Association of hemorrhage-to-treatment time with outcomes in patients with brainstem cavernous malformations: a nationwide cohort study

Background: Brainstem cavernous malformations (BSCMs) often present with haemorrhage, but the optimal timing for microsurgical intervention remains unclear. This study aims to explore how intervention timing relates to neurological outcomes in haemorrhagic BSCM patients undergoing microsurgery, offering insights for clinical decisions. Methods: A total of 293 consecutive patients diagnosed with BSCMs, who underwent microsurgery were identified between March 2011 and January 2023 at two comprehensive centres in China, with a postoperative follow-up duration exceeding 6 months. Utilizing logistic regression models with restricted cubic splines, distinct time groups were identified. Subsequently, matching weight analysis compared these groups in terms of outcomes, new haemorrhage rates, cranial nerve deficits, and perioperative complications. The primary outcome was an unfavourable outcome, which was defined as a mRS score greater than 2 at the latest follow-up. Results: Among the 293 patients, 48.5% were female, median age was (39.9±14.3) years, and median haemorrhage-to-treatment time was 42 days. Patients were categorized into acute (≤21 days), subacute (22–42 days), and delay (>42 days) intervention groups. After matching, 186 patients were analyzed. Adjusted analysis showed lower unfavourable outcome rates for acute [adjusted odds ratio (OR), 0.73; 95% CI, 0.65–0.82; P <0.001] and subacute (adjusted OR, 0.83; 95% CI, 0.72–0.95; P =0.007) groups compared to the delay group. Subacute intervention led to fewer cranial nerve deficits (adjusted OR, 0.76; 95% CI, 0.66–0.88, P <0.001). New haemorrhage incidence didn’t significantly differ among groups. Conclusions: For haemorrhagic BSCMs patients, delayed microsurgical intervention that exceeded 42 days after a prior haemorrhage were associated with an increased risk of unfavourable neurological outcomes.