Posterior Fossa Tumor Resection Research Articles

Use of jugular venous pressure to optimize outcomes of vestibular schwannoma resection: a review of the literature and proof of concept

Background: Surgical resection of vestibular schwannoma (VS) and other benign posterior fossa tumors is often curative if gross total resection is achieved, however, these lesions pose unique challenges due to their intricate location and proximity to critical structures. Approaches for resection often utilize lateral head rotation and neck flexion in order to optimize the surgical field. However, this may inadvertently occlude cerebral venous drainage, elevating intracranial pressure (ICP) and increasing intraoperative bleeding, potentially increasing the operative risk to patients. Methods: We review relevant literature regarding the effects of head rotation and neck flexion on internal jugular vein (IJV) occlusion and ICP, and highlight the notion that head rotation and flexion may occlude the ipsilateral IJV, increasing ICP. Subsequently, we propose a novel technique using continuous, real-time monitoring of jugular bulb pressure (JBP) to detect obstructions in jugular venous flow and guide optimal head positioning prior to VS resection. Results: As proof of concept, we present a single-patient case in which JBP monitoring was employed to optimize head positioning prior to a VS resection, which shows a significant reduction in JBP compared to traditional positioning. Conclusion: This innovative approach offers promise in enhancing the safety and efficacy of intracranial surgery for VS and other neurosurgical procedures.

Delayed symptomatic cerebral vasospasm following vestibular schwannoma resection: illustrative case.

Symptomatic cerebral vasospasm following posterior fossa extraaxial tumor resection is a rare phenomenon, with only 13 cases previously reported in the literature. The condition appears similar to vasospasm following supratentorial tumor resection, intraaxial posterior fossa tumor resection, and aneurysmal subarachnoid hemorrhage (aSAH). The majority of patients were not evaluated for vasospasm prior to symptom onset, leading to a delay in diagnosis. The authors present their experience in a 56-year-old female who developed delayed cerebral vasospasm after excision of a solid-cystic vestibular schwannoma. Routine postoperative brain computed tomography showed evidence of subarachnoid hemorrhage in the basal cisterns. She was discharged on the 9th postoperative day. On the 11th day after tumor excision, she developed left hemiparesis, dysarthria, and dysphagia and was readmitted. Angiography confirmed bilateral diffuse cerebral vasospasm. The patient responded to standard hyperdynamic therapy used for vasospasm secondary to aSAH. Symptomatic distant cerebral vasospasm after posterior fossa extraaxial tumor excision is a rare but challenging complication with a very high morbidity rate in reported cases. A high index of suspicion is required for early diagnosis and prompt management for a favorable outcome.

Characterizing the association between CSF biomarkers and risk for ventriculoperitoneal shunt following posterior fossa tumor resection in a case-control study

BackgroundRecalcitrant hydrocephalus necessitating permanent cerebrospinal fluid (CSF) diversion is a known complication after resection of a posterior fossa tumor (PFT). Various CSF contents, such as protein and other markers, have been variably correlated with the need for permanent CSF diversion. This study aims to evaluate which CSF laboratory values are associated with permanent CSF diversion following PFT resection in adults. MethodsThis study queried our multi-institutional database (Central Nervous System Tumor Outcome Registry at Emory; CTORE) consisting of 617 adult patients with PFT resections from 2006 to 2021. Retrospective data was collected from the 89 patients of this cohort that required EVD placement. Patients were stratified into two groups: those that required a shunt following EVD removal (n = 30) and those that did not (n = 40). CSF variables collected included glucose, protein, nucleated cell count, and presence of infection. An unadjusted logistic regression was performed to assess exposures associated with shunt requirement and unadjusted odds ratios (ORs) and their associated 95 % confidence intervals (CIs) were obtained. ResultsImmediately following surgery, no CSF variables were significantly associated with shunt placement. Except for post-operative CSF being not-clear (OR: 4.15 (1.47–12.56), p = 0.009) and CSF glucose (OR: 0.97 (1.03–1.07), p = 0.031) all other variables were not significantly associated with shunt at time point 2. ConclusionIn our retrospective analysis, most routinely collected CSF values were not associated with permanent CSF diversion via a ventriculoperitoneal shunt following PFT resection. Further research is needed to identify other potential predictive markers.

