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本期为Worldneurosurgery定期连载的河南省人民医院张长远医师终审的《动脉瘤大师级神作--Seven Aneurysms》著作第四期。本期主要内容为 血管控制，《Seven Aneurysms 》系列内容包括 Section I The Tenets：1. 在显微镜下操作；2. 蛛网膜下腔的解剖；3.脑牵拉；4.血管控制；5.临时阻断；6.永久夹闭；7.检测；8.脑皮层造瘘；9.术中破裂。Section II The Approaches: 10.翼点入路; 11.眶颧入路; 12.前纵裂入路; 13.远外侧入路。Section IIIThe Seven Aneurysms: 14.后交通动脉瘤; 15.大脑中动脉瘤; 16.前交通动脉瘤; 17.眼动脉动脉瘤; 18.胼周动脉瘤; 19.基底动脉分叉动脉瘤; 20.小脑后下动脉动脉瘤。 《Seven Aneurysms》著作系列回顾： 第一期：神外医师基本功-- 在显微镜下操作技巧----Seven Aneurysms系列 第二期：神外医师基本功--蛛网膜下腔的解剖---Seven Aneurysms系列 第三期：神外医师基本功--脑牵拉---Seven Aneurysms系列 第四期：Vascular Control--血管控制 ■ Contingency Planning--应急方案 A reality of aneurysm surgery is that the technical skill and surgical experience do not eliminate the risk of intraoperative aneurysmal rupture. The dangerous combination of aneurysm fragility and surgical manipulation sometimes precipitates rupture, and the neurosurgeon must prepare for this catastrophe. Vascular control is a simple concept: afferent arteries that supply antegrade blood flow to an aneurysm, and efferent arteries that might supply retrograde blood flow, are exposed for occlusion with temporary clips. In practice, vascular control can be difficult because of limited operative exposure, anatomic obstacles, or interfering aneurysm domes. 动脉瘤外科的一个现实情况是手术技巧和手术经验并不能完全消除术中动脉瘤破裂的风险。动脉瘤容易破裂的危险因素和手术操作等因素的综合造成动脉瘤破裂，神经外科医生必须为这种灾难性情况做好准备工作。血管控制是一个简单的概念: 流入动脉内的血流顺行进入动脉瘤，流出动脉则将动脉瘤流出的血液排向远端，这些动脉需要暴露以便临时夹闭。实际上，由于动脉瘤的显露有局限性、解剖时视线的阻挡或者（为避免）干扰动脉瘤顶部，动脉瘤远、近端血管的控制可能会存在困难。 Successful aneurysm management begins with the development of a systematic contingency plan. With each case, before entering the operating room, the neurosurgeon must envision intraoperative disaster in every conceivable form and then develop strategies to deal with it. Forethought enables the neurosurgeon to prepare the patient, exposing the patient’s neck for proximal carotid control or suction decompression, harvesting a donor vessel for possible bypass, or inserting a groin sheath for intraoperative angiography. Forethought reminds the neurosurgeon early during the dissection to gain proximal and distal control, preselect temporary and permanent clips, and protect the brain with barbiturates. Forethought replays in the neurosurgeon’s mind the microsurgical maneuvers to control aneurysmal rupture: direct tamponade with a cottonoid, suction, temporary clipping, trapping, and permanent clipping of the aneurysm. Deliberate thoughts about disaster permeate the operation, readying the neurosurgeon and the operative team for a swift response. Negative thoughts are usually suppressed by surgeons, but must be addressed. Over time, this process of contingency planning becomes instinctive, and the microsurgical mechanics of the rupture response become almost a reflex. Still, we must always pause to consider the elements of vascular control that lie outside of the immediate surgical field to prepare them in advance. 动脉瘤的成功治疗需要一个系统的应急计划。每个病例，在进入手术室之前，神经外科医生必须预见任何形式的术中紧急情况，并且有相对应的策略来解决它。有预见性的神经外科医生会为手术做好以下准备：显露患者颈部以便颈动脉的近端控制；（阻断远、近端血流后）的抽吸减压；准备供体血管以便进行血管搭桥；预留股动脉鞘以便术中造影。神经外科医生的预见性使其在进行动脉瘤近、远端控制的解剖分离之前就明确如何选择临时和永久性夹闭、用巴比妥类药物保护大脑。预见性思维使神经外科医生有计划的控制显微外科操作技巧以预防动脉瘤的破裂：直接用脑棉填塞、吸引、临时夹闭、永久夹闭动脉瘤。对于术中紧急情况的深思熟虑应当渗透到操作的每一步，可以使神经外科医生和手术团队迅速应对紧急情况。消极应付的想法通常被外科医生压制下去，但真正解决问题的方法还是要按预案进行。随着临床的积累，制定应急计划的过程成为本能，应对动脉瘤破裂的显微外科技术成为条件反射。不过，我们还是要在术中不时停下来对当下手术区域的血管控制进行思考，提前做好准备。
