Abstract
Background The anterolateral thigh (ALT) perforator flap is one of the most widely used flaps
in reconstructive microsurgery. This study investigated a previously unexplored and
clinically relevant aspect of perforator anatomy: the “box junction” (BxJn), the point
at which the perforator arises from its source vessel. Negotiating the BxJn can be
a challenging and time-consuming step in flap harvest, due to the neurovascular structures
in the area which must be protected from injury. However, as the presence and location
of these structures have yet to be clearly defined, painstaking exploration is necessary
on each occasion. Knowledge of BxJn anatomy could allow surgeons to harvest the ALT
flap more rapidly and safely.
Methods We dissected 20 cadaveric thighs and identified perforators to the ALT region and
investigated the neurovascular anatomy at their BxJns.
Results In 51 BxJns, two clinically relevant vascular structures were identified: an intramuscular
artery arising from the perforator (23, 45% of cases) and a “deep” artery to the underlying
muscle arising from the source vessel (29, 57% of cases). We confirmed the consistent
presence of motor nerve branches and describe one previously unreported, clinically
significant variation, in which the nerve to vastus lateralis crosses the BxJn (12,
24% of cases); 36, 71% of BxJns contained at least one vascular and one neural structure.
Conclusion Our study confirms that the BxJn is a site of potentially complex and challenging
neurovascular anatomy for the surgeon. Based on these results, we propose an algorithm
to guide inexperienced surgeons in negotiating this area.
Keywords
anterolateral thigh flap - anatomy - approach - safety - vasculature