National multicentered retrospective review of clinical and intraoperative factors associated with the development of cerebellar mutism after pediatric posterior fossa tumor resection.

Cerebellar mutism (CM) is characterized by a significant loss of speech in children following posterior fossa (PF) surgery. The biological origin of CM remains unclear and is the subject of ongoing debate. Significant recovery from CM is less likely than previously described despite rigorous multidisciplinary neuro-rehabilitational efforts. A national multi-centered retrospective review of all children undergoing PF resection in four midsized Canadian academic pediatric institutions was undertaken. Patient, tumor and surgical factors associated with the post-operative development of CM were reviewed. Retrospective identification of PF surgery patients including those developing and those that did not (internal control). The study identified 258 patients across the 4 centers between 2010 and 2020 (mean age 6.73years; 42.2% female). Overall, CM was experienced in 19.5% of patients (N = 50). Amongst children who developed CM histopathology included medulloblastoma (35.7%), pilocytic astrocytoma (32.6%) and ependymoma (17.1%). Intraoperative impression of adherence to the floor of the 4th ventricle was positive in 36.8%. Intraoperative abrupt changes in blood pressure and/or heart rate were identified in 19.4% and 17.8% of cases. The clinical resolution of CM was rated to be complete, significant resolution, slight improvement, no improvement and deterioration in 56.0%, 8.0%, 20.0%, 14.0% and 2.0%, respectively. In the cohort of children who experienced post-operative CM as compared to their no-CM counterpart, proportionally more tumors were felt to be adherent to the floor of the 4th ventricle (56.0% vs 49.5%), intraoperative extent of resection was a GTR (74% vs 68.8%) and changes in heart rate were noted (≥ 20% from baseline) (26.0% vs 15.9%). However, a multiple regression analysis identified only abrupt changes in HR (OR 5.97, CI (1.53, 23.1), p = 0.01) to be significantly associated with the development of post-operative CM. As a devastating surgical complication after posterior fossa tumor surgery with variable clinical course, identifying and understanding the operative cues and revising intraoperative plans that optimizes the child's neurooncological and clinical outcome are essential.

Tension Subdural Hygroma Following Resection of Posterior Fossa Tumour in a Child

Persistent hydrocephalus is common in child after resection of posterior fossa tumours. Occurrence of subdural hygroma, but is very rare, with only few cases reported. We report the rare case of a child who developed a tense subdural hygroma with stable hydrocephalus, in the early postoperative period, following posterior fossa tumour resection. We describe the distinctive clinical, radiological and pathological features associated with the development of a tense subdural hygroma. We also discuss the management by cerebrospinal fluid diversion, which includes either a ventriculoperitoneal or subduroperitoneal shunt. This unique condition is distinguished from external hydrocephalus by features that are critical to the management strategy. 
 Keywords: Child, Posterior fossa tumour, Postoperative period, Hydrocephalus, Subdural hygroma, Hygroma, External hydrocephalus.

Posterior fossa tumor resection in children: a case report and the role of intraoperative neurophysiologic monitoring

Introduction/Background: Surgery plays a crucial role in the surgical management of posterior fossa tumors in children, but maximizing the resection while preserving function remains challenging. Along with other tools available to the surgeon, intraoperative neuromonitoring aims at improving safety during these complex interventions. This case report highlights the role of real-time intraoperative neuromonitoring during surgery and its impact on the surgeon's decision-making process. Case report: We present the case of a 10-year-old boy with a fourth ventricle medulloblastoma, who underwent microneurosurgical resection under intraoperative neuromonitoring. The use of neurophysiological monitoring yielded relevant information during the tumor dissection of the floor of the fourth ventricle, the most crucial step of surgery, thus helping the surgeon to change tactics to minimize long-term neurological deficits. Conclusion: In combination with meticulous microneurosurgery techniques, modern anesthetic regimens, and ultrasonic aspiration, intraoperative neuromonitoring adds up to the surgeon's armamentarium for increasing safety and improving outcomes following surgery for pediatric patients bearing posterior fossa tumors.

