Vastus Lateralis Motor Nerve Can Adversely Affect Anterolateral Thigh Flap Harvest

Abstract

Two patterns of vastus lateralis motor nerve anatomy can adversely influence anterolateral thigh flap elevation. One involves the motor nerve passing through the main vascular pedicle. The other occurs when multiple perforators are required to support large flaps with the motor nerve passing between these perforators. In some cases, the course of the nerve may require transection of the nerve, with a subsequent deficit in vastus lateralis function. In similar cases, if the nerve is preserved, the vascular pedicle may require significant modification, which may possibly compromise flap perfusion.

The Unfavorable Anatomy of Vastus Lateralis Motor Nerves: A Cause of Donor-Site Morbidity after Anterolateral Thigh Flap Harvest

“…A study by Casey et al described two major variations of the motor nerve anatomy that may risk denervation of the vastus lateralis and indeed adversely affect anterolateral thigh flap harvest: a course of the motor nerves through the vascular pedicle or a course between perforators supplying the flap. 14 Limitations of that particular study included the fact that it was a retrospective chart review, that it was noted that some charts did not record the nerve anatomy, and that it was a clinical study limited by exposure of the nerves during flap harvest. The current study comprises a thorough cadaveric study of the nerves to the vastus lateralis, identifying the incidence of unfavorable nerve anatomy and relating this nerve anatomy to the vascular supply of the anterolateral thigh flap.…”

“…3,5 The cause of donor-site morbidity following anterolateral thigh flap harvest may be multifactorial; however, damage to the nerve supply to the vastus lateralis has been implicated as a cause of donor-site morbidity. 14 The motor nerves to the vastus lateralis, arising from the femoral nerve, are intimately related to the vascular pedicle supplying the anterolateral thigh flap and may be damaged and/or sacrificed during flap harvest. A study by Casey et al described two major variations of the motor nerve anatomy that may risk denervation of the vastus lateralis and indeed adversely affect anterolateral thigh flap harvest: a course of the motor nerves through the vascular pedicle or a course between perforators supplying the flap.…”

Use of the descending branch of the lateral femoral circumflex vessels as a composite interposition graft in lower extremity reconstruction

“…Care should be taken to avoid injury to the motor nerve branches to the vastus lateralis muscle, which can be intimately related to the vascular bundle. 15,16 Following the harvest of the composite arteriovenous graft, the vastus lateralis muscle maintains its perfusion from several minor perforators. 17 The use of an arterial interposition graft has been well documented in the literature.…”

Management of Facial Paralysis due to Extracranial Tumors

“…14 Furthermore, because of redundancy proximally, sacrifice of branches of the MNVL is routinely performed during ALT pedicle harvest (irrespective of grafting needs) without impairing postoperative function. 15 Animal evidence suggests that an additional advantage of improved rapidity and quality of neural regeneration may be achieved through use of a nerve graft with matching motor (rather than sensory) modality. 16,17 Once tumor margin clearance and adjunctive ablative procedures are completed, the ALT vascular pedicle is divided, the MNVL graft is harvested, and a 2-cm wide and 10-cm long slip of fascia lata is also removed from the harvest site laterally.…”