Catapano Joshua S, Rumalla Kavelin, Srinivasan Visish M, Lawrence Peter M, Larson Keil Kristen, Lawton Michael T
J Neurosurg. 2022 Mar 25;137(5):1462-1476. doi: 10.3171/2022.1.JNS212690. Print 2022 Nov 1.
Brainstem cavernous malformations (BSCMs) are complex, difficult to access, and highly variable in size, shape, and position. The authors have proposed a novel taxonomy for pontine cavernous malformations (CMs) based upon clinical presentation (syndromes) and anatomical location (findings on MRI).
The proposed taxonomy was applied to a 30-year (1990-2019), 2-surgeon experience. Of 601 patients who underwent microsurgical resection of BSCMs, 551 with appropriate data were classified on the basis of BSCM location: midbrain (151 [27%]), pons (323 [59%]), and medulla (77 [14%]). Pontine lesions were then subtyped on the basis of their predominant surface presentation identified on preoperative MRI. Neurological outcomes were assessed according to the modified Rankin Scale, with a score ≤ 2 defined as favorable.
The 323 pontine BSCMs were classified into 6 distinct subtypes: basilar (6 [1.9%]), peritrigeminal (53 [16.4%]), middle peduncular (MP) (100 [31.0%]), inferior peduncular (47 [14.6%]), rhomboid (80 [24.8%]), and supraolivary (37 [11.5%]). Part 1 of this 2-part series describes the taxonomic basis for the first 3 of these 6 subtypes of pontine CM. Basilar lesions are located in the anteromedial pons and associated with contralateral hemiparesis. Peritrigeminal lesions are located in the anterolateral pons and are associated with hemiparesis and sensory changes. Patients with MP lesions presented with mild anterior inferior cerebellar artery syndrome with contralateral hemisensory loss, ipsilateral ataxia, and ipsilateral facial numbness without cranial neuropathies. A single surgical approach and strategy were preferred for each subtype: for basilar lesions, the pterional craniotomy and anterior transpetrous approach was preferred; for peritrigeminal lesions, extended retrosigmoid craniotomy and transcerebellopontine angle approach; and for MP lesions, extended retrosigmoid craniotomy and trans-middle cerebellar peduncle approach. Favorable outcomes were observed in 123 of 143 (86%) patients with follow-up data. There were no significant differences in outcomes between the 3 subtypes or any other subtypes.
The neurological symptoms and key localizing signs associated with a hemorrhagic pontine subtype can help to define that subtype clinically. The proposed taxonomy for pontine CMs meaningfully guides surgical strategy and may improve patient outcomes.
脑干海绵状血管畸形（BSCMs）结构复杂，难以触及，其大小、形状和位置变化很大。作者基于临床表现（综合征）和解剖位置（MRI检查结果），提出了一种针对脑桥海绵状血管畸形（CMs）的新分类法。
将所提出的分类法应用于两位外科医生30年（1990 - 2019年）的经验。在601例行BSCM显微手术切除的患者中，551例有合适数据，根据BSCM位置进行分类：中脑（151例[27%]）、脑桥（323例[59%]）和延髓（77例[14%]）。然后根据术前MRI确定的主要表面表现对脑桥病变进行亚型分类。根据改良Rankin量表评估神经功能结局，评分≤2定义为良好结局。
323例脑桥BSCMs分为6种不同亚型：基底型（6例[1.9%]）、三叉神经周围型（53例[16.4%]）、脑桥中部脚型（MP）（100例[31.0%]）、脑桥下部脚型（47例[14.6%]）、菱形型（80例[24.8%]）和橄榄上型（37例[11.5%]）。这个两部分系列的第1部分描述了这6种脑桥CM亚型中前3种的分类基础。基底型病变位于脑桥前内侧，与对侧偏瘫相关。三叉神经周围型病变位于脑桥前外侧，与偏瘫和感觉改变相关。MP型病变患者表现为轻度小脑前下动脉综合征，伴有对侧半身感觉丧失、同侧共济失调和同侧面部麻木，无颅神经病变。每种亚型首选单一手术入路和策略：基底型病变首选翼点开颅和经岩前入路；三叉神经周围型病变首选扩大乙状窦后开颅和经小脑脑桥角入路；MP型病变首选扩大乙状窦后开颅和经小脑脑桥中部入路。在143例有随访数据的患者中，123例（86%）获得了良好结局。这3种亚型与其他任何亚型之间的结局无显著差异。
与出血性脑桥亚型相关的神经症状和关键定位体征有助于在临床上定义该亚型。所提出的脑桥CM分类法对手术策略有重要指导意义，可能改善患者结局。
