Frontotemporal-Orbitozygomatic Approach

Abstract

The frontotemporal-orbitozygomatic (FTOZ) approach developed by Hakuba in 1977 as an osteoblastic bone flap for tumoral and aneurysmal pathologic findings offers a craniotomy with a wide shallow working area and optimal brain exposure with minimal brain retraction. This procedure provides a low vantage point with a wide angle of exposure to the contents of the inferior frontal lobe, parasellar region, cavernous sinus, interpeduncular cisterns, and floor of the anterior and middle fossa. Most procedure variations are fashioned in a nonosteoplastic fashion using deep structures such as the inferior orbital fissure and/or the superior orbital fissures. Unfortunately, published articles have drawn little attention to the cosmesis and complexity of the procedure. A simpler and less timeconsuming FTOZ craniotomy approach compared with previous reports is recommended here. An osteoplastic technique with improved long-term cosmesis that eliminates the necessity of use of the inferior orbital fissures with no need to expose the malar eminence and, if required, translocation of the temporal process of the zygoma rather than removal with the bone flap is discussed. The authors present techniques with cadaveric and skull models for performing a simplified osteoplastic FTOZ craniotomy via 3 procedures (1-piece, 2-piece, and modified) and discuss the merits and use of each procedure. Although the procedures can be performed in a nonosteoplastic fashion, the osteoplastic method is recommended for longterm cosmesis and good functional outcome. The authors' preference for most pathologic lesions treated is the modified procedure because of its simplicity, ease, adequate exposure, and shorter required operating time.T he frontotemporal-orbitozygomatic (FTOZ) approach was developed in 1977 and first introduced into the neurosurgical armamentarium in 1986 by Hakuba and colleagues. 1 It was a 1-piece osteoplastic bone flap with the intent of providing excellent exposure obliquely of the parasellar region and the interpeduncular fossa with the shortest possible working distance. Many variations have emerged since the original description as a 1-piece or 2-piece procedure. 2-17 Most investigators suggested a nonosteoplastic craniotomy, with the exception of 1 group, 17 and the cosmesis of such interventions, principally of temporal muscle atrophy with asymmetry and slumping, resulting in temporal fossa depression is seldom addressed. In addition, the devascularization of the free bone flap with antecedent atrophy and suboptimal healing along the craniotomy line with a heightened risk of infection is not mentioned.This article describes the technical details of performing a simple but easy osteoplastic FTOZ via 3 avenues: 1-piece procedure, 2-piece procedure, and modified 1-piece procedure. The simplicity of the technique is attributed to the lack of need for the use of the inferior orbital fissures in the procedure. Furthermore, the zygomatic arch is not removed separately or as part of the bone flap but is rather translocated with the...

Modified Orbitozygomatic Approach without Orbital Roof Removal for Middle Fossa Lesions

“…The OBZ approach without orbital roof removal (modified OBZ approach) provides basal exposure of the anterior and middle fossa structures. Therefore, we suggest that this approach is useful for patients with vascular lesions of the carotid bifurcation, anterior cerebral artery or bifurcation of the basilar artery, as well as lesions of the sellar and parasellar region, of the lateral wall of the cavernous sinus and in all lesions that compromise the sphenoidal wing in its medial extremity (anterior clinoid process) [ 2 , 6 , 10 ].…”

“…The frontotemporal OrBitoZygomatic (OBZ) approach is considered one of the main accesses and one of the most applied procedures in skull base surgery [ 2 , 10 , 14 , 22 , 24 ]. Hakuba first described the OBZ access in 1986, which resulted from small changes in the fronto-temporo-sphenoidal craniotomy [ 11 ].…”

“…OBZ craniotomy combines the advantages of the pterional and pretemporal approaches, but improves the angle of the microscope view. Hence, it provides the best view for brain injuries in the floor of the anterior and middle cranial fossa [ 2 , 5 , 6 , 10 , 22 ].…”

“…Main variants of the OBZ approach include those in which osteotomies are performed as one-piece [ 1 , 2 , 22 , 24 ], two-piece [ 2 , 20 - 22 , 24 , 25 ], or three-piece bone flaps [ 4 , 5 , 18 ]. In all of these, a craniotomy is carried out that allows resection of the frontotemporal fragment, the roof, and the lateral wall of the orbit, of the zygoma lateral surface, and of the zygomatic process of temporal bone, in one, two, or three segments, respectively [ 24 ].…”

“…However, all of the surgical variants have potential complications of the orbital osteotomy : the development of enophthalmos, and the functional and cosmetic defects arising from this [ 2 , 22 , 24 ]. To avoid these complications, we have developed a variant of the OBZ approach in which we avoid the orbital osteotomy, and instead perform orbital drilling.…”