What is replantation?

Replantation: Surgical Reattachment of Amputated Body Parts

Replantation is a microsurgical procedure that aims to restore an amputated body part to its anatomical site, preserving both function and appearance. This technique has become the standard of care for many types of traumatic amputations, with outcomes dependent on multiple factors related to the patient and injury characteristics.

Definition and Basic Principles

• Replantation refers to the surgical reattachment of a completely severed body part, restoring its blood supply, nerve function, and structural integrity 1
• The procedure requires microsurgical techniques to reconnect blood vessels, nerves, tendons, and bones to restore function 1
• Success is measured not just by tissue survival but by functional recovery and quality of life improvements 1

Indications for Replantation

Strong Indications

• Thumb amputations (critical for hand function) 2
• Multiple digit amputations 2, 3
• Amputations in children (better regenerative capacity) 2, 3
• Bilateral hand amputations 2
• Hand amputations at wrist to upper forearm level 2
• Distal fingertip amputations (Zone I) 2

Relative Indications

• Single digit amputations (case-by-case basis) 2
• Zone II amputations (middle phalanx to PIP joint) 2

Contraindications

• Life-threatening associated injuries (patient stabilization takes priority) 2
• Technically impossible cases (severe crushing or avulsion with extensive tissue damage) 2
• Self-inflicted injuries (psychological evaluation needed first) 2
• Prolonged warm ischemia time beyond salvage window 3

Time Window for Successful Replantation

• The optimal window for replantation is within 12 hours of amputation for best outcomes 4
• Maximum ischemia times: approximately 12 hours of warm ischemia and 24 hours of cold ischemia for digits 3
• More proximal amputations (arm, forearm) tolerate shorter ischemia times 3
• Earlier surgical intervention correlates with better functional outcomes and lower mortality 4

Proper Preservation and Transport

• Handle the amputated part only by the edges to prevent damage to fragile tissues 4
• Never place the amputated part directly in ice or water as this causes osmotic damage to cells 4
• Proper packaging: wrap in saline-moistened gauze, place in sealed plastic bag, then place bag on ice 4
• If dirty, briefly rinse under cold running water before packaging 4

Surgical Technique

• Meticulous microsurgical technique is essential for success 1
• An "assembly line" approach is used for multiple digit replantations 3
• Sequence typically involves:
  1. Bone fixation/shortening
  2. Tendon repair
  3. Arterial anastomosis
  4. Venous anastomosis
  5. Nerve repair
  6. Skin closure 3

Special Considerations for Lower Extremity Replantation

• Lower extremity replantation is technically feasible but has more stringent selection criteria 5
• Sensory recovery is critical - patients without potential for nerve recovery are poor candidates 5
• Partial replantation may be considered when complete replantation is not possible 6
• For the lower limb, osteocutaneous transfers with protective sensation can facilitate prosthesis fitting 6

Factors Affecting Success

• Patient factors: age, comorbidities, and smoking status affect healing 4
• Injury mechanism: clean-cut amputations have better outcomes than crush or avulsion injuries 1, 3
• Level of amputation: distal amputations generally have better functional recovery 1
• Ischemia time: shorter ischemia times correlate with better outcomes 4, 3

Post-operative Care and Monitoring

• Close monitoring for vascular compromise is essential as secondary ischemia times are shorter 3
• Comprehensive occupational therapy is crucial for functional recovery 1
• Multiple secondary procedures may be needed to optimize function 1
• Patient commitment to rehabilitation is essential for success 1

Outcomes and Expectations

• Young patients with distal, cleanly amputated extremities have the best functional outcomes 1
• Crush or avulsion injuries have less favorable functional results 1
• Patients should be informed about the potential need for multiple surgeries and extensive rehabilitation 1
• When successful, replantation provides superior functional and aesthetic results compared to prosthetic alternatives 5

Partial Replantation

• When complete replantation is not possible, partial tissue transfer from the amputated part may preserve length and function 6
• This approach can facilitate prosthesis fitting and preserve proximal joint function 6
• Osteocutaneous microsurgical transfers can provide stable weight-bearing surfaces for lower limb amputations 6