Latissimus Dorsi-Rib Osteomyocutaneous Flaps for Composite Cranial Defects: A Case Series and Anatomical Study

Abstract

PURPOSE: Latissimus dorsi-rib osteomyocutaneous flaps (LDRFs) are versatile in reconstructing compromised composite defects of the cranium. The flap restores the contour of the skull, protects the brain, and improves neurologic status. There are benefits to using autologous rib instead of alloplastic material; however, rib viability and flap success rely on adequate blood supply. Our aim was to present the outcomes of 6 patients treated with LDRF and provide an anatomical basis for this flap. METHODS: Six patients with cranial defects treated with LDRF were evaluated retrospectively. Defect size, etiology, previous reconstructive attempts, outcomes, and complications were assessed. Red latex was injected into the subscapular arterial system of 20 fresh cadaver sides. In the prone position, latissimus dorsi muscle was dissected from the ribs in a mediocaudal to superolateral direction to locate interconnecting vessels between the thoracodorsal and lateral posterior intercostal systems. The number, diameter and length of perforators, and distance from midline were measured. RESULTS: All patients had a history of ≥2 previous failed reconstructions. Defects were secondary to gunshot injury, post-CVA cranioplasty, postablation irradiation, and postfrontal intracranial hemorrhage cranioplasty. Three defects were reconstructed using 2 ribs, whereas the remaining 3 patients received 1 rib. A prolene mesh was used to fill in the donor site defects in 4 patients. Follow-up ranged from 6 to 35 months. All patients had stable reconstructions. Headache resolved in 2 patients after reconstruction, and neurologic status improved in 2 patients. An average of 13.75 perforators could be localized in each cadaveric latissimus dorsi muscle. No perforator was found for the seventh rib. Not all cadaver sides contained perforating vessels for the eighth and 12th ribs. The distance from the midline to the first perforator was not different between the ribs (P = 0.499). Perforator diameter and pedicle length tended to decrease at more inferior rib levels. The 10th rib (4.65 ± 2.01) followed by ninth rib (3.7 ± 1.63) had the highest number of perforators. The eighth and 12th ribs contained the least perforators. The eighth rib had the longest perforators (4.26 ± 1.52 cm). CONCLUSION: The LDRF can successfully address large composite cranial defects, provide support, and enhanced contour with negligible donor-site morbidity. The 10th followed by the ninth rib has the best vascular supply for this flap. If 2 ribs are considered for the flap, the ninth and 11th are recommended. If only 1 rib is necessary for reconstruction, the 10th is ideal.