Summary Replantation is the reconstruction of an amputated portion of the upper extremity secondary to trauma. Diagnosis of an amputated digit is contingent on absence of blood supply (cold, white digit, without soft tissue attachment). Treatment involves prompt transportation of the amputated tissue and stepwise reconstruction prior to tissue ischemia and meticulous post-operative care. Epidemiology Incidence 90% of upper extremity amputation occurred after trauma Demographics 4:1 male-to-female ratio Anatomic location most amputations occur at the level of the digits Etiology Pathophysiology mechanism of traumatic amputation sharp dissection blunt dissection avulsion crush Presentation History timing of injury type and location of amputation number of digits involved preservation of amputated tissue associated injury past medical history Examination stump examined for zone of injury tissue viability supporting tissue structures contamination amputated portion inspected segmental injury bone and soft tissue envelope contamination Indications Indications for replantation after trauma primary indications thumb at any level multiple digits through the palm wrist level or proximal to wrist almost all parts in children relative indications individual digits distal to the insertion of flexor digitorum superficialis [FDS] (Zone I) ring avulsion through or above elbow Contraindications to replantation primary contraindications severe vascular disorder mangled limb or crush injury segmental amputation prolonged ischemia time with large muscle content (>6 hours) relative contraindications single digit proximal to FDS insertion (Zone II) ring finger injuires in zone II have better cosmesis and grip strenth with 4th ray resection and 5th ray transposition medically unstable patient disabling psychiatric illness tissue contamination prolonged ischemia time with no muscle content (>12 hours) Treatment Transport of amputated tissue indications any salvageable tissue should be transported with the patient to hospital modality keep amputated tissue wrapped in moist gauze in lactate ringers solution place in sealed plastic bag and place in ice water (avoid direct ice or dry ice) wrap, cover and compress stump with moistened gauze Operative time to replantation proximal to carpus warm ischemia time < 6 hours cold ischemia time < 12 hours distal to carpus (digit) warm ischemia time < 12 hours cold ischemia time < 24 hours general operative sequence of replantation vascular shunt first (for proximal replantation with large muscle mass to minimize warm ischemia time) bone fixation +/- shortening (after irrigation and debridement of soft-tissue and bone) extensor tendon repair artery repair (repair second after bone if ischemic time is >3-4 hours) venous anastomoses flexor tendon repair nerve repair skin +/- fasciotomy finger order thumb, long, ring, small, index for multiple amputations structure-by-structure sequence is most efficient digit-by-digit sequence takes the most time Postoperative Care Environment keep patient in warm room (80°F) avoid caffeine, chocolate, and nicotine Replant monitoring skin temperature most reliable concerning changes include a > 2° drop in skin temp in less than one hour or a temperature below 30° celsius pulse oximetry < 94% indicates potential vascular compromise Anticoagulation adequate hydration medications (aspirin, dipyridamile, low-molecular weight dextram, heparin) Arterial Insufficiency treat with release constricting bandages place extremity in dependent position consider heparinization consider stellate ganglion blockade early surgical exploration if previous measures unsuccessful thrombosis secondary to vasospasm is most common cause of early replant failure Venous congestion treatment elevate extremity leech application releases Hirudin (powerful anticoagulant) Aeromonos hydrophila infection can occur prophylaxis with Ciprofloxacin or Bactrim heparin soaked pledgets if leeches not available Complications Replantation failure most frequently cause within 12 hours is arterial thrombosis from persistent vasospasm decreased palmar width with ray resection Stiffness replanted digits have 50% of total motion tenolysis is most common secondary surgery Myonecrosis greater concern in major limb replantation than in digit replantation Myoglobinuria caused by muscle necrosis in larger replants (forearm and arm) can lead to renal failure and be fatal Reperfusion injury mechanism thought to be related to ischemia-induced hypoxanthine conversion to xanthine allopurinol is the best adjunctive therapy agent to decrease xanthine production Infection Cold intolerance