Evaluating Predictors of Successful Postoperative Day 1 Discharge Following Posterior Fossa Tumor Resection

Current trends in surgical neuro-oncology show that early discharges are safe and feasible with shorter lengths of stay (LOS) and fewer thromboembolic complications, fewer hospital-acquired infections, reduced costs, and greater patient satisfaction. Traditionally, infratentorial tumor resections have been associated with longer LOS and limited data exists evaluating predictors of early discharge in these patients. The objective was to assess patients undergoing posterior fossa craniotomies for tumor resection and identify variables associated with postoperative day 1 (POD1) discharge. A retrospective review of posterior fossa craniotomies for tumor resection at our institution was performed from 2011 to 2020. Laser ablations, non-tumoral pathologies, and biopsies were excluded. Demographic, clinical, surgical, and postoperative data were collected. 173 patients were identified and 25 (14.5%) were discharged on POD1. Median length of stay was 6 days. The POD1 discharges had significantly better preoperative Karnofsky performance scores (p<0.001) and modified Rankin scores (p=0.002) and more frequently presented electively (p=0.006) and without preoperative neurologic deficits (p=0.021). No statistically significant difference in 30-day readmissions and rates of PE, UTI, and DVT was found. Univariate logistic regression identified better preoperative functional status, elective admission, and lack of preoperative hydrocephalus as predictors of POD1 discharge, however only the latter remained significant in the multivariable model (p=0.001). Discharging patients on POD1 is feasible following posterior fossa tumor resection in a select group of patients. Although we found that the only independent predictor for a longer LOS was preoperative hydrocephalus, larger, prospective studies are needed to confirm these findings.

Application of the Robotic-Assisted Digital Exoscope for Resection of Posterior Fossa Tumors in Adults: A Series of 45 Cases.

Complete safe resection is the goal when pursuing surgical treatment for posterior fossa (PF) tumors. Efforts have led to the development of the exoscope that delineates tumors from non-neoplastic brain. This investigation aims to assess patient outcomes where PF tumor resection is performed with the exoscope by a retromastoid or suboccipital approach. A retrospective analysis was conducted for patients with PF tumors who underwent exoscope resection from 2017 to 2022. Patient demographics, clinical, operative, and outcome findings were collected. Extent of resection studies were also performed. Associations between perioperative data, discharge disposition, progression-free survival (PFS), and overall survival (OS) were evaluated. A total of 45 patients (22 male patients) with a median age of 57 years were assessed. Eighteen (40%) and 27 patients (60%) were diagnosed with malignant and benign tumors, respectively. Tumor neurovascular involvement was found in 28 patients (62%). Twenty-four (53%) and 20 (44%) tumors formed in the cerebellum and cerebellopontine angle cistern, respectively. One tumor (2%) was found in the cervicomedullary junction. The mean extent of resection was 96.7% for benign and malignant tumors. The PFS and OS rate at 6 months (PFS6, OS6) was 89.7% and 95.5%, respectively. Neurological complications included sensory loss and motor deficit, with 11 patients reporting no postoperative symptoms. Of the neurological complications, 14 were temporary and 9 were permanent. The exoscope is an effective intraoperative visualization tool for delineating PF tumors. In our series, we achieved low postoperative tumor volumes and a high gross total resection rate.

