Anatomic study of the femur-vastus intermedius muscle-anterolateral thigh osteomyocutaneous free flap

Summary

Introduction

Resection of head and neck malignancy usually causes facial defects and esthetic deformities. Among the wide range of free flaps available for reconstruction, a novel chimeric free flap—the femur-vastus intermedius muscle-anterolateral thigh osteomyocutaneous free flap (FVATLO flap)—has been demonstrated for clinical use. In this study, we illustrate the anatomy and harvest of the FVATLO flap.

Methods

Eighteen fresh cadavers without damage to either thigh were recruited for dissection. Blood supply to the vastus intermedius muscle and femur were traced and recorded. The diameter, circumference of the middle part of the femur, and thickness of the femoral cortex were measured.

Results

The major blood supply to the vastus intermedius muscle showed two patterns of origin. The first arising from the descending branch of the lateral circumflex femoral artery (LCFA-db) accounts for 78% of the cases (28/36), and the second arising from the transverse branch of the lateral circumflex femoral artery (LCFA-tb) accounts for 22% (8/36). Blood supply to the femur consists of two major sources: one from branches penetrating through the nutrient foramen on the posteromedial surface of the femur to the medullary cavity, and the other from the periosteum branches spreading over on the femoral surface. No visible branch from the vastus intermedius muscle to the underlying periosteum was found. The mean diameter, femoral circumference, and mean cortical thickness were 26.30 mm, 85.58 mm, and 6.85 mm, respectively.

Conclusion

Considering that there is only one injured donor site, the FVALTO flap is an alternative chimeric flap for cases with a large amount of soft tissue loss together with small bony defects.

Introduction

Resection of malignancy in the head and neck region usually causes facial defects and esthetic deformities. Postoperative reconstruction has been a challenging issue for a long time. The development of microvascular anastomosis with vascularized free flap makes it possible for the reconstruction to sustain a relatively normal appearance.

Among the wide range of free flaps available for reconstruction, the anterolateral thigh free flap has become a workhorse flap for reconstruction in the head and neck region, owing to its various advantages, especially its constant and long vascular pedicle, large abundance of soft tissues, and covert donor-site.^1,2 However, it loses its popularity when it comes to a case with bony defect, then bone-containing flaps, such as fibular osteomyocutaneous free flap based on the peroneal artery,³ iliac osteomyocutaneous free flap with deep circumflex iliac artery,⁴ vascularized scapular flap based on the circumflex scapular artery⁵ as well as clavipectoral osteomyocutaneous free flap pedicled from the thoracoacromial artery,⁶ play the role instead. In 2011, Acarturk et al.⁷ gave the first to report about the femur-vastus intermedius muscle-anterolateral thigh osteomyocutaneous free flap (FVATLO flap) applied in the reconstruction of a case with complex lower extremity defects. Five years later, Brody et al.⁸ introduced its first application in head and neck reconstruction. Both articles described detailed steps for harvesting this innovative flap and reported satisfactory outcomes in clinical practice. However, knowledge of the anatomic characteristics and blood supply of the femur-vastus intermedius flap is still vague and unfamiliar to most surgeons. In the following study, we illustrate the anatomy and fabrication of the FVATLO flap.