A 32-year-old man came to the emergency room after suffering a traffic accident, with severe trauma to the left hand and other polyconcussions.
Physical examination shows:
-1st finger: loss of dorsal cutaneous substance at the level of proximal phalanx. -2nd finger: loss of dorsal substance, with involvement of the extensor and flexor apparatus and bone gap at the border of the distal phalangeal joint fracture.
1.
A first emergency intervention was performed with the following procedures:
-1st finger: debridement of non-viable soft tissues, transosseous anclage of the extensor mechanism in F2 and coverage with a soft-tissue autoinjection of the flap - distal section of the flap amputation neck 2
Debridement and skin coverage of the radial part of the finger with a heterodigital 3rd finger flap.
The result of this first emergency intervention was one hand with 1st, 4th and 5th functional fingers.
1.
The function of the clamp between 1 and 4 or 5 fingers was not fully satisfactory.
For this reason it was decided to reconstruct the third finger of the hand with a total microsurgical transposition of the second toe ipsilateral5.
For good preoperative planning, anatomical diagnostic studies, such as CT angiography, were performed to determine the type of main vascularization of the finger.
This is one of the most important steps of the intervention, since the vascularization of the second toe has multiple anatomical variants that are key to the successful dissection of the finger.
The most frequent anatomical variants of its vascularization are 6:
a.
Ar dorsalis pedis bifurcates and forms the first dorsal metatarsal artery that runs superficially to the first dorsal interosseous muscle and deep plantar artery.
In this case, vascularization of the second finger with the first dorsal metatarsal artery is sufficient.
The clinical case is included in this subgroup.
b.
Location of the dorsal interosseous muscle.
This variant is the most frequent.
c.
The first dorsal metatarsal artery is poorly developed or absent.
The plantar artery is developed and vascularizes 1st and 2nd fingers.
It is usual to use the contralateral foot but in this case the ipsilateral foot was chosen because, according to the angio-CT, it had vascularization of the first subgroup, and this allowed a simpler arterial dissection.
The right finger was the 2nd group and dissection was performed.
Surgical technique7,8
The microvascular system of the toe is very sensitive, so intraoperatively local papaverine and sympathetic vegetative block were used to achieve vasodilation with an axillary catheter and a continuous infusion pump 0.15% lebupivacaine.
Two surgical teams were assembled, one for the foot and the other for the hand.
In a first field, the receptor zone was prepared.
The vascular system and the collateral nerves of the third finger were dissected.
The cables of the extensor and flexor tendon of the third finger were located.
The stump incision was extended to dissect the second intermetatarsal space, a predictable site of vascular microanastomosis.
The 1st phalanx was prepared for a stable osteosynthesis.
Simultaneously, in a second surgical field, the second toe of the left foot was approached with a dorsal incision with 'longing' and 'in situs in the first intermetatarsal space',
The intermetatarsal artery was located above the interosseous muscle as predicted.
It was dissected from the artery to the base of the second finger, respecting to the maximum the venous network and sectioning the tendon of the extensor digitorum longus, and the tendons and extensor digitorum shortus.
Next, a proximal osteotomy of the second metatarsal was performed, with disarticulation of the metatarsophalangeal joint.
The intermetatarsal ligaments section facilitated the identification of plantar nerves, dissecting them to achieve maximum length.
1.
The next step was to transfer the toe to the receiving area of the hand.
Priest was performed with two Kirschner wires.
Subsequently, flexor and extensor tendon sutures were performed, with a slight envelope.
Then, the 2nd intermetatarsal space was tunneled to perform the microanastomosis of the flap to the intermetatarsal vein (termino-terminal) and the vein a.
Microsuture of the digital nerves of the toe to the collateral nerves of the stump of the 3rd finger of the hand.
Once the neurovascular microanastomosis had been completed, the skin was sutured to avoid drying.
Finally, the soft parts were closed.
Simultaneously to flap transfer, the donor area of the foot was closed.
Proximal resection of the second metatarsal was performed for a better approximation of the first and third fingers.
To achieve good stabilization of the metatarsal transverse arch, intermetatarsal deep transverse ligaments were sutured.
A drain was placed and the skin was sutured with a good apposition of 1st and 3rd fingers.
Good postoperative management is essential for the success of surgery.
For this purpose, a pillowing bandage was applied, establishing the hand with the arm slightly elevated and maintaining adequate temperature.
Low molecular weight heparin and platelets 5% were used as fundamental postoperative medication, in addition to sympathetic vegetative block (to achieve vasodilation), with axillary catheter and continuous infusion pump of alvobupivacaine 0.12 was maintained.
Currently, after adequate and intense rehabilitation, the patient has recovered satisfactory gross pinch function in the operated hand9.
The aesthetic result is not fully satisfactory, which probably requires some future improvement10.
