Effect of Decompressive Craniectomy on Perihematomal Edema in Patients with Intracerebral Hemorrhage

BackgroundPerihematomal edema contributes to secondary brain injury in the course of intracerebral hemorrhage. The effect of decompressive surgery on perihematomal edema after intracerebral hemorrhage is unknown. This study analyzed the course of PHE in patients who were or were not treated with decompressive craniectomy.MethodsMore than 100 computed tomography images from our published cohort of 25 patients were evaluated retrospectively at two university hospitals in Switzerland. Computed tomography scans covered the time from admission until day 100. Eleven patients were treated by decompressive craniectomy and 14 were treated conservatively. Absolute edema and hematoma volumes were assessed using 3-dimensional volumetric measurements. Relative edema volumes were calculated based on maximal hematoma volume.ResultsAbsolute perihematomal edema increased from 42.9 ml to 125.6 ml (192.8%) after 21 days in the decompressive craniectomy group, versus 50.4 ml to 67.2 ml (33.3%) in the control group (Δ at day 21 = 58.4 ml, p = 0.031). Peak edema developed on days 25 and 35 in patients with decompressive craniectomy and controls respectively, and it took about 60 days for the edema to decline to baseline in both groups. Eight patients (73%) in the decompressive craniectomy group and 6 patients (43%) in the control group had a good outcome (modified Rankin Scale score 0 to 4) at 6 months (P = 0.23).ConclusionsDecompressive craniectomy is associated with a significant increase in perihematomal edema compared to patients who have been treated conservatively. Perihematomal edema itself lasts about 60 days if it is not treated, but decompressive craniectomy ameliorates the mass effect exerted by the intracerebral hemorrhage plus the perihematomal edema, as reflected by the reduced midline shift.背景：脑出血（Intracerebral Hemorrhage）进程中，血肿周围水肿（Perihematomal Edema, PHE）可引发继发性脑损伤。目前，去骨瓣减压术（Decompressive Craniectomy）对脑出血后血肿周围水肿的影响尚不明确。本研究回顾性分析了接受去骨瓣减压术与保守治疗的患者的血肿周围水肿病程变化。 方法：本研究在瑞士两所大学医院开展，回顾性分析本团队已发表的25例患者队列的100余幅计算机断层扫描（Computed Tomography, CT）影像。所有CT扫描覆盖了自患者入院至发病后100天的全部随访时段。其中11例患者接受去骨瓣减压术治疗，14例采取保守治疗。采用三维容积测量法评估水肿及血肿的绝对体积，并以最大血肿体积为基准计算相对水肿体积。 结果：去骨瓣减压术组患者的血肿周围水肿绝对体积在发病后21天内从42.9 ml升至125.6 ml（增幅192.8%），而对照组患者该指标从50.4 ml升至67.2 ml（增幅33.3%）（第21天差值Δ=58.4 ml，p=0.031）。去骨瓣减压术组与对照组的水肿峰值分别出现在发病后第25天与第35天，且两组患者的水肿均需约60天方可回落至基线水平。发病后6个月时，去骨瓣减压术组有8例（73%）患者、对照组有6例（43%）患者获得良好预后（改良Rankin量表（Modified Rankin Scale）评分0~4分，P=0.23）。 结论：与保守治疗患者相比，接受去骨瓣减压术的患者血肿周围水肿体积存在显著升高。未接受干预的血肿周围水肿病程可持续约60天，但去骨瓣减压术可改善脑出血及血肿周围水肿所引发的占位效应（Mass Effect），该改善可通过中线移位（Midline Shift）程度降低得到体现。