Neurosurgical Department, University of Pisa, Pisa, Italy.
Neurosurgery. 2009 May;64(5 Suppl 2):331-42; discussion 342. doi: 10.1227/01.NEU.0000334430.25626.DC.
To review our experience with the surgical management of craniovertebral junction malformations, focusing on the selection of surgical approach, management of the associated Chiari malformation, and postoperative instability.
During a 7-year period (May 2000-May 2007), 34 patients with a mean age of 55 years (age range, 32-75 years) underwent transoral surgery for fixed or nearly fixed ventral compression at the craniovertebral junction caused by basilar invagination and/or atlantoaxial dislocation. Chiari malformation was detected in 13 patients. The most common presenting signs were motor deficits (88%), followed by sensory loss (35%). All patients but one who had posterior stabilization performed elsewhere underwent single-stage anterior decompression and posterior occipitocervical fixation. Adjuncts to the transoral approach were tailored to the local anatomy (severity of basilar invagination, extent of mandibular excursion) found in each patient. Posterior fossa decompression was performed in 3 patients with Chiari malformation.
Thirty-one patients were alive at the time of the last follow-up evaluation (average, 3.7 years; range, 0.5-7.5 years). Of the 28 surviving patients admitted with preoperative motor impairment, 24 patients (86%) improved at least 1 Nurick grade, whereas the grade did not change in 4 (14%) patients. There were 2 (6%) perioperative deaths, and 1 other patient died subsequently of causes unrelated to surgery. Surgical morbidity was 18% and included dural laceration, cerebrospinal fluid leak with meningitis, malocclusion, oral wound dehiscence, and occipital wound infection. Delayed instability occurred in 1 patient because of cranial settling of the C2 vertebral body.
Successful decompression of the abnormal craniovertebral junction requires extensive preoperative evaluation, appropriate tailoring of the operative approach, and an adequate learning curve. Transmaxillary approaches are useful adjuncts to the transoral approach in patients with severe basilar invagination or in cases of limited jaw mobility. Anterior decompression has been proven effective in relieving obstruction of the subarachnoid space at the foramen magnum in most patients with associated Chiari malformation.
回顾颅颈交界区畸形的手术治疗经验，重点探讨手术入路的选择、相关 Chiari 畸形的处理以及术后不稳定的问题。
在 7 年期间（2000 年 5 月至 2007 年 5 月），34 例平均年龄 55 岁（年龄范围为 32-75 岁）的患者因颅底凹陷症和/或寰枢椎脱位导致颅颈交界区固定或几乎固定的腹侧压迫而接受经口手术治疗。13 例患者发现 Chiari 畸形。最常见的表现体征为运动功能障碍（88%），其次为感觉丧失（35%）。除了 1 例在其他地方接受了后路稳定治疗的患者外，所有患者均接受了一期前路减压和后路枕颈固定术。根据每位患者的局部解剖情况（颅底凹陷程度、下颌骨活动范围），采用经口入路的辅助手段。在 3 例伴有 Chiari 畸形的患者中进行了后颅窝减压。
在最后一次随访评估时，31 例患者存活（平均随访时间为 3.7 年，范围为 0.5-7.5 年）。在 28 例术前存在运动功能障碍并接受治疗的存活患者中，24 例（86%）至少改善了 1 个 Nurick 分级，而 4 例（14%）患者的分级未发生变化。有 2 例（6%）患者围手术期死亡，另 1 例患者随后死于与手术无关的原因。手术并发症发生率为 18%，包括硬脑膜撕裂、脑脊液漏伴脑膜炎、咬合不正、口腔伤口裂开和枕部伤口感染。1 例患者因 C2 椎体颅底沉降而发生迟发性不稳定。
成功减压异常颅颈交界区需要进行广泛的术前评估、适当调整手术入路以及充分的学习曲线。在严重颅底凹陷症或下颌骨活动度有限的患者中，经口入路的辅助手段经上颌入路是有用的。前路减压已被证明对大多数伴有 Chiari 畸形的患者有效，可以缓解枕骨大孔区蛛网膜下腔的梗阻。
