Replantation in Emergency Medicine Follow-up

Updated: Sep 12, 2017
  • Author: Mark I Langdorf, MD, FAAEM, FACEP, MHPE, RDMS; Chief Editor: Harris Gellman, MD  more...
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Follow-up

Further Inpatient Care

Surgeons must be skilled at microvascular reanastomosis and be able to achieve a 90% patency rate in a 1-mm – diameter vessel in laboratory animals. [15]

If the vessels of partial or complete finger amputations are suitable for anastomosis, a successful replantation with excellent functional and esthetic recovery can be achieved.

Repair may be performed with an axillary nerve block with bupivacaine, which provides anesthesia lasting 12-16 hours. However, children must have general anesthesia because they do not tolerate axillary block well.

The surgical sequence for replantation varies slightly with amputations distal and those proximal to the wrist and with the mechanism of injury (clean cut, crush, avulsion). Since injury distal to the wrist is more common, the following surgical sequence is delineated:

  • With tourniquet-induced ischemia and use of a microscope, the stump is debrided of all crushed tissue, foreign bodies are removed, and the vessels and nerves are identified and tagged. The amputated part then is similarly debrided, with irrigation of the cut end, while maintaining cooling. Vessels and nerves are identified and tagged. [16]
  • Bones are fixed with K wires, intramedullary screws or pegs, or small plates with screws.
  • The extensor tendon is repaired by using horizontal mattress 4-0 polyester sutures. A tendon graft may also be necessary if a sufficient length of tendon is not available. Finally, if extension is deemed expendable, arthrodesis (joint fusion) may be performed. Then, the flexor tendon is repaired with sutures.
  • Arterial repair is performed next. Brisk blood flow from the proximal vessel should be confirmed prior to vascular anastomosis. Restoration of proximal blood flow may require relief of vascular compression, warming of the patient, administration of adequate blood volume, elevation of the patient's blood pressure, irrigation of the proximal part with warmed lactated Ringer solution, intraluminal flushing with papaverine solution, and correction of systemic metabolic acidosis.
  • Even with a technically successful arterial/venous anastomosis, hemodynamic compromise or insufficient anticoagulation may lead to digital ischemia. As soon as the diagnosis of "no reflow phenomenon" is confirmed, an intra-arterial catheter should be considered followed by an antithrombotic protocol. [17]
  • To avoid thrombosis, reconnect only normal intima visualized under the microscope. A vein graft may be necessary. [16, 18]
  • Tourniquet-induced ischemia may be continued until the anastomosis is complete, although bolus injection of heparin is recommended to prevent thrombosis.
  • Ideally, two veins should be repaired for each artery. No tension should be present on the vessels. If no suitable vein can be found, artery-only replantation can be attempted.
  • Due to the damage associated with avulsion injuries, various vein grafts, vessel transfers from adjacent digits, and venous flow-through flaps have all been demonstrated to increase survival of avulsed fingers.
  • Perform nerve repair next, with fascicular or bundle repair. A nerve graft may be necessary.
  • Skin coverage with grafts or flaps is the final step.

See the images below.

After 2-digit replantation. After 2-digit replantation.
Surgical amputation of a left big toe. Surgical amputation of a left big toe.
Toe-to-thumb transfer. Toe-to-thumb transfer.

Postoperative anticoagulation with heparin, aspirin, and occasionally dextrans is commonly used to prevent thrombosis. A survey of surgeons in the United Kingdom showed that the use of dextran is not uniform and not necessarily beneficial for outcome. [19] Because of their adverse effects profile, dextrans are less commonly used than aspirin.

Venous insufficiency is reported as the most common complication encountered after replantation, often occurring by postoperative day 3, with an incidence of 7 – 32%. In addition to aspirin, heparin and low molecular weight heparins to prevent thrombosis, pinpricking, milking and medical leeches can be used to induce external bleeding until venous outflow is reestablished. Heparin pledgets placed on a nail bed incision have also been described. [8, 20, 21, 22]

For artery-only replants, injected fluorescein dyes and quantitative fluorometers are used to observe vessel integrity in the digit and monitor for development of a venous outflow tract.

