Microsurgical management of pediatric ependymomas of the fourth ventricle via the trans-cerebellomedullary fissure approach: A review of 26 cases

Abstract

Abstract. In the present study, the microsurgical management of 26 ependymomas of the fourth ventricle in children via the trans-cerebellomedullary fissure (CMF) approach was reviewed and evaluated. Clinical data were obtained from 26 ependymomas of the fourth ventricle treated with microsurgery using the trans-CMF approach from March 2006 to September 2010 at the Department of Neurosurgery of The First Affiliated Hospital of China Medical University (Shenyang, China). These data were collected and analyzed. Suboccipital median posterior fossa craniotomy and trans-CMF approach were performed in all cases for the microsurgical removal of the tumors. An additional incision was performed in the inferior medullary velum of 5 patients, in order to obtain adequate exposure of the tumors. As a result, all tumors were well exposed during surgery. Gross total resection (GTR) was achieved in 22 cases, near total resection (NTR) in 3 cases and subtotal resection (STR) in 1 case. All excised tumors were pathologically confirmed. No mortality occurred intraoperatively, and no patient presented with mutism or any other surgery-related complications. One patient suffered from postoperative hydrocephalus and received ventriculoperitoneal shunting, which relieved the symptoms. Over the 3.0-7.5-year follow-up period (mean, 4.8 years), tumor relapse occurred in 1 case with GTR, 2 cases with NTR and 1 case with STR. In total, 3 patients succumbed to tumor relapse and 4 were lost to follow-up. According to the literature and the clinical experience of the present authors, the trans-CMF approach provides safe and sufficient access to the fourth ventricle without the requirement of an incision in the inferior vermis. This approach prevents damage to the normal cerebellum and improves the surgical outcome. Tumor removal, restoration of cerebrospinal fluid circulation and preservation of brainstem function are factors that should be taken into consideration during surgery. For patients with residual tumors, adjuvant radiotherapy and/or chemotherapy may be beneficial.

Fourth ventricle tumors in children: complications and influence of surgical approach

“…Presenting symptoms in this series were most commonly found to be vomiting and ataxia, which is in keeping with other pediatric fourth ventricle tumor series. [4][5][6] Younger patients were more likely to present with ataxia, which is plausible because older children have betterdeveloped cerebellar motor function. Older patients were more likely to describe visual changes and headache on presentation, owing to greater language capacity.…”

“…In so doing, the fourth ventricle can be accessed without any transgression of neural tissue. Since the first surgical case series describing its use in 11 pediatric fourth ventricle tumors, 9 several more have been published in pediatric, [4][5][6][7][8] adult, 12 or mixed 10,21 cohorts. Table 4 shows an exploration of common features across the published pediatric series.…”

“…This has been thought to influence the development of postoperative truncal ataxia and cerebellar mutism syndrome (CMS). 3 Reports of neurological morbidity following fourth ventricle tumor resection are largely restricted to small pediatric [4][5][6][7][8][9] or combined adult and pediatric series, [10][11][12] and describe patient groups that are heterogeneous with respect to preoperative comorbidities, tumor location within the posterior fossa, and tumor histology and grade.…”

The Clinical and Prognostic Impact of the Choice of Surgical Approach to Fourth Ventricular Tumors in a Single-Center, Single-Surgeon Cohort of 92 Consecutive Pediatric Patients

“…Since Dandy's original report (3), the transvermian route has been the most used approach to access the fourth ventricle (13). Dailey (12) and other authors (15)(16)(17)(18)(19)(20)(21)(22)(23)(24) considered the vermian incision by default as the main responsible for cerebellar mutism, although clear evidence of this is still lacking. Moreover, the reported more limited control of the laterality offered by this approach motivated some authors (5)(6)(7)(8)(9)(10)(11) to explore the natural corridor of the cerebellomedullary fissure (CMF) opening of the tela choroidea and the inferior medullary velum, to avoid any incision of cerebellar parenchyma.…”

Anatomic Variability of the Morphometric Parameters of the Fourth Ventricle of the Brain

“…Most of the cases require operative treatment. [4][5][6] These tumors change the configuration of the ventricle and liquor passage through the system. There is a lot of data in the literature about changes of capacity of ventricular system and alterations of the shape and symmetry of the ventricles in patients with mental health diseases, particularly patients with schizophrenia.…”