| |
Once the vessels to the transplant have been ligated and the toe transferred to the hand, the bony stabilization is accomplished expeditiously to keep ischemia time to a minimum. Tendon repairs are then carried out in the standard fashion, using multiple weaves to provide solid, strong junctures that can be moved in the early postoperative period. The microscope is then swung into position and the arterial anastomosis performed first. This may be in an end-to-end or end-to-side fashion, depending on the location of the recipient vessels and the residual blood supply to the hand. Once the anastomoses are completed, they must be kept moist at all times and covered with a skin flap or skin graft as soon as possible. The nerve repairs should be accomplished with the same degree of care as the vessel repairs because sensory return is second only to blood supply in importance. If flap cover is not possible without tension, split-thickness skin grafts placed directly on the anastomoses are acceptable and much preferred to a tight wound closure.
Operative Sequence
PLATE I-1
 A.
B.
Dorsal (A) and palmar (B) views of a hand that has sustained an extensive
injury, with loss of the thumb through the proximal third of the metacarpal,
loss of the entire second and third rays, and more residual injury to
the long finger. The goal in reconstructing this hand is to provide three-finger
chuck pinch between the thumb transplant and the remaining little and
ring fingers and a three-finger grip between the thumb and the ulnar portion
of the palm. Unfortunately, the width of the palm is seriously compromised
by the missing second and third metacarpal bones, so that twist-grip strength
is weak even with the best reconstruction. The deep palmar arch is present
with its dominant ulnar contribution. The neuromas of the common volar
digital nerves to the first, second, and third web spaces and the thenar
eminence are ghosted in. The flexor pollicis longus is caught in scar
tissue at the level of amputation through the metacarpal. On the dorsal
surface, the cephalic vein and portions of the dorsal venous arch are
present in good position as recipient vessels. The extensor pollicis longus
can be seen on the ulnar side of the anatomic snuffbox, which is bounded
on the radial side by the abductor longus and the extensor brevis. In
the depths of the snuffbox, the dorsal radial artery can be seen crossing
down to the base of the first web space where the princeps pollicis dives
between the heads of the first dorsal interosseous muscle. Branches of
the superficial radial nerve cross the snuffbox and end in neuromas at
the amputation levels of the thumb and the index and long fingers. All
of these key structures must be identified and tagged during the hand
dissection.
|
|
C. Lateral view of the proposed great-toe transplant. The large saphenous
vein can be seen coming down the medial aspect of the dorsum of the ankle
and foot from just in front of the medial malleolus to fan out over the
dorsum and down the medial side of the great toe. The deeply placed dorsalis
pedis artery is shown in lateral view as it descends on the periosteum
or the tarsal bones to the base of the first metatarsal area, where it
sends off its communicating penetrating branch to the deep plantar system.
This area is the key to the entire foot dissection. In this case, the
dorsalis pedis artery is depicted as continuing distally beyond this penetrating
branch as a dominant superficial first metatarsal artery. Unfortunately,
this anatomic situation occurs in fewer than 60% of our clinical cases.
As it reaches the end of the web space, additional communicators are shown
penetrating to the deeper plantar system. The flexor hallucis tendon is
seen running along the plantar surface of the great toe into the sole
of the foot.
next page... |