Patients are encouraged to avoid smoking and caffeine for a month because these may enhance vasoconstriction.

Viability of the replanted limb is no longer the sole determinant of success; functional recovery, preoperative and postoperative risks, and duration of treatment are vital factors in making the decision to perform replantation.

The duration of treatment, including rehabilitation, should not exceed 2 years; if it does, the replantation is not thought worthwhile. Amputation with early fitting of prosthesis is a viable alternative in these cases.

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Inpatient & Outpatient Medications

Postoperative anticoagulation with aspirin and dextrans is recommended to prevent thrombosis. Patients are encouraged to avoid smoking and caffeine for a month because these may enhance vasoconstriction.

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Transfer

The prevalence of severe associated injuries is 0.8%. Prior to considering transfer, ensure that the patient has no life-threatening conditions other than the amputation, if applicable. Transfer is indicated in the following cases:

  • Amputations of thumbs and/or multiple digits
  • Amputations in children
  • Amputations of individual digits distal to the superficialis insertion
  • Complete amputations that might benefit from acute microsurgical reconstruction (eg, revascularization, coverage of free flap)
  • Clean amputations at the palm, wrist, or forearm

Use of the Internet to transmit high-resolution images, including photographs and radiographs, of potential cases for replantation and use of a digital camera in the ED to facilitate replantation consultation might prevent unnecessary transfer of patients.

Contraindications to transfer include the following:

  • Significant associated injuries
  • Coexisting medical problems (eg, recent stroke, myocardial infarction) that prohibit surgery
  • Prolonged warm ischemia time (>12 h), especially with limb amputations

Relative contraindications to transfer include the following:

  • Amputation of single digits in adults through or proximal to the proximal interphalangeal joint
  • Multilevel injuries
  • Injuries caused by a severe crush-avulsion mechanism
  • Severe contamination
  • Wide segmental tissue injury

Use of bulky dressings should be avoided during transport because these can conceal bleeding. Bleeding should be controlled before applying the dressing or before cooling the distal extremity without perfusion.

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Complications

See the list below:

  • Arterial insufficiency is one of the most common causes for replantation failure. Other causes include venous congestion and thrombosis.
  • Detection of perfusion disturbances in digit replantation can be achieved by using near-infrared spectroscopy and serial quantitative fluoroscopy. Near-infrared spectroscopy measurement of tissue oxygenation correlates with fluorescein monitoring and digit perfusion. This noninvasive monitoring is easy, reliable, safe, and useful in postoperative monitoring of digit replantation. [23]
  • Venous insufficiency is a common complication of digital replantation. Lin et al have reported successful use of a subdermal pocket procedure, used either at the time of replantation if no suitable vein is available after digital artery anastomosis or as a salvage procedure to restore venous drainage. [24]
  • Infection may occur.
  • Systemically, myonecrosis leading to rhabdomyolysis and renal insufficiency may occur if significant muscle mass that was transiently ischemic is replanted. These occur with forearm or lower leg replantations but not with finger replantations.
  • Osteomyelitis may occur.
  • Function may be limited after replantation.
  • Cold intolerance of the replanted limb is a universal problem. Similarly, cold-induced vasospasm occurs in essentially all patients.
  • Sensitivity to light touch and 2-point discrimination frequently is impaired, while limitations in the flexion of joints distal to the replantation vary.
  • Cosmetic deformity may occur.
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Prognosis

Success rates as high as 90% have been reported for complete and incomplete amputations.

Multivariate analysis of factors that favor functional recovery after finger replantation or revascularization showed better recovery for patients younger than 40 years compared with older patients. Injuries caused by a sharp mechanism have a better prognosis than those caused by a crush mechanism; injuries caused by a crush mechanism have a better prognosis than those caused by avulsion; and injuries at the middle phalangeal level have a better prognosis than those at the proximal level. A meta-analysis showed that smoking, diabetes, and avulsion or crush injury are poor prognostic factors in replantation of amputated digits. [5]

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