Replantation
Michael S. Gart
INTRODUCTION
The first upper extremity replantation was performed in Boston, MA by Dr Ronald Malt in 1962.1
Three years later, Komatsu and Tamai reported the first successful digital replantation.2
In order to be truly “successful,” a replanted part must function as well as or better than the available prosthetic technology.
Although surgeons can now technically replant nearly any severed part, recent focus has been on identifying patients who will have excellent functional outcomes following replantation.3
Pathoanatomy
An amputation in the upper extremity severs soft tissue, muscle/tendon, nerve, blood vessels, and bone.
The status of each of these structures will dictate the functional outcome of the replanted part(s).
In particular, severe nerve injury may preclude replantation, particularly with proximal upper extremity amputations, because an insensate extremity without motor function will ultimately be less useful than a prosthetic.
In digital amputations, the neurovascular bundles run volar to the mid-axis of the digit, between Grayson’s (volar) and Cleland’s (dorsal) ligaments.
Digital veins can be reliably located in the dorsal subcutaneous tissue.
Knowledge of the flexor tendon anatomy is critical because amputations through zone II will often have poor functional outcomes due to a high incidence of postoperative adhesions.
The thumb is responsible for nearly half of all hand function and, even with poor range of motion, a replanted thumb will provide the best functional outcome.4
Mechanism of Injury
Mechanism of injury is among the most important determinants of replantation success rates and ultimate functional outcomes.
Tool injuries (saws, agricultural machinery) are a common source of digital or hand/wrist level amputations.
New table-saw technology can stop a saw blade immediately upon contact with skin to reduce the potential for amputation.5
Polytrauma patients may present with crush or avulsion amputations.
Epidemiology
In the United States, digits and thumbs account for the vast majority of upper extremity amputations; however, several hundred patients suffer more proximal amputations each year.
More than 45 000 traumatic digital amputations occur each year in the United States.9
Most patients suffering amputation are males, with a mean age of 40 years.10
Patients treated at large urban hospitals and/or academic medical centers are more likely to undergo replantation.10
African-American patients and uninsured patients are less likely to undergo replantation than Caucasian or privately insured patients.11
EVALUATION
History
If possible, the patient’s age, handedness, smoking status, medical comorbidities, and time of injury should be obtained.
The time since amputation and method of preservation of the amputated part(s) should be noted.
The patient’s occupation and need for timely return to work may be important in determining treatment (ie, replantation vs revision amputation).
Physical Examination
Every effort should be made to minimize the time from injury to definitive treatment.
The amputated parts and distal stump should be photographed and x-rays obtained prior to any attempted replantation (Figure 54.1).
ACUTE MANAGEMENT
Acute Patient Management
Patients presenting with traumatic amputations must be thoroughly evaluated by a trauma service for other life-threatening injuries, which take treatment priority.
Replantation is only considered in medically stable patients after appropriate resuscitation.
Any ongoing hemorrhage from the proximal stump should be controlled with external compression because vessel ligation or clamping can cause additional vessel damage.
Patients should be started on prophylactic antibiotics and given tetanus prophylaxis preoperatively.
 FIGURE 54.1 Preoperative radiographs (A, B) and intraoperative photos (C, D) of multilevel hand and multiple digit amputation. Photos courtesy of Jason H. Ko, MD. |
 FIGURE 54.1 (continued) |
Acute Management of the Amputated Part(s)
Preservation of the amputated part is critical to replantation success. More metabolically active tissues (eg, muscle) are less tolerant of ischemia than tendon, bone, etc.
Generally accepted ischemia times for reliable replantation are <12 hours of warm or <24 hours of cold ischemia for digital amputations and <6 hours of warm or 12 hours of cold ischemia for major upper extremity amputations.14
Ideally, amputated parts are wrapped in saline-soaked gauze and immediately placed on ice or in a plastic bag and submerged in an ice water bath at 4°C.
Amputated parts should not be placed directly on ice or in water because this may cause freezing or further damage to the tissues.
While the patient is being evaluated, the amputated part(s) should be taken to the operating room to identify and prepare important structures for replantation15,16 (Figure 54.2).Related posts:
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