3D Endoscope-Assisted Transtubular Approaches to the Pineal Region

Background: The pineal region is an anatomically complex and deeply situated with a tight neurovascular network. Standard microsurgical approaches to this area have been associated with major neurological deficits, deep venous infarction, and brain stem dysfunction. We investigate a series of 3D endoscope-assisted transtubular approaches to the pineal region approaches using a minimally invasive tubular retractor system.

Methods: Supracerebellar-infratentorial, including the median, paramedian and extreme lateral variants, and occipital transtentorial approaches were performed on five preserved cadaveric heads (10 sides) injected with colored latex. A ViewSite Brain Access System (Vycor Medical, Inc., Boca Raton, Florida, United States) of tubular retractors was used. Minicraniotomies or 2- to 3-cm burr holes were fashioned for each specimen with the aid of neuronavigation (Brainlab AG, Feldkirchen, Germany). The tubular retractor was introduced under direct 3D endoscopic visualization. Following observation of crucial neurovascular structures, dissection through the retractor was performed using bayonetted microinstruments. Surgical exposure and maneuverability were qualitatively evaluated for each approach by three surgeons using a scoring system.

Results: The pineal region—including the superior and inferior colliculus, origin of the trochlear nerve, and the quadrigeminal plate—was successfully accessed in all the cases. The tubular retractor enabled adequate anatomical visualization and provided stable occipital and cerebellar retraction. Byonetted instruments and bipolar cautery were passed through the tubular retractor without difficulty, and the tubular retractors applied rigid, constant, and equally distributed pressure onto the impacted surfaces. The technique facilitated dissection of the neurovascular structures within the pineal region.

Conclusion: An endoscope-assisted transtubular approach to this region is both safe and effective for the management of pineal lesions, though the use of routine retractors and their potential complications, in some cases, cannot be avoided. Further clinical studies are necessary to determine potential complication rates.