近日，长征医院神经外科孙伟医生团队, 在脊髓脊柱类神经外科国际知名期刊《neurospine》杂志发表脊髓海绵状血管瘤手术相关研究成果, 旨在阐明脊髓海绵状血管瘤的手术效果及预后因素. MD安德森癌症中心神经外科 Claudio E. Tatsui教授就该研究成果发表评论：
脊髓海绵状血管畸形（SCCM）是相对罕见的实体，占所有脊髓血管病变的5%至12%，主要影响颈椎和胸椎段。据估计，患有这种病症的患者中，大约有12%有SCCM的家族史，最多有16.5%有伴随性颅内海绵状血管瘤[1]。通常在中年时确诊，有关性别偏好的数据存在分歧[1]。它们可能是无症状的，也可能表现为不同程度的脊髓病变症状。慢性渐进的症状似乎源于微出血、微循环变异和部分血栓形成，而急性表现通常与明显出血有关[2]。手术是治疗症状明显的病例的主要方法，尽管适当的时机和患者选择存在争议[1]。
在这项研究中，研究者[3]描述了他们在治疗症状性SCCM的微创手术方面的经验。评估了临床表现、手术结果以及与自发性出血和神经系统结果有关的因素。神经系统结果使用修改后的McCormick评分（MMCS）进行测量。手术由两名经验丰富的外科医生使用后路进行，包括椎板切除或椎板成形。在所有病例中均使用了显微手术技术，并根据SCCM在实质内的位置，在中线或沿着后外沟进行脊髓切开术。
本研究分析了2014年6月至2021年5月间在单一中心接受治疗的29例连续患者（12名女性和17名男性）的结果。目前的队列在许多方面与先前的研究相似[1,4]，然而，它们在男性优势（1.4:1比例）和膀胱/肠功能障碍优于运动/感觉功能障碍的患病率增加方面有所不同。7名患者（24.1%）出现严重的术前缺陷（MMCS IV/V）。需要强调的是，MMCS主要表现为运动和感觉功能，而该系列中的很大一部分个体出现了与内脏功能障碍相关的症状。尽管这不是本研究的目的，但在术后的括约肌控制和疼痛评分方面更好地描述结果可能会很有趣，因为SCCM很少见，文献中的报告有限。
在他们的系列中，所有患者均实现了全切除，其中一些患者在手术后经历了短暂的神经功能下降。在最后的随访中，19名患者（65.5%）神经功能客观改善，而6例（20.7%）的表现下降。在有复发性出血的患者中发生了不利的结果，而年龄较大和术前MMCS评分较低与更好的功能结果相关[3]。有趣的是，慢性表现和症状持续时间较长与更好的结果一致，与最近的系统回顾结论相矛盾，后者报告手术前症状持续时间小于3个月将导致更好的功能状况[5]。支持早期干预的论点包括，对病变周围神经组织的慢性损伤产生的胶质化可能干扰显微外科解剖，增加术后神经功能缺陷的可能性，并且在急性出血后建议早期手术，当创造了解剖平面且未形成粘连时[4,6]。然而，当前研究表明，当由经验丰富的外科医生进行适当而谨慎的显微解剖时，即使在SCCM沿着慢性时间轴呈现的复杂病例中，也可以实现功能改善。
本研究发现的年度出血率为2.1%。18例病例（62.0%）与急性出血有关，其中一半的患者在术前发生了再出血事件。较小的病变出血风险较高，急性表现的术前MMCS较差[3]。胸段位置和复发性出血被发现能预测不良结果，作者主张在这类情况下进行早期手术干预。
总的来说，该研究提供了宝贵的信息，表明手术在慢性表现的患者中可能具有更好的效果，并提供证据表明胸段位置和复发性出血与较差的功能结果相关。与先前报告的人口统计学和临床表现的差异表明在这一人群中存在异质性。在临床实践中，识别更有可能从早期手术中受益的患者子群至关重要。相反，对于出血风险较低的患者，特别是当SCCM深入且未与脊髓背侧表面接触时，手术风险可能超过了益处，这也是相关的。
Spinal cord cavernous malformations (SCCM) are relatively rare entities comprising 5%– 12% of all spinal cord vascular lesions, affecting mostly the cervical and thoracic segments. It is estimated that 12% of patients affected by this condition will have positive family history of SCCM and up to 16.5% will have associated intracranial cavernomas [ 1]. Diagnosis is usually made at the midages and data on sex predilection is divergent, although gathered evidenced supports the existence of an equilibrium [1]. They may be asymptomatic or present as variable degrees of myelopathy. Chronic progressive symptoms seem to originate from microhemorrhage, microcirculatory variations, and partial thrombosis, whereas acute presentations are often related to frank hemorrhage [2]. Surgery is the mainstay treatment for symptomatic cases, although the appropriate timing and patient selection is subject of debate [1]
In this elegant study, Cai et al. [ 3] describe their experience on microsurgical treatment of symptomatic SCCM. Clinical presentation, surgical outcomes, and factors related to spontaneous hemorrhage and neurological outcomes were assessed. The neurological outcome was measured using the modified McCormick scale (MMCS). Surgeries were performed by 2 experienced surgeons using a posterior approach with either laminectomy or laminoplasty. Microsurgical technique was used in all cases and the myelotomy was performed in the midline or along the posterior lateral sulcus, depending on SCCM position inside the parenchyma.
