Pozzati Eugenio, Marliani Anna Federica, Zucchelli Mino, Foschini Maria Pia, Dall'Olio Massimo, Lanzino Giuseppe
Department of Neurosurgery, Sections of Neuroradiology and Pathology, Bellaria Hospital, Bologna, Italy.
J Neurosurg. 2007 Dec;107(6):1113-9. doi: 10.3171/JNS-07/12/1113.
The four types of cerebrovascular malformations may sometimes be combined and more often occur in pairs; triads are exceptional. The authors present six patients with the clinicoradiographic profile of mixed vascular malformations of the brainstem, including cavernous malformation (CM), capillary telangiectasia, and developmental venous anomaly (DVA).
Five patients (one of whom was a child) suffered from hemorrhage, suggesting that this complex association has a high bleeding potential. Progressive growth, rebleeding, and de novo occurrence of the associated CM were documented in three cases. Magnetic resonance imaging of the brain was obtained in all patients by using one or more of the following modalities: T1-weighted sequences before and after gadolinium administration; T2-weighted sequences; T2-weighted fluid attenuated Inversion recovery; T1-weighted fast spin echo; and diffusion weighted, diffusion tensor, and perfusion imaging in three cases.
Three patients were surgically treated with the intention of excising the hemorrhagic lesion, but only two patients had their malformations successfully removed. In the third case, diffuse pontine telangiectasia precluded the safe excision of the CM. Histological examination demonstrated a blended pathological milieu characterized by coalescent telangiectasia and venules associated with loculated endothelial chambers resembling an immature or de novo CM. Three patients were treated conservatively; recurrent minor hemorrhage occurred in one case. The authors found these malformations to be arranged in two basic relationships: CM inside the telangiectasia and CM in the radicles of the DVA. Stenosis of the main venous collector and dilation of the medullary veins were important findings.
The pathogenesis of this malformation may be referred to a developmental deviance of the brainstem capillary-venous network associated with transitional vessels and loculated endothelial vascular spaces related to genetic and acquired origins, probably in a restrictive venous outflow milieu.
四种类型的脑血管畸形有时可能合并出现，且更常见的是成对出现；三联畸形则较为罕见。作者报告了6例具有脑干混合性血管畸形临床放射学特征的患者，包括海绵状畸形（CM）、毛细血管扩张症和发育性静脉异常（DVA）。
5例患者（其中1例为儿童）发生出血，提示这种复杂的关联具有较高的出血风险。3例记录了相关CM的进行性生长、再出血和新生情况。所有患者均通过以下一种或多种方式进行脑部磁共振成像检查：钆剂注射前后的T1加权序列；T2加权序列；T2加权液体衰减反转恢复序列；T1加权快速自旋回波序列；3例患者还进行了扩散加权、扩散张量和灌注成像。
3例患者接受手术治疗，旨在切除出血性病变，但只有2例患者的畸形成功切除。在第3例中，弥漫性脑桥毛细血管扩张症妨碍了CM的安全切除。组织学检查显示为混合性病理环境，其特征为合并的毛细血管扩张症和小静脉，伴有类似未成熟或新生CM的局部内皮腔。3例患者接受保守治疗；1例出现复发性小出血。作者发现这些畸形存在两种基本关系：毛细血管扩张症内的CM和DVA根部的CM。主要静脉收集器狭窄和髓静脉扩张是重要发现。
这种畸形的发病机制可能与脑干毛细血管 - 静脉网络的发育异常有关，与过渡血管以及与遗传和后天因素相关的局部内皮血管间隙有关，可能处于限制性静脉流出环境中。
