Tips and tricks of spinal cord biopsy: insights from a multicenter series of 61 patients

Purpose: Whenever the radiological and clinical presentation of diffuse spinal cord lesions pose diagnostic and therapeutic dilemmas, the role of primary spinal cord biopsies (SCB) can represent a crucial surgical step to guide further management. However, the benefits of SCB comes with the risks of significant neurological worsening and potentially non-diagnostic findings. An evidence-based algorithm to assess the appropriateness of SCB and its chances of successful diagnosis is currently lacking. Method: A multicenter retrospective study was conducted across 8 tertiary neurosurgery European centers and included all patients undergoing primary SCB between January 2005 and December 2020. The main objective of this study was to assess the positive diagnostic rate, while the secondary objective was to evaluate the rate of neurological deterioration. Results: Histological diagnoses were obtained in 91.8% (56/61) of cases. Lesions spanning more than three spinal levels were significantly associated with non-diagnostic biopsies (p = 0.03). Neurological deterioration occurred in 47.5% (29/61) of patients, with 48,3% recovering within three weeks. Independent risk factors for postoperative deterioration included low-grade glioma (LGG) (p = 0.005) and lymphoma (p = 0.007). Intraoperative Ultrasound (IoUS) was significantly associated with reduced postoperative deficits (p = 0.030). Surprisingly, preoperative clinical and radiological diagnoses differed from histopathological findings in 47.5% of cases. Conclusion: SCB are relatively safe and effective diagnostic procedures despite their inherent risk of significant perioperative neurological worsening. The decision to undertake a primary SCB should always be made in a multidisciplinary setting after careful review of clinical and diagnostic findings.