Yotsuya Medical Cube, Chiyoda-ku, Tokyo, Japan
The dorsum of the hand has numerous extensor tendons and can be easily exposed. It is possible to use an artificial dermis to raise granulation tissue and then conduct a skin graft, however this tends to lead to adhesion of the tendons and contracture of the MP joints. Covering this area using a skin flap requires a thin skin flap, however it is not necessary to reconstruct sensory function. A flap is chosen that can become a tendon gliding surface.
Both pedicled and free abdominal flaps are practical because they can be thinned.
If the thinner skin flap is required, the temporal fascia flap can be used.
Thinning of the groin flap is difficult, and they are difficult to use except covering amputation stumps. The blood flow of the reverse flow posterior interosseous flap is unstable.
Use of negative pressure wound therapy is indicated for a skin graft.
Selectable Flaps and Surgical ProceduresPedicled abdominal flapFree temporal fascia flapDorsal metacarpal arterial flapReverse flow radial forearm flapFree dorsalis pedis flap with tendonsFree abdominal perforator flapAdipofascial flap by dorsal branch of ulnar arteryFree or pedicled groin flapReverse flow posterior interosseous flapSkin graft pressure method using negative pressure wound therapy
The difficulty level of each surgical procedure is shown subsequent to the procedure title (e.g., Level of Difficulty: 2). The levels range from 1 to 5, with level 1 indicating a preliminary level and level 5 indicating a very advanced level.
3.1 Pedicled Abdominal Flap (Level of Difficulty: 3)
Vascular pedicle Superficial epigastric blood vessels
Size A width for direct suture closure is normally 8–10 cm. Can make longer than 20 cm from lower abdominal region
Advantage Stable blood flow. Simple operating technique. Rich amount of tissue. The end can be made thinner. By rolling the base of the skin flap and creating a tubed flap, there is no need for lining of the flap, and the patient can shower from an early stage because there is no raw surface. And by creating a long tubed flap, it increases the level of freedom of the upper arm, preventing contracture of the shoulder joint
Disadvantage Surgery is performed in two stages
3.1.1 Operation Procedures
Procedure 1: The abdominal flap is created from the lower abdomen to the upper abdomen, along the center of the lateral abdomen in line with the path of the superficial epigastric artery. The height of the flap is decided by placing the wounded hand against the abdomen region
A flap base of between 8 and 10 cm is required for creating a tube out of the flap. The length of the flap is set to two times the length of the area to be covered.
The end of the flap becomes dog eared and so is resected.
Refer to Section of
“Reconstruction of forearm region/Pedicled abdominal flap” in Chap. 2
Procedure 2: The skin flap is dissected at the layer above the anterior sheath of the rectus abdominis (fascia of external oblique muscle of the abdomen)
Procedure 3: The skin flap donor site is sutured closed directly. If necessary, a continuous suction drain is inserted
Procedure 4: A large amount of fat is removed from the margins of the flap. If an insufficient amount of fat is resected, the superficial epigastric artery for the tubed pedicle flap will be pinched, causing circulatory insufficiency, so as much fat is removed as possible
If circulatory insufficiency occurs to the flap, the flap becomes pale and blisters appear on the tube. In such a case the stitches should be removed.
Procedure 5: For the base of the flap, enough fat is removed without damaging the superficial epigastric artery. The end of the flap used for covering the wound of hand is made even thinner
For the end of the flap, as long as the subcutaneous vascular plexus has been retained it is possible to remove fat down to around a thickness of 1 cm.
Procedure 6: The base of the flap is sutured and made into a tube shape
(a, b) Procedure 7: The wound of the hand is covered by the flap
The suturing should be done tightly.
In particular, confirmation should be made that the stitching between the posterior side of the flap and the hand is tight to avoid making a fistule.
Procedure 8: A towel should be placed between the elbow and the axilla, and the upper arm is fixed in place
The only bandaging for the upper arm is applied to the wrist.
Procedure 9: The entire upper arm is loosely tightened using an abdominal belt. Make it possible for the patient to move their elbow and shoulder within the abdominal belt
Procedure 10: The flap is separated two weeks later. Care must be taken not to apply stress to the flap margins for wound closure
A toe transplant is the best option for making a metacarpal hand a functioning hand
If trying to obtain an aesthetic hand, then an artificial hand prosthesis is the best option (Photo left. Appearance of an artificial hand prosthesis attached to photo for 10 above), but if the goal is to make a metacarpal hand a functioning hand, a toe transplant is the best option (Photo right. Separate case).
Refer to Section of “Toe transfer/Metacarpal hand : Double toe transfer” in Chap. 9
3.2 Free Temporal Fascia Flap (Level of Difficulty: 4)
Advantage Extremely thin. Useful for covering exposed tendons and bones of hands and feet. Donor scar isn’t obvious on haired area. Possible to harvest two temporal fascia flaps
Disadvantage Hemorrhagic. Requires careful attention to stop bleeding. If dissecting layer is too superficial can lead to hair loss. Harvesting of deep fascia is somewhat complex
3.2.1 Operation Procedures
Procedure 1: The hair is not cut. All hair is first washed in isodine liquid, which is then washed out with distilled water. Rubber rings are attached to Pean forceps and the hair on both sides of the incision line is twisted by the forceps, and the rings released to bind the hair
Procedure 2: An incision is made in line with the hair stream, and the area above the temporal fascia is dissected. This area is hemorrhagic, so bleeding is carefully stopped using a bi-polar apparatus
When dissecting, care is taken to avoid a large amount of hair root being exposed in the scalp.
The temporal branch of the facial nerve runs along a line about 1 cm below the tragus to a point 1.5 cm lateral of the eyebrow, so this point should be marked.
When dissecting the anterior section of the fascia, attention must be paid to the path of the temporal branch of the facial nerve, being careful not to go over the line marked on the skin.
Procedure 3: An incision is made in the anterior, superior and posterior margin of the fascia flap, the fascia flap is dissected and turned downwards. In between the two fascia flaps is loose connective tissue that can be easily removed with the fingers. Make sure that the deep fascia isn’t removed at the same time
The fascia flap becomes narrower as it moves proximally, and anterior of the ear it is made up of only the superficial temporal blood vessels.
The vein often runs close to the ear while the artery is about 1 cm posterior.
Procedure 4: The flap is dissected up to the superior margin of the zygomatic arch, the blood vessels confirmed and the fascia flap harvested
The auriculo-temporal nerve is harvested together with the temporal blood vessels, however this doesn’t affect function.
When closing the donor site, a continuous suction drain must be inserted. A minimal subcutaneous suture is conducted deep, while a stapler suture is conducted for the surface of the skin.
Procedure 5: The photo shows the skin defect of dorsum of right hand. Exposure of the extensor tendons present. (Photo reproduced from Hirase, Y., et al.: temporoparietal free fascial flap. Journal of Japanese Society for Plastic and Reconstructive Surgery 10:649–657, 1990)
Procedure 6: Anastomosis is performed with the radial artery and comitant vein (or cutaneous vein) in the snuff box, and the exposed extensor tendons wrapped with the fascia flap. A split-thickness skin graft is performed over the fascia, and a tie-over bolster dressing is applied
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