■ Proximal Control--近端控制 Points of proximal control are identified preoperatively on angiography, exposed early, and prepared thoroughly enough to place a temporary clip under duress or under blood. Points of proximal control include the ophthalmic segment of the supraclinoid internal carotid artery (ICA) for posterior communicating artery (PCoA) aneurysms, the M1 segment for middle cerebral artery (MCA) aneurysms, the bilateral A1 segments for anterior communicating artery (ACoA) aneurysms, the A2 segment for pericallosal artery (PcaA) aneurysms, the cervical ICA for ophthalmic artery aneurysms, the basilar trunk for basilar bifurcation aneurysms, and the intradural vertebral artery (VA) for posterior inferior cerebellar artery (PICA) aneurysms. Some aneurysms have additional proximal supply that can feed an aneurysm, like retrograde flow in PCoA with PCoA aneurysms, or retrograde flow in ophthalmic artery (OphA) with OphA aneurysms. 术前进行血管造影术确定动脉瘤近心端血流的控制点，早期彻底显露控制点，并且做好足够的准备以便在紧急或出血的情况下放置临时动脉瘤夹。近端控制点包括以下：后交通动脉(PCoA)动脉瘤的控制点在床突上颈内动脉(ICA)的眼动脉段、大脑中动脉(MCA)动脉瘤的控制点在M1段、前交通动脉瘤的控制点在双侧A1段、胼周动脉瘤的控制点在A2段、眼动脉动脉瘤的控制点在颈内动脉、基底动脉分叉部动脉瘤的控制点在基底动脉主干、小脑后下动脉动脉瘤的控制点在椎动脉硬膜内段。有些动脉瘤有额外的近端供血动脉供养同一动脉瘤，例如PCoA动脉瘤中PCoA的逆行血流，或者眼动脉动脉瘤中眼动脉(OphA)的逆行血流。 Special moves are needed with some aneurysms to gain proximal control. The falciform ligament can be cut to move proximally on the ICA for proximal PCoA and some OphA aneurysms. The genu of the corpus callosum can be resected to expose the A2 segment for PcaA aneurysms. The posterior clinoid process can be removed to expose the basilar trunk for control of basilar bifurcation aneurysms. The extradural VA can be exposed to control PICA aneurysms that abut the dural ring. There is a range of proximal control, from proximal-proximal control to distal-proximal control. Proximal- proximal control may be distant from the aneurysm and enable collateral arteries to supply it (e.g., cervical ICA occlusion with ophthalmic aneurysms). In addition, temporary occlusion at more proximal points can compromise blood flow in perforators that lie between the temporary clip and the aneurysm (e.g., proximal M1 segment occlusion and diminished perfusion of lenticulostriate arteries with MCA aneurysms). Distal-proximal control adjacent to the aneurysm is usually more complete and preferable. 部分动脉瘤的近端控制点需要一些特定的操作。例如可以切除ICA镰状襞向近端移动控制点以便对相对近心的PCoA和OphA动脉瘤采取近端控制。胼胝体膝部切开可以暴露A2段以便对PcaA动脉瘤进行近端控制。后床突磨除可以暴露基底动脉干以便对基底动脉分叉部动脉瘤进行近端控制。可以显露硬膜外的VA以便控制邻近硬膜环的PICA动脉瘤。近心端血流控制有一系列的方法，有远离瘤颈的近心端控制，有接近瘤颈的近心端控制。远离瘤颈的近心端控制点可能会远离动脉瘤，难免有一些侧枝动脉对动脉瘤供血(如眼动脉瘤远离瘤颈的近心端控制：闭塞ICA)。此外，临时夹闭会对动脉瘤和临时夹闭之间的穿支血流灌注产生影响(如，近MCA动脉瘤的近心端M1段夹闭会造成纹状体动脉梗阻或灌注减少)。