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An Urban Experience
L. Findji1
1Fitzpatrick Referrals, Oncology and Soft Tissue surgery, Guildford, United Kingdom
Skin reconstruction. Advanced techniques
Climbing up the “ladder” of reconstruction techniques (cf. “Skin reconstruction. Basic techniques”), when simple primary closure is not possible and no local  aps are available to cover a wound, axial pattern  aps should be considered. If no axial pattern  ap is deemed suitable, appropriate distant  aps and free skin grafts should next be sought. This second part will focus on axial pattern  aps, distant  aps and free skin grafts.
Axial pattern  aps
Skin  aps are either subdermal (relying on the subdermal vascular plexus) or axial (relying on a direct cutaneous artery).
Axial pattern  aps are determined by the area of
skin vascularised by a major direct cutaneous artery (angiosome), after which it is named (Figure 1a). Many direct cutaneous arteries which can be used to perform axial  aps have been described. Provided this artery
is preserved, such  aps are more robust and survive
on greater lengths compared to equivalent subdermal  aps. They can even be islanded, i.e. entirely cut out from the donor site apart from their vascular pedicle (Figure 1b). However, axial  aps cannot be elevated in any direction: their design has to follow the description of the cutaneous area vascularised by the chosen direct cutaneous artery. The anatomical landmarks of each axial pattern  ap is provided in their original description and in textbooks. The most commonly used axial  aps include the caudal super cial epigastric, thoracodorsal, omocervical, deep circum ex iliac and caudal auricular  aps.
Figure 1: Vascularisation of axial  aps. Peninsular  ap (a), island  ap (b)
Skin  aps, either subdermal or axial, are transposed with their own vascularisation and can survive on poorly vascular beds or over cavities.
Distant  aps are subdermal  aps which can be used for reconstruction of wounds on limb extremities (distal to the elbow or sti e). Ideally, the wound, or at least
part of it, is lateral. Extensive, circumferential wounds (degloving injuries) are very good indications. With these  aps, the wound is taken to the excess skin rather than the other way round, like in other  aps. With distant  aps, the reconstruction is by necessarily staged, as their principle is to give enough time for a vascularised portion of skin to heal on the wound to reconstruct, suf ciently to be secondarily detached from the trunk and survive on its neovascularisation from the wound. These  aps include hinge and pouch  aps, depending on whether
a monopedicular or a bipedicular subdermal  ap is elevated on the trunk. Pouch  aps (“tunnelisation”) are safer both because of their double pedicle and because they immobilise the leg better. The disadvantages of these  aps are to require that the patient tolerate having the treated leg maintained against the trunk during the  rst phase of the reconstruction. Very heavy patients or patients with severe orthopaedic issues of the remaining limbs may not be good candidates for this technique. In any case, a degree of ankylosis is expected when the leg is released, but is usually resolves spontaneously or with minimal physiotherapy.
To perform a distant  ap, the leg to treat is brought to the trunk and a skin  ap is elevated from the trunk to cover the wound. This is left to heal 7-18 days depending on the age of the dog and whether the  ap is released from the trunk progressively or not. If a circumferential wound is to be covered, enough skin is harvested from the trunk to be wrapped around the released leg and cover the medial aspect of the wound. If the wound to reconstruct is large, closure of the donor site may itself require the use of skin  aps.

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