2020年11月接诊一例来自天津的17岁女性患儿（163cm，65kg），主诉：突发抽搐一次，排查时发现颅内占位1月余。患儿1个月前无明显诱因突发意识丧失伴四肢抽搐，持续时间不详，于当地医院发现颅内病变，遂来我院就诊。我院头颅CT/CTA示：左侧额叶异常高密度；左额动静脉畸形；头颅MRI示：左额叶异常血管影，动静脉畸形可能性大（28×24×37mm）。DSA示：畸形血管团，考虑动静脉畸形。
图1 CT：左侧额叶可见不规则团状迂曲稍高密度影；CTA：左额可见异常血管团，左侧ACA、MCA皮层支增粗参与供血，皮层见粗大引流血管汇入上矢状窦.MRI：左侧额叶见异常血管团，大小约28×24×37mm，SWI呈混杂信号，增强示病灶轻度强化.DSA：畸形血管团由左侧ACA、MCA参与供血，并见粗大的引流血管引流至上矢状窦.
患儿左额脑动静脉畸形诊断明确，合并症状型癫痫，具备手术指征，依据天坛医院小儿神外诊疗规范，患儿于2020年11月19日在神经导航引导下，行左侧额顶入路AVM切除术。剪开硬膜后，沿纵裂探查左侧额叶，见畸形血管团，色红、团块蚯蚓状，范围约2×3×4cm,中线处可见一支粗大引流静脉汇入上矢状窦，导航精确划定病变范围，依次游离畸形血管团前界、外侧、后界，见两支分别来源于左侧大脑前动脉、左侧大脑中动脉的粗大供血动脉，蛇牌720动脉瘤夹两枚予以夹闭后电凝切断，畸形血管团质地明显变软并缩小，继而游离中线处，电凝切断粗大引流静脉，畸形血管团完整切除。手术顺利，术中出血100ml，未输血。
图2 术中所见及标本照片.
术后患儿恢复良好，无新增神经系统阳性体征，术后复查头颅CT/CTA/MRI/DSA显示畸形血管团完整切除。病理回报示：动静脉畸形.术后10天顺利出院，随访中。
图3 术后CT/CTA/MRI/DSA显示：左额动静脉畸形血管团完整切除.
治疗体会
颅内动静脉畸形（arteriovenous malformations，AVM）是常见颅内血管性疾病，本质上是一团发育不良的血管，其供血动脉与引流静脉直接相连，之间无正常毛细血管床，形成高流量、低阻力的瘘管，将血液从动脉直接分流到静脉系统1。人群发病率约为50/10万2，发病年龄多在20-40岁3，儿童患者仅占发病人群的15%4。约半数患者合并颅内出血，20%-25%的患者可表现为局灶或全面性癫痫发作，15%的患者合并头痛、认知功能障碍，甚至无任何症状5-9。
我们认为，手术切除畸形血管团是治疗AVM的首选方案，一旦手术完整切除，患儿可以终身治愈。澳大利亚高级医学院的David Bervini等人在2014年的一组单中心427例未出血颅内AVM手术研究中曾报道，Spetzler–Martin分级在I-II级的患者术后出现严重并发症仅为2%10；美国波士顿儿童医院和犹他儿童医院在对97名AVM患儿术后中位随访时间65个月的研究中发现，Spetzler–Martin分级为I、II级的患儿分别有82.8%和63.9%术后未出现神经功能缺失，且所有患儿中，85.5%术后可独立生活11；加利福尼亚大学脑血管病研究中心的一项232例报道Spetzler–Martin分级I-II级患者手术死亡率为0%12。可见，针对颅内AVM，尤其是属于Spetzler–Martin分级I-II级患者，应积极手术予以根治，效果良好。
至于血管介入栓塞治疗，通常用于术前缩小AVM体积、术中降低出血风险。若以治疗为目的单纯血管内栓塞，治愈率仅为51%13-15，栓塞术中出血风险高达7%16，故一般不建议单独应用栓塞治疗AVM。
关于立体定向放射治疗（伽玛刀），优势在于一旦成功，便可以最小的风险获得最大的收益17-23，但问题有二：第一，放疗完成后，血管不会立即闭塞，而是需要一段潜伏期才能闭塞至最大程度，最长可达4年；第二，放疗会导致毗邻正常脑组织放射性损伤1。一组多中心1051例AVM患者的回顾分析中，放疗后治愈率为75.2%，出血率7.2%，其它并发症发生率6.5%，死亡率1.2%12。治疗效果优于单纯血管内介入栓塞，不及手术治疗。
本例患儿病变位于非功能区、团块样较局限，供血动脉明确，引流静脉较表浅，Spezler-Martin分级为II级，首选开颅手术治疗。Lawton等人认为1，AVM切除术的关键点有两个：一是引流静脉最后切断；二是尽可能靠近畸形血管团切除病变，保护毗邻脑组织。因此，应用术中神经导航，精准定位病灶范围，引导切除供血动脉及引流静脉，就显得尤其重要。
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