接近瘤颈的近心端控制通常更完全、更可取。 A dome that lies between the neurosurgeon and the point of proximal control can rupture en route to proximal control. This dangerous relationship exists with inferiorly projecting MCA aneurysms that block the M1 segment, inferiorly projecting ACoA aneurysms that block the contralateral A1 segment, anteriorly projecting basilar bifurcation aneurysms that block the basilar trunk, and anteriorly projecting pericallosal aneurysms that block the A2 segment. The dissection path veers more proximally around these aneurysm domes, or alternatively reroutes to the distal side of the aneurysm. For example, the M1 segment of an inferiorly projecting MCA aneurysm often arcs superiorly and can be accessed from behind the aneurysm, following the superior trunk from distal to proximal to arrive at M1 segment. Similarly, the contralateral A1 segment of an inferiorly projecting ACoA aneurysm often arcs superiorly and can be accessed from behind the aneurysm, following ACoA across to the contralateral A1-A2 junction. Subtle anatomic relationships between proximal arteries and aneurysms domes often dictate dissection strategy. Proximal control gives the neurosurgeon the confidence for the dissection to progress and should be established as early as possible. 动脉瘤顶部位于手术医生和近端控制点之间时，在进行动脉瘤近端控制的手术过程中可能存在瘤顶破裂的风险。这种风险存在指向下方的MCA动脉瘤对M1段的遮挡，指向下方的ACoA动脉瘤对对侧A1的遮挡，向前突出的基底动脉分叉部动脉瘤对基底动脉主干的遮挡，向前突出胼周动脉瘤对A2段的遮挡。这多要求在接近动脉瘤顶部时改变分离动脉瘤的路径，或者选择其它途径到动脉瘤的远侧。例如，指向下方的MCA动脉瘤M1段通常弓背向上，从而可以从动脉瘤的基底部方向接近，顺着上干从远端向近端到达M1段。同样的，向下指向的ACoA动脉瘤，其对侧的A1段通常弓背向上，可以从动脉瘤基底部方向，顺着前交通动脉到达对侧A1-A2交界处。动脉瘤近端动脉和动脉瘤顶细微的解剖关系通常决定解剖的策略。近端控制给了神经外科医生进一步进行动脉瘤解剖的信心，应该尽早建立动脉瘤的近端控制。
■ Distal Control--远端控制 Temporary occlusion of efferent branch arteries is only needed in certain situations: persistent back-bleeding after intraoperative aneurysm rupture controlled with temporary clips on all proximal arteries; persistent aneurysm turgor after temporary occlusion of proximal arteries that prevents aneurysm collapse or further dissection; aneurysm trapping for suction decompression; and deliberate opening of the aneurysm for deflation, thrombectomy, or coil extraction. The ease of gaining distal control depends on aneurysm location and is often inversely related to the ease of proximal control. For example, the proximal control of VA is straightforward with most PICA aneurysms, but the distal VA vanishes into the depths of the exposure and is obscured by lateral medulla. Conversely, the distal PcaA and the callosomarginal artery (CmaA) may be easy to control for most PcaA aneurysms, but the proximal A2 segment may vanish below the genu and rostrum of the corpus callosum. As with proximal control, points of distal control are identified preoperatively on angiography, exposed early, and prepared thoroughly enough to place a temporary clip under duress or under blood. Their exposure does not occur as early as that for points of proximal control. Distal control occurs naturally because dissecting efferent