Acute Complications of Pre-Resection CSF Diversion in Posterior Fossa Tumors with Hydrocephalus
Authors: Moges Kaleab Tesfaye 
Published: May 2023

Study background and significance: Posterior fossa tumors are a common pathology worldwide and often present with obstructive hydrocephalus. In the year 2021 CSF diversion for acute hydrocephalus from brain tumors was the most common performed emergency procedure in Tikur Anbessa hospital. It is a clinical dilemma choosing the mode of management for the hydrocephalus as it could be a lifesaving procedure but with a risk of unfortunate and devastating outcome. Objective: The aim of the study will be to evaluate the acute complications that occur with CSF diversion procedures that are done for obstructive hydrocephalus in the presence of posterior fossa mass before tumor resection. Method: It will be prospective observational study conducted at Tikur anbessa specialized hospital, which will be held from March 2021 up to October 2022. The research will involve all patients who have undergone CSF diversion procedure for obstructive hydrocephalus from posterior fossa tumors prior to tumor resection and patients will be followed for the first 48 hours post operatively. Patient’s presentation, nature of the posterior fossa tumor on imaging, post-operative clinical status and post op imaging will be taken to account. Result: In the study time frame of 18 months there were 89 patients who came with acute obstructive hydrocephalus from posterior fossa of which all underwent CSF diversion procedure before tumor resection. 52.8% were pediatrics and 47.2% where adults. The most common tumor location was vermian (31.5%) followed by cerebellar hemisphere (29.2%), 4th ventricular (25.8%) and the rest 9% account for cranial nerve and extra axial location. The largest tumor was 9.8cm but the median was 5.1cm. Based on the size they were categorized in to 3 groups, 71.9% were tumor size 4-6cm, 22.5% had a tumor size of >6cm and there were 5.6% with tumor size <4cm. Of the CSF diversion procedures performed 93.3% were VPS, EVD and ETV account for 3.4% each. All were followed for 48 hours post op and 8 patients had clinical deterioration after CSF diversion was done, and all patients with clinical deterioration underwent urgent non -contrast CT scan. They were found to have upward herniation, intra-tumoral bleeding, intraventricular hemorrhage or a combination of these findings. Of the 8 patients that deteriorated 5 died without successful resuscitation. The rest 3 improved and underwent definitive surgery. The risk for postoperative deterioration was 8.9% and 48-hour mortality was 5.6%. Variables were chosen to check association with the outcome (post-operative deterioration). Variables tested include age of the patient, tumor size and tumor location, all did not have statistically significant relationship with outcome (post-operative deterioration and 48-hour mortality). The association between the type of intervention and outcome could not be checked as there were not enough samples representing ETV/EVD performed, and majority (93.3%) were VPS. Conclusion: Through our research we tried to investigate the causes of acute deterioration after CSF diversion done for obstructive hydrocephalus from posterior fossa tumors by assessing the tumor size, location the type of intervention. Through our research we were not able to find any association from investigated factors and post-operative deterioration. Because of our limitation (the low number of sample size and not having enough number of ETV and EVD in the study population) we recommend further research is needed to have more information in this problem.