The outcome of using zolpidem for treatment of postoperative posterior fossa syndrome in children with brain tumor

Abstract Introduction: At present, there is no supporting evidence-based therapy of proven efficacy to treat posterior fossa syndrome (PFS) after surgical resection of posterior fossa tumors in children where only 22% of patients may experience a full recovery. However, zolpidem, a nonbenzodiazepine hypnotics drug, seems to be a possible treatment option for PFS symptoms. Methods and Materials: This was a retrospective chart review for all children with brain tumors younger than 15 years diagnosed with confirmed PFS after surgical resection at King Abdulaziz Medical City, Jeddah, and received zolpidem to alleviate the PFS symptoms between May 2016 and April 2019. Results: A total of 6 pediatric patients who experienced PFS symptoms (median of 4 days, range 1–7 days) were included. The most commonly observed symptoms were irritability, hypotonia, swallowing deficit, unsteady walking, and delayed speech. To alleviate the PFS symptoms, zolpidem was commenced 2–5 days postoperatively. The median duration of use was 13.5 days. During the hospital course, recovery of speech was observed after 2 weeks in most patients (50%) while 83.3% of patients recovered their normal speech in 4 months although not fully ambulated. No discontinuation of zolpidem use was reported because of adverse events. Conclusion: Most of our children (83.3%) who experienced PFS postresection responded to zolpidem trials which may represent a promising research field.

Blood Loss in Operation Is Independently Predictive of Postoperative Ventriculoperitoneal Shunt in Pediatric Patients With Posterior Fossa Tumors

BackgroundTo identify the risk factors for postoperative hydrocephalus and the need for ventriculoperitoneal (VP) shunt after posterior fossa tumor (PFT) resection in pediatric patients and establish a predictive model. MethodsA total of 217 pediatric patients (≤14 years old) with PFTs who underwent tumor resection from November 2010 to December 2020 were divided into a VP shunt group (n = 29) and non-VP shunt group (n = 188). Univariate and multivariate logistic regression were performed. A predictive model was established based on the independent predictors. Receiver operating characteristic curves were generated to determine the cutoff values and areas under the curve (AUCs). The Delong test was performed to compare the AUCs. ResultsAge less than three years (P = 0.015, odds ratio [OR] = 3.760), blood loss (BL) (P = 0.002, OR = 1.601), and locations at fourth ventricle (P < 0.001, OR = 7.697) were the independent predictors. The predictive model was as follows: total score = age (<3; yes = 2, no = 0) + BL + tumor locations (fourth ventricle; yes = 5, no = 0). The AUC of our model was higher than those of age less than three years, BL, locations at the fourth ventricle, and compound factors (age <3 + locations) (0.842 vs 0.609, 0.734, 0.732, and 0.788, respectively). The cutoff values of the model and BL were 7.5 points and 2.75 U, respectively. ConclusionsBL, age less than three years, and tumors at the fourth ventricle were independent predictors. Model scores over 7.5 points predict a high risk.

Contribution of tumor characteristics and surgery-related factors to symptomatic hydrocephalus after posterior fossa tumor resection: a single-institution experience.

Pediatric patients are at risk of persistent hydrocephalus after posterior fossa tumor resection. The relationship between surgery-related factors and postoperative symptomatic hydrocephalus has not been elucidated. The objective of this study was to analyze features influencing postoperative hydrocephalus in Chinese children. The authors retrospectively evaluated 197 patients younger than 15 years of age who underwent posterior fossa tumor resection at their institution from January 2015 to June 2021. The outcome was whether children underwent CSF diversion within 6 months of resection. Preoperative characteristics, surgery-related factors, and postoperative features were included to identify independent prognosticators. A new logistic model containing independent prognosticators was developed and compared with the modified Canadian Preoperative Prediction Rule for Hydrocephalus (mCPPRH). In this study, 30 patients (15.2%) underwent CSF diversion within 6 months after tumor resection. Tumor location and consistency, intracranial or spinal tumor metastasis determined by perioperative cerebral and spinal MRI, intraoperative blood loss, ventricular blood as determined on postoperative CT, and pathology were statistically significant variables in the univariate analysis. The only two independent predictors of postoperative symptomatic hydrocephalus were tumor metastasis (OR 3.463, 95% CI 1.137-10.549; p = 0.029) and postoperative ventricular blood (OR 4.212, 95% CI 1.595-11.122; p = 0.004). The final logistic model comprising tumor metastasis and postoperative ventricular blood was found to have better discrimination than the mCPPRH. Tumor characteristics and surgery-related features were associated with postoperative symptomatic hydrocephalus. Tumor metastasis and postoperative ventricular blood were found to be important prognosticators of persistent hydrocephalus.