arteries is part of defining an aneurysm neck. Distal control can be challenging when efferent arteries are hidden behind the dome of an aneurysm (like the inferior trunk with laterally projecting MCA aneurysms, or the contralateral A2 segment with superiorly projecting ACoA aneurysms), or when they are deep in the surgical field (like the contralateral P1 segment with some basilar bifurcation aneurysms). As with proximal control, dome avoidance is critical. 需要临时夹闭动脉瘤载瘤动脉流出端的特定情况: 术中动脉瘤破裂且动脉瘤的供血动脉已经临时夹闭，仍然有持续返流的；动脉瘤的供血动脉已经临时夹闭但仍然张力较大，为预防动脉瘤破裂或需进行进一步的解剖；孤立动脉瘤以便抽吸减压；为了较轻松地打开动脉瘤以便减轻占位、切除血栓或取出弹簧圈。远端控制难易取决于动脉瘤的位置并往往和近端控制的难易呈负相关。例如，小脑后下动脉动脉瘤需要进行椎动脉的近端控制，在（枕下侧方入路）手术时可以直接显露控制点，但椎动脉远端在手术视野的深部消失，被延髓侧方阻挡。相反的情况，大多数胼周动脉瘤（经额纵裂入路时）其远端的胼周动脉及胼缘动脉容易控制，但其近端A2段的视线可能被胼胝体膝和胼胝体嘴阻挡。与近端控制一样，远端控制点经术前血管造影术确定，早期彻底显露并在充足的准备下进行出血或孤立时的临时夹闭。远端控制不像近端控制那么早，当流出动脉紧贴动脉瘤颈，显露瘤颈需要分离流出动脉时，自然需要对其远端进行控制。当流出动脉隐藏在动脉瘤顶后方，其远端控制具有挑战性 (如指向侧方的MCA动脉瘤的下干，或者指向上方的前交通动脉瘤的对侧A2部分)，或当他们位于手术区域的深部(如一些基底动脉分叉动脉瘤对侧的P1段)。和近端控制一样，避免损伤动脉瘤顶部是至关重要的。
■ No Control --无控制 In some cases, vascular control may be inaccessible. A lowlying basilar bifurcation aneurysm may have a basilar trunk that remains out of reach despite drilling away the posterior clinoid process and the dorsum sella. A calcified, atherosclerotic ICA harboring a PCoA aneurysm may be accessible, but the proximal parent artery wall may not collapse with temporary clipping. Inability to gain control may be disquieting enough to halt the operation. Contingency plans may need to be activated, such as exposing the cervical ICA to control the PCoA aneurysm on the atherosclerotic ICA or deploying a balloon-tipped catheter to temporarily occlude the basilar trunk to control the low-lying basilar bifurcation aneurysm. More elaborate measures, such as using hypothermic circulatory arrest for an uncontrolled basilar bifurcation aneurysm, may require aborting the operation and revising the surgical plan. Alternative therapies, such as endovascular therapy, might have increased appeal at these moments. The neurosurgeon faces a choice between establishing vascular control, aborting the operation, or continuing without control. If the decision is to proceed without vascular control, the dissection must focus on the aneurysm neck and meticulously avoid the dome, and the surgeon must be ready to place a permanent clip if the aneurysm ruptures prematurely. 在某些情况下，血管可能无法控制。低位基底动脉分叉部动脉瘤可能有一个低位的基底动脉分叉，有时候虽然磨除了后床突和鞍背依然无法显露基底动脉。钙化、动脉粥样硬化的ICA上的PCoA动脉瘤可以采用血管控制的方法进行临时夹闭，但载瘤动脉近端的管壁在上临时夹后可能不会塌陷（临时夹的力量无法夹闭硬化的管壁）。无法进行血管控制可能会令人不安并停止手术操作。此时，可能需要采用应急计划，如针对ICA动脉粥样硬化的PCoA动脉瘤，需要暴露颈部以便控制ICA，或者针对低位的基底动脉分叉部动脉瘤，预先放置球囊导管以便术中临时阻断基部动脉主干以进行近端控制。更为详尽的措施，比如使用低温停循环来进行无法血管控制的基底动脉分叉部动脉瘤的手术，可能需要手术中止和修改手术计划。在这些时刻采用替代方法，如血管内治疗可能会更有吸引力。神经外科医生会在血管控制、中止手术、或未控制血管情况下继续手术之间进行选择。如果决定在无血管控制下继续进行手术，则在解剖时特别是进行动脉瘤颈部解剖时必须小心翼翼，并要十分小心的避开动脉瘤顶部，同时必须准备一个永久动脉瘤夹以备动脉瘤过早破裂。 编译者：冯刚，北京大学首钢医院，神经外科，硕士。 审校1：九江市第一人民医院，神经外科，胡炜，主任医师，医学博士。 审校2：九江市第一人民医院，神经外科，杨枫，主任医师。 终审：河南省人民医院，神经外科，张长远。 |
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