PIVH is a unique subtype of intracerebral hemorrhage characterized by hemorrhage confined to the ventricular system. Because of the overall rarity of PIVH, related studies in pediatric population remain even scarce, which has made identifying consistent characteristics of PIVH difficult.[1-7] The present study analyzed 18 cases of pediatric PIVH treated at our center (Table 1) between 2010 and 2016. Several unique characteristics were found regarding etiology, treatment and clinical outcome. The results of our study may help achieve a better understanding of pediatric PIVH.
Interestingly, sex distribution varied significantly in previous adult studies.[6, 7, 10, 11] Among the patients in study of Marti-Fabregas et al. and Srivastava et al., the majority were male (38.5% and 37.03%, respectively),[7, 10] whereas some other studies by Hameed et al. and Giray et al. showed an opposite trend, in which there were more males (60.0% and 58.3%, respectively) than females.[6, 11] Our studies reported a more balanced distribution between boys and girls. In our cohort, the sex ratio was male-female 0.8:1, which demonstrated no obvious difference in the sex distribution among pediatric PIVH patients. Research findings have proved that gender difference may have affected the incidence and physiopathologic process of stroke.[12, 13] However, the impact of gender on pediatric PIVH is yet to be determined in further studies.
Previous studies reported various etiological constitution of PIVH.[1-7, 10, 11, 14] In most studies, the most common possible etiology for adult PIVH was hypertension (from 50.0% to 80%).[3, 5, 6, 11]
Flint et al. reviewed 99 PIVH patients who underwent a catheter angiogram in 15 case series, presented that AVM seemed to be the most common (54.5%) underlying vascular abnormality in adult PIVH, followed by aneurysm (39.4%), and Moyamoya disease (5.1%).[15] Our study presented quite a similar constitution: AVM in 66.7% of the 18 pediatric patients, Moyamoya disease in 11.1%, aneurysm in 5.6%. Only 3 children in our study could not be identified with vascular disorders, which was inconsistent with elder patients in previous reports.[1-5, 10, 11]
To date, because of a lack of related research, the appropriate method to achieve maximum benefit for pediatric PIVH patients remain unknown. An external ventricular drainage (EVD) remains the current primary method for PIVH with obstructive hydrocephalus. In our study, 83.3% of pediatric patients with PIVH underwent a surgical procedure, and 4 of the 5 patients (90.0%) with acute hydrocephalus received EVD. In previous reports among elder population, this percentage was much lower.[1-7, 10, 11, 14, 15] The mass effect of intraventricular hemorrhage (IVH) and acute obstructive hydrocephalus caused by IVH may be basic pathophysiologic factors in PIVH, which can elevate intracranial pressure (ICP) and decrease cerebral perfusion.[16] EVD is assumed to drain cerebrospinal fluid out of ventricular system, reducing ICP. However, EVD alone is inadequate and is often occluded with blood clots.[17] Besides. EVD cannot change the blood clot resolution rate after IVH, failing to relieve communicating hydrocephalus.[18, 19] Studies have explored the effectiveness and safety of the concomitant use of antifibrinolytics to decrease the complications of EVD.[20, 21] However, the debate on which method is better for pediatric PIVH is continuing.
Previously reported case series in adult PIVH had relatively unfavorable clinical outcomes, with in-hospital mortality ranging from 13.3% to 42.0%. However, in contrast, only 1 patient (5.6%) in the present pediatric cohort did not survive at discharge, and another patient with idiopathic PIVH died one month after discharge because of rebleeding. In our study, favorable outcomes (mRS≤2) were observed in 14 cases (77.8%) at discharge, and at the 3-month follow-up, the number increased to 15 patients (83.4%). Our pediatric PIVH patients had better outcome compared to previous adult studies. This might be partly thanks to the improved diagnostic ability, allowing the early recognition of benign cases. Furthermore, rapid access to neurological intensive care and acute management strategies in our hospital may help these pediatric PIVH patients achieve better clinical outcomes.
There are several limitations in our study. First, the patient number was relatively small, with only 18 pediatric patients. Second, this study was a single-center retrospective cohort which lacked randomization between groups. Besides, this study was a chart review, in which some study patients could have been missed in our identification process. Furthermore, because of the absence of guidelines for PIVH, our treatment strategies, might have been applied with controversy. A further multicenter clinical trial with a larger sample size is warranted to provide better insights of pediatric PIVH.