External ventricular drainage in the management of pediatric patients with posterior fossa tumors and hydrocephalus: a retrospective cohort study.

To determine whether intraoperative adjunctive EVD placement in patients with a posterior fossa tumor (PFT) led to improved surgical, radiographic, and clinical outcomes compared to those who did not receive an EVD. Patients were grouped as those who underwent routine intraoperative adjunctive EVD insertion and those who did not at time of PFT resection. Patients who pre-operatively required aclinically indicated EVD insertion were excluded. Comparative analyses between both groups were conducted to evaluate clinical, radiological, and pathological outcomes. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were computed for post-operative outcomes. Fifty-five selected patients were included, 15 who had an EVD placed at the time of PFT resection surgery, and 40 who did not. Children without an EVD did not experience a higher rate of complications or poorer post-operative outcomes compared to those with an EVD placed during resection surgery. There was no significant difference in the degree of gross total resection (p = 0.129), post-operative CSF leak (p = 1.000), and post-operative hemorrhage (p = 0.554) between those with an EVD and those without. The frequency of new cranial nerve deficits post-operatively was higher in those with an EVD (40%) compared to those without (3%, p = 0.001). There was a trend towards more frequently observed post-operative hydrocephalus in the EVD group (p = 0.057). The routine use of EVD as an intraoperative adjunct in clinically stable pediatric patients with posterior fossa tumors and hydrocephalus may not be associated with improved radiological or clinical outcomes.

Effect of administration of tranexamic acid on blood loss and transfusion requirements in children undergoing posterior fossa tumor excision: a retrospective cohort study.

Surgical resection of posterior fossa tumors (PFT) in the pediatric age group often results in significant intraoperative blood loss. The primary objective was to assess the effect of tranexamic acid (TXA) on blood loss and transfusion requirement in pediatricpatients undergoing excision of PFT. In this retrospective study, all pediatric patients ≤ 18years, who underwent PFT resection over a period of 7years, were included. The patient and surgical characteristics, estimated blood loss (EBL), the need for blood and blood product transfusion, use of crystalloids, vasopressors, and any adverse events like seizures and thromboembolic events were recorded and compared between Group A who received TXA andGroup B who did not. The study included 50 patients, out of which 36 belonged to Group A and 14 to Group B. The median age was 8years (IQR, 2-17) and the mean BMI was 16.46 ± 4.11kg/m2. The mean EBL was 224.29 ± 110.36ml in group A (n = 36) and 362 ± 180.11ml in group B (n = 14) (p = 0.007). The intraoperative volume of crystalloid use was significantly higher in group B (p = 0.04). The requirement of blood and blood product transfusion was similar between the groups, but the volume of blood transfusion per kg body weight was higher in group B, 8.3 (IQR, 6.7-11.1)ml/kg in Group Aversus 10.5 (IQR, 8.1-16.1) ml/kg in Group B (p-value 0.3). The rates of complications noted in the form of seizures and thromboembolic events were comparable. The use of TXA in the pediatric population undergoing PFT resection aids in reducing blood loss during the surgery without increasing complications.

