21 Digital Replantation and Revascularization

Alexandra Tilt and Mitchell A. Pet

Abstract

Digital replantation and revascularization are technically challenging procedures which present with little warning. In this time-pressured situation, attention to Advanced Trauma Life Support (ATLS) protocol and a meticulous medical history are critical for determining operative candidacy. Traditional indications for replantation are reviewed in this chapter, with additional discussion of how indications have evolved in modern practice. Important elements of the preoperative discussion and informed consent are outlined. Once the decision to pursue replantation has been made, a directed and efficient operative plan is critical for success. This chapter provides a detailed summary of the authors’ preferred technique for single finger digital replantation, and commentary on special considerations for thumb and multiple digit replantation.

Digital replantation – microsurgery – indications for replantation

21 Digital Replantation and Revascularization

I. Patient Evaluation

Advanced Trauma Life Support (ATLS)
- First priority is identification of other injuries; amputation is a distractor.
History
- Time and mechanism of injury.
- Occupation, handedness, and social situation.
- Complete medical history to elucidate comorbidities in anticipation of general anesthesia and hospitalization.
Physical examination
- Incomplete and complete amputations:
  - Level of injury and degree of contamination.
  - Radiographs of hand and amputated part.
- Incomplete amputations:
  - Color and capillary refill, doppler assessment of each digital vessel.
  - Test sensation in each digital nerve distribution prior to any local anesthesia.
  - Active tendon examination and/or passive tenodesis.
Preoperative testing
- Complete blood count (CBC), basic metabolic panel (BMP), prothrombin time (PT)/international normalized ratio (INR), consider type and screen.
- Electrocardiogram (EKG) and chest X-ray based upon medical history.

II. The Amputated Part

In the field and during transport, an amputated part should be wrapped with salinemoistened gauze, placed in a plastic bag, and then put on ice.
- Do not submerge the part or put it directly on ice.
Digits can tolerate up to 12 hours of warm or 24 hours of cold ischemia for successful replantation or revascularization. ¹
Bleeding vessels should be controlled with direct pressure or a gentle compressive dressing. Tourniquet, cautery, and ligation are discouraged in the absence of persistent and dangerous hemorrhage.
Discard nothing. Unreplantable digits may still be used for spare parts (nerve, skin, bone, or tendon graft).

III. Indications and Decision-Making

A. Traditional Indications for Replantation

Thumb amputation.
Multiple digit amputation.
Partial or total hand through the palm, wrist, forearm, elbow, or above.
Almost any part in a child:
- Technically more difficult, but excellent functional results when successful.
Single digit amputation distal to the flexor digitorum superficialis (FDS) insertion:
- Zone I outcomes are superior to Zone II. ²

B. Traditional Contraindications to Replantation

Severely crushed or mangled parts.
Amputations at multiple levels.
Amputations in patients with other serious injuries/diseases.
Severe atherosclerotic disease.
Prolonged warm ischemia.
Mentally or medically unstable patient.
Individual finger amputation in an adult at a level proximal to the FDS insertion.

C. Indications in Modern Practice

The decision to perform replantation/revascularization in cases of single non-thumb digital amputation is shared by the patient and surgeon. This decision process is complex, and is influenced by numerous factors that must be weighed in each individual circumstance.
- Mechanism, level, and ischemia time.
- Age and medical comorbidities
  - Risk of prolonged anesthesia and hospitalization should be a primary concern.
- Physical and occupational demands
  - Manual laborers will likely return to work sooner with revision amputation compared with replantation and should be counseled as such.
- Social factors.
- Cultural and personal values.
- Availability of postreplantation care and occupational therapy.

IV. Informed Consent

Informed consent should include replantation with possible nerve allograft or autograft, vein autograft, skin autograft, and revision amputation.
The alternative of revision amputation should be specifically discussed.
Important disclosures:
- Replantation is effort-intensive, and may necessitate prolonged time out of work.
- Anesthetic and hospital-associated complications are possible.
- Attempted replantation is not always successful. Postoperative digital necrosis requiring amputation is possible.
- Leech therapy may be indicated, and it may necessitate blood transfusion.
- Postoperative stiffness and subnormal sensation are likely.
- Secondary surgery may be recommended