation is now occurring in several areas
throughout the world.
3. Advances in organ transplant (in particular, donor-related
kidney and liver with careful tissue HLA matching) have demonstrated
improved organ and patient survival in many life-threatening
conditions. Success in transplantation of solid organs has
steadily improved both technically and with improved immune
suppression.
4. Public perception and expectations are high, yet they are
without a clear understanding of the inherent risks of these procedures,
both acute risks and chronic immune suppression risks.
5. We know that the hand is a complex organ of nerves, muscle,
tendon, and vessels covered by an immune intolerant skin. Both
humoral and cell mediated immune suppression is required. (9)
While hand transplants have been contrasted to kidney transplants, a
transplanted hand is not equivalent to any parenchymal tissue such as
the kidney or liver. (10) (11) (12) And while a comparison of a
hand transplant to a kidney transplant as equal with respect to the
“improved quality of life”, statistics and analysis clearly
demonstrate that kidney transplants save lives when one appreciates that
with sustained renal dialysis, there is a mortality rate of 21%.
Measuring Success
How do we judge the success of hand transplants? At this point
in time, the metrics of success are not clear. (1) (10) (11)
Most agree that hand transplant success should be measured at several
levels. The first level of success is sustained revascularization
without rejection, now approaching two and half years with controlled
untoward events. The second level of success is a limb with
sensibility, proprioception, and central acceptance. The third
level is the sum of the associated risks of infection, tumor, and other
complications associated with immune suppression, counterbalanced
against the potential gain of a functioning hand. Finally,
function of that vital organ of sensation and communication must be
restored sufficiently so that the patient has the perception that his or
her new hand is a natural part of the recipient’s body.
While the digits of the transplanted hand will move and provide pinch
and grasp because of the connections to the extrinsic forearm muscles,
movement resulting from independent action of the transplanted intrinsic
muscles has not been observed. Furthermore, it is not clear that
sensibility, so essential to hand expression and advanced manual skills,
will be present. The hand is considered by many to be a
representative mirror of the mind. (11) It must provide
coordinated bimanual skills. It must reflect central perceptions
of coordinated, integrated meaning. From most observations of the
results of composite tissue transplantation to date, the measurement of
function of the human hand transplantation at this level has not been
convincingly demonstrated.
Results of Animal Studies
Animal models have been extensively studied, and the results are not
encouraging. Lee and Mathes have presented many of the current
concerns. (13) Jensen and Mackinnon have reviewed over 250
publications on the subject of results of limb allograft transplantation
in experimental models. (14) Failure rates are beyond acceptable
limits. (15) (16) A successful transplant in animal
experimental models remains a challenge simply because of the large
amounts of immune suppression required for survival of the
transplant. The complications of such medications, at least in
animal models, are currently overwhelming. (17) (18) (19)
(20) It appears at the present time nearly impossible to
provide a viable limb in the experimental models without significant
risks from the immune suppressive medications. Post transplant
risks in animals including acute rejection, medication toxicity (both
nephrotoxicity and neurotoxicity), and infection from opportunistic
organisms remain significant challenges. Despite disappointing
results in the pig and primate, hopeful research continues. (21)
Most authorities believe that these same risks are also present in
the human model. Renal transplants have an average of 1.5 septic
episodes per year, and 80% have at least one serious infectious episode
within the first year post transplant. (22) (23) Malignant
tumors related to immune suppression are reported between 8-20%, with
carcinomas of the skin and lips at 30%. (24) (25) Finally,
historical data on renal and liver transplants indicate that the overall
survival at fifteen years ranges between 30 - 60% depending upon the age
of donor, HLA matching, age and disease status of the donor, and time
from transplant. (26) (27) Recognizing these facts related to
single organ transplantation, there must also be concern that a hand
transplant might develop chronic rejection and therefore need to have
the transplantation procedure repeated eight to ten years from the index
procedure to continue to provide the intended purpose. The
potential need for a second transplant, combined with the risk of
long-term immune suppression, is important historical information that
must be presented to a potential hand transplant recipient.
Ethical Concerns
Ethical concerns must also be considered in the delicate balance of
risk and reward when evaluating a patient for limb transplant.
(28) What is the patient’s ability to understand the risks
and make appropriate judgments? Are the patient’s
expectations realistic? Is the patient’s psyche prepared for
rejection events, repeated control of infectious episodes, the daily
required immune suppression medications, the concern of the unknown
related to ultimate function and potential chronic rejection? How
good is this “quality of life” with a new limb when daily
medications are required to maintain its viability? Can a limb be
easily removed (amputated) if both surgeon and patient recognized that
chronic rejection is occurring with so much personal time and effort
invested by both the surgeon and patient? Mr. Hallam and his
surgeons struggled over this issue for many months before the limb was
finally amputated in England. (4)
The transplanted hand, like the transplanted pancreas or a vocal
cord, may provide improved quality of life, but the impact of a
transplanted hand has not been objectively measured. Hand
transplant may improve the patient’s psyche, family interactions,
and even give a sense of fullness. However, before hand
transplants can move forward to the potential that they represent (and
that potential is acknowledged to be very great), these procedures
should achieve a greater measure of success 1) in sustained animal
models; 2) with compatible HLA matching of potential donor to the
recipient; 3) with improved bench to bedside immune suppression without
requirements of long-term immune treatment; and 4) with recipient tissue
tolerance alone or with low risk immune suppression.
Caution
We applaud the studious approach of the current pioneering
investigators of hand transplantation but strongly encourage them to
proceed slowly, cautiously, and with measured concern of the risk and
benefits to man. For those that wish to go forward with any type
of composite tissue transfer, it is important that transplant teams be
developed that are experienced in large organ transplants, aware of
advances in immune suppression medications, and include hand surgeons
within such teams who not only bring microsurgical skills but also the
ability to provide a clear understanding to the potential recipient a
knowledge of hand function by which success may be measured. At
this time, the ASSH continues to urge great caution and a measured
approach to the patient requesting a limb transplant. We encourage
all surgeons to await the outcomes of the current human experimental
studies before additional combined trials are considered. The
public, especially those with traumatic loss of limb, must be carefully
counseled and advised regarding the substantial risks to limb and life
associated with these procedures to date.
© 2006 American Society for Surgery of the Hand
|
|