The present study analyses the outcome in 29 consecutive patients (12 females and 17 males) treated in a single center from June 2014 to May 2021. The current cohort is similar in many aspects to prior studies [ 1,4], however, they differ in a male predominance (1.4:1 ratio) and an increased prevalence of bladder/bowel dysfunction over motor/sensory dysfunction. Seven patients (24.1%) presented severe preoperative deficits (MMCS IV/V). It is important to highlight that the MMCS focuses on motor and sensory functions, while a large proportion of individuals in this series had symptoms related to visceral dysfunction. Although not being the purpose of this study, a better description of the outcome in terms of sphincter continence and pain scores would be interesting as SCCM are rare and reports in the literature are limited.
In their series, all patients had a gross total resection, with some experiencing a transient neurological decline after surgery. By the last follow-up, 19 patients (65.5%) had an objective improvement of neurological function and 6 cases (20.7%) declined in performance. Unfavorable outcomes occurred in patients with recurrent hemorrhages, whereas older age and lower preoperative MMCS scores correlated with better functional results [ 3]. Interestingly, chronic presentation and longer duration of symptoms were consistent with better outcome, conflicting with the conclusion of a recent systematic review that reported duration of symptoms less than 3 months prior to surgery to lead a better functional status [5]. Arguments favoring early intervention include that chronic damage to the perilesional neural tissue produces gliosis that can interfere with microsurgical dissection, increasing the chances of postoperative neurological deficits and early surgery is recommended after an acute hemorrhage, when the blood has created a dissection plane and adherences were not formed [4,6]. Nevertheless, the current study demonstrate that functional improvement can be achieved when appropriate and careful microdissection is performed by an experienced surgeon, even in complex cases of SCCM presenting along a chronic timeline.
The annual hemorrhage rate found in this study was 2.1%. Eighteen cases (62.0%) had symptoms related to acute hemorrhage, with half of these patients presenting recurrent events. Smaller lesions had higher risk of bleeding and acute presentations had worse preoperative MMCS [ 3]. Thoracic location and recurrent bleeding were found to predict poor outcome and the authors advocate early surgical intervention in such cases.
In conclusion, this study brings valuable information as it shows that surgery may have better results in patients with chronic presentation and provide evidence that thoracic location and recurrent hemorrhage associate with poorer functional outcome. The discrepancies in demographical and clinical presentation to previous reports suggest the occurrence of heterogeneity in this population. Identifying subsets of patients who are more likely to benefit from early surgery is of great importance in clinical practice. The contrary is also relevant, as surgical risks may overcome benefits in patients at low risk of bleeding, especially when the SCCM is deep seated not in contact with the dorsal pial surface.
1. Gross BA, Du R, Popp AJ, et al. Intramedullary spinal cord cavernous malformations. Neurosurg Focus 2010;29:E14.
2. Clatterbuck RE, Eberhart CG, Crain BJ, et al. Ultrastructural and immunocytochemical evidence that an incompetent blood-brain barrier is related to the pathophysiology of cavernous malformations. J Neurol Neurosurg Psychiatry 2001; 71:188-92.
3. Cai Z, Sun W, Dai XHW, et al. Surgical outcomes of symptomatic intramedullary spinal cord cavernous malformations: analysis of consecutive cases in a single center. Neurospine 2023;20:810-21.
4. Badhiwala JH, Farrokhyar F, Alhazzani W, et al. Surgical outcomes and natural history of intramedullary spinal cord cavernous malformations: a single-center series and meta-analysis of individual patient data: clinic article. J Neurosurg Spine 2014;21:662-76.
5. Asimakidou E, Meszaros LT, Anestis DM, et al. A systematic review on the outcome of intramedullary spinal cord cavernous malformations. Eur Spine J 2022;31:3119-29.
6. Kurokawa R, Endo T, Takami T, et al. Acceptance of early surgery for treatment of spinal cord cavernous malformation in contemporary Japan. Neurospine 2023;20:587-94.