Intracranial hemorrhagic risk after cortical brain biopsy during shunt surgery for idiopathic normal pressure...

This study prospectively compared postoperative intracranial hemorrhagic complications following shunt surgery for idiopathic normal pressure hydrocephalus (iNPH) in patients undergoing the procedure with or without a concomitant cortical brain biopsy.

All patients undergoing shunt surgery for iNPH at our institution between January 1, 2018, and December 31, 2025, were prospectively enrolled. Patients were allocated to shunt surgery with or without a cortical brain biopsy. Postoperative intracranial complications were assessed using cranial computed tomography (CT), with predefined outcomes including (1) symptomatic intracranial hemorrhage and (2) asymptomatic minor radiological hemorrhage or infarction. In addition, intracranial hemorrhages requiring surgical treatment within three months postoperatively were recorded.

A total of 588 patients was included (294 per group). Symptomatic intracranial hemorrhage occurred in 2/588 patients (0.3%), with one case in each group (risk difference 0.0%, 95% CI - 0.9 to + 0.9). Asymptomatic radiological findings were observed in 6.3% of patients and were similarly distributed between groups (risk difference - 0.3%, 95% CI - 4.3 to + 3.6). Intracranial hemorrhage requiring surgical treatment within 3 months occurred in 3.6% of patients, without group differences.

In this large prospective cohort, intracranial hemorrhagic complications after shunt surgery for iNPH were rare. No signal of increased hemorrhagic risk was observed with the addition of cortical brain biopsy although small differences in rare complications cannot be excluded.