Key-words:
Endoscopic third ventriculostomy - hydrocephalus - infant
Introduction
Endoscopic third ventriculostomy (ETV) has become the procedure of choice for the
treatment of occlusive hydrocephalus with reported high success rate mainly for aqueduct
stenosis.[[1]] ETV has an advantage over ventriculoperitoneal (VP) shunt insertion, as it enables
the patient to remain device free. However, its efficacy, even now, is widely discussed
in the literature.[[2]] Some reports have shown poor success rates in infants as compared to older infants.[[3]]
The aim of this study is to analyze and report our experience with ETV for the treatment
of hydrocephalus in 30 children under 1 year of age, including preterm low birth weight
infants.
Materials and Methods
This is a prospective study of 30 infants under the age of 1 year who underwent ETV
in our institution during the period of January 2014 to December 2018. A detailed
history, physical examination, and computed tomography scan was done in all the cases.
Of total 30 infants, there were 25 cases of congenital hydrocephalus with aqueductal
stenosis, two cases of Dandy–Walker cyst, two cases of cerebellopontine angle arachnoid
cyst both infants had low Glasgow Coma Scale, so we performed ETV first as emergency
basis and one case of posttubercular meningitis. ETV success score was calculated
preoperatively to evaluate the percentage success of ETV as advised by Kulkarni et
al. [[Table 1]].
Table 1: Preoperative endoscopic third ventriculostomy success score
ETV success score was 40% for one infant, 50% for 19 infants, 60.5% for two infants,
70% for four infants, and 80% for four infants.
ETV was performed using a rigid pediatric endoscope (Karl Storz, Tuttlingen, Germany),
size 17F. The scope was introduced through the anterior fontanels, or a burr hole
was placed just anterior to the coronal suture in the mid pupillary line in the patients
with small fontanel.
The floor of the third ventricle was punctured using a Fogarty catheter, and the fenestration
was enlarged using a Fogarty catheter balloon. Successful creation of stoma was confirmed
by appreciating clap sign as the indicator of establishing cerebrospinal fluid (CSF)
flow as well as visualization of basilar artery complex intraoperatively.
Complications of ETV such as intraoperative bleeding, postoperative infections, CSF
leak, and failure of procedure were evaluated.
ETV success was defined clinically by the criteria of improvement in the patient neurological
status (e.g., alertness, feeding, status of anterior fontanel, and head circumference),
and surgically, as no further CSF diversion procedure required during the follow-up
period of 1 year. We did not use any radiological parameter to assess the success
of ETV as a very low socioeconomic status and affordability of our patients.
The follow-up period was ranged from 12 to 48 months.
Results
A total of 30 infants under the age of 1 year were studied. Male:female ratio was
2:1. The mean age was 6.75 months (ranged from 1.5 to 12 months). Twenty of them were
<6 months, and ten infants aged between 6 and 11 months. Five infants born preterm
have low birth weight [[Table 2]].
Table 2: Patients characteristics
Clinical improvement in infants <6 months and infants aged 6 months to 1 year was
15 (60%) and 8 (80%), respectively. Of five prematures, low birth weight infants,
one has improved (20%), while 22 (88%) out of 25 full-term normal birth weight infants
showed clinical improvement, which was sustained during the follow-up period, and
this was statistically significant (P < 0.001) [[Table 3]].
Table 3: Clinical improvement
The overall success rate of ETV was 76.66% (23/30). In patients with obstructive hydrocephalus
secondary to aqueduct stenosis, the success rate was 21 out of 25 (84%), the success
rate in CP angle arachnoid cyst was 1 out of 2 (50%), and Dandy–Walker cyst was 1
out of 2 (50%) [[Table 4]].
Table 4: Etiology of hydrocephalus
Four of the five preterm infants required a permanent VP shunt. There were two cases
of intraoperative bleeding which stopped after continuous irrigation in one case,
while the procedure had to be abandoned in another patient due to continuous bleeding.
Four cases developed CSF leak from the burr hole site, which may be associated with
very thin cortex. Leak stopped in three cases on postoperative days 3–5 with conservative
management, and one case required resuturing of pericranium graft. One case developed
meningitis who recovered with proper antibiotic treatment [[Table 5]].
Table 5: Complications
Discussion
The overall clinical success rate of ETV in our study was 76.66%. These results are
comparable to other studies which show the success rate of 64%–85% in infants.[[4]],[[5]],[[6]]
Under the age of 1 year, ETV also has a higher success rate in case of aqueduct stenosis
than in case of other etiology although significantly less than in older children.[[7]],[[8]]
The failure rate of ETV was 23.33% (7/30) in the present study, including six cases
of persistence of clinical signs and symptoms of hydrocephalus in the follow-up period,
which may be due to the reclosure of stoma with the formation of the arachnoid membrane.
Apart from the age, etiology as the determinant factors for the success of ETV in
full-term infants for preterm low birth weight infants maturity at birth and their
birth weight should be addressed further for the high failure of ETV in this particular
subset of patients, and one case in which procedure was abandoned due to persistent
intraoperative bleeding.
The failure rate of ETV in low birth weight premature infants (n = 5) was higher (80%)
as compared to full-term normal birth weight infants (16%).[[9]],[[10]] Reasons for the low efficacy of ETV in preterm low birth weight infants are still
debatable but distensible head with its immature skull may be real culprit, which
would prevent an adequate flow through the ETV, and it may be responsible for insufficient
pressure gradient between the cortical subarachnoid spaces and the venous sinuses
as advised by Zucchelli and Galassi.[[11]]
In the present study, the overall complication rate was 23.33%. The most common complications
included CSF leak (13.33%), intraoperative bleeding (6.66%), and infection (3.33%)
results were comparable to other studies.[[12]],[[13]],[[14]]
The overall shunt rate post-ETV was 23.33% (7/30), of this, 71.4% (5/7) of shunt required
in 0–6-month age group infants, and 28.6% of shunt placement done in 6–12-month age
group infants.[[15]]
Conclusion
ETV can be considered a safe and effective modality for the initial treatment of hydrocephalus
in full-term normal birth weight infants, while the success of ETV in preterm low
birth weight infants need further study of maturity at birth and birth weight as the
determinant factors for the success of ETV in this special group.
