In 1995, Goel described, for the first time in the literature, a transfalcine surgical approach to contralateral hemispheric lesions.1 Subsequently, Goel and Shah introduced a posterior cranial fossa transtentorial approach for tumors located entirely within the middle cranial fossa.2 Both approaches emphasized functional preservation over operative proximity and exemplified how re-examining anatomical constraints can redefine surgical strategy and safety. TRANSFALCINE APPROACH FOR CONTRALATERAL HEMISPHERIC TUMORS The interhemispheric approach was initially described by Dandy3 and later popularized by Yasargil in the 1970s and 1980s with the adoption of microsurgical techniques.4,5 Since then, it has become a common operative corridor in neurosurgery. With improved understanding of venous anatomy and cerebral eloquence, this approach has undergone continuous refinement. In 1995, more than three decades ago, Goel described the transfalcine approach to contralateral hemispheric intra-axial brain tumors as a deliberate operative concept.1 The description of a contralateral corridor for deep-seated tumors at a time when magnetic resonance imaging was still emerging, and neuronavigation was not yet fully established, exemplifies forward-thinking microsurgical philosophy. Approaching a tumor from the contralateral, nonedematous hemisphere, rather than retracting the diseased brain, introduced a novel paradigm in neurosurgery. In 1997, Goel further described a bilateral approach incorporating a contralateral transfalcine route combined with an ipsilateral interhemispheric approach for pericallosal arteriovenous malformations.6 Earlier, Machado de Almeida et al. had reported a contralateral parafalcine interhemispheric approach for callosal arteriovenous malformations.7 Currently, the contralateral transfalcine approach is widely employed for falcine meningiomas, intraparenchymal tumors such as gliomas, metastases, cavernomas, abscesses, intraventricular tumors, and, less frequently, for pericallosal arteriovenous malformations. This approach is particularly indicated when a direct ipsilateral route would require excessive cortical manipulation, retraction, or transgression of eloquent brain regions. Although the operative distance may be longer, it often provides a safer surgical corridor with safer and reduced cortical handling. In addition, it may offer a more favorable angle of vision and improved visualization of deep-seated structures. The primary objective is to minimize manipulation of critical brain areas in the tumor-affected hemisphere. Despite its advantages, Goel1 cautioned against potential limitations. Prolonged retraction of the normal hemisphere carries a risk of injury, and venous damage on the normal contralateral side can have significant clinical consequences. Furthermore, the increased depth of the lesion and the narrow operative window created through the falx may limit maneuverability within deep surgical corridors. Appropriate patient positioning facilitates gravity-assisted brain retraction. The operative technique involves a relatively large parafalcine craniotomy exposing the edge of the superior sagittal sinus. Using meticulous microsurgical dissection, the brain is gently retracted to expose the falx, with careful preservation of venous structures. A sufficiently large falcine incision is made to access the contralateral hemisphere. Neuronavigation and cortical mapping can assist in accurate tumor localization and safe cortical entry. GOEL’S POSTERIOR CRANIAL FOSSA TRANSTENTORIAL APPROACH FOR MIDDLE CRANIAL FOSSA TUMORS Goel and Shah described, for the first time in the literature, a posterior cranial fossa transtentorial approach for tumors located entirely within the middle cranial fossa.2 Since then, this surgical corridor has been applied to a wide range of neurosurgical pathologies, including tumors, vascular lesions such as cavernomas and arteriovenous malformations, medial temporal lobe tumors, and amygdalohippocampectomy procedures. Tentorial incision and transtentorial surgery have been utilized for several decades. Drake popularized the subtemporal transtentorial route for basilar apex aneurysms.8 Middle cranial fossa transtentorial approaches to the petrous apex, petroclival, and clival regions are well-established techniques. Kawase et al.’s approach, involving drilling of the petrous apex to access the posterior cranial fossa from a middle fossa corridor, has become a standard skull base strategy.9 Goel further described a tentorial dural flap to facilitate exposure of posterior fossa lesions through a middle fossa approach.10 The posterior cranial fossa supracerebellar infratentorial approach has long been the most commonly used route for pineal region tumors.11 Goel et al. introduced a novel strategy for “tentorium-based” epidermoid tumors involving the tentorial hiatus with extension into both supra-and infratentorial compartments.12 These tumors, previously labeled as cerebellopontine angle epidermoids, were re-conceptualized based on their origin, location, and extension along the tentorium within peri-brainstem cisterns. The surgical strategy involved initial supracerebellar exposure followed by a tentorial incision to access the middle cranial fossa component. With increasing experience, Goel and Shah recognized that selected epidermoid tumors confined entirely to the middle cranial fossa could be optimally approached via a posterior cranial fossa transtentorial route.2 This approach provided direct access to lesions within the supratentorial location while minimizing temporal lobe retraction and avoiding manipulation of the internal carotid artery and its branches. Goel and Muzumdar also described, for the first time, a supracerebellar approach to petroclival meningiomas13 – a modification of the retrosigmoid approach previously described by Samii et al.14 The supracerebellar route has since gained popularity for petroclival meningiomas. The ability to incise the tentorium and operate within both the posterior and middle cranial fossae adds versatility to this approach. Although feasible in the lateral or Concorde positions, the sitting position may facilitate surgical exposure. Drilling of the petrous apex can further expand the operative corridor. Such expanded posterior cranial fossa approaches were initially described by Samii et al. and later refined by Tatagiba.15 CONTEMPORARY RELEVANCE Over the past decade, the use of both contralateral transfalcine and transtentorial approaches has increased significantly. Advances in neuronavigation and endoscopic assistance have expanded their indications and safety. These approaches are now widely regarded as conceptually elegant surgical strategies that reflect the evolution of neurosurgery toward functional preservation. Although they may involve longer operative distances, their goal is to provide safer corridors with reduced neurological morbidity. Mastery of brain retraction techniques remains essential for successful application. When appropriately selected, these approaches represent powerful tools in modern neurosurgery and underscore the principle that the safest surgical route is not always the shortest. These contributions thus represent an important milestone in the evolution of contemporary neurosurgical practice.
Atul Goel (Fri,) studied this question.