Quantitative verification of the keyhole concept: a comparison of area of exposure in the parasellar region via supraorbital keyhole, frontotemporal pterional, and supraorbital approaches

Abstract

The area of exposure of the parasellar region through the smaller supraorbital keyhole approach is as adequate as the larger pterional and supraorbital approaches. The keyhole concept can be verified quantitatively as follows: 1) a wide area of exposure on the skull base can be obtained through a small keyhole skull opening, and 2) the side opposite the opening can also be visualized.

The Supraorbital Keyhole Craniotomy through an Eyebrow Incision: Its Origins and Evolution

“…In the setting of vascular pathologies, there may be some difficulty with using two suction tubes in managing prematurely ruptured aneurysms or to obtain proximal control [13, 22, 46, 47]. Some have even recommended against this approach for vascular lesions for this reason [47].…”

“…A prominent orbital rim may impede the surgical degree of freedom, and some authors have advocated the addition of an orbital osteotomy to improve surgical freedom and access for vascular pathologies [16, 48]. A similar concept led to similar adaptations to traditional approaches to frontal base and parasellar lesions in the past [46, 49–52]. A number of authors have described different vascular pathologies safely treated through this approach, but we feel it should be limited to those with significant experience with the approach, and it may not be the best approach for some lesions (such as in subarachnoid hemorrhage, giant aneurysms, or vascular lesions in the posterior circulation) in comparison to more traditional approaches (see Table 1) [13, 22, 46, 47].…”

“…The authors suggest that a more medial craniotomy can be performed without damage to the supraorbital nerve by dissecting below calvarium and elevating pericranium with the supraorbital nerve to expose calvarium for craniotomy without damage to the nerve [53]. Certainly, staying at least 5 mm lateral to the supraorbital notch or foramen with the craniotomy has significantly reduced the risk of supraorbital palsy as well [13, 22, 46]. Incision into the orbicularis oculi should be made along the margin of the muscle superiorly with the muscle dissected with pericranium inferiorly to spare the fibers.…”

“…Previous studies have shown no increased risk of infection, and leaving the eyebrow intact allows for a better cosmetic result [2, 3, 5, 7, 46]. It is important that the skin incision be placed laterally to the supraorbital notch to avoid forehead numbness from injury to the supraorbital nerve during surgery [2, 5, 21, 22].…”

Intradural Procedural Time to Assess Technical Difficulty of Superciliary Keyhole and Pterional Approaches for Unruptured Middle Cerebral Artery Aneurysms

“…When compared with a standard pterional approach, the area of exposure of the parasellar region through a superciliary keyhole approach has already been quantitatively verified as adequate and similar2). In addition, surgical minimalism with tailoring the exposure to the patient's anatomy and surgical lesion has led to the application of a superciliary keyhole approach5), which offers many advantages as follows : 1) small (3.5 cm) operative wound, 2) short operative duration due to the short cranial opening and closing time, 3) less intraoperative blood loss, 4) rarer occurrence of an epidural hematoma, 5) minimal damage to the temporalis muscle, 6) rarer occurrence of wound dehiscence or wound related pain, and 7) early return to work and normal life121314).…”