Vascular Disorders, Amputation, and Replantation
Mechanism and ischemia time
Vascular disorders. Raynaud phenomenon is vasospastic and managed medically (calcium channel blockers, warming, smoking cessation). Hypothenar hammer syndrome follows repetitive palmar trauma, producing ulnar artery aneurysm or thrombosis with emboli to the ulnar digits; angiography is diagnostic. Buerger disease is a small-vessel inflammatory occlusion in young smokers treated by smoking cessation. Thoracic outlet syndrome gives ulnar-sided symptoms with positive provocation tests.
Amputation. Preserve length whenever the stump can be sensate and durable; a proximal phalanx amputation usually leaves a better hand than a ray amputation.
Replantation. Indications: thumb, multiple digits, wrist or forearm, and any pediatric amputation. Warm ischemia tolerance is roughly 6–8 hours for muscle-containing parts and up to 12–24 hours for digits with cooling. Sequence: debridement, bone fixation, extensor tendon, arterial and venous anastomoses (vein grafts as needed), then flexor tendon and nerve. Venous congestion is treated with leeches; arterial insufficiency requires re-exploration.
Ring avulsion. Urbaniak classification: I (adequate circulation), II (arterial inflow only, requiring venous repair), III (complete amputation).
Traps: using leeches for arterial thrombosis (they do not help); assuming a single digital artery is always inadequate when the opposite artery and palmar arch are intact; and ignoring ischemia time in muscle-containing parts.
Rule of thumb: thumb, child, wrist, and multiple digits are the replant indications; digits tolerate longer warm ischemia than forearm muscle.