Endoscopic Treatment of Arachnoid Cyst - Proceedings of All India Seminar on Biomedical Engineering 2012 (AISOBE-2012) - page 29

improvement occurred in 20 cases after endoscopic treatment while one infant with
quadrigeminal region arachnoid cyst required a ventriculo-peritoneal (VP) shunt.
There was no mortality or any other complication except CSF leak in three patients.
CSF leak stopped in two cases within 7 days' time. These patients required 2-3
ventricular taps. The third infant with quadrigeminal region arachnoid cyst required
VP shunt. Hospital stay ranged from 4 to 12 days with an average of 5.4 days.
Mean operating time was 50 min ranging from 40 to 90 min. The third ventricu-
lostomy was done in the same sitting in 8 cases of quadrigeminal region arachnoid
cysts; all these cases were associated with hydrocephalus. Both the procedures
could be done by single burr hole placed about 3-4 cm anterior to coronal suture.
There was gross ventriculomegaly in all these children. Minimum of 1 cm hole was
made in all the cases taking care not to injure cranial nerve and vessel.
Discussion
The natural history and pathogenesis of arachnoid cyst remain poorly defined.
Arachnoid cysts are commonly thought to arise from either congenital defects or
trauma. There are reports of the spontaneous development of arachnoid cyst [ 6 , 21 ].
Although most arachnoid cysts remain static fluid-filled compartments throughout
life, some of them can be enlarged, exerting a mass effect on adjacent neural
structures [ 22 , 23 ]. There are reports of spontaneous disappearance of a suprasellar
arachnoid cyst [ 24 , 25 ]. These cysts may rupture producing subdural hygroma or
chronic sub dura hematoma [ 26 ]. MR CSF flow imaging with a phase contrast cine
sequence can be a reliable alternative to invasive CT cisternography for the func-
tional evaluation of arachnoid cysts [ 27 ]. Optimal treatment guidelines are not yet
established [ 24 ]. Alaani et al. [ 28 ] suggested a conservative management approach
to the majority of these cysts as the cysts may not show change in size on repeated
MRI scan and the patients' symptoms may not progress over the period of follow-up.
The preferred treatment for symptomatic arachnoid cysts is surgery. The
indications for surgery are the presence of progressive hydrocephalus or intra-
cranial hypertension [ 29 ]. The cystoperitoneal shunt was associated with clinical
improvement in most cases [ 1 ]. Cysto ventricular shunting was also found to be
simple as well as effective and reliable [ 2 ]. Shunt dependency and slit ventricle
syndrome after cystoperitoneal shunting was found to be a real problem [ 5 , 30 , 31 ].
Insertion of an internal shunt from the cyst to the subdural compartment is also
considered as a valuable alternative in the treatment of arachnoid cysts [ 3 ].
Arachnoid cysts can be successfully treated with a cystoperitoneal shunting with a
programmable valve [ 4 , 5 ]. Microsurgical keyhole fenestration was also found to be
a safe and effective surgical procedure for the treatment of arachnoid cysts [ 12 - 14 ,
32 ]. Factors that influence outcome are the rate of volume reduction and cyst
location [ 32 ]. Results are good if the cyst is in vicinity of the cistern/ventricle.
Endoscopic procedures were found to be safe and effective in our series also.
Another advantage of this procedure is that third ventriculostomy can be done in