Free-hand Frameless Pinless Electromagnetic-Navigation (AXIEM™)-Guided Brain Lesion Biopsies: An Institution Based Experience from a Low-Middle-Income Country

Objectives: To evaluate the precision and safety of a novel technique of free-hand frameless pinless AXIEM™-based navigation guided biopsy of deep-seated brain lesions in a low-middle income country.

Methods: This retrospective study included 45 patients who underwent free-hand frameless pinless AXIEM™-based navigation guided biopsy of deep-seated brain lesions using the Medtronic-Stealth S7 system over a 5-year period (January 2019 to December 2023) at the Department of Neurosurgery, Punjab Institute of Neurosciences, Lahore, Pakistan.

Results: A total of 45 patients were included in this study. There were 4 (8.9%) patients in the 1 to 20 years age group, 10 (22.2%) in 21 to 40 years, 24 (53.3%) in 41 to 60 years and 7 (15.6%) were above 60 years. Mean age (years) was 47.29 ± 17.192 SD. Mean time (minutes) for procedures was 37.87 ± 9.6 SD. There were 28 (62.2%) male and 17 (37.8%) female patients. Among patients reviewed in this study 2 (4.4%) had lesions in Corpus Callosum, 8 (17.8%) in Lobar region, 5 (11.1%) were Multiple/Metastatic and 30 (66.7%) were in Thalamus/Internal Capsule/Basal Ganglia. Size of lesions was less than 1 cm in 4 (8.9%) cases, 1-2 cm in 29 (64.4%) and 2 to 3 cm in 12 (26.7%) cases. There were 18 (40%) patients with lesions on the left side, 21 (46.7%) on the right side, 4 (8.9%) bilateral and 2 (4.4%) in the midline. Most cases were performed in local (40%) or local with IV sedation (48.9%) and a few in general anesthesia (11.1%). Biopsy results were successfully diagnostic in 40 (88.9%) and non-diagnostic in 5 (11.1%) patients. Glioblastoma WHO Grade IV was seen in 20 (44.4%) patients, Diffuse Astrocytoma WHO Grade II in 5 (11.1%), Anaplastic Astrocytoma WHO Grade III in 2 (4.4%), Pleomorphic Xanthoastrocytoma in 1 (2.2%), Lymphoma in 7 (15.6%) and Metastasis in 5 (11.1%) patients. Asymptomatic minor haemorrhage was seen in 3 (6.7%) patients, massive haemorrhage in 2 (4.4%), hydrocephalus in 1 (2.2%), surgical site infection in 1 (2.2%) and 38 (84.4%) patients had no complications.

Conclusions: AXIEM™-based Medtronic-Stealth S7 is a quick, reliable, real-time and secure neuronavigation system for taking a free-hand, frameless and pinless biopsy of deep-seated lesions in the brain.