Endoscopic-assisted parieto-occipital interhemispheric precuneal transtentorial approach for microsurgical resection of vermian arteriovenous malformation: operative video and technical nuances

Abstract

In this illustrative video, the authors demonstrate resection of a superior vermian arteriovenous malformation (AVM) using the endoscopic-assisted parieto-occipital interhemispheric precuneal transtentorial approach. Lateral positioning allows for gravity-assisted access to the interhemispheric fissure without retractors. The parieto-occipital trajectory is useful in patients who have a steep tentorial angle and avoids manipulation of the occipital lobe and visual cortex. In addition, the authors utilize an angled endoscope, which allows full inspection of the resection bed after AVM removal to visualize areas hidden from the microsurgical view to minimize the chance of residual disease in a deep corridor with multiple visual obstructions.The video can be found here: https://youtu.be/hk9nIIdtqbI

Comparison Between the Supracerebellar Infratentorial and Precuneal Interhemispheric, Transtentorial Approaches to the Cerebellomesencephalic Fissure: An Anatomoradiological Study and Illustrative Cases

“…[32][33][34] Modern adjuncts including endoscopic assistance may be used to carefully inspect deep-seated cavities, and indocyanine green injection can help localize the straight sinus before cutting the tentorium-although we use Doppler ultrasound. 6,11,35,36 While we performed a large parasagittal craniotomy on our specimens for illustrative purposes and to facilitate dissection in embalmed specimens, the use of image guidance and endoscope assistance in a clinical setting allow for tailored approaches that often result in smaller craniotomies. In addition, despite the PCIT's trajectory being longer, in the lateral position, gravity allows the parietal lobe to fall away from the falx, allowing the surgeon to shorten the working distance the approach by moving the hands into the interhemispheric fissure.…”

“…For arteriovenous malformations, careful attention should be paid to the venous drainage. Zhao et al 6 demonstrated the use of the PCIT for a vermian arteriovenous malformation with a superior to inferior long axis with drainage superiorly. As such, the PCIT afforded the optimal trajectory and early visualization of the draining vein, which could eventually be accessed and sacrificed when the rest of the nidus had been disconnected.…”

“…1,2 These regions harbor diverse pathological entities including primary pineal tumors, gliomas, meningiomas, cavernous malformations, and arteriovenous malformations. 2-8…”

“…1,2 These regions harbor diverse pathological entities including primary pineal tumors, gliomas, meningiomas, cavernous malformations, and arteriovenous malformations. [2][3][4][5][6][7][8] To reach lesions in these regions, variants of the supracerebellar infratentorial approach (SCIT) are popular. 3,[9][10][11][12][13] The angle of approach, however, is restricted craniocaudally, and may prove insufficient for some lesions that extend inferiorly.…”

“…Thus, to provide a greater superior to inferior trajectory, recent publications have demonstrated the efficacy of the precuneal interhemispheric transtentorial approach (PCIT). 2,3,6,14 The PCIT maximizes the craniocaudal trajectory of a supratentorial corridor by shifting the craniotomy superiorly and, consequently, the trajectory inferiorly. Although the supracerebellar approach and its variations have been compared with the occipital transtentorial approach by several qualitative and quantitative studies, none have described the comparative efficacy of the PCIT and the midline SCIT for lesions of the dorsal brainstem and cerebellomesencephalic fissure.…”