Balasa Artur, Kunert Przemysław, Bielecki Mateusz, Kujawski Sławomir, Marchel Andrzej
Department of Neurosurgery, Medical University of Warsaw, Warsaw, Poland.
Department of Exercise Physiology and Functional Anatomy, Ludwik Rydygier Collegium Medicum in Bydgoszcz Nicolaus Copernicus University in Torun´, Bydgoszcz, Poland.
Front Surg. 2022 May 19;9:895444. doi: 10.3389/fsurg.2022.895444. eCollection 2022.
Pseudomeningoceles (PMCs) as abnormal collections of cerebrospinal fluid are quite common findings on follow-up MRI after Chiari decompression surgery (CDS). However, the importance of their identification has not been truly determined, especially when PMCs are described occasionally in the process of radiological follow-up. We retrospectively analyzed surgical outcomes and imaging findings after CDS depending upon the occurrence and thickness of PMCs.
A total of 76 adult patients who underwent CDS were analyzed. The clinical and radiological outcomes of patients with a pseudomeningocele (wPMC) were evaluated and compared to those of patients without a pseudomeningocele (w/oPMC). Radiological morphometric measurements were performed and compared between groups. Comparisons of the maximal PMC thickness were made within the wPMC group.
PMCs were recognized in 27 (35.5%) patients, of whom 3 (11.1%) required reoperation. Differences in satisfactory result rates regarding gestalt assessment and Chicago Chiari Outcome Scale were statistically insignificant between the w/oPMC and wPMC groups ( = 1 and = 0.56, respectively). The postoperative syringomyelia decrease and cerebellar tonsil elevation were similar between the groups ( = 1 and = 0.74, respectively) in the long-term follow-up. Additionally, the clinical or radiological outcomes with radiological details were not related to PMC thickness in the long-term follow-up. However, radiological details showed the cooccurrence of PMCs with a postsurgical of cerebello-tentorial distance increase ( < 0.05), basion-pontomedullary sulcus distance decrease ( < 0.05) and tonsillo-graft distance decrease ( < 0.05).
We found no significant relationships between PMC presence or thickness and clinical or radiological outcomes. However, postoperative changes within the posterior fossa associated with PMCs resemble brain sagging, which occurs in intracranial hypotension. Therefore, extradural cerebrospinal fluid escape may also be responsible for symptoms in some patients with PMCs after CDS.
假性脑脊膜膨出（PMC）作为脑脊液的异常聚集，是Chiari减压手术（CDS）后随访MRI上相当常见的表现。然而，其识别的重要性尚未得到真正确定，尤其是在放射学随访过程中偶尔描述PMC时。我们根据PMC的发生情况和厚度，回顾性分析了CDS后的手术结果和影像学表现。
共分析了76例接受CDS的成年患者。对有假性脑脊膜膨出（wPMC）患者的临床和放射学结果进行评估，并与无假性脑脊膜膨出（w/oPMC）患者的结果进行比较。进行放射学形态学测量并在组间进行比较。在wPMC组内对最大PMC厚度进行比较。
27例（35.5%）患者发现有PMC，其中3例（11.1%）需要再次手术。在整体评估和芝加哥Chiari结果量表方面，w/oPMC组和wPMC组的满意结果率差异无统计学意义（分别为=1和=0.56）。在长期随访中，两组术后脊髓空洞症的减轻和小脑扁桃体的抬高相似（分别为=1和=0.74）。此外，在长期随访中，具有放射学细节的临床或放射学结果与PMC厚度无关。然而，放射学细节显示PMC与术后小脑幕切迹距离增加（<0.05）、颅底-脑桥延髓沟距离减小（<0.05）和扁桃体-移植物距离减小（<0.05）同时出现。
我们发现PMC的存在或厚度与临床或放射学结果之间没有显著关系。然而，与PMC相关的后颅窝术后变化类似于颅内低压时发生的脑下垂。因此，硬膜外脑脊液漏出也可能是一些CDS后PMC患者出现症状的原因。
