THE TYPE I V-Y ADVANCEMENT THORACODORSAL
ARTERY PERFORATOR (T.A.P.) FLAP IN THE TREATMENT
OF AXILLARY HIDRADENITIS SUPPURUTIVA.
N.Rehman, R.Y.Kannan, M.S.U.Hassan, N.B.Hart
Department of Plastic Surgery, Castle Hill Hospital, Hull HU16 5JQ, UK.
INTRODUCTION :
Apocrine glands are racemose glands where several glands open into a common pilosebacous orifice. Found in the axilla, groin and perineum, they are characterised by the
fact that a part of its wall forms its secretions. In hidradenitis suppurutiva, it is thought
that keratin plugs block these glands, causing the formation of abscesses which become
infected. This forms a vicous cycle of inflammation and scarring which soon spreads to
the other glands in this honeycomb to give rise to the stellate appearance of the disease.
Eventually, secondary infection sets in, usually Staphylococcus aureus. The actual
aetiology for this disease is not known although it is commoner in women and smokers.
The current treatment of hidradenitis suppurutiva is mainly surgical. Initial
experiences with excision were not ideal since there were high rates of recurrence.
Perhaps this was due to the tendency of the operating surgeon to be lenient with the
margin of excision as methods of closure were not adequate. Recently, Soldin et al have
shown that excision of all hair-bearing skin in the axilla is sufficient to eradicate the
disease while wide excision with a 2 cm margin is excessive. With perforator-based
fascio-cutaneous flaps taken from either the posterior arm or the lateral chest wall or both,
it is now possible to close these sizeable defects as well provide sufficient soft-tissue bulk
to cushion the axillary vessels beneath. Similar techniques had been described in the
1970s but only with a 1:1 ratio since these were not perforator-based.
We have managed to cover these defects without resorting to the equal or unequal
double-opposing V-Y advancement flaps ( Types IIA and IIB ). In fact, a single V-Y
advancement flap based on the consistent and reliable musculo-cutaneous perforators of
the thoracodorsal artery was sufficient to close the defect after removal of all hair-bearing
skin down to the axillary vessels in our patients with good results.
PATIENTS AND METHODS :
With the patient in the lateral position and the ipsilateral arm abducted at 90º, two to
three perforators along the anterior border of the latissimus dorsi were located using a
hand-held Doppler device. Its vascular territory encompasses a quadrilateral area ( figure
1 ) bordered superiorly by the third rib, inferiorly by the seventh rib, posteriorly by the
lateral scapular border and anteriorly by the mid-axillary line. A single V-Y advancement
flap based on the marked out musculo-cutaneous perforators of the thoracodorsal vessels
was planned as shown in figure 2.
All hair-bearing skin in the axilla was then excised down to the axillary vessels
( Figure 3 ). The V-Y flap was dissected sub-fascially beginning anteriorly. Next, the
superior border of the flap was elevated and finally its posterior border. Once islanded,
sub-fascial dissection gradually released the flap until it was sufficiently lax to close the
primary defect. No additional effort was taken to isolate the perforators as the flap
advanced comfortably. Once haemostasis was achieved, the flap was closed from below
upwards starting with the secondary defect, gradually coaxing the flap into a diamond
shape as shown in figure 4. The flap was then inset using subcutaneous and subcuticular
absorbable sutures. A single drain was inserted posteriorly.
Perioperative antibiotics were administered for upto a week after surgery. We found
that defects of upto 12 x 8 cms could be closed using this technique with sufficient
freedom of movement at the shoulder joint. All patients were discharged within 48 hours
after removal of the drains and were followed up in clinic.
DISCUSSION :
Several types of local flaps to close these defects have been described. Broadly
classified into advancement and transposition flaps, various permutations and
combinations have been pieced together.The end result is a significant number of
procedures available to the surgeon. The aim here is to perform a simple, convenient,
reliable flap to preserve form and function.
V-Y advancement flaps based on perforators have been described before. Niranjan et
al described two techniques namely the lateral thoracic perforator based V-Y
advancement flap and the double opposing V –Y advancement flap based on the posterior
arm and the lateral chest wall perforators. However, the narrow vascular pedicle and the
inconsistent course of these perforators make them unreliable. Schwabegger et al have
used a similar V-Y advancement flap but based on random perforators and not
specifically thoraco-dorsal perforators.
The flap described here is a perforator flap based on the musculocutaneous branches of
the thoracodorsal vessels which supply the latissimus dorsi muscle and the skin over the
muscle. In our case series, we found no need to dissect down to the thoracodorsal vessels
as one would in a typical TAP flap though it is an option for larger defects. Baudet et al
showed that this system of vessels was highly reliable being present in all cases with large
vessel diameters and easily located. Angrigiani et al first described in 1995, free
perforator flaps based on the thoracodorsal artery whilst preserving the latissimus dorsi.
Original cadaveric studies show that an axial pattern fascio-cutaneous flap can also be
taken on one or two vessels arising as direct septocutaneous branches from the
thoracodorsal vessels. Unfortunately, it is present in only 47% of cases and is therefore
too inconsistent to base the flap on.
The advantages of the TAP flap over its contemporaries are numerous. It is reliable
and reproducible as the subscapular-thoracodorsal arterial system is robust and
predictable. Dissecting sub-fascially preserves the fascial plexus thus allowing a length to
width ratio of 3:1. The vascular system supplies a large quadrilateral paddle of skin
( shaded area in figure 1 ), allowing it to close large axillary defects. In the longer term,
there is no need to immobilize the shoulder and the scar is easily hidden along the
posterior axillary fold. Furthermore, it provides excellent colour and texture match to the
axillary fossa whilst preserving the axillary folds.
Unlike Schwabegger et al, we have had no need to either include muscle in the flap or
to dissect out the perforators to close adjacent axillary defects. This has resulted in a
simpler, safer and more user-friendly flap that is the ideal choice of achieving cover after
excision of the hair-bearing skin of the axilla as exemplified by our high success rate. As
such, we highly recommend its use in clinical practice both in the treatment of axillary
hidradenitis suppurutiva and the closure of axillary defects.