The effect of hyperventilation versus normoventilation on cerebral oxygenation using near infrared spectroscopy in children undergoing posterior fossa tumor resection: A randomized controlled cross-over trial

BackgroundThis study aims to compare the effect of two different ventilation strategies on cerebral oxygenation in children undergoing posterior fossa tumor excision surgeries. MethodsChildren scheduled for posterior fossa tumor surgeries were enrolled in this randomized, double-blinded, controlled cross-over trial. After induction of general anesthesia and positioning, participants were randomized to have mild hyperventilation for 30 min (phase 1) followed by normal ventilation for another 30 min (phase2) (early hyperventilation group, n = 23), or normal ventilation for 30 min (phase 1) followed by hyperventilation for 30 min (phase 2) (early normoventilation group, n = 19). Our primary outcome was cerebral oxygenation, measured using near-infrared spectroscopy (NIRS). Other outcomes included the intracranial pressure (ICP), brain relaxation score at the end of phase 1, and frequency of nadir NIRS. ResultsForty-two children were available for final per protocol analysis. The cerebral oxygenation decreased after the hyperventilation phase compared to the baseline values and the corresponding phases of normoventilation. The mean difference [95% confidence intervals (CI)] in cerebral oxygen saturation between the hyperventilation and normal ventilation readings was 13.45 ± 1.14% [11.14–15.76] and 11.47 ± 0.96% [11.14–15.76] in the left and right sides, respectively (p-values <0.0001). Both carryover and period effects were not significant. The ICP at the end of phase 1 did not differ between the two groups: 22.12 ± 3.75 mmHg vs. 23.26 ± 4.33, mean difference [95%CI]: −0.78 [−3.05 to 1.5], p = 0.49. Brain relaxation score was similar in the two groups. ConclusionIn children undergoing posterior fossa craniotomy, moderate hyperventilation reduced cerebral oxygenation without significant improvement of the surgical brain relaxation or the ICP.

Prevalence of dysphagia following posterior fossa tumour resection in children: the Alder Hey experience.

Surgery for posterior fossa tumours (PFTs) in children is associated with bulbar palsy and swallowing difficulties although this risk is not well defined in the literature and issues contributing to dysphagia following surgery are not fully understood. This study aims to study the eating, drinking and swallowing function of children following PFT resection in a specialist paediatric neurosurgery centre. This included the frequency and duration of dysphagia, the risk of aspiration and the link between tumour type and dysphagia. This is a retrospective review of children undergoing surgery for PFT between 2014 and 2019. Information was obtained from the patients' hospital and speech and language therapy (SLT) notes, oncology database and clinical letters. The International Dysphagia Diet Standardisation Initiative (IDDSI) Framework was used to describe food and fluid modifications. Seventy children had surgery to resect a posterior fossa tumour at Alder Hey from 2014 to 2019. Thirty-one children were included in the study following referral to SLT. Videofluoroscopy (VF) was undertaken at our institution in 68% (21/31) of cases. Fifty-two percent (11/21) of children aspirated or were considered at risk, and 55% (6/11) of those who aspirated showed silent aspiration. After 3months, 43% (13/30) still required modified food and/or fluid textures, with this proportion reducing as time progressed. By tumour type, VF was performed in 5/7 medulloblastoma patients with 3/5 showing aspiration and 3/3 silently aspirating; in 8/9 patients with ependymoma with 4/8 patients aspirating with 2/4 showing silent aspiration; and 6/12 glioma patients with 4/6 aspirating with 1/4 showing silent aspiration. Swallowing difficulties, including silent aspiration, are an important complication of PFT resection. A proportion of children will need ongoing food and/or fluid modification. Further study into dysphagia following PFT resection is indicated.

