Association Between Preoperative Midline Shift Growing Rate and Outcomes of Decompressive Craniectomy in Patients with Malignant Middle Cerebral Artery Infarction

Background: Whether preoperative midline shift and its growing rate are associated with outcomes of decompressive craniectomy in patients with malignant middle cerebral artery infarction is unknown. Methods: We retrospectively included patients: 1) who underwent decompressive craniectomy for malignant middle cerebral artery infarction in West China Hospital from August 2010 to December 2, 2018) who had at least two brain computed tomography scans before decompressive craniectomy. Midline shift was measured on the first and last preoperative computed tomography scans. Midline shift growing rate was calculated by dividing Δmidline shift value using Δ time. The primary outcome was inadequate decompression of the mass effect. Secondary outcomes were 3 month death and unfavorable outcomes. Results: Sixty-one patients (mean age 53.7 years, 57.4% (35/61) male) were included. Median time from onset to decompressive craniectomy was 51.8 h (interquartile range: 39.7-77.8). Rates of inadequate decompression, 3 month death, 3 month modified Rankin Scale 5-6 and 4-6 were 50.8% (31/61), 50.9% (29/57), 64.9% (37/57) and 84.2% (48/57), respectively. The inadequate decompression group had a higher midline shift growing rate than the adequate decompression group (median: 2.7 mm/8 h vs. 1.4 mm/8 h, P=0.041). No intergroup difference of 3 month outcomes was found in terms of preoperative midline shift growing rate. Conclusion: Higher preoperative midline shift growing rate was associated with inadequate decompression of decompressive craniectomy in patients with malignant middle cerebral artery infarction.