Introduction: Trigonocephaly with its premature fusion of the metopic synostosis is associated with a risk of cerebral compression and several craniofacial morphological deformations. Numerous surgical techniques have been proposed to enlarge and reshape the forehead. They all carry a risk of bleeding during osteotomies, especially in the region of the superior sagittal sinus (SSS) encased in the early fused suture and of the paired metopic transosseous emissary veins superior to the glabella, which is typical of this type of synostosis. In fact, these paired metopic transosseous veins are often, if not always, the source of major bleeding when torn during the elevation of the frontal flap.
Technical note: A simple technical variant may prevent or at least easily control bleeding in this region during the early phases of the surgical repair. The technical variant to the standard surgical techniques utilized to correct trigonocephaly consists in preserving a triangle of bone above the glabella (about 4 cm at the base and 4 cm in height). The triangle of bone contains the initial segment of the SSS and the emissary metopic veins draining the frontal poles. After removing the frontal flap in a conventional manner, this technical variant allows to detach the veins as well as the SSS from the surrounding bone structures under direct visualization, also in case of vessels running partially encased in the bone. Once the venous structure is detached and hemostasis controlled, this last piece of frontal bone may be removed without unnecessary "iatrogenic" bleeding.
Conclusion: The propounded procedure does not prolong the surgical time significantly and does not require additional surgical skills or equipment.
Keywords: Complications; Emissary veins; Metopic synostosis; Nasion; Sagittal sinus.