Image-guided biopsy of intracranial lesions in children, with a small robotic device: a case series.

BACKGROUND AND OBJECTIVES: Robot-assisted biopsies have gained popularity in the last years. Most robotic procedures are performed with a floor-based robotic arm. Recently, Medtronic Stealth Autoguide, a miniaturized robotic arm that work together with an optical neuronavigation system, was launched. Its application in pediatric cases is relatively unexplored. In this study, we retrospectively report our experience using the Stealth Autoguide, for frameless stereotactic biopsies in pediatric patients. METHODS: Pediatric patients who underwent stereotactic biopsy using the Stealth Autoguide cranial robotic platform from July 2020 to May 2023 were included in this study. Clinical, neuroradiological, surgical, and histological data were collected and analyzed. RESULTS: Nineteen patients underwent 20 procedures (mean age was 9-year-old, range 1-17). In four patients, biopsy was part of a more complex surgical procedure (laser interstitial thermal therapy - LITT). The most common indication was diffuse intrinsic brain stem tumor, followed by diffuse supratentorial tumor. Nine procedures were performed in prone position, eight in supine position, and three in lateral position. Facial surface registration was adopted in six procedures, skull-fixed fiducials in 14. The biopsy diagnostic tissue acquisition rate was 100% in the patients who underwent only biopsy, while in the biopsy/LITT group, one case was not diagnostic. No patients developed clinically relevant postoperative complications. CONCLUSION: The Stealth Autoguide system has proven to be safe, diagnostic, and highly accurate in performing stereotactic biopsies for both supratentorial and infratentorial lesions in the pediatric population.

Jugular foramen stenosis in external hydrocephalus in infants.

OBJECTIVE: To measure the size of jugular foramina in infants affected by external hydrocephalus (EH) and in a control group, to support the hypothesis that a jugular foramen (JF) stenosis may determine dural venous sinus alterations and increased venous outflow resistance as main pathophysiological factor. METHODS: Minimum, maximum, and mean values of JF areas were measured in a series of phase-contrast magnetic resonance venous angiography (angio MRV PCA3D) performed on 81 infants affected by EH. Results were compared with a group of 54 controls. RESULTS: Smaller JF area was significantly smaller in patients versus controls (43.1 ± 14.6 vs. 52.7 ± 17.8; p < 0.001) resulting in a significantly smaller mean JF areas in patients vs. controls (51.6 ± 15.8 vs. 57.0 ± 18.3; p = 0.043). In patients, smaller JF areas were significantly associated with higher venous obstruction grading score (VOGS) both on the right (p = 0.018) and on the left side (p = 0.005). Positional plagiocephaly (cranial vault asymmetry index > 3.5%) was more frequent among EH patients than controls (38/17) but the difference was not significant (p = 0.07). In the 38 plagiocephalic patients, JF area was smaller on the flattened side than the contralateral in a significant number of cases both in right (21/7) and left (9/1) plagiocephaly (p < 0.0005) as well as the mean area (48.2 + 16.4 mm2 vs. 57.5 + 20.7 mm2, p = 0.002) and VOGS was significantly higher on the plagiocephalic side than on the contralateral side (1.6 ± 1.1 vs. 1.1 ± 0.9, p = 0.019). CONCLUSION: In this series of infants affected by EH, the mean size of the ostium of both JF resulted significantly smaller than controls. JF stenosis was significantly associated with higher degrees of venous obstruction on both sides, suggesting a direct extrinsic effect of JF size on dural sinus lumen and possible consequent effect on venous outflow resistance. Positional plagiocephaly, when present, was associated with a decreased JF area and increased VOGS on the flattened side.

Low-grade epilepsy-associated tumors: Epilepsy outcome and antiseizure medication discontinuation after lesionectomies as first-line surgical approach in pediatric population.

OBJECTIVE: This study aimed to evaluate epilepsy outcome and antiseizure medication (ASM) discontinuation after lesionectomies as first surgical approach in pediatric population diagnosed with low-grade epilepsy-associated neuroepithelial tumors (LEATs). METHODS: We conducted a retrospective study. Thirty-six consecutive patients with histological diagnoses of LEATs who underwent surgery between 2018 and 2021 at our institution were included. The clinical and surgical data were retrospectively analyzed. RESULTS: Thirty (83.3%) of 36 patients are free of disabling seizures (Engel class I) and 19 (63,4%) of them are classified as Engel Ia. In 17 (47.2%) patients, ASM could be discontinued. The mean age at surgery was 8.6 years (±4.04) and the mean age at onset of epilepsy was 7.2 years (±3.8), whereas the mean duration of epilepsy in months at the time of surgery was 21.3 months (±23.7). The epileptogenic tumor was in the temporal lobe in 20 (55.5%) patients. Because of seizure persistence, a second or a third surgery was necessary for six patients (16.7%) and four of them had residual lesions (three in temporal and one in extratemporal site). No perioperative complications were recorded, including acute seizures, with a median hospitalization time of 7 days. Shorter epilepsy duration at time of surgery as long as a single ASM was significantly correlated with an Engel class I outcome (p-value = .01 and p-value = .016, respectively). Focal seizure semeiology was associated with an increased probability of antiseizure medication discontinuation (p-value = .042). SIGNIFICANCE: Our findings confirm that shorter epilepsy disease duration, monotherapy before surgery, and seizure semeiology are determinant factors for a positive seizure outcome and medication discontinuation, also with less invasive surgical approaches such as lesionectomies. However, considering the intrinsic multifactorial epileptogenic nature of LEATs, a tailored surgical approach should be considered to optimize clinical and seizure outcome, especially for lesions located in the temporal lobe.