SURG-36. EVALUATION OF SURGICAL RESULTS AND PREDICTIVE FACTORS OF HYDROCEPHALUS IN PEDIATRIC PATIENTS WITH POSTERIOR FOSSA TUMORS

Abstract INTRODUCTION Infratentorial tumors represent 45 to 60% of all brain tumors in children and are associated with hydrocephalus in 70 to 90% of cases. The aim of this study is to describe and analyze the surgical results and correlate them with the incidence of hydrocephalus, as well as identify predictive factors of hydrocephalus in pediatric patients underwent to a surgical treatment of posterior fossa tumors. METHODS This is a retrospective observational study, based on demographic, clinical and radiological information of pediatric patients underwent to surgical resection of posterior fossa tumors by a single group between 2011 and 2019. RESULTS We included 135 patients with a mean age of 7.56 years, mean follow-up of 35.7 months and overall survival of 18.8 months. Considering the histology, most tumors were pilocytic astrocytomas (34.1%), followed by medulloblastomas (27.4%) Total resection was achieved in 77.8% and tumor recurrence was observed in 16.2%. The rate of hydrocephalus was 36.3%, with most shunt procedures performed preoperatively. There was a high rate of complications associated with shunting (42.9%), mostly represented by infection (71.5%). Patients with hydrocephalus were younger (p = 0.001), showing a faster evolution between the onset of symptoms and diagnosis (p = 0.008). Tumor volume (p = 0.1) and location (p = 0.32) were not statistically significant for hydrocephalus, however, the presence of leptomeningeal disease (p = 0.001) was. The resection rate was also significant, with lesions totally resected showing the best results (p = 0.009). Regarding tumor histology, 33.3% of patients with medulloblastoma and 62.5% of patients with ependymoma were shunted. CONCLUSION One third of children with posterior fossa tumors will require a shunt procedure. Some factors should guide the neurosurgeon during patient counseling and surgical planning to minimize the use of permanent shunts and avoid related complications.

Resection of posterior fossa tumors in the semi-sitting position in children younger than 4 years of age

PurposeThe semi-sitting position for resection of posterior fossa tumors is a matter of ongoing debate. Here we report about our experience with this approach in children younger than 4 years of age.MethodsWe retrospectively analyzed data of children younger than 4 years of age operated on in our institution in the semi-sitting position over a 15-year period. Patients were intraoperatively monitored for venous air embolism (VAE) by transthoracic Doppler (TTD) or transesophageal echocardiography (TEE). The severity of VAE was classified according to the Tübingen grading scale. Intraoperative incidents of VAE were recorded and the patients’ course was followed postoperatively with a special focus on possible complications.ResultsTwenty-four children (18 boys, 6 girls) were operated on in the semi-sitting position (26 operations). Mean age was 2.2 years (± 1.0), range between 0.4 and 3.9 years. External ventricular drains were inserted in 18 children with hydrocephalus preoperatively. VAE was detected in 6 instances during surgery (6/26 (23.1%)). In 3 patients with grade 1 VAE, no additional treatment was necessary. In one patient with grade 2 VAE, intracardiac air suction via the central venous catheter was performed, and in two patients with grade 4 VAE, additional cathecholamine-infusion was administered. No major intraoperative complications occurred. Postoperative CT images showed pneumocephalus in all children. In two children, small asymptomatic impression skull fractures at the site of the Mayfield pin occurred. Revision surgery was necessary in one child with a suboccipital CSF fistula.ConclusionThe semi-sitting position for resection of tumors in the posterior fossa in children younger than 4 years of age can be safely performed in experienced centers taking special caution to detect and treat potential complications in an interdisciplinary setting.

Management of Acute Postoperative Bilateral Vocal Cords Paralysis after Surgical Resection of Posterior Fossa Tumor (Case Report)

Bilateral vocal cords paralysis is a serious condition that can be due to pathology of the vocal fold itself, damage to the cranial nerves ensuring their mobility, or central neurological disorders. In this article, we present a case of a 13-year-old girl who was admitted to the intensive care unit postoperatively for posterior cerebral fossa tumor surgery. She was reintubated after an extubation failure as a result of laryngeal dyspnea with stridor and chest in-drawing. The examination revealed damage to III, VI, and IX nerves with the immobility of vocal cords that were abducted towards the midline. A weaning tracheotomy was performed with a good clinical evolution and the patient was discharged 13 days after the surgery with maintained follow-ups. We report this case for its rarity.

Adult medulloblastoma: a case report

BackgroundMedulloblastoma is a malignant brain tumor that is common in children but very uncommon in adults, especially those older than 40 years, accounting for less than 1% of all primary brain tumors in adults. Although surgery and radiotherapy play an important role treatment of adult medulloblastoma, the use of chemotherapy is controversial. This is the first instance of adult medulloblastoma at the Ocean Road Cancer Institute in Tanzania.Case descriptionWe report the case of a 51-year-old female of African ethnicity who was diagnosed with high-risk hemispheric posterior cranial fossa medulloblastoma of classic type with World Health Organization central nervous system grade 4 and Chang stage M0. Immunohistochemistry, reticulin stain, and molecular subtyping could not be done because they were not available. She was treated by subtotal posterior cranial fossa tumor resection followed by adjuvant concurrent chemo-craniospinal radiation and adjuvant chemotherapy.ConclusionEven in adults over 50 years old, medulloblastoma should be included in the differential diagnosis of posterior fossa tumor. Adult medulloblastoma is a very rare and very heterogeneous tumor, but it has a good prognosis. Immunohistochemistry and molecular subclustering are difficult to implement in low-income countries such as Tanzania owing to cost. Treatment of adult medulloblastoma is highly heterogeneous among (and even within) facilities. There is no evidence that the extent of resection enhances survival. While craniospinal radiation therapy improves survival, there is controversy about the role of chemotherapy in managing adult MB.

Role of CSF flow parameters in diagnosis and management of persistent postoperative hydrocephalus

ObjectiveTo investigate the extent to which preoperative CSF flow parameters through the aqueduct of Sylvius predicted persistent postoperative hydrocephalus (PPH) in patients with posterior fossa (PF) tumors after surgery. MethodsTwenty patients with PF tumors were enrolled in this prospective cohort study between June 2016 and June 2018. Imaging studies included conventional computerized tomography (CT) scan, magnetic resonance imaging (MRI) with and without gadolinium contrast and phase contrast (cine) magnetic resonance imaging (PC-cMRI). The authors determined the clinical predictors and anthropometric characteristics that caused PPH. CSF flow parameters through the aqueduct of Sylvius were analyzed among patients. In addition, the CSF flow parameters of various clinical predictors associated with PPH were evaluated. ResultsOf the 20 patients, 11 were females, and 9 were males. The mean age of patients was 30.4 ± 16.06. Sixteen patients had PPH, while 4 patients did not (PPH-). The mean aqueductal CSF stroke volume (ACSV) was 4.7 ± 2 (µl/sec), and the mean backflow was 4.8 ± 0.8 (µl/sec). ACSV between PPH + and PPH - groups, were significantly correlated (P = 0.038). However, ACSV between patients with preoperative hydrocephalus and those without preoperative hydrocephalus did not correlate (=0.66). Among other CSF parameters such as peak flow volume (P = 0.211), forward flow volume (P = 0.350), mean flow volume (P = 0.767) and net backward flow volume(P = 0.02), only net backward flow revealed a significant correlation between PPH + and PPH- groups. Metastasis (P = 0.47), tumor location (P = 0.37) and sex (P = 0.92) did not correlate with the need for hydrocephalus treatment. However, the presence of papilledema correlated with the need for hydrocephalus treatment (P = 0.002). ConclusionOur findings showed that although a decreased ACSV correlated with the occurrence of PPH, the presence of preoperative hydrocephalus before posterior fossa tumor resection did not suggest hydrocephalus will persist in surgery.