Discussion
Achilles region reconstruction is one of the most challenging topics of
lower limb repair for plastic surgeons. The Achilles tendon is the
strongest tendon of the body and has a very thin and supple overlying
skin. The tibial neurovascular bundle is located just medial to the
Achilles tendon. Several factors should be carefully evaluated to ensure
successful outcomes of reconstruction; these include age of the patient,
exposed vital structures, size of the defect, comorbid diseases,
presence of scars, history of previous surgery, infection, medications,
smoking, and patient expectations.1,2 During
reconstruction in this region, neurovascular bundle repair and
tendon-skin-soft tissue reconstruction can be performed together or
sequentally, as per need. In the presence of a ruptured, necrotic or
weakened tendon, reconstruction should be performed concomitantly with
soft tissue-skin repair. Therefore, the orthoplastic approach is
neccessary for such repairs.
According to the meta-analysis and algorithm developed by Hackenberg et
al.9, primary tendon suturation is suitable for repair
of defects sized < 2 cm; V-Y tendinoplasty, tendon transfer,
tendon rotation, plantaris, flexor hallucis longus, peroneus brevis and
flexor digitorum longus tendon plasties and combinations can be applied
for defects ranging from 2–5 cm in size. For Achilles defects sized
6–10 cm, free tendon/muscle transplantations, fascia replacement
plasties, allografts, or synthetic materials can be used. Several
surgical interventions have been described for reconstruction of soft
tissue defects, ranging from secondary skin healing to use of free flaps
and amputation; the choice depends upon exposure of vital structures and
tissue vascularity.12,13 According to Monnere et
al.14, adequate neo-Achilles tendon can be formed with
skin-soft tissue reconstruction without Achilles tendon repair. However,
according to a meta-analysis by Ochen et al.15,
operative treatment is associated with reduced rate of re-rupture of the
Achilles tendon. In our opinion, it seems reasonable to perform
operative treatment for Achilles tendon rupture.
In the present study, three patients had injuries in the form of skin
abrasions. Secondary healing was achieved by medical dressings performed
in the outpatient setting. Ankle foot orthoses were used for one week in
these patients with the ankle in the neutral zero position to improve
wound healing. At the end of one week, full motion was allowed with open
dressing. Secondary healing is beneficial for clean Achilles wounds with
small overlying skin defects. Repta et al.16 employed
STSG following NPWT therapy for repair of tendon exposure and skin
defect in patients with peripheral vascular disease. We also achieved
satisfactory results with NPWT plus STSG treatment in two patients with
diabetes mellitus and in one patient in whom the free flap operation had
to be stopped due to peroperative atrial fibrillation (Case 8). However,
prolonged hospitalization and graft adaptation problems are some of the
drawbacks of this approach. Application of NPWT plus STSG treatment is
particularly appropriate for patients with small skin defects, those
with compromised vascular supply, or for whom free flaps cannot be
applied. Although conventional methods such as secondary healing, NPWT,
and skin grafts are preferred in some patients, development of infection
in this region is liable to impair epithelialization and graft
adaptation. In addition, it is difficult to achieve long-term stable
coverage with conventional treatment due to chronic shoe friction.
Use of local flap is another option; however, use of local flap around
the Achilles region entails a certain degree of risk. Distal lower
extremity is a relatively dangerous part of the body for use of local
flaps. Owing to this issue, perforator or perforator based flaps have
been inreasingly used in recent years17,18. We
performed perforator based flap reconstructions for shallow small skin
defects. Use of local flap not only helps maintain the color but also
allows for shallow skin replacement. The main problem in this area is to
find a reliable perforator for flap nourishment. For this purpose, we
relied on Mohan’s hot spot theory19 and performed
superselective angiography to identify the reliable perforator located
nearest to the defect.
On the other hand, in terms of anatomic replication, the thickness of
flap used in the Achillles area should be very thin. Currently,
supermicrosurgical techniques allow for repair of shallow skin-soft
tissue defect repairs with use of super-thin free flaps by skilled
operators. Suprafascial flap dissection, perforator dissection, and
perforator to perforator anastomosis are main challenges in
supermicrosurgery. Using this principle, Hong et al.20have described foot and Achilles repairs with use of super-thin gluteal
perforator flaps and posterior interosseous perforator flaps. Since
super-thin free flaps contain only superficial subcutaneous tissue and
skin, these might be suitable alternatives for reconstruction of skin
overlying the Achilles tendon. These flaps can be harvested and
anastomosed based on perforator vessels without causing any damage to
the main vessels in the donor and recipient areas21.
While the aforementioned repair techniques require a very high level of
surgical skill and instrumentation, donor area scars (gluteal and dorsal
forearm) may not be preferred in some patients. In our study, free SCIP
and MSAP flaps were used for this area in two patients. The main purpose
of SCIP flap application was to create a thin layer where the shoe is in
contact with the Achilles region. The MSAP flap was applied to adhere to
the principle of not changing the position of the patient during surgery
and using a thin flap again. The main drawback with the use of MSAP flap
is that pedicle dissection is relatively difficult. However, appropriate
postoperative results were obtained with both flaps.
As mentioned earlier, concomitant repair of soft tissue and tendon can
be performed in the Achilles region. Lin et al.22performed skin-soft tissue reconstruction with posterior tibial
perforator flap while repairing the Achilles tendon with free fascia
lata graft. They mentioned that this approach can be used safely,
especially in children. Although, this approach offers the advantage of
single-stage surgery and avoidance of free flap complications in
children, a more anatomical repair may be preferred with single-session
composite flaps in such cases. Li et al.23 performed
NPWT therapy and free flap surgery following prompt debridement, and
achieved satisfactory results in children with mangled extremities.
Dobke et al.24 used the free temporopatietal fascia
flap for soft tissue repair and the galeal extension of the fascia for
Achilles tendon reconstruction. Although they achieved long-term stable
tendon repair, a long scar in the scalp, especially in males, can be
considered as a major drawback of this method. In addition to previous
options, the number of multiple donor areas can be reduced to a single
area by using chimeric free flaps. Wei et al.25 used
composite free groin flaps for complex Achilles region reconstructions.
In addition to tendon reconstruction, they also performed calcaneal bone
and skin-soft tissue reconstruction. While the main advantage of the
mentioned flap is their thinness and composite nature, the long-term
risk of abdominal hernia can be considered as a disadvantage. Deiler et
al.5 performed reconstruction of complex Achilles
region defects with free composite TFL flap. The fascial component of
the flap was used for Achilles tendon reconstruction, while the skin
portion was used for reconstruction of the overlying tissue. The
disadvantage of this approach is that it may require debulking for good
aesthetic results, especially in patients who have thick
skin-subcutaneous tissue on the lateral aspect of thigh.
The technique of flow-through repair was first described by Soutar et
al.26 in 1983. Ever since, this technique has been
used to protect the circulation in the distal extremity, especially in
traumatic complicated lower extremity defects. Several reports have
described the use of this approach for the reestablishment of
circulation in the extremity and repair of complicated lower limb
defects. Koshima et al.27 used the thin LD perforator
flap, Özkan et al.23 used the radial forearm flap, and
Yang Z et al.24 used the ALT flap in flow-through
fashion. However, significant scarring and seroma problems in the donor
area may restrict the use of these flaps.
Especially in single artery extremities, without harming the remainder
artery, cross-leg free flow-through, cross-leg pedicled or cross-leg
flow-through flaps can be used as alternatives to flow-through free
flaps28-30. In the present study, we used cross-leg
reverse sural artery flap (CLRSAF) and cross flow-through LD (CFTLD)
flap in order to protect the exposed Achilles tendon. We obtained
satisfactory resuls with both flaps; however, postoperative awkward
position is the main drawback of this approach. Instead of a free flap
surgery, the main reasons for using CLRSAF were previous operations in
dorsal leg and single artery extremity. Circulation of the CLFTLD flap
was preferred from the opposite extremity because the patient was in the
subacute traumatic period according to Godina’s timing of microvascular
reconstruction, and was exposed to electrical burns. Both reasons may
cause thrombotic events after free flap
surgeries.31,32
In addition to use of flow-through flaps, repairing the affected nerve
in the distal limb complex defects is of special importance. Agarwal et
al.33 transferred saphenous nerve to the posterior
tibial nerve, which helped restored protective sensations in the heel.
One of the patients in the present study had a complex defect involving
the Achilles tendon, posterior tibial artery, vein, and nerve. The
tendon and vessels were reconstructed with composite flow-through
ALT-TFL flap while the posterior tibial nerve was grafted with the
contralateral proximal sural nerve graft. This was because the patient’s
distal sural nerve had burned and the proximal healthy sural nerve was
nonfunctional. The patient was able to walk two months after the
operation; EMG performed one year after the operation showed restoration
of protective sensation in the heel. Using this method, the three main
vital structures and the skin were reconstructed in a single operation.
Pre- and postoperative imaging is very important in the context of
complex repairs. In the present study, vascular structures were
evaluated preoperatively with color Doppler, CT, or MRI angiography.
While planning the local flaps, we were inspired by the perforator zones
and hot spots described by Taylor, Abraham, Saint Cyr, and Mohan. Most
hot spots can be found adjacent to joints and at the midpoint between
two joints in the extremities; however, in the trunk, the perforators
are clustered parallel to the posterior and anterior midline, and in the
midaxillary regions10,19,34,35. We performed
superselective digital substraction angiography36(SDSA) in one patient who had a small skin defect over the Achilles
tendon. SDSA helped identify the stereotaxic location and direction of
the perforator located nearest to the defect (Fig. 1b). Finally, similar
to an axial flap, we harvested a perforator based flap according to the
course of the perforating vessel, and avoided the risk of necrosis.
Moreover, this approach complied with the ‘like to like reconstruction’
principle. We believe that this method allows for harvesting of reliable
pedicled flaps and application of ‘like to like repair’ even in the
coldspot regions specified by Mohan et al19. Of
course, high radiation dose is the most important drawback of this
method. IGA, which is frequently used to evaluate the viability of
mastectomy skin flaps, has recently been applied for assessment of skin
flaps prior to their transfer37,38. IGA helps identify
the viable portion of the flap and the location of the nutrient vessels.
In our study, we also performed IGA for the perforator flap harvesting
and free flap follow-up. Use of IGA helped decrease the flap dissection
time, avoided dissection errors, and decreased the risk of flap
necrosis.
The main limitations of this study was the small number of patients.
Although lower leg injuries are frequently encountered in clinical
practice, the focus of this study was specifically on the Achilles
region, and not the whole lower limb.