Rediscovery of the transcerebellar approach: improving the risk-benefit ratio in robot-assisted brainstem biopsies

Abstract

OBJECTIVE Conventional frame-based stereotaxy through a transfrontal approach (TFA) is the gold standard in brainstem biopsies. Because of the high surgical morbidity and limited impact on therapy, brainstem biopsies are controversial. The introduction of robot-assisted stereotaxy potentially improves the risk-benefit ratio by simplifying a transcerebellar approach (TCA). The aim of this single-center cohort study was to evaluate the risk-benefit ratio of transcerebellar brainstem biopsies performed by 2 different robotic systems. In addition to standard quality indicators, a special focus was set on trajectory selection for reducing surgical morbidity. METHODS This study included 25 pediatric (n = 7) and adult (n = 18) patients who underwent 26 robot-assisted biopsies via a TCA. The diagnostic yield, complication rate, trajectory characteristics (i.e., length, anatomical entry, and target-point location), and skin-to-skin (STS) time were evaluated. Transcerebellar and hypothetical transfrontal trajectories were reconstructed and transferred into a common MR space for further comparison with anatomical atlases. RESULTS Robot-assisted, transcerebellar biopsies demonstrated a high diagnostic yield (96.2%) while exerting no surgical mortality and no permanent morbidity in both pediatric and adult patients. Only 3.8% of cases involved a transient neurological deterioration. Transcerebellar trajectories had a length of 48.4 ± 7.3 mm using a wide stereotactic corridor via crus I or II of the cerebellum and the middle cerebellar peduncle. The mean STS time was 49.5 ± 23.7 minutes and differed significantly between the robotic systems (p = 0.017). The TFA was characterized by longer trajectories (107.4 ± 11.8 mm, p < 0.001) and affected multiple eloquent structures. Transfrontal target points were located significantly more medial (−3.4 ± 7.2 mm, p = 0.042) and anterior (−3.9 ± 8.4 mm, p = 0.048) in comparison with the transcerebellar trajectories. CONCLUSIONS Robot-assisted, transcerebellar stereotaxy can improve the risk-benefit ratio of brainstem biopsies by avoiding the restrictions of a TFA and conventional frame-based stereotaxy. Profound registration and anatomical-functional trajectory selection were essential to reduce mortality and morbidity.

Stereotactic frame-based biopsy of infratentorial lesions via the suboccipital-transcerebellar approach with the Zamorano-Duchovny stereotactic system—a retrospective analysis of 79 consecutive cases

“…Therefore, further studies with a higher number of cases are necessary. In modern times, the rise of artificial intelligence (AI) and robot-assisted biopsies are still poorly investigated but could be valuable tools to optimize safety [ 14 , 20 ].…”

Robot‐assisted stereoencephalography vs subdural electrodes in the evaluation of temporal lobe epilepsy

“…Prior to the introduction of the neurosurgical robot, iVEEG was based on SDE (ie 40 patients). Of the 40 patients, 14 (35%) received temporal SDE, exclusively (ie 7.3 ± 3.1 [1][2][3][4][5][6][7][8][9][10][11][12] electrodes per patient). In contrast, 26/40 (65%) patients underwent additional SDE implantation to cover nontemporal areas (ie 2.3 ± 2.2 [1-10] electrodes per patient).…”

“…With the introduction of the surgical robot, iVEEG was based on robot-assisted SEEG (n = 20; SEEG), exclusively. All SEEG patients received both temporal and nontemporal electrodes (ie 9.3 ± 1.4 [7][8][9][10][11][12] SEEG per patient). Bilateral temporal recordings were performed in 19/60 (32%) of all patients (SDE: 13/40, 33%; SEEG: 6/20, 30%).…”

“…6 However, SEEG with conventional frame-based stereotaxy turned out to be very time-consuming and the trajectory selection is occasionally impeded by the geometry of the stereotactic frame. [7][8][9] The temporal lobe and its mesial structures (eg hippocampus) are one of the most common brain regions to develop epileptogenicity in medically intractable epilepsy. 10 Hence, there is extensive experience on SDE-based iVEEG of temporal lobe epilepsy.…”

“…The introduction of stereoelectroencephalography ( SEEG ) in the 1950s promised a simplification of iVEEG and a reduction of the surgical risk 6 . However, SEEG with conventional frame‐based stereotaxy turned out to be very time‐consuming and the trajectory selection is occasionally impeded by the geometry of the stereotactic frame